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mtbdudex 02-03-2011 06:55 PM

1 Attachment(s)
Background:
I've been thinking to make a separate thread on the DIY construction methods of hang-able acoustic panels, that can be located specifically only where needed.
Also moveable as your speaker type/location changes, your treatment needs may change.
Currently none exist that give a really good start-finish, I've searched AVS forum.

Just these for Fabric frames, which are integrated as part of the wall itself, not hanging and specific locatable.
(these are great threads btw for those whole wall coverage methods)
Fabric Frames - GPowers Thread , Another Fabric Frame Thread - Canvas Stretcher Bars

In my viewpoint, the Acoustical Treatments Master Thread is more for the theory, science, and practical application for acoustics of your particular room situation/issue, not the DIY construction methods, that will clutter it too much.

This thread purpose is NOT what your rooms acoustic needs are, rather once you study, plan, and develop your rooms acoustic needs, how to go about building it yourself.
[edit] since making this thread some specific acoustic issues have been discussed and addressed, however there are other more suitable threads for the theory, think of this as the application thread.

So, here it is, a dedicated thread for DIY construction methods of hang-able acoustic panels, to start I plan on sharing what I've done:
-DIY side wall absorption panels construction and hanging, https://www.avsforum.com/avs-vb/showthread.php?p=19947559#post19947559
https://www.avsforum.com/content/type...t/400/flags/LL

-DIY ceiling absorption panels panels construction and hanging
https://www.avsforum.com/avs-vb/showthread.php?p=19987283#post19987283 and https://www.avsforum.com/avs-vb/showthread.php?p=20074007#post20074007
https://www.avsforum.com/content/type...t/400/flags/LL https://www.avsforum.com/content/type...t/400/flags/LL


-Here is removable lower tri-corner superchunk bass trap made with 1/2-13 thd rod and OC705, from post #40 https://www.avsforum.com/avs-vb/showthread.php?p=19993984#post19993984
and Upper tri-corner bass traps (since I made these it's been proven via gas flow resistivity its best for deep traps like these to use pink fluffy)
https://www.avsforum.com/avs-vb/showthread.php?p=20085872#post20085872
https://www.avsforum.com/content/type...t/400/flags/LL..https://www.avsforum.com/content/type...t/300/flags/LL
Eric helped with his pink fluffy version of my movable corner bass traps
https://www.avsforum.com/forum/19-ded...l#post22131618 .https://www.avsforum.com/content/type...t/400/flags/LL

Discussion related to corner bass traps; gas flow resistivity, why cover them to reflect mid-high's, etc

others in this thread:
-smokarz built his own side wall 2' x 4' panels, post #36 here https://www.avsforum.com/avs-vb/showthread.php?p=19993492#post19993492
https://www.avsforum.com/content/type...t/400/flags/LL

-localhost127 built his own side wall 4" thick 2' x 4' panels with exposed sides for more absorption , post # 86 here https://www.avsforum.com/avs-vb/showthread.php?p=20271296#post20271296
https://www.avsforum.com/content/type...t/400/flags/LL


There are already "fixed" bass trap threads, here are links to them.
AVS site:

Show us your custom made corner bass traps (pics)
(btw, as of 2/5/0-11 pepar updated his pict links, I need chinaclipper and pred02 to do same )
Other site:
Gearslutz.com, here is a link to their "How I built my bass (broadband) traps..." sticky, over 31 pages of info!
http://www.gearslutz.com/board/bass-traps-acoustic-panels-foam-etc/87464-how-i-built-my-bass-traps.html

I added my own twist to building corner superchunk with "green" material, some might like a different approach.
https://www.avsforum.com/avs-vb/showthread.php?p=20588838#post20588838 https://www.avsforum.com/content/type...t/400/flags/LL..https://www.avsforum.com/content/type...t/400/flags/LL

I'd like others who make DIY hang-able acoustic panels, whether absorption, diffusion, reflection, etc. to also feel free to add your construction techniques/methods there.
>>We need to learn from you!

[edit Feb 2, 2011]
placeholder for those already done DIY hang-able acoustic panels-pm me your details and I'll post link here

Side note:
I have this general suggestion for those wanting to learn about acoustics:

A) read this Acoustics/Treatment Reference Guide , via gearslutz, its a easy read in layman terms, starts you off with basics and good foundation with practical discussion. Studio acoustics and Home Theater acoustics.
From that, simple/straight forward advice via Jens Eklund:
Quote:

1. Learn how to make measurements: REW - Room EQ Wizard Home Page
Don’t do anything without measurements.

2. Define your MLP (Master listening position). Confirm with measurements.

3. Identify and treat your modal and SBIR - Speaker Boundary Interference Response related issues and educate yourself about different bass-absorbing techniques.
Other info: SBIR by Bryan Pape

4. Treat areas that otherwise creates early reflections.

5. If the room is big enough, add diffusers

Always base your decisions regarding different treatment, on measurements. Avoid thin porous only absorbers (including wall to wall –carpet, drapes etc.) unless a measurement indicates the need for it.


B) Knowing that for “best” audio/sound in a listening room, these parameters are tackled in prioritized order:
1. Speaker location, 2. Listener position, 3. Acoustic treatments, 4. Electronic correction.
Understand the small room acoustic model you will follow.
Looking at this link, everyone can see visually the various small room models, it's 7 pages from the book "Acoustics and Psychoacoustics Applied"
http://eetimes.com/design/audio-desi...n?pageNumber=0

C) If you have desire for more knowledge:
-read one of many books out there, a great 1st book is "Master Handbook of Acoustics" by F. Alton Everest, a perfect follow-up book is "Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms" by Floyd Toole.
-shameless plug for Ethan Winers book also, "The Audio Expert".
https://www.avsforum.com/content/type...t/200/flags/LL .. https://www.avsforum.com/content/type...t/200/flags/LL .. https://www.avsforum.com/content/type...t/200/flags/LL

-study Ethan Winers site, http://www.ethanwiner.com/acoustics.html
-Become familiar with the different small room acoustic models for home listening spaces
-This is also a 101 read on Room Acoustics, http://www.crutchfield.com/learn/learningcenter/home/speakers_roomacoustics.html
-SAE Home Acoustics info site has many definitions and explanations http://www.sae.edu/reference_material/audio/pages/fullindex.htm
-There are many other sites on the web, like
........One of the first ones, StudioTips small room acoustics forum http://forum.studiotips.com/index.php,
........Acoustical measurements defined Rives audio http://www.positive-feedback.com/Issue12/rives2.htm,
........RPG Acoustics Library papers http://www.rpginc.com/news/library.htm, etc.
-Be careful of info overload all at once

D) Measurement info/threads:

-online downloadable file with the Sound System Engineering chapter 6 on measurements http://www.focalpress.com/uploadedFi...0240808307.pdf
-Get the hardware side of REW down quickly, this thread by member omegaslast dummy's guide on setting up REW and his blog http://polaraudio.blogspot.com/2012/01/calibration.html easy 101 read with pictures to walk you thru the mechanical of set-up and taking measurements
-Highly recommend Nyal Mellor's site, http://www.acousticfrontiers.com/Aco...surements.html , and a very detailed/helpful white paper http://blog.acousticfrontiers.com/st...ist.%20Rms.pdf
-Room Measurement & Treatment by "fotto" (Floyd)
https://www.avsforum.com/content/type...t/400/flags/LL
- Envelope Time Curve - ETC - Impulse gearslutz thread
-Using energy time curve for acoustic analysis: by "mtbdudex" (Mike R)
-Why just using 1" thick porous absorber treatment is "wrong" https://www.avsforum.com/t/1369498/ea...anel-thickness
-https://www.avsforum.com/t/1421599/etc-isd-gap-question ETC - ISD gap by
-Basic acoustic measurement primer v2.1 (via gearslutz "DanDan")
-http://www.realtraps.com/art_measuring.htm
https://www.avsforum.com/content/type...t/400/flags/LL
-https://www.avsforum.com/t/1316623/di...#post_20147783 DIY Custom-Printed Movie Poster Acoustic Panels
-first reflection software: https://www.avsforum.com/t/822273/fre...#post_22619555
-a while back I downloaded this Measurement/calibration sequence from Dennis Erskine.
RoomMeasurementSet-up.zip 4.990234375k . file

mtbdudex 02-03-2011 06:58 PM

Goals:
-Build a simple yet sturdy frame to hold 2' x 4' 2" thick fiberglass for absorption panels

-Keep frame fastening simple as possible, ie screws instead of dovetails/etc. Many ways to build a box.

-simple hanging method employing needed space to have 2" gap between side wall and fiberglass
(I desired more low freq absorption than just first order absorption, else direct mtg to wall would suffice for that, ask those Q pro/con in Master Acoustics thread.)

1st prototype Mock-up 2' x 4' panel w/o cloth cover.
This was quick and dirty, I used scrap 1 x 4, and routered a 2" wide 1/4" deep channel down the center to hold the fiberglass.
1" x 4" pine frame will be stained, just OC703 itself will be wrapped.
There will be a 1/2" or 3/4" gap @ back of fiberglass to frame edge on front side, and 1" or 3/4"gap @ backside.
https://lh3.googleusercontent.com/_F...0/_MG_3973.jpg

Cutting speaker cloth and wrapping OC703
https://lh3.googleusercontent.com/_F...0/_MG_3933.jpg

Frontside and backside.
https://lh3.googleusercontent.com/_F...0/_MG_3935.jpg . https://lh3.googleusercontent.com/_F...0/_MG_3936.jpg

Yes, for the frame enclosed panels I plan not to use spray adhesive, just pinned.
At some point in future I'd like to spend a few $'s and have a printed pattern for the panels, this makes that upgrade option easier.

Ok, so the trial came out ok, but i learned a few things:

1) make and use jigs for repeatability
2) I made the 2" wide router channel 1/2" from the front edge, and 1" from the back edge, which was too close for screw to bite into good, so changed that to 3/4" both sides

Next post shows how I made (6) frames and then hung them

mtbdudex 02-03-2011 07:23 PM

Router set-up, since I did not have a table saw router extension (about $300), I made my own as shown.
>>Caution, exposed moving parts here, use with care.
I used a MILESCRAFT TurnLock 3-in-1 Router Guide Kit Model #1223, flipped upside down and clamped a board parallel to it for straight feed.
I used a 1" bit bought from HD for about $25.
Set the router @ 3/4" in from edge, a "fat" 5/16 deep, make 2 passes.


Material list for each 2' x 4' panel:
-(2) 1" x 4" x 6' pine boards for main frame boards
-(2) 1" x 4" x 23 1/4 for top/bottom "z" channel mounting board
-box 1 5/8" coarse drywall screws

Each 1" x 4" 6' pine board is cut 23 1/4" for top/bottom, the remaining piece becomes a side piece.

Edge boards are complete routered with 2" channel as shown.


Side pieces are routered as shown with the 1" bit (again make 2 passes) within 5/16 of the edge.


Use a secondary router with small bit to make the corners tighter as shown


Here is the drill jig I made for quick repeatability of the side board screw holes:


Using it to drill holes into the side boards
>>Having these true and square will ensure when using them to guide the 1 5/8 drywall screws into the top piece you won't have any problems.


I wanted the drywall screws to sit flush, used larger bit and carefully took away small bite of material as shown

(a counterboar bit is perferable method as "erkq" pointed out. In a pinch I take the drill that is slightly bigger than the screw head, do a manual mini-counterboar slowly, then put the drill in reverse and give full power with pressure.
The angled face of the drill going backward will remove all burrs/etc and make a fine seating area for the screw.)


Corner clamps to hold square while screwing in.
Careful, set torque to NOT go all the way in, do final tightening by hand or wood may split


I forgot to take a picture of the (2) "Z"channel braces, since they are 3/4" thick they fit flush inside the frame.
I located them 12" and 36" down from top, each had (2) drywall screws each side to keep from twisting when hanging onto the "Z" channel.

mtbdudex 02-03-2011 07:30 PM

Wrapping fiberglass 101, it's itchy be careful!

Cut to size, my speaker grille fabric came from Joanns, 60" wide, I bought 15 yards, $8/yard with coupon normal $9.99/yard.


wrap a side and pin with 1 3/4" pins, angles to stay in from tension.


Complete the wrap, it's my first time, got decent at wrapping and pinning.
Went real quick w/o mess.


Frontside mounted.............Backside mounted (after stained the frame)

mtbdudex 02-03-2011 07:44 PM

Hanging 101 for DIY framed 2' x 4' acoustic panels:

I used alum "z" from ats acoustics, http://www.atsacoustics.com/item--ac...are--IK12.html


They were set 3" in from each frame edge to have invisible look and the frame sorta just float there.

Note:
Wall to frame spacer/holders were pre-made, pre-drilled (each then acts as its own drill jig for holes into the wall), and painted wall color prior.
Mine were 19" wide and 3 1/2 tall, and 1 1/2 inches thick, basically scrap stuff I had lying around.

Measure twice, use blue tape for visual markers, locate top holder, mine was a 1 1/2" thick piece so the panel would have 2" air gap.
Hold with hand, drill into drywall with 3" deck screw, mini-level assures level, Locate bottom holder, drill into drywall with 3" deck screw.



Remove, use drilled holes to locate the 50lb plastic dywall anchors------Re-attach top/bottom holders, using 3" deck screw.


If measurements done correctly slight tweaks to get level----


this shows 2" air gap



That's all for tonight, later I'll post my acoustic cloud DIY making/hanging method....

I should say:
-the cloth wrapped fiberglass is nicely held rigid in, no worries about it ever coming out, even due to my kids possible "abuse".
That's why I made channels instead of just "boxing it in"....I was un-sure about the robustness of just that way.
-a 3 point mtg, 2 top and 1 bottom, is very secure and quite easy to locate and level, don't be concerned so much.
-the WAF is extremely high on these, she likes them!

erkq 02-03-2011 09:19 PM

Quote:
Originally Posted by mtbdudex View Post

I wanted the drywall screws to sit flush, used larger bit and carefully took away small bite of material as shown

Nice job, detailed presentation. Thanks! But this struck me... just a little thing, though... why not just use a counter-sink?

mtbdudex 02-04-2011 07:03 AM

Quote:
Originally Posted by erkq View Post

Nice job, detailed presentation. Thanks! But this struck me... just a little thing, though... why not just use a counter-sink?

I agree - and edited the post above, the right tool for the job approach, honestly I don't have any countersink bits, just never bought them.
In a pinch I take the drill that is slightly bigger than the screw head, do a manual mini-counterboar slowly, then put the drill in reverse and give full power with pressure.
The angled face of the drill going backward will remove all burrs/etc and make a fine seating area for the screw.
My 75 year old dad has countersink bits and I've used them countless times growing up in the 70's, since he does not do DIY anymore I'll get them as "hand-down-to son" next time I visit.

Suntan 02-04-2011 07:26 AM

Quote:
Originally Posted by mtbdudex View Post

1st prototype Mock-up 2' x 4' panel w/o cloth cover.

Leave it to a professional engineer to make a prototype first.

Anyway, good job on the pictorials, more pictures of DIY is always a good thing.

For my on walls, I made the traditional frame for the 703 out of wood, then used one each of these guys:



-Suntan

jayn_j 02-04-2011 07:32 AM

I would worry about vibration issues with a conventional picture hanger. It is designed to hold the top of the frame 1/4" away from the wall, so it would have most of the frame hanging free.

I'd consider a french cleat top and bottom. Another thought is what I do for poster frames. I string a triangle of picture wire inside the frame. The constuction of the frames means the wire is held about 3/8" in from the back surface. When I hang the frame, the weight will pull the wire taught and this in turn pulls the frame tight against the wall.

smokarz 02-04-2011 08:13 AM

great work mtbdudex, thanks!



Quote:
Originally Posted by jayn_j View Post

....I'd consider a french cleat top and bottom. Another thought is what I do for poster frames. I string a triangle of picture wire inside the frame. The constuction of the frames means the wire is held about 3/8" in from the back surface. When I hang the frame, the weight will pull the wire taught and this in turn pulls the frame tight against the wall.

would you provide a bit for details for this method? sounds interesting...

mtbdudex 02-04-2011 08:18 AM

Quote:
Originally Posted by Suntan View Post

Leave it to a professional engineer to make a prototype first.

Anyway, good job on the pictorials, more pictures of DIY is always a good thing.

For my on walls, I made the traditional frame for the 703 out of wood, then used one each of these guys:

-Suntan

How'd they work for you? Any rattles like jayn_j mentioned?
Prior to deciding I was going to have the 2" air gap, I was going to do something similiar, use these on wall with screws on the frame back - screw would be wedged in the "v" slot was my thinking, then felt at (4) corners to induce some tension into the system for rattle free.
Not sure how that would have turned out, since I did not "prototype it"
Now, I can see accuracy for leveling would be much harder with these than "z" clips.


Quote:
Originally Posted by jayn_j View Post

I would worry about vibration issues with a conventional picture hanger. It is designed to hold the top of the frame 1/4" away from the wall, so it would have most of the frame hanging free.

I'd consider a french cleat top and bottom. Another thought is what I do for poster frames. I string a triangle of picture wire inside the frame. The constuction of the frames means the wire is held about 3/8" in from the back surface. When I hang the frame, the weight will pull the wire taught and this in turn pulls the frame tight against the wall.

I was 90% going to do the DIY French Cleat method - my DIY screen uses them, but was worried about rattles and more so the need for more accuracy for level adjustment.
The "z" clips are really quite forgiving for alignment, about 1" of bearing surface up/down and side/side, that makes leveling not an issue.
Plus, they securly grab each other in a force/spring tension clamp, pretty slick guys at very reasonable cost.

Suntan 02-04-2011 10:49 AM

Quote:
Originally Posted by mtbdudex View Post

How'd they work for you? Any rattles like jayn_j mentioned?
Prior to deciding I was going to have the 2" air gap, I was going to do something similiar, use these on wall with screws on the frame back - screw would be wedged in the "v" slot was my thinking, then felt at (4) corners to induce some tension into the system for rattle free.
Not sure how that would have turned out, since I did not "prototype it"
Now, I can see accuracy for leveling would be much harder with these than "z" clips.

Works fine. My panels are about 2.5" total depth (with 2 703 recessed in about a quarter inch. But they would work the same even at 4 out (you just need to bring a surface back to the wall to hang it at the top and one at the bottom to stabilize it.)

As I completely wrapped the frames with the fabric, the fabric buffers between the walls and keeps things from rattling. If a person were to do bare frames like yours, they may want to put one of these at each corner.



As for centering. If you measure and put the cleat in the center, you should be good to go. Once again, the resistance of the fabric (or the rubber bumpers) against the wall allows you to trim the panels into plumb and they will stay there. Perhaps a little more attachment would be prudent if you have panels in high traffic areas. But mine are most up front and away from traffic (I growl at people if they think about stepping up on the stage )

You can get a view of mine here:



As for the suggestion of double French cleats by someone Talk about overkill. I'm not filling these things with shot, just insulation.

-Suntan

smokarz 02-04-2011 11:48 AM

Quote:
Originally Posted by Suntan View Post

Works fine. My panels are about 2.5" total depth (with 2” 703 recessed in about a quarter inch. But they would work the same even at 4” out (you just need to bring a surface back to the wall to “hang it” at the top and one at the bottom to stabilize it.)


hi, could you expand on this a bit further? i am looking for details....

sorry, i am not very technical when it comes to diy stuff...

i am making the same type of panels that you have......2" 703, 1"x3" pine (2.5" actual depth). covered the whole thing with fabric.

jayn_j 02-04-2011 11:50 AM

When I said double french cleats, I meant one on the top and one on the bottom. The bottom one is not for weight. It traps the bottom and keeps it tight against the wall.

Smokarz, I don't have access to a drawing program here. I'll try to take a picture tonight. Basically, I created the frame and placed three eyelets recessed 3/8 - 1/2 inch in from the back edge. Two eyelets are 1/3 of the way down on each side. One is in the center of the bottom. Then string picture wire to complete the triangle. Pull until it is semi-taught, but allow 1/2 inch or so of play when pulling on the top. I mounted two heavy picture hanging hooks on the wall.

To mount, center the frame over one of the hooks, reach behind and snap it in place. Pull the frame horizontally so the hooked side is toward its closest edge. Reach behind and snap the other edge in place. Center the frame on the hooks so it hangs level.

The tension of the wire will pull the frame back tight into the wall. I use something similar to Suntan's dots, except they are flat and about 1/8 thick. Use 6 of them for a 27x41 frame.

Suntan 02-04-2011 12:10 PM

Quote:
Originally Posted by jayn_j View Post

When I said double french cleats, I meant one on the top and one on the bottom. The bottom one is not for weight. It traps the bottom and keeps it tight against the wall.

Yeah, I know.

Even still, just one French cleat is total overkill for these things. They aren't that heavy.

If you're worried about them rattling, or being bumped off the wall by passersby, there are better methods of securing them than just having them rest on French cleats.

-Suntan

smokarz 02-05-2011 10:06 AM

anyone with more methods for hanging panels, please share. thanks

mtbdudex 02-10-2011 04:55 AM

While driving in a small industrial park this past weekend in Brighton I saw this print shop, stopped in and asked them about printing acoustic panels.

We talked for about 10 minutes, they can do what is needed and gave me (2) samples. The material is white then they print the image you have.
Just ballpark cost was $100-120 for a 54" x 56" printed panel, the roll is 54" wide so actually they are flexible to the other dimension.
There is a "fixed" cost for their time/set-up, then printing more than one may have some overall lower cost.
I gave both samples the "breathe" test, and both were flowable, which is needed for mid-hi freq.
What I'll do further before ordering some is get an already printed piece from them on both materials and take some measurements.
The blocky looking one was slightly less flowable.
Since I have speaker cloth, that will be my baseline.
(tests are to my ability @ home and inside, if summer I'd do outside for more accurate, since I work for auto OE and we have a full vehicle size NVH lab, I might be able to do a "g-job" during a lunch session for accurate tests)

I scanned the info, hard to see the 2 types of cloth weave in the scan.


Since another hobby of mine is Astrophotography, Top 10 in 2010 to shoot (Astronomy, non telescope) , I'll probably take some better pictures of the Milky way, Andromeda galaxy, etc, and use those for the prints.
(I'm getting a decent tracking mount/scope shortly)

Suntan 02-10-2011 05:55 AM

Quote:
Originally Posted by mtbdudex View Post

While driving in a small industrial park this past weekend in Brighton I saw this print shop, stopped in and asked them about printing acoustic panels...

Just in case you were not aware, you can have panels made with your choice of print.

Here is one, but there are a number of other places that will do it too.

http://www.gikacoustics.com/gik_artpanel.html

Kinda takes the DIY out of it, but the option is there.

-Suntan

mtbdudex 02-10-2011 07:08 AM

Quote:
Originally Posted by smokarz View Post

anyone with more methods for hanging panels, please share. thanks

I'd also like to add some of you with completed Home Theaters may have your DIY hanging panels methods buried in your HT build thread, PM me that build/thread/post and I'll put a link in this thread top post to yours with "credit" to you.
fwiw, I'll be making some non-framed panels for my front wall in near future.

Quote:
Originally Posted by Suntan View Post

Just in case you were not aware, you can have panels made with your choice of print.

Here is one, but there are a number of other places that will do it too.
http://www.gikacoustics.com/gik_artpanel.html
Kinda takes the DIY out of it, but the option is there.
-Suntan

Those are sweet looking panels, and considering the time I've put into mine their prices are very reasonable for those not into DIY, as are some of the other sites (RealTraps, etc).

What I like about doing it with this small company is they are local - helping Michigan economy, I can have face-face time, etc.

smokarz 02-10-2011 07:42 AM

Quote:
Originally Posted by Suntan View Post
Leave it to a professional engineer to make a prototype first.

Anyway, good job on the pictorials, more pictures of DIY is always a good thing.

For my on walls, I made the traditional frame for the 703 out of wood, then used one each of these guys:



-Suntan

i went to home depot, picked up 12 of these for my frames.

smokarz 02-10-2011 07:44 AM

Quote:
Originally Posted by mtbdudex View Post
I'd also like to add some of you with completed Home Theaters may have your DIY hanging panels methods buried in your HT build thread, PM me that build/thread/post and I'll put a link in this thread top post to yours with "credit" to you.
fwiw, I'll be making some non-framed panels for my front wall in near future.

.......

i do not have an HT build thread, just didn't have time...my HT room was built in roughly 2 weeks....

i will try to take some photos of the panels and post them here.....

Mike_WI 02-10-2011 10:08 AM

Quote:
Originally Posted by mtbdudex View Post
While driving in a small industrial park this past weekend in Brighton I saw this print shop, stopped in and asked them about printing acoustic panels.

We talked for about 10 minutes, they can do what is needed and gave me (2) samples. The material is white then they print the image you have.
Just ballpark cost was $100-120 for a 54" x 56" printed panel, the roll is 54" wide so actually they are flexible to the other dimension.
There is a "fixed" cost for their time/set-up, then printing more than one may have some overall lower cost.
I gave both samples the "breathe" test, and both were flowable, which is needed for mid-hi freq.
What I'll do further before ordering some is get an already printed piece from them on both materials and take some measurements.
The blocky looking one was slightly less flowable.
Since I have speaker cloth, that will be my baseline.
(tests are to my ability @ home and inside, if summer I'd do outside for more accurate, since I work for auto OE and we have a full vehicle size NVH lab, I might be able to do a "g-job" during a lunch session for accurate tests)

I scanned the info, hard to see the 2 types of cloth weave in the scan.


Since another hobby of mine is Astrophotography, Top 10 in 2010 to shoot (Astronomy, non telescope) , I'll probably take some better pictures of the Milky way, Andromeda galaxy, etc, and use those for the prints.
(I'm getting a decent tracking mount/scope shortly)
Very cool.
I'm interested to see your results.

Mike

myfipie 02-10-2011 11:16 AM

Quote:
Originally Posted by Suntan View Post

Just in case you were not aware, you can have panels made with your choice of print.

Here is one, but there are a number of other places that will do it too.

http://www.gikacoustics.com/gik_artpanel.html

Kinda takes the DIY out of it, but the option is there.

-Suntan

The printing process is called Dye-sublimation. Basically the print is dyed into the fabric instead of printed on the fabric. If you print on the fabric it would clog it which would take away from the absorption.

BTW one of my favorite painters in Germany gifted me a HUGE digital file of one of my favorite paintings from him. Truly was a honor as I think I am the only one to get it. It is DD Ramone in the picture playing in the late 70s (I believe) in Munich. Florian Süssmayr, the painter took the picture when he was a teen then painted it about 6 years ago.



I still need to take some pictures of it hanging in my condo.

erkq 02-10-2011 11:36 AM

Quote:
Originally Posted by myfipie View Post

If you print on the fabric it would clog it which would take away from the absorption.

Here's some fabric you are supposed to be able to paint with a high pressure sprayer and it will retain its AT properties: http://www.acoustex.com/Colorcard_custom.html

mtbdudex 02-10-2011 12:39 PM

Quote:
Originally Posted by Mike_WI View Post

Very cool.
I'm interested to see your results.
Mike

Hey Mike, my telescope purchase will be early March - so for the next 1-2 months this is in planning/study phase.
Taking many images, stacking them, then the Post Processing (Apple Aperture 3, Adobe CS5, and DSS - Deep Space Stacker) is something I've gotten decent at, but for my "keepers" to print I'll probably be really picky.
fwiw, this is the mount/tripod, I've not decided on the actual optic tube just yet.
Vixen Optics SPHINX SXW Motorized Equatorial Telescope Mount w/ HAL130 Tripod

Quote:
Originally Posted by myfipie View Post

The printing process is called Dye-sublimation. Basically the print is dyed into the fabric instead of printed on the fabric. If you print on the fabric it would clog it which would take away from the absorption.

BTW one of my favorite painters in Germany gifted me a HUGE digital file of one of my favorite paintings from him. Truly was a honor as I think I am the only one to get it. It is DD Ramone in the picture playing in the late 70s (I believe) in Munich. Florian Süssmayr, the painter took the picture when he was a teen then painted it about 6 years ago.

I still need to take some pictures of it hanging in my condo.

Glenn;
Thx for advice on the printing process, I'll review that with the place I found and it they arent capable then I'll have to do more looking.
Like I said, after making my DIY panels I can really appreciate all the time and effort your company (and the other suppliers) go into making a quality product.
Simply, I love wood products and yours are 1st class beautiful!

Looking fed to seeing your pict of the acoustic artwork hanging in your Condo

Quote:
Originally Posted by erkq View Post

Here's some fabric you are supposed to be able to paint with a high pressure sprayer and it will retain its AT properties: http://www.acoustex.com/Colorcard_custom.html

Thx erkq for the link, I'll have to confirm the place I found what material and process they use, and if not suitable then yours is on my list to contact.

mtbdudex 02-10-2011 10:01 PM

Today's project: Home Theater Ceiling Acoustic "Cloud", status: 1 Completed and installed!
It actually handles the 2nd row 1st reflection points, I'm holding off making the 1st row 1st reflection points Acoustic "Cloud" until I'm done with Bass traps in the corners and do some detailed room readings.

Final BOM:
-(1) 1" x 10" x 12' pine board (ripped into (2) 4" wide boards)
-(1) 1" x 6" x 10' pine board (for the ends and the mid sections)
-Fabric, 56" wide, cut 13' 2" (I got 20 yard roll for all my wall treatments except the side wall ones, which used black speaker cloth)
-drywall screws, 1 5/8 for the end/mid section pieces, 1" for the T and L braces
-T and L braces
- #6 J hooks
-black paint
-electric stapler and staples (I used 5/16 for this project)

I built a 2' x 12' x 4" deep box as shown:


Note: I separated each 2' x 4' sheet "zone" with a 1" x 4" x 23 13/16 support, reason 3/16 shy of 24" is I wanted to "grab" the 2' x 4' sheet lengthwise by tightening the screws, it worked and held the fiberboard nicely.

I used a 24" clamp to squeeze the 2 outside boards together as I did the final tighten.

Has anyone tried to find 1" x 6" x 12' straight lumber lately?
I actually had better luck buying 1" x 10" x 12', dead straight, and then ripping it exactly 4" thick to hold the (2) stacked OC703 sheets.
Got (2) 4" wide 12' long pieces that way, dead straight.
Important to look at the endgrain of boards you buy also, you want boards from the outer rings of the tree, they are more stable.


Having used the simulation software for the 1st reflection points, transferred those locations via blue tape onto the ceiling.
Confirmed their accuracy with 1' x 4' mirror and my wife....she was on ladder holding the mirror flat to the ceiling while I was the one sitting in the chair analyzing
Then, with the build wood box, get exact mtg locations via blue tape and much measurement/cross checking. I'm hanging these into the ceiling joists also.


btw, My favorite tool for long straight lines is still this "Strait-Line 64001 Laser Level", $39 @ Home Depot 6 years ago, it has little pins that hold it even upside down.


I found a simple bread knife worked perfectly fine to cut the OC703


Buy lots of hardware, then decide exact method OJT (on the job)....this is after all my 1st time doing this.
I ended up going with #6 J hooks for both the panel and ceiling, and black chain. Will return most of the stuff you see here.
(and those ATS Acoustic plastic screw in anchors I posted above, they are ok for single panel but not for huge beast like this.)


Made this handy drill jig so I can have straight/inline screws.
The 5 minutes it takes to make these pays off with good results later.


Paint the silver hanging hooks black, use a box as spray booth


Add T and L supports to the box, and of course the fabric ordered and delivered (I got 20 yards of 56" wide forest green fabric).
Cut fabric and get ready to use that electric stapler!


Part II coming shortly....

mtbdudex 02-10-2011 10:21 PM

Home Theater Ceiling Acoustic "Cloud" - Part II

Showing detail of T and L braces, I was worried about hanging and wanted some insurance for rock solid box.
Note: I drilled and pre-installed all J-hooks, so after the fabric was wrapped I just had to find the hole and re-install them.
Plus, gave exact placement for ceiling transfer of matching locations.


One side stapled taught.


Flip up on edge, now its a 2 person job, my wife pulled down to keep the fabric taught while I stappled.
I should state I was worried about wrinkles, I pulled slightly lengthwise on each end and put 2 temp staples to keep tension longwise for no wrinkles, it worked.


Finish stapling, it's like wrapping a big Christmas gift, keeping the material taught so no wrinkles is the secret.


Edges wrapped like a box gift, this is ceiling side so "perfection" not needed here, still want a secure wrap.


Black hooks and chain waiting for the big box.
Hopefully all the measurements were transferred to ceiling correct, holes drilled correct, etc. Measure 3 times, drill once.


Ta-da! My wife and I hung the panel this morning, here is my youngest son checking it out. 2 ladders, and attaching the far side chain first, then the near side chain.


here is pict from rear of theater, only once did my drill go too far and the chuck "bit" into the ceiling drywall, I spackled and painted that since this pict.
My boy wants to know everything dad is doing and why....luv the guy so much!


The projector beam exits @ 13" from the ceiling, and the screen top edge (image edge) is @ 18" from the ceiling.
This panel is 4" thick and almost 12" from ceiling at the bottom, I hung it low for more bass trapping, and also atheistically its same as the LH side soffit.
The pj light beam is about 2 1 /2 inched below this trap here, so no interference.

Note for other future HT builders:
Consider ceiling light locations relative to speaker location for possible 1st order acoustic treatments......
This 2nd row ceiling treatment catches some of the light from those 3 can lights, but its not so bad.
However, my 1st row - possible acoustic ceiling cloud, would block all 3 lights, so I'll need to address that at later date.

Next up: removable corner bass traps - I need to clean in back of those chairs, only way is removable bass traps.
Here my "prototype", a 24" x 24" x 37" triangle and a 17" x 17" x 24" triangle from pink foam board.
Confirming how high I can go with the bigger/deeper triangle before the sconce (about 5' 6" or so), then will use the smaller size up to the ceiling.

smokarz 02-11-2011 08:08 AM

nicely done.

i must say, your carpet is mesmerzing...

mtbdudex 02-11-2011 11:28 AM

Quote:
Originally Posted by smokarz View Post
nicely done.

i must say, your carpet is mesmerzing...
Thx, it felt good to get the cloud done and hung.

The carpet, we liked the HT theme in it, and at the time our walls were bare.
Plus, there are some reds/blues in it if we wanted to use those for wall accent colors in some future re-do....
Thx for remining me, I owe the guy who sold me the carpet a HT picture, and was waiting for my acoustic panels to go up before taking one....just my 1st row couch is getto and due for replacement April when bonus checks come in.

Returning stuff at Home Depot during lunch, I was studying how to do removable corner bass traps.
I bought some handrail and may "play" with that this weekend.

While my side wall hanging frame panels are fresh in my mind, I saw 2 possible methods/options for others to consider:

1) Use steel stud frame instead of wood.
3 5/8" wide, easy to make a box, and the edges would naturally grab the fiberboard.
Of course you'd want to wrap them with the fabric material, unless you wanted a industrial look and painted them instead.
Bonus: They have some holes in the sides so you'd get some "extra" absorption, or more closely match the test specs since I've read their absorption Coefficients @ various hz are done on panels totally exposed, edges included.

2) Use Glass block plastic channel instead of wood.
4" wide, easy to make a box, and the edges would naturally grab the fiberboard. These are exactly 48" tall, perfect for 2' x 4' sheet, 3 needed per panel.

Possible rivits to hold the channels to each other, with an inner angle channel if needed?
First make the box and see how sturdy it would be before adding reinf.

Steel studs....................................................... ..glass block channel
...

I'd like to see how other DIY'rs have done theirs, so far nobody has PM'd me anything....
Guess once they make their's they move onto other things and don't read these threads, since not on their mindset.

smokarz 02-11-2011 11:39 AM

Quote:
Originally Posted by mtbdudex View Post
.............
I'd like to see how other DIY'rs have done theirs, so far nobody has PM'd me anything....
Guess once they make their's they move onto other things and don't read these threads, since not on their mindset.

don't worry. i will upload some photos the next time i get around to working on the frames again.

so far, i managed to get 3 completed last weekend and since it's my first time doing it, i wanted to focus on trying to get it done right.

mtbdudex 02-11-2011 04:12 PM

Driving home from work, after my lunch Home Depot visit, this idea came to me.

Why not use thd rod for the moveable SuperChunk design?
It could easily work, no flexing/warping ever.

Pict is pretty self explain, bottom and top are piece of wood - thick mdf comes to mind.
You can make the 3 rods "invisible" by having then @ the corners and wrapped, or you go with an "industrial look" and have the 2 outside corner ones visible. I show a rod connector in blue, since I think normal Home Depot thd rods are not 9' long.....
[edit 2-18-2011; thd rod comes in 6' length max at Home Depot / Lowes]
I'm sure with little looking I could get my hands on some from a local supply house.


Feedback, thoughts, comments?

(I used thd rod for my IB subwoofer also)

scl23enn4m3 02-11-2011 04:19 PM

The threaded rods are good idea. You might need to cross brace them though, I'm not sure how sturdy the fill would be. Then again, being compressed between the floor and ceiling would probably keep them sturdy too. Have you thought about creating two traps and stacking them on top of each other? If you are going floor to ceiling, it might be hard to remove them. I'm trying to picture it in my head and it seems like you'd have to slide them to the edge of the riser to be able lay them flat.

You have a PM coming your way too, I have a question about your paint .

mtbdudex 02-11-2011 04:44 PM

Quote:
Originally Posted by scl23enn4m3 View Post

The threaded rods are good idea. You might need to cross brace them though, I'm not sure how sturdy the fill would be. Then again, being compressed between the floor and ceiling would probably keep them sturdy too. Have you thought about creating two traps and stacking them on top of each other? If you are going floor to ceiling, it might be hard to remove them. I'm trying to picture it in my head and it seems like you'd have to slide them to the edge of the riser to be able lay them flat.

You have a PM coming your way too, I have a question about your paint .

Honestly - we think alike - 5 minutes after I posted I thought the same, "how will I put this into place?".
I agree on the 2 piece design, or, making the top with a 1" gap for loading and then putting a mldg/fabric fold up there to hide it.
Since it's on my riser, which is 12" high, I could build it and load it that way w/o being constrained by the ceiling for most of it.

I learned my lesson on that 30 years ago when I was a beginning tool designer, I designed a tool to assemble 3 sheetmetal brackets onto a inner structure piece of a car.
I thought I was a "hot shot" designer, except after the parts were loaded and spotwelded, the jig could not be un-loaded! Everyone does that at least once my boss said, I was humbled and learned a valuable lesson.
Re-designed it before it was actually built (that's why there were checkers who checked junior designers work back in the day).
I'd use many-many pieces of steel/other that were in here the Central Steel Catalog...
.............................................To design machines like this - all on drafting board, this is from 1984:


sorry for trip down memory lane there, getting back to acoustic DIY panel methods.....

mtbdudex 02-12-2011 03:09 AM

I never heard of Gearslutz.com until yesterday, just registered there.....kinda overloaded looking at all the acoustic stuff there.
Also I see quite a few commercial people here also over there as well, small community @ that level of expertise.

Here is a link to their "How I built my bass (broadband) traps..." sticky, over 31 pages of info!
http://www.gearslutz.com/board/bass-...ass-traps.html
(I added the above to post #1 as well)

I'll be scanning from it and post 2-3 links/images of what I'd call "easy, movable bass traps" from it here as reference.

DIYHomeTheater 02-12-2011 05:24 AM

Interesting. I wonder if there are easier methods for building frames using lightweight metal framing and screws. Or even CPVC? The Fiberglas could be made to extend over the frames and completely hide the metal. Less labor and no warping. Thoughts?

smokarz 02-12-2011 07:59 AM

here is how i built my panels:

1 - the frames, 24"x48" with panel nails and gorilla glue




2 - instead of stapling the fabric to frame, i used a small strip of wood panel, rolled up the fabric and nailed it to the frame. i find this method a little quicker and fabric stretch more evenly.






3 - wires in the back for support, just extra precaution even though the OC 703 fits snuggly into the frame anyway.




4 - one sidewall is completed, the other still need another piece or two.



smokarz 02-12-2011 08:06 AM

i gotta say, these panels made a huge difference.

we watched the eagles farewell tour blu-ray again, and music just feel so tight and clear.

next up are corner bass traps. still scouting forum for diy samples/methods.

mtbdudex 02-12-2011 09:00 AM

Quote:
Originally Posted by smokarz View Post

i gotta say, these panels made a huge difference.

we watched the eagles farewell tour blu-ray again, and music just feel so tight and clear.

next up are corner bass traps. still scouting forum for diy samples/methods.

Good job making them and thx for posting!

smokarz 02-12-2011 09:21 AM

thanks, i am anticipating your bass trap build.

mtbdudex 02-12-2011 09:44 AM

Quote:
Originally Posted by smokarz View Post

thanks, i am anticipating your bass trap build.

Here's what I've got so far on my rear broadband bass traps.

Each stack is (6) sheets of 2" thick 2' x 4' OC705 panels, cut 24" x 24" x 34".
The 24 triangles stack just over 48" high, I've decided to make them removable "corner tables".
The base board mldg will be removed and cut down after these done, so it will look integrated nicely.
fwiw: I have some more....Star Trek stuff to display, the 3D chess set, some ST:TOS replica phaser and tricorder, etc, collected over 20+ years.
So, the top will be nice wood, while the bottom possible mdf or even some leftover OSB I have. The 1/2 thd rod comes in 72" size.

Now, above that display zone, which will get light w/o shadows via the sconces, will either be a 17" x 17" x 24" superchunk as shown on LH side, or a more visually pleasing triangular patch as shown on RH side, tbd.
Note: That Home Depot bag on the center table has (2) blue box AC gang boxes, I was going to move those sconces today fwd about 8" so I could have floor-ceiling "big" superchunks, but by putting a table top I've decided to not to do that.

(the boys and I watched a movie last night, sorry for the clutter)

For now, actually tonight while kids sleep, now is time for me to take room measurements with REW to see how the room has responded to these added bass treatments.
I'll post that in the Master Acoustics Thread for review there by the experts.
Until I take measurements, not sure if I should leave the room side of the superchunks open for mid-hi freq, or block them with cardboard (which will let the low freq still pass thru).

I'll take measurements with them open and just put a sheet of cardboard in front of each and re-take measurements.

Regarding cutting the superchunks out of the 2' x 4' sheets, I started with the big bread knife, did 4, then tried the electric turkey knife.
My experience, the manual knife was MUCH easier to get dead straight and perpendicular lines cut, the electric knife seemed to walk on its own slightly, giving a wavy edge, not style points.


Here you can see what I'm talking about.
The bottom 4 were cut by hand/bread knife, the next 4 by electric knife.
It's not that much more time for hand/bread knife, 1st pass with edge guide sets the line, then 4 more passes holding the knife at a low 15-20 degrees gives perfect straight and perpendicular edge.
I suppose a jig could be made to ensure the electric knife is straight and perpendicular, but this manual method worked for me easily.

mtbdudex 02-15-2011 12:34 AM

With REW_v5 working on my iMac - a significant upgrade from v4, Room EQ Wizard (free measurement and parametric EQ setup software) .
I decided to take measurements of the bass traps with and w/o paper to decide mid-hi freq blockage and resultant RT60 differences.

I've got more readings to take before making decision to leave the frt face unblocked

vs blocked.

before I put the fabric over them

meanwhile in the garage, via makeshift paint/infra red warm booth I'm painting the thd rods......and the attach nuts/washers



I'm hoping to have the 2 big bass traps done by this weekend, then work on the smaller/upper ones.

erkq 02-15-2011 08:13 AM

Quote:
Originally Posted by mtbdudex View Post

meanwhile in the garage, via makeshift paint/infra red warm booth I'm painting the thd rods......and the attach nuts/washers

Lookin' good!

I look at other's construction threads and I'm SO much the "do the bare minimum" guy. I just rough up my washers with an orbital, put them out on newspaper and spray them.

mtbdudex 02-15-2011 08:49 AM

Quote:
Originally Posted by erkq View Post

Lookin' good!

I look at other's construction threads and I'm SO much the "do the bare minimum" guy. I just rough up my washers with an orbital, put them out on newspaper and spray them.

Thx, and I'm with ya, whatever works within our time constraint.

For this, I had the boxes lying around, the big box is what my 2' x 4' panels came in, so why not do the "stinky" spraying in the garage and spare the wife/kids that smell.
Took just a few minutes to set-up.

I did the ceiling hooks in the basement bathroom with the fan on in that small box that held the washers/nuts, still the smell got out a little.

mtbdudex 02-15-2011 08:48 PM

Tonight's progress:
-2nd coat of paint on the thd rod and hardware in the garage

-final cut/paint the OSB base.
I added a 1 1/4 perimeter of 3/4 OSB so the thd rod/nuts won't be resting on the floor directly. Painted green, same as walls.


-Final cut/sand/stain the birch top board


Maybe tomorrow these "Mikes Mondo Corner Bass traps" might get assembled and put into the room.
Each will weigh 50+ lbs, looking back at my original plan of 1 huge removal bass trap.....nope that's 100+ lbs of weight, glad I went "1/2 size" then an additional trap in the top corners

My boys want to climb them and jump off of them already....we need spring/summer so bad!

mtbdudex 02-16-2011 07:07 PM

Good progress made today on these beasts, they are huge, big, and sturdy
(YouTube video clip will show that)

Layout the cut big triangles, cut back corner 3" x 3" 45 deg for clearance to rear thd rod


Stack 'em, trying to keep the leaning tower straight/aligned as it gets higher...


Me next to my the 4' stack, showing size of this beast.
However, mistake I made was NOT putting the rods in 1st before loading the triangles, so I had a PIA to get the rods in...lesson for #2
After fiddling here are the rods installed



I did NOT pre-cut the thd rod in the garage, had no way of knowing how much the OC705 would compress.
I actually can compress easily 1", more than 2", but the 1/2" birch ply top flexes too much at 2", I settled on 1" of compression, it felt very sturdy and solid.
Green tape for cutting spot, my wife held the rod top while I used a Dewalt 18v buzzsaw.
Load in room, check for ingress/egress of loading the trap etc.
No other issues appeared to prep for fabric covering time


[edit: note added March 2, 2011 related to using drywall edging]

Quote:


Use drywall edging on the corners for crisp edge look, lessons learned from the upper corner bass traps post #72/73 has details on that https://www.avsforum.com/avs-vb/showt...0#post20085920


Cut the mid-hi freq blocker (kraft paper here) for the front face, install and hold with simple 1 3/4" craft pins


Cut the 56" wide fabric (roll size), for this first one I cut just 3/4" extra top/bottom (to 50", compress size is 48.5 "), it worked but for the 2nd one I increased that to 1" top/bottom extra for wrapping safety.
I should say this is a GLUE-LESS/PIN-LESS build for the fabric, I just use pins for the top to start, put the top birch ply board down and compress/tighten, keeping fabric not attached, and tuck the fabric in at the bottom.


1st one "done", front face side
 


mtbdudex 02-16-2011 07:16 PM

cont....

Backside looks good, needs covering


Now, the 2nd one went much quicker and smoother!
Make a 3 rod frame with base and top, gave 5" extra for loading.
This worked best for aligning the loose big triangles for flatness.


Kraft paper installed on 2nd bass trap:


Close-up showing 1" of extra material on the top before clamping down the birch ply.


2nd one done, and backside covered


Loaded into the HT room, RH side one is the 2nd one made, it came out a little better.


I'm taking measurements using REW just now....will post a few of those later as reference.
Not too much graphs here, as this is a construction thread, I'll post majority of those in the Master Acoustics thread, since I have some Q's.

mtbdudex 02-17-2011 11:04 AM

YouTube video showing how these can be moved around.

 

 


mtbdudex 02-17-2011 01:41 PM

Quote:


Quote:
Originally Posted by Mike_WI View Post

Very cool.
I'm interested to see your results.

Mike

Quote:
Originally Posted by myfipie View Post

The printing process is called Dye-sublimation. Basically the print is dyed into the fabric instead of printed on the fabric. If you print on the fabric it would clog it which would take away from the absorption.


I still need to take some pictures of it hanging in my condo.

Quote:
Originally Posted by erkq View Post

Here's some fabric you are supposed to be able to paint with a high pressure sprayer and it will retain its AT properties: http://www.acoustex.com/Colorcard_custom.html

I'm still waiting for you to post that picture Glenn

Update on DIY artwork acoustic fabric panels:
The printer is a HP 9000 series Designjet Low-solvent,
http://www.hp.com/united-states/desi...0/index_f.html
Quote:


Media width up to 64" wide
• High speed printing, 176 ft2/hr at 720 x 720 dpi resolution
• Low-solvent inks for longevity and durability with vivid color
• Three integrated heaters for proper ink adhesion at fast print speeds
• Take-up reel for long, unattended print runs



They are going to give me a printed 8" x 10" sample of each material, I'll do the breath test, then follow-up by nearfield speaker test without and with the material in front of my Berrigner 8000 mic. Probably not the most accurate, but the only way I can get some objective data.

smokarz 02-17-2011 03:52 PM

wow, looking real good mike.

i must say those bass trap are HUGE.

smokarz 02-18-2011 09:23 AM

going to mount some panels to the ceiling next.

any method for flush mounting?

mtbdudex 02-18-2011 10:12 AM

Quote:
Originally Posted by smokarz View Post

going to mount some panels to the ceiling next.

any method for flush mounting?

smokarz;
Flush meaning "fixed permenant"?
Ceiling panels....if you can suspend them a few inches they will also help with bass absorption , 1/4 wave guideline is air gap = thickness of panel for optimized return of freq's absorb vs intrusion.

How about the screw in anchors @ ats acoustics and some drywall anchors into the ceiling and 14ga wire??

If you want them totally flush, how about those nails with plastic 1 1/4 dia heads I see in the drywall area?
I'm guessing use 6/sheet, these could hold the fiberglass up to the ceiling, then you just wrap them while on the ceiling, it could be a simple job really.


Quote:
Originally Posted by smokarz View Post

wow, looking real good mike.

i must say those bass trap are HUGE.

Huge, but managable and moveable at 50-ish lbs each, there would be NO way I'd want to make moveable floor/ceiling ones out of the big triangles (24" x 24" x 34") 100lbs+ each, that's asking for trouble!

Next up for this weekend:
The upper corner removable bass traps that will go above these, most likely they will be the "smaller" triangles 17" x 17" x 24".

mtbdudex 02-20-2011 03:16 AM

Upper bass traps update: both will be removable and not fixed/built onto the wall.

These will be just 24" tall-ish, I'll use 3/18-16 thd rod, stick with the 1/2" birch plywood for both top/bottom, and on the top use the T-nuts so it can mount flush to the ceiling.


Plan A:
"smaller" triangles 17" x 17" x 24".
I was just going to build these, then I was wondering about what was the largest size I could build/fit up there?


Plan B:
I'll call this the "Trapezoid wedgie bass trap", consists of smaller triangles 17" x 17" x 24" blending into the biggie 24" x 24" x 34" to get more low freq absorption.
The thd rod will be hidden inside the bass trap except will show on the bottom.


I'm 90% going with Plan B, I think it will look nicer up there and the hidden rods is better for the upper location.
Unless I move those sconces full 24" x 24" x 34" size won't fit.

Additional 1/2" Birch plywood and thd rod/hardware bought yesterday.
This afternoon is build time.
I've got an idea on hidden holding system, will work on it a little more and if its doable will go with that.

btw, not all the Star Trek stuff will stay there, it will be de-cluttered, just showing my kids some of the stuff I had back in the day.
And YES, those Star Wars glasses are original Burger King glasses from the early 1980's, and those are genuine Apollo 13 glasses as well.
Unfortunately, Leonard Nimoy has not signed my "I am Not Spock" book...

Am I the only geek here with this stuff??
My kids think it's all COOL

BruceD 02-20-2011 07:40 AM

Mike,

Really good project progress reports, I'm impressed with your results. I'm in Northern Indiana and trying to figure out how to do something similiar.

Did anybody see or try the NuWool product,
cellulose instead of fiberglass ?

Your fiberglass knife cutting experiences for the triangles is what I'm trying to figure out for this cellulose product. Guess I'll have to call and find out.

Anyway thanks for all the great ideas.

Also trying to figure out how the pdf test results from Riverbank Acoustical labs compares to OC703 fiberglass.

Anybody have any experience with this cellulose type compressed product ?

smokarz 02-20-2011 08:13 AM

Quote:
Originally Posted by BruceD View Post

Mike,

Really good project progress reports, I'm impressed with your results. I'm in Northern Indiana and trying to figure out how to do something similiar.

Did anybody see or try the NuWool product,
cellulose instead of fiberglass ?

Your fiberglass knife cutting experiences for the triangles is what I'm trying to figure out for this cellulose product. Guess I'll have to call and find out.

Anyway thanks for all the great ideas.

Also trying to figure out how the pdf test results from Riverbank Acoustical labs compares to OC703 fiberglass.

Anybody have any experience with this cellulose type compressed product ?

nope, never tried them...but wow...~$230 for 12 pieces (24x48x2).

i can get 36 pieces of 703 for that price.

mtbdudex 02-20-2011 05:59 PM

Quote:
Originally Posted by BruceD View Post

Mike,

Really good project progress reports, I'm impressed with your results. I'm in Northern Indiana and trying to figure out how to do something similiar.

Did anybody see or try the NuWool product,
cellulose instead of fiberglass ?

Your fiberglass knife cutting experiences for the triangles is what I'm trying to figure out for this cellulose product. Guess I'll have to call and find out.

Anyway thanks for all the great ideas.

Also trying to figure out how the pdf test results from Riverbank Acoustical labs compares to OC703 fiberglass.

Anybody have any experience with this cellulose type compressed product ?


Well looking at the data it sure seems to have much better low freq absorption characteristics....
http://www.acoustimac.com/index.php/...oinsul422.html
Quote:


Quote:


Sound Absorption Coefficients (1/3 Octave Band Center Frequencies. HZ)

Hz
100 125 250 500 1000 2000 4000
2" Thickness 0.38 .39 .63 1.18 1.11 1.06 1.09

An even greener alternative to cotton insulation:

Cotton insulation works as well as its fiberglass counterparts, however this material can be prone to mold and is not as biodegradable and recyclable as cellulose which is made from recycled newspapers and cardboard products.

Better Performance than Fiberglass!

Oh yes, it’s true! This cellulose based insulation has even higher absorption coefficients than our standard insulation material, so not only is it more eco-friendly, it also outperforms its fiberglass and mineral wool counterparts hands down.

Quote:


Freq 125 HZ 250 HZ 500 HZ 1000 HZ 2000 HZ 4000 HZ NRC
OC-703 (2") 0.17 0.86 1.14 1.07 1.02 0.98 1.00

Quote:


Freq 125 HZ 250 HZ 500 HZ 1000 HZ 2000 HZ 4000 HZ NRC
OC-705 0.16 0.71 1.02 1.01 0.99 0.99 0.95

and when you compare the online price of 705 to this ....so you get your cake (better low freq absorption) and get to eat it too (lower cost/6 pcs).....I need more 705, now I'll re-think that and consider this.
Thx for posting!
(Bruce - let me know what they say about cutting it, if a serrated bread knife does it same as thru OC703/705 that would be nice.)

For their ECOUSTIMAC line, has there been 3rd party testing to confirm their claims?
I'd hate to be 1st on the block in avs community to use them.....I wonder if Ethan W/Dennis E/others have used their product.....

mtbdudex 02-21-2011 07:39 PM

Today's progress;
(2) "Trapezoid wedgie bass trap's" frames cut, stained, painted blk thd rod/hardware, assembled.
When you tighten the nuts up there is very little flex in this assembly, even prior to having the insulation in it.
There are other ways to make these obviously, but the thd rod IMO is easy, simple, and adjustable.

They are shown upside down here, that is how I'll cut/load them, starting from the big 24" x 24" x 34" triangles, and blending into the 17" x 17" x 24" as last one.
The 3/8-16 T-nut's worked perfect, nice and flush for ceiling mtg.


I'm needing more OC705 or the new stuff BruceD brought up, ECOUSTIMAC Eco Friendly DIY Insulation.
I need (6) sheets of 2" 2' x 4' panels for these 2 bass traps, then I need (18) more sheets of same for my front wall bass traps...I'm, leaning towards the ECOUSTIMAC stuff.

As Ethan W has said quite often, "You can never have too many bass traps"

mtbdudex 02-22-2011 07:07 AM

I just spoke with ECOUSTIMAC sales staff, there is no shipping discount if I order one case (6 2" 2' x 4' panels) or three (18 panels).
Therefore I ordered one case for now to tryout this material for the upper rear wall bass traps, hopefully I'll have it by Friday and can complete them this upcoming weekend.

Therefore, to keep progress I'll now work on the 1st row ceiling acoustic cloud during the week.
Some minor lessons learned from the 2nd row panel I made 2 weeks ago I'll try and doument for others (small easier making steps, etc).

snooktarpon 02-25-2011 03:10 AM

I have some questions about wrapping the panels around the wood frames with fabric:

How do you wrap the fabric at the corners of the frames?
Do you cut out a square section of fabric at each corner (so you just can wrap the fabric around the sides without any folds)?
Do you overlap the fabric to ensure the wood is not visible?

mtbdudex 02-25-2011 08:23 AM

Quote:
Originally Posted by snooktarpon View Post

I have some questions about wrapping the panels around the wood frames with fabric:

How do you wrap the fabric at the corners of the frames?
Do you cut out a square section of fabric at each corner (so you just can wrap the fabric around the sides without any folds)?
Do you overlap the fabric to ensure the wood is not visible?

snooktarpon;
My side wall panels wood frames were left exposed, I only wrapped the OC703 with fabric.

Member "luma" did a good explaination with his method of wrapping fabric over wood frames, look here https://www.avsforum.com/avs-vb/showthread.php?t=1316623

For the ceiling panels, which I did wrap fabric over wood, I did NOT cut any fabric, rather just wrapped the ends exactly like a gift box.
IMO that can be done tight and look good.
Just pratice it and adjust your method on the fly....

Take picts of your build and post them here!
Have fun and enjoy the better acoustics.

From post#27 in this thread:
Quote:


Edges wrapped like a box gift, this is ceiling side so "perfection" not needed here, still want a secure wrap.


mtbdudex 02-26-2011 04:25 AM

Quote:
Originally Posted by mtbdudex View Post

I just spoke with ECOUSTIMAC sales staff, there is no shipping discount if I order one case (6 2" 2' x 4' panels) or three (18 panels).
Therefore I ordered one case for now to tryout this material for the upper rear wall bass traps, hopefully I'll have it by Friday and can complete them this upcoming weekend.

Good news/bad news.

Good news:
Got the ECOUSTIMAC eco line stuff, non itchy, Friday 3pm delivered.

Bad news:
Its not truly 2' x 4'.
Both OC703 and OC705 are EXACTLY 24" x 48", I've got my triangle templates cut to make those.

I was about to use those on the ECOUSTIMAC eco line stuff, and something just did not line up.
So, like the old addage measure twice, cut once, I measured them they are....23 1/8" x 47 1/8". All 6 panels measure that.
Sounds small but when you've designed your templates AND your bass trap to a full 24" x 48" adjusting at the last minute is a PIA!
I'll post picts later.
From their website, http://www.acoustimac.com/index.php/...oinsul422.html, they state (and I'm quoting here):
Quote:


Each panel measures 48"x24"x2"

Now, I'm making templates for those "reduced size" 23 1/8" x 47 1/8".

PTAaron 02-27-2011 08:25 AM

Looking forward to seeing how they turn out! That is pretty annoying about the sizing being off by so much though! That seems like something they should mention in their product information.

mtbdudex 02-28-2011 03:12 AM

Home Theater Ceiling Acoustic "Cloud" - Part III 1st row

Quote:
Originally Posted by mtbdudex View Post

Home Theater Ceiling Acoustic "Cloud" - Part II

This 2nd row ceiling treatment catches some of the light from those 3 can lights, but its not so bad.
However, my 1st row - possible acoustic ceiling cloud, would block all 3 lights, so I'll need to address that at later date.

Made the 1st row Acoustic "Cloud", it was finished Thur Feb 24 and installed that evening.
Very similar to the 2nd row with some changes noted below:

Change 1:
I made the end cross braces 23 3/4" instead of 24" like prior, this gave a good "squeeze" grip onto the rigid OC703.
(1st one I only made the inside cross braces smaller)
Really, my wife and I lifted the cloud frame with the OC703 and it was held tightly inside, of course the fabric was securely stapled as prior.


Change 2:
I wanted to only catch the 1st reflections, yet wanted same size as 2nd row for aesticts, so using the mirror on the ceiling (2 person job), the blue tabe shows the boundary for seeing the speakers on each end.
I therefore blocked the mi-hi frequency by using a 12" x 24" piece of kraft paper on the LH side and a 18" x 24" piece of kraft paper on the RH side.
By doing so I still will get the broadband bass effects there w/o over damping the room.


Change 3:
Installed, I added extra chain links into the 8 chains, in future I could lower these 2" or even 4" and add more OC on top for more broadband bass absorption - this is a future option just making easier now by doing this.
Currently I'm 12" below the ceiling with 4" depth of OC703.
By the 1/4 wave guideline I should be using 6" depth currently, I've got 6 sheets of OC703 unused, if I don't use them for some limited rear wall absorber (instead of diffuser since 2nd row is quite close to rear wall) then they will go "in the clouds" ..


I have 2 ideas on the 1st row ceiling lighting, that is side project.

Note:
For my side wall treatments with exposed framing I was really concerned about the fibergalss panels not being "gripped"/held - the young kids issue for me, that is why I went thru all the hassle of the routered center.
Now, with the 1/4" squeeze" seem's that might work as well, and much easier.
Lesson learned for others making side treatment panels with fully exposed frames to consider.
(I did not want to put something like 1/4 round mldg there either to trap the wrapped fiberglass panel, though that is another option)

cybrsage 02-28-2011 06:05 AM

Quote:
Originally Posted by mtbdudex View Post

I'm still waiting for you to post that picture Glenn

Update on DIY artwork acoustic fabric panels:
The printer is a HP 9000 series Designjet Low-solvent,
http://www.hp.com/united-states/desi...0/index_f.html




They are going to give me a printed 8" x 10" sample of each material, I'll do the breath test, then follow-up by nearfield speaker test without and with the material in front of my Berrigner 8000 mic. Probably not the most accurate, but the only way I can get some objective data.


Did you ever test this? I have one of these at work which I can use - but I have no material to test with. I am very interested in your results.

mtbdudex 02-28-2011 06:42 AM

Quote:
Originally Posted by cybrsage View Post

Did you ever test this? I have one of these at work which I can use - but I have no material to test with. I am very interested in your results.


Actually I just got email Thursday that the 8" x 8" samples from the local guy are ready for my pick-up, but was too busy to stop by last week.
I'll be getting them tonight on way home from work and test them weekend of 3/5, or more likely 3/12 when the other samples from Spoonflower come in for efficiency and comparision will be more apples-apples https://www.avsforum.com/avs-vb/showt...0#post20055530
Quote:
From: SBT - Brighton
To: Mike
Sent: Thu, February 24, 2011 2:09:11 PM
Subject: RE: 8x8 acoustic pict samples


Hello Mike,

We have your samples ready for pickup anytime

Thank you,
Aaron


On Feb 24, 2011, at 8:36 AM, "SBT - Brighton" wrote:

Hello Mike,

These are beautiful images, I will call you once I have the samples printed

Because the ink typically does not clog the holes on either material, I believe the smaller mesh will work better for your application

Talk to you soon.

Thank you,
Aaron


mtbdudex 02-28-2011 05:14 PM

I picked up the local Acoustic transparent printed image samples, pinned them to the side wall panels, and did some visual comparisons.
(those are my upper corner bass traps done as well, the mounting brackets are being painted/drying now.)

The fine weave is on top, the blocky weave is on bottom:




Fine Weave:


Blocky weave:


Screen light reflection test, 5 sec exposure-side shot


Onlook shot


My visual observations:The fine weave is too flat and does not hold the color pigments as well as the blocky weave.
The block weave appears to be glossy to semi-glossy, the image does show decent, better in person than the picture shows.

Both passed the breath test, Aaron (the local shop manager) told me after printing they pealed the fabric off its backing, and it does appear the majority of the holes before/after is same.
Based on my observation, blockage by this process is a non-issue.

My image for frequency testing is using REW:
-driving thru the Ext In and bypass any in A/V processing of signal
-put one of my main speakers in front/center of room for equal distance from walls (reduce the SBIR as much as possible)
-take near field test with microphone centered on tweeter,
-then with cloth between at 0 degrees, then 15/30/45 degree.
-Repeat centered on midrange.
-Repeat for other sample.
-Compare freq plots.

I'll make a simple test stand out of PVC pipe to hold the samples and easy consistent rotate 15 deg increments.

cybrsage 03-01-2011 07:24 AM

What fabric was used for both? I agree, I like the looser weave better.

I have a basic question...if these panels prevent reflections (or minimize them), how does a bi/dipole speaker do its job? I thought the purpose was to have the sound reflected all over the place to simulate real life....that is how it gets its dispersion.

mtbdudex 03-01-2011 08:50 AM

Quote:
Originally Posted by mtbdudex View Post

Good news/bad news.

Good news:
Got the ECOUSTIMAC eco line stuff, non itchy, Friday 3pm delivered.

Bad news:
Its not truly 2' x 4'.
Both OC703 and OC705 are EXACTLY 24" x 48", I've got my triangle templates cut to make those.

I was about to use those on the ECOUSTIMAC eco line stuff, and something just did not line up.
So, like the old addage measure twice, cut once, I measured them they are....23 1/8" x 47 1/8". All 6 panels measure that.
Sounds small but when you've designed your templates AND your bass trap to a full 24" x 48" adjusting at the last minute is a PIA!
I'll post picts later.
From their website, http://www.acoustimac.com/index.php/...oinsul422.html, they state (and I'm quoting here):


Now, I'm making templates for those "reduced size" 23 1/8" x 47 1/8".

My fact based data from this past weekend, pictures!
Sorry for rant here, I will email and contact acoustimac directly on this.

The 6 panels taken out of box:


All measured consistent 23 1/8" wide .........................................47 1/8" tall


Having to adjust my cutting tempaltes for slightly different size
(I have a large one I also used not shown here)


Their panels were slightly less than 2" thick also, like 1" and a "fat" 7/8", when stacked gave a different height than using OC705 would.
Here is where I designed these for OC705, already cut the threaded rod, and this was with the OC705 (if used) compressed.
Luckily I had enough material to make 2 more 24x24x34 triangles and added a 13th piece to each to take this gap up.


Note:
The shipping box for the OC703 and OC703 was 13" in depth (outside cardboard dim) from atsacoustics - and they were stuffed tightly in it, the ECOUSTIMAC eco line box was 12.5" deep (outside cardboard dim).

Shipping weight, each 6 panels 2" thick 2' x 4':
From UPS label:
OC703 = 26 lbs
OC705 = 51 lbs
ECOUSTIMAC eco line = 29.2 lbs

I'm hoping the acoustic absorbtion properties of the ECOUSTIMAC eco line are truly what they advertise, I "trust" them, but how to verify?
I don't have that ability.....
I'm feeling slight buyers remorse here guys, I like being "GREEN" and the non-itchy usage, but these little things sorta take the winds slightly outta my "GREEN" sails.

[update]
This issue is closed, see post #76 details https://www.avsforum.com/avs-vb/showt...1#post20087341

mtbdudex 03-01-2011 08:56 AM

Quote:
Originally Posted by cybrsage View Post

What fabric was used for both? I agree, I like the looser weave better.

I have a basic question...if these panels prevent reflections (or minimize them), how does a bi/dipole speaker do its job? I thought the purpose was to have the sound reflected all over the place to simulate real life....that is how it gets its dispersion.

I don't know the exact fabric spec (yet), I;ve asked that in email to Aaron.
Plus, I should have use correct printer profiles for my image export.
portion of my email:
Quote:


Q’s:
1: Is there a printer driver for the HP 9000 series Designjet and this material I should have used that would give “better” colors?
My monitor is color calibrated with a Spyder3, yet these appear overall darker than what I exported.
Also, need the print profile for the blocky material used to ensure best quality output, I assume there is one just like for different papers there are.

2: For the blocky material have you told customers to add some specific post processing in Photoshop CS5 (sharpening/definition/bring up levels on highlights/etc) for a crisp and detailed output?

After searching HP website: Which specific model HP Designjet do you have? The 9000s or the 9000sf?
I should have downloaded the printer driver prior to exporting the files, I just used a generic sRGB profile, that may be the issue with the darkness I feel the images have.
I printed same images to Costco via their print driver and it matched exactly to my monitor.
(fwiw, I have a Mac and use OSX 10.6.6 and Photoshop CS5.)
http://h20000.www2.hp.com/bizsupport...riesId=1153506

On the dipole speaker Q (for front mains), do a search in the master acoustic thread, I've seen that in there multiple times.

I'm not treating the rear/side surround speaker reflections at all, nor sure if I will ......I've seen some people use diffusers for those....I've not studied that far yet....still researching....

pfp 03-01-2011 02:47 PM

Quote:
Originally Posted by mtbdudex View Post


I'm hoping the acoustic absorbtion properties of the ECOUSTIMAC eco line are truly what they advertise, I "trust" them, but how to verify?

Really? They already misled you on the dimensions. If it were me I'd be wondering what else they "fudged".

Taxi 03-01-2011 04:39 PM

Quote:
Originally Posted by pfp View Post

Really? They already misled you on the dimensions. If it were me I'd be wondering what else they "fudged".

I think we should let them give their side of the story before we start accusing them of misleading anybody. Maybe they cut them that size so the finished product is 2x4 with the wood surround? Maybe it was just a simple mistake?

mtbdudex 03-01-2011 05:43 PM

Quote:
Originally Posted by pfp View Post

Really? They already misled you on the dimensions. If it were me I'd be wondering what else they "fudged".

Quote:
Originally Posted by Taxi View Post

I think we should let them give their side of the story before we start accusing them of misleading anybody. Maybe they cut them that size so the finished product is 2x4 with the wood surround? Maybe it was just a simple mistake?

I sent them email about 10 minute ago, that is start of dialog and mutual understanding.
Hopefully they give me fact based and logical response.

However, simple mistake, no way!
It is so easy to have a template and Quality Control measures to do this job.
I've audited OE auto suppliers who do this "cotton shoddy" work day in and day out with much closer tolerance control.

All I'm asking for is what I bought, 24" x 48", so design can be done before material arrives. It's not "lumber", where a 2 x 4 is really 1 1/2" x 3 1/2".
They'd get crucified in the HVAC business if some person designed ductwork exactly (24" x 48") and @ the jobsite their material arrived and was 23 1/8" x 47 1/8".

IF their end product is 23 1/8" x 47 1/8" nominal, with 1/8" variation, they should advertise as such, and we could know that upfront and design for it.
That's not asking too much I feel in this day and age of 6 sigma QC/etc.

[update]
This issue is closed, see post #76 details https://www.avsforum.com/avs-vb/showt...1#post20087341

mtbdudex 03-02-2011 08:36 AM

Part II Upper bass traps

Starting from here:
Quote:
Originally Posted by mtbdudex View Post


Plan out the cuts to maximize material usage....I had an image on how to do this and just sketched it out like this.
Each sheet I used as fully as possible.


Using newly made templates for the 23 1/8" x 47 1/8" sheets I have, start cutting and stacking, cut in reverse order, ie, the big one first and smallest last.
This is big template........................Smallest template showing placement


This cotton product is much harder to cut thru than OC703/705, so I bring out the turkey knife. Still cuts came out not nicely, determined my blades were dull and sharpened them , much better after sharp blades.



2 traps cut and stacked! I will use those "extra" pieces shown, part of my material usage plan.


I was not 100% satisfied with how the lower corner bass traps edges looked, so decided to tryout using drywall edging. I picked the white paper covered ones to minimize any issue with shiny reflection being seen thru the fabric. If need be, I would have painted them green, but that was not needed.


I used fishing line to secure the the bottom side and screws the top side.

mtbdudex 03-02-2011 08:48 AM

Part III Upper bass traps

1 done with material stacking, added loose pieces with sticky spray, worked great.


Putting on the Kraft paper to block mid-hi frequencies:


1st one wrapped and done!
Those drywall edges made all the difference, I'm going to add those as lesson learned to lower bass trap post. Much crisper look.




Installing into the HT room.
I used a 30+ year old hydraulic bottle jack as 3rd hand...


Both installed


Detail LH side....................................RH side


That completes the Rear wall broadband bass treatments.

side note:
I've used that exact same red hydraulic bottle jack back in the late 1970's when I had my 1969 Ford Torino with 390FE engine with 427 med-riser race parts, I was a car jock back then & re-built my engine 3 times...blew up 2 engines before 18 years old.
It was good to help lift up stuff (trans/whatever) to align during engine "re-entry" back into the car.
This is 1979, I'm the guy with blue coveralls on leaning on the engine cherry picker.
Yes, I had a 2 x 4 "Dual Quad" set-up as well in my 11th grade high school, can we say 400+ REAL horsepower and leaded gasoline.

scl23enn4m3 03-02-2011 09:44 AM

Wow, those traps greatly exceeded my expectations. You have skill bringing your ideas to reality. Clean lines and more shelf space! I like the halves more than a full trap now. The downside to a full trap is it makes the back of the room seem smaller, but this give the illusion it's still open.

PTAaron 03-02-2011 12:29 PM

Those upper traps look great!
How does the room sound?

mtbdudex 03-02-2011 01:00 PM

Quote:
Originally Posted by mtbdudex View Post

All I'm asking for is what I bought, 24" x 48", so design can be done before material arrives. It's not "lumber", where a 2 x 4 is really 1 1/2" x 3 1/2".
They'd get crucified in the HVAC business if some person designed ductwork exactly (24" x 48") and @ the jobsite their material arrived and was 23 1/8" x 47 1/8".

IF their end product is 23 1/8" x 47 1/8" nominal, with 1/8" variation, they should advertise as such, and we could know that upfront and design for it.
That's not asking too much I feel in this day and age of 6 sigma QC/etc.

I got a phone call directly from Sal, he also sent this email:
Quote:
From: ACOUSTIMAC <>
Date: March 2, 2011 2:50:02 PM EST
To: Mike and Michelle R <>
Subject: Re: ISSUE with size NOT 24" x 48" Re: Acoustimac - Acoustic Panels and Bass Traps: Order # update
By the way those are some monster bass traps!! They look cool!!!!
Sal
On Wed, Mar 2, 2011 at 2:49 PM, ACOUSTIMAC <> wrote:
Hi Michael,

I am sorry to hear that the insulation you received was short. Please give me a call at your convenience and I will either send you replacement or work out something else with you. I hope to hear back from you.

Thank you for your business and sorry about the inconvenience.

Sal

They have 2 different size, the one I was shipped 23 1/8 x 47 1/8 is for their pre-made frames so the outside dimension to customer is 24" x 48".
I was wrongly shipped those, they do have full 24" x 48" stock as well.

Sal offered for me to ship back my stuff for free exchange (too late, already done), or some other $$ (partial refund or good discount on next buy).

I have to assess my future needs and decide which route I'll go, I'm ok with their response and he truly wants to keep the customer happy and admitted it as their mistake.

Case closed.

mtbdudex 03-02-2011 01:10 PM

Quote:
Originally Posted by scl23enn4m3 View Post

Wow, those traps greatly exceeded my expectations. You have skill bringing your ideas to reality. Clean lines and more shelf space! I like the halves more than a full trap now. The downside to a full trap is it makes the back of the room seem smaller, but this give the illusion it's still open.

Quote:
Originally Posted by PTAaron View Post

Those upper traps look great!
How does the room sound?

Thx guys! It feels good to have those done and turning out decently, I was worried with them hanging up high if they looked so-so what people would say...
And scl23enn4m3 I agree, having a shelf is functional and the 2 traps helps keep the room "openness feeling" decent along the rear wall.

PTAaron - I posted this in another thread;
Quote:
Did you treat your entire room at once, or did you treat just the first reflection points and then try it out?
I studied, planned, and implemented in stages.
Here is what I did in order and simple subjective opinion, scale 1-5, 5 being highest ranking;
-side wall treatments first - very noticable rank 5
-2nd row acoustic cloud - noticable rank 3.5 or 4, not as much as side wall treatments
-Rear wall lower bass traps - very noticable, rank 4.5 or 5
-1st row acoustic cloud - noticable, rank 3 or 3.5
-Rear wall upper bass traps - noticable, rank 4

Ethan W (and some others) recommend you tackle the bass traps 1st, then from there your side wall 1st reflections, then determine what needs treatment after that.
There is a diminishing return on $$ vs benefites gained, both subjective and objective.
Only each individual can judge when to stop and accept their acoustics "as is".

Funny thing, my ear definitley is now tuned better for acoustics, and I can hear a echo among the center channel and my rear wall back to my DW lamiante screen, it forms a echo chamber!
That's why people say go AT screen to elimiante that issue, now I will study on specific portion of rear wall diffusor and/or thin absorber to minimize that.....

That is my subjective ranking, this weekend I'll get REW hooked up and take objective measurements and post those as well, for fact based data/graphs correlation to the subjective rankings.

mtbdudex 03-06-2011 07:53 PM

In response to a PM:
The upper bass traps are just sitting on (2) L brackets each, gotten from Lowes in the outside deck building area, painted them green.
By simple geometry they are trapped up there, not even attached screws to lower wood piece.
I did put 3/4" round felt on the top/ceiling piece to space it off the ceiling and ensure no vibrations.
Also on the wood edge to space it off the back/side walls, no issue with vibrations at all.


Other:
I did not take REW frequency readings this weekend for the bass improvements.
My AT picture samples for the side wall treatments from "spoonflower" are due later this week, therefore I will tackle that project (which supplier to work with on AT picture fabric) with the improved Bass readings at same time.
(it's a lot of cables/etc getting REW up and running......)
Quote:


Spoonflower Shipment Confirmation - Order #xxxxxxx
Thank you very much for your order from Spoonflower.com. Refer to this email for any information related to your order or visit your My Account page at: http://www.spoonflower.com/users/xxxxxx
Your Order has been shipped!
Shipping Method: We ship using the USPS, which typically takes less than a week. International orders may take quite a bit longer.
Order Detail:
Date ordered: Feb 24th, 2011 03:18 PM
Date shipped: Mar 4th, 2011 09:26 PM
Kit item ordered: Collection sampler of collection 'Test acoustic samples' by mtbdudex
Item Cost: $20.00
Shipping: $2.00
Order Total: $22.00
If you have any questions or concerns, please email [email protected] or call +1 (000) 1234567
Thanks for your support of Spoonflower. Now get out there and make something!
Thanks for your purchase!


mtbdudex 03-08-2011 03:27 AM

Got the samples in from Spoonflower last night, simply I was blown away by the picture quality!

Same test as before, I added the Spoonflower to the bottom, also a few from ats acoustics as comparison.

I did the breath test, comparing the Spoonflower material vs the ats acoustic sample pack I have http://www.atsacoustics.com/item--St...ack--1034.html

Subjective rating via breath test:
1) Spoonflower fabric passed more air than the ats acoustic sample I had for the microsuede
2) Spoonflower fabric passed same air - or slightly easier - as the ats acoustic sample cotton weave sample
3) The ats acoustic burlap definitely passed the breath test the most.

Picture quality comparison:
(these are all my original photos, so I can compare them)

This is w/o flash with HT lights on about 50%:


Pict with flash (white balance set according for each shot):


These close ups are all straight from my T1i camera, RAW format w/o any post processing added.
#1 ; the detail in the craters is fantastic, nearly same as original


#2 ; this racoon fine fur detail again quite good


#3 ; the star trails kept streaks and the star colors


#4 ; this B-17 shot in B&W was to see how it fared for B&W....really good


#5a ; tree @ night via spoonflower


#5b tree @ night (blocky weave from local supplier)


#6 reflection test - passed with flying colors!
The cotton weave has less sheen.


Ding - ding - ding: we have a clear winner! Spoonflower .
(Thx luma for pointing them out)

Very impressed with the picture quality, color matching seems spot on, much detail is there, only the star field with the 5 meteorites proved too much for their process to reproduce.

I will take objective freq comparisions later, however I see absolutely no reason not to recommend the spoonflower fabric and process for anyone looking to have Acoustic transparent artwork for their acoustic treatment panel covers.

[edit 3-9-2011: use their Quilting Weight Cotton, http://www.spoonflower.com/spoonflower_fabrics]
Quote:
Quilting Weight Cotton: $18/yard ($16.20 with designer discount)

100% cotton fabric with a soft hand, easy to sew

* 42" wide printable area (107 cm)
* 3.2 oz per square yard
* 78x 76 threads per inch
* Appropriate for quilting, appliqué, shirting, blouses, dresses, children's clothing
* Estimated shrinkage 3%
* Wash on delicate setting, warm or cool using phosphate-free detergent

Knoppies 03-12-2011 03:07 PM

These french cleats are made from glass filled nylon and are extremely tough. Also used for hanging large speakers on walls. Just do a Tamik Design Google search.

mtbdudex 03-13-2011 06:36 PM

After doing the subjective "breath test" of various fabrics for the AT-ness (Acoustic Transparency ability), I did want to do some objective testing to get a feel for the AT-ness frequency wise of the various fabrics I've been considering for the art coverings on the wall treatments - and share with others.

This past Saturday I built a $20 test fixture out of 1 1/2" PVC pipe, used a closet flange to bolt it to leftover 3/4" OSB 19" x 19" board.
The "T" tee fitting is NOT glued to the 24" upright for easy rotation to simulate various angles of interaction like in real life off side walls / ceiling.

Quick and easy, and holds the test sample via tape.

The test zone is 16" x 16" so I can read the midrange and tweeter drivers separately by adjustment of the mic boom stand.
My Paradigm Monitor 9 midrange driver is 32.0" above base and tweeter driver is 37.25" above base.
I marked the baseboard every 15 degrees 0-15-30-45-60.
(but did not take measurements @ 15 or 30 deg)

The fixture is set to be 4.25 inches from the cone center, and the measurement mic is 0.75 behind the fabric being measured.

If I made the fixture closer to the speaker then I could only rotate it to 30 deg before it hit the speaker sides.
I realized not perfect "nearfield", but my goal here is to quantify the change in frequency amplitude being passed thru the various fabric's to compare the subjective breath test with objective AT data.
(and learn by doing)

As used in the HT, my RH/LH main speakers are 24" from side wall and 28" from back wall, toed inward slightly.
For this Sunday afternoon quick round of testing I did NOT put them more centered in the room.....
I had about 90 minutes to do all this in the basement while my 2 boys (7 and 5) were in the 2nd floor loft playing games, so had to work quickly.
(with HVAC/other off to lower the sound floor)

Here it is at 0 degrees measure (simulating direct reflection @ 0 deg)....Here it is at 45 degrees measure (simulating reflection @ 45 deg)


Here is the fabric from spoonflower being measured.
All measurement were done with REW5 driving thru the Ext-IN, bypassing any processing.
(cables and "stuff" everywhere)


Side view of set-up.........front 3/4 view of set-up


I took over 30 measurements via REW5, iMac 24", Behringer ECM8000, and will group them into logical parings for comparison purposes and review.
-Baseline of Midrange and tweeter w/o any fabric
-Midrange and tweeter thru spoonflower fabric @ 0,45,60 degrees
-Midrange and tweeter thru local supplier blocky fabric @ 0,45,60 degrees
-Midrange and tweeter thru kraft paper @ 0,45,60 degrees
-Midrange and tweeter thru 3/4" pink hard insulation board @ 0,45,60 degrees (for comparison to kraft paper for blocking mid-hi freq in bass traps)

Again, the fixture is set to be 4.25 inches from the cone centers, and the measurement mic is 0.75 behind the fabric being measured. Not perfect nearfield but close for this purpose.

I'll post those graphs later with my comments for discussion.

xzener 03-13-2011 06:51 PM

So I was thinking while installing my inwall speakers today, it would be nice to have an acoustically transparent movie poster to cover my rear surrounds.

Do you think it would be possible to print a movie poster on say movie screen material??

mtbdudex 03-14-2011 03:34 AM

Quote:
Originally Posted by xzener View Post
So I was thinking while installing my inwall speakers today, it would be nice to have an acoustically transparent movie poster to cover my rear surrounds.

Do you think it would be possible to print a movie poster on say movie screen material??
I understand your Q - if AT movie screen material is great for the projected light visual AND is AT, why not use that for printed coverings on rear surrounds (and possible fabric covers for acoustic treatments I'll add).

I'm simply not sure the printing process used by the online place spoonflower.com or the local place (used a HP 9000 series Designjet that is fed by material on a std size roll ) could do that.
Each uses equipment with its own set-up parameters.

Can you follow-up with an inquiry to the supplier who sell's AT movie screen material with your Q?
Can it be "printed on"? Has it been done before?
What size roll does their material come on? etc.

I'd be interested that result as well.

mtbdudex 03-14-2011 10:04 AM

Set-up:
REW5, iMac 24", Behringer ECM8000, test date March 13, 2011
The fixture is set to be 4.25 inches from the cone centers, and the measurement mic is 0.75 behind the fabric being measured.
As used in the HT, my RH/LH main speakers are 24" from side wall and 28" from back wall, toed inward slightly.

I measured the midrange @ its center height position (32.0")and tweeter @ its center height position (37.25")
Did the 75db calibration @ midrange position and did not re-calibrate for tweeter position.
Applied 1/3 octave smoothing for all these, if subwoofer then I would have applied 1/12 octave smoothing.

paradigm monitor 9 Crossovers specs:
3rd-order electro-acoustic at 1.9 kHz
2nd-order electro-acoustic at 500 Hz


They graphed like this as baseline w/o any thing between them and the mic:
(Blue is midrange, purple is tweeter)
Chart 1 Baseline chart:


Note:
1) I always show the "baseline" midrange/tweeter curve for visual compaision on respective charts.
2) I always ran the measurement 80hz - 20khz, and plotted that way also.
3) When looking at the charts, the midrange you should look at the 500-1.9k freq zone, the tweeter the 1.9k and above freq zone

Spoonflower cotton cloth charts
Chart 2a Midrange with spoonflower cotton cloth, baseline and @ 0, 45, 60 degrees


Chart 2b Tweeter with spoonflower cotton cloth, baseline and @ 0, 45, 60 degrees


>>My conclusion from the midrange/tweeter charts: spoonflower cotton cloth is AT and good to go for acoustic absorber panels usage.

Charts showing mi-hi freq blockage:
Chart 3a Midrange with kraft paper, baseline and @ 0, 45, 60 degrees


Chart 3b Tweeter with kraft paper, baseline and @ 0, 45, 60 degrees


>>My conclusion from the midrange/tweeter charts: Clearly krafty paper does block significant hi freq, it appears not as good at mid-freq blockage

This show the "freq blockage" of kraft paper vs 3/4" pink foamboard:
Chart 4


>>My conclusion from the midrange: Clearly 3/4" pink foamboard does block significant mid and hi freq compared to the kraft paper
(I forgot to do same test for tweeter kraft vs 3/4" pink foamboard, maybe on Part III will do)

This shows a comparision of tweeter for baseline, spoonflower, and kraft @ 0 deg
Chart 5


This shows a comparision of midrange for baseline, spoonflower, and kraft @ 0 deg
Chart 6



I might re-do these as Part III with the speakers more mid room to more remove any wall interaction from these readings, but my quick experience gained is these fabrics seem more AT than I had guessed they would. But, this is my 1st time doing this so no real frame of reference.
I've not come across anyone else here @ AVS doing these, could be burried in the 200+ page Master Acoustics thread, that thread would be so much more useful if an index was at the beginning...There is great info burried in it, lost, and then re-talked about again. I truly feel for Dennis/Ethan/Terry/Ted/Others for answering q's multiple times.

mtbdudex 03-14-2011 12:28 PM

Spoke with "Sal" @ acoustimac,http://www.acoustimac.com/index.php/...5/category/10/ .
I just ordered (3) more cases of their "ECOUSTIMAC Eco Friendly DIY Insulation (4 lbs/ft) 48"x24"x2" -Case of 6 ", guaranteed by Sal to be 24" x 48".
He gave me discount price on the 1st case due to prior situtation.
If I get these Friday 3/18 weekend project will be doing the Front Wall Broadband Bass Traps.
The front LH Corner will get a full floor-ceiling 24"x24"x34" superchunk, while on RH side due to IB sub I'll handle the top tri-corner only.
I've been trying to make all the acoustic treatments non-fixed, however for a whole floor-ceiling bass trap looks like a fixed one is best design.
The front RH top tri-corner will be similiar to the Rear upper bass traps I've made earlier.

localhost127 04-07-2011 09:59 AM

just found this thread - nice work ,everyone.
just wanted to chime in --- those making frames that wrap around the oc703 (or equiv) need to take into account edge diffraction. an ETC graph will verify that you are properly absorbing all first reflections.

if you do NOT build a frame around the insulation, then you are effectively gaining 50% area coverage on a 4" thick trap (because the sides of the panel are exposed and able to absorb ingress/incident energy as well) -- just a FYI.

here's my contribution.
note, if you build a backing frame only, this leaves the sides of the panels open, eliminates edge diffraction off (what would be) a wooden frame wrapped around the insulations, and also provides an air gap (which is vital for porous absorption), spacing it off the wall. --- and also provides something to staple the rear and front fabric to.















cheers,

localhost127 04-07-2011 02:29 PM

mtbdudex,
very nice work on the corner chunks
i dont believe i saw any waterfall plots? if you really want to see how effective the corner chunks can be, take watefall plots (0-300hz, 0-500ms) and that will give you a good idea of the modal ringing that was cured and what still needs to be addressed. freq response is only one part of the story! time domain will tell you more.
cheers,

aackthpt 05-02-2011 11:25 AM

Your graphs aren't going to show any difference below about 850 Hz since that is roughly the frequency corresponding to 16" wavelength. Below that will just refract right around it. Someone did a test on Gearslutz like this (though with a different aim, like trying to figure out absorption for a material or something), and Ethan suggested the only accurate way to do this all the way down is to make a door of the material and mount it in a wall then run this type of test (after the guy got roundly and obtusely beaten down by SAC, heh). I can find the thread in my info stash if you'd like.

That said, great testing! I may want to use this stuff for some of my panels, so thank you for leading the way on testing it! This test method is awesome, and would be very useful for whatever sort of fabric was under consideration.

When I chose fabrics, I went to the fabric store with someone else, and not only chose one that I could breathe freely through, but also one that preserves the sound of my voice well when I speak through it. I figure that is a pretty decent fabric store test of AT.

Hopefully I didn't miss this from before: how are you removing reflections from the analysis? Tight (really tight) windows?

And did you use any sort of reflective facing on your chunk-style corner bass dampers?

localhost127 05-02-2011 04:47 PM

Quote:
Originally Posted by aackthpt View Post

Your graphs aren't going to show any difference below about 850 Hz since that is roughly the frequency corresponding to 16" wavelength. Below that will just refract right around it.

this is entirely incorrect. you must have taken something out of context within that conversation.

yes, larger wavelengths diffract around - this is why we place bass traps in the corners

aackthpt 05-02-2011 05:59 PM

Quote:
Originally Posted by localhost127 View Post

this is entirely incorrect. you must have taken something out of context within that conversation.

yes, larger wavelengths diffract around - this is why we place bass traps in the corners

I wasn't referring to your stuff localhost127, I was referring to testing the AT transparency that mtbdudex was doing. YOU didn't post any graphs to which to refer! I doubt we are in disagreement on the acoustics. If I am incorrect that there will little difference between measured response with and without the 16 inch panel in place (regardless of material) below 850Hz, then please explain!

I'm sure that your panels as well as those mtbdudex has up, and his superchunk-style corners, are effective. With the caveat that, to have an actual meaningful conversation, we'd have to hash out the precise meaning of "effective" under a certain circumstance!

I apologize for not making it clear to whom and about what I was referring.

localhost127 05-02-2011 07:34 PM

Quote:
Originally Posted by aackthpt View Post

I wasn't referring to your stuff localhost127, I was referring to testing the AT transparency that mtbdudex was doing

ahh, my mistake as well.

and i might note (regarding mtb's testing), when it comes to broadband absorption of specular energy (reflections), we shouldn't be measuring frequency response - but instead use the ETC to measure total specular energy at a reflection point before, and after the broadband absorption has been placed. since ETC is frequency independent, this will tell us how much the overall reflection has been attenuated. we don't care about absorption of specific frequencies. this is to attenuate early reflections, so all we care about is the total energy of the reflection and if the broadband absorber satisfied the requirements (e.g. attenuate signal -20dB of the original signal).

this is a must read regarding different types of fabric:
http://www.gearslutz.com/board/bass-...absorbers.html

specifically, this post:
http://www.gearslutz.com/board/6424136-post4.html

aackthpt 05-02-2011 08:06 PM

It just came to me a moment ago that SPL only doesn't account for all energy in an acoustical system as you say. Comparing ETC is one route to fix that. I believe another is to compare phase as well as SPL.

I know I don't have a complete grasp of control theory and this whole thing of phasors and such (need some study!) but I think I do recall needing both to completely characterize the behavior of a system.

I haven't completely reviewed the threads to which you linked, but I do think that SAC is suggesting to run the ETC in a scenario wherein the panels are placed on the wall in the room, which is a bit of a different setup than mtb's with the sound firing through the material under test. Such a test (of a specific reflection present / not present rather than mtb's looking for sound passed through or not) would definitely give you the actual needed information but has the disadvantage (I think) that it is not possible in practice to window the analysis (to see the frequencies reflected / absorbed) while maintaining enough frequency resolution to be useful.

But then the question "How much sound at a certain frequency goes through this material" is a different one from "What is the performance of an absorbent panel faced with X fabric vs Y fabric vs bare". The first actually has the advantage that one could use a material testing well as a grille cloth too. I think that's an intriguing idea, actually. Anyway, the answer always depends on the question asked!

I think if you just ran an ETC with mtb's setup, you might be able to compare the height of the initial response (if the software isn't normalizing) but since most energy is in low frequencies there could probably be a high-ish HF reflectivity and/or absorption and not see a large difference.

I think we run into the issue here of whether it is better to test a system as a whole or to reduce the system down into component parts and test them individually. Both have merit in a given situation, and ideally both would probably be done.

localhost127 05-03-2011 08:21 AM

Quote:
Originally Posted by aackthpt View Post

I haven't completely reviewed the threads to which you linked, but I do think that SAC is suggesting to run the ETC in a scenario wherein the panels are placed on the wall in the room, which is a bit of a different setup than mtb's with the sound firing through the material under test. Such a test (of a specific reflection present / not present rather than mtb's looking for sound passed through or not) would definitely give you the actual needed information but has the disadvantage (I think) that it is not possible in practice to window the analysis (to see the frequencies reflected / absorbed) while maintaining enough frequency resolution to be useful.

i think the question that needs to be asked, is why are we measuring the frequency response of a broadband panel (meant to absorb/attenuate early specular reflections), to determine if a particular fabric bears any change??

broadband absorption should *only* be placed at areas of incident energy that will be reflected towards the listening position within the ISD. (ignoring bass traps/LF modal issues - an entirely different approach).

we do not care about removing/absorbing XdB energy at Y frequency from the room. we are discussing specular reflections, which should not be broken down by frequency.

absorption isn't to be placed blindly in a room unless there is a specific need to address specular energy at that particular location (measured within the time domain).

i dont believe testing the frequency response of different 'fabrics' on a broadband (specular) absorber panel is necessarily relevant. the ETC is the tool that will display whether *any* energy is not being attenuated to the design requirement (and making it to the listening position). and thus, thicker absorption can be placed, the panel can be mounted differently to change the angle of incidence, or the absorption could be spaced further from the wall --- and retested via ETC to verify the broadband absorber is performing to combat the problem it was procured for.


again, i recommend anyone interested to read this post:
http://www.gearslutz.com/board/6424136-post4.html
as well as the rest of that thread.

Quote:
But then the question "How much sound at a certain frequency goes through this material" is a different one from "What is the performance of an absorbent panel faced with X fabric vs Y fabric vs bare". The first actually has the advantage that one could use a material testing well as a grille cloth too. I think that's an intriguing idea, actually. Anyway, the answer always depends on the question asked!

I think if you just ran an ETC with mtb's setup, you might be able to compare the height of the initial response (if the software isn't normalizing) but since most energy is in low frequencies there could probably be a high-ish HF reflectivity and/or absorption and not see a large difference.

the initial response (direct signal from speaker --> ears) will not change.
we can place a fabric on the broadband absorber, measure pre- and post- via the ETC, and see if there is suddenly any energy being reflected from the absorber. we don't care if the fabric has a change in absorption at a particular frequency or even a freq range. we only care about the total energy (independent of frequency) that is reflected and thus will combine at the listening position with the original signal.

angle of incidence is very important! and mtb's test regarding the 'reflectivity' of one particular fabric will not necessarily translate to another user's room, as angle of incident will vary. we also must bear in mind the absorber itself (without fabric) will tend to reflect (e.g OC703).

Quote:
I think we run into the issue here of whether it is better to test a system as a whole or to reduce the system down into component parts and test them individually. Both have merit in a given situation, and ideally both would probably be done.

when it comes to specular energy (reflections), we measure with ETC one speaker at a time - so we can realize and then attack the specific reflection points that are impeding the ISD from each sound source (speaker).

if anyone has anything to add or correct, please chime in!
but i think spending so much time and energy on the frequency response for sonic energy that functions as rays is not entirely relevant during the treatment process. fixing the issues in the time-domain will generally solve the frequency response problems for us. absorbing first reflection points attenuates the reflection that would otherwise combine at the listening position with the original signal constructively and destructively, to impede on us the most conventional frequency response issues (e.g. comb-filtering). by addressing specular energy via the time-domain (and ETC) --- this will likely solve the bulk of the freq response issues.

one can then use the frequency response (waterfall) from 0-300hz, and begin to address modal and decay issues for the sonic energy that functions as waves.

aackthpt 05-03-2011 09:19 AM

Quote:
Originally Posted by localhost127 View Post

i think the question that needs to be asked, is why are we measuring the frequency response of a broadband panel (meant to absorb/attenuate early specular reflections), to determine if a particular fabric bears any change??

I agree that's a good question. I noted the possible use of the fabric as grille cloth to point out that the testing done isn't actually answering that question. But I think that the testing mtb is doing has value, because I could see people wanting grille cloth printed with pretty pictures to stretch over surrounds installed in columns or for false walls - anywhere that accurate direct sound through the fabric is desired.

Quote:
Originally Posted by localhost127 View Post

... mtb's test regarding the 'reflectivity' of one particular fabric will not necessarily translate to another user's room, as angle of incident will vary.

On the other hand I am sure the idea was that if he can prove a fabric acoustically transparent at a range of incidence angles (he tested normal/45/60), that the incidence angle then is not an important factor in performance of a device as its covering is concerned. This point of view could have its utility.

It's also worth noting that using ETC is beyond 99% of DIY type / amateur's capabilities or level of interest and time to spend on acoustics. They just want some simple guidelines on how to treat their rooms, and there's nothing wrong with that. It's perfectly workable and as long as they don't get exposed to too much broscience it produces a result that fits the purposes of their listening space. It's not as though anyone reading the DIY thread is working on acoustics at Skywalker Sound.

localhost127 05-03-2011 10:46 AM

Quote:
Originally Posted by aackthpt View Post

It's also worth noting that using ETC is beyond 99% of DIY type / amateur's capabilities or level of interest and time to spend on acoustics. They just want some simple guidelines on how to treat their rooms, and there's nothing wrong with that. It's perfectly workable and as long as they don't get exposed to too much broscience it produces a result that fits the purposes of their listening space. It's not as though anyone reading the DIY thread is working on acoustics at Skywalker Sound.

i have to respectfully disagree. if a user is 'capable' of measuring the frequency response via sine sweep, then they can just as easily measure ETC.

can an automotive performance tuner give tuning advice over the phone without measurements of the engine? would we expect one to?

browsing through these forums, there doesn't seem to be any lack of measurements (or enthusiasm for measurements) regarding the freq response. there is no reason why we cannot except people to also perform ETC when they are looking to address issues outside of the LF/modal region. especially when those same people may be looking to cure specular freq response issues --- and may not even realize that the ETC tool (in the time-domain) can likely solve the bulk of their freq response problems!

tell me - if a user goes through the time, energy, money, trouble, etc, to build their own broadband panels, how do they know for certain they are placed properly? the mirror trick is a rough estimate. the only way to know for sure if the panels are placed correctly and are attenuating the reflection to the desired requirements (eg -20dB) for the entire listening position (which could be quite large) - is to verify via ETC, one speaker at a time.

users are expressing interest in room treatments, DIY, etc. we need to encourage that measurements are equally as important as the treatments themselves. measurements should be taken prior to procuring treatments, so one knows the specific issues they need to combat. measurements need to be taken again after treatment has been placed, to verify the original problem has been addressed!. measurements also help us test to verify we have placed the treatments in areas where they are most effective.

without measurements, we seem to have this sweeping generalizations regarding absorption. look how many users are treating entire walls with absorption. absorption needs to be surgically placed only at required areas. the object is not to create a dead room! and even worse, we have some who have installed insulation across their entire wall(s), but then also only do so with insufficient thickness in order to absorb the full range of specular reflections! a measurement would quickly show this. why would one want to suck all of the HF energy out of the room, and leave the mid/lower specular energy free to cause interference? this is a prime example when people install (for example) 1" OC703 covering their entire wall.

while one can assume all reflections points via a mirror and place broadband absorption at sidewall, ceiling, rear wall early reflection points, they may not even be aware that there are other areas of incident that are equally destructive (coffee table), until they can measure with an ETC.

if a user is also applying diffusion (which many seem to do), then the decay trail of the ETC becomes another visual aid to determine how the energy is decaying within the room.

yes, there are many who are not in a position to take measurements (nor they may simply not care) --- but that shouldn't stop us from exploring the proper effectiveness of troubleshooting and applying treatment to combat specific issues within a room - and communicating this throughout the community.

fotto 05-03-2011 11:08 AM

localhost....what software do you use to make measurements with (REW?). I would like to understand proper way to set up a sweep for an ETC (I use REW).

aackthpt 05-03-2011 01:23 PM

Quote:
Originally Posted by localhost127 View Post

i have to respectfully disagree. if a user is 'capable' of measuring the frequency response via sine sweep, then they can just as easily measure ETC.

Actually we don't disagree, I just have a softer spot for the ideal vs. the practical.

All tools have their uses; it is just a matter of applying the appropriate tool for the specific purpose.

mtbdudex 05-09-2011 04:36 PM

aackthpt, localhost127, fotto....I missed your comments in this thread.

I'm willing to learn and improve my knowledge and capability based on your comments.

aackthpt (John) is coming to the HEMI meet @ my home we are having this Saturday 14th, we will discuss this then as info sharing for all members who will be there.

mtbdudex 05-09-2011 04:46 PM

Quote:
Originally Posted by localhost127 View Post

mtbdudex,
very nice work on the corner chunks
i dont believe i saw any waterfall plots? if you really want to see how effective the corner chunks can be, take watefall plots (0-300hz, 0-500ms) and that will give you a good idea of the modal ringing that was cured and what still needs to be addressed. freq response is only one part of the story! time domain will tell you more.
cheers,

I saved the measurements, so I can generate the waterfall plots also, will do and post again.

Quote:
Originally Posted by aackthpt View Post

Your graphs aren't going to show any difference below about 850 Hz since that is roughly the frequency corresponding to 16" wavelength. Below that will just refract right around it. Someone did a test on Gearslutz like this (though with a different aim, like trying to figure out absorption for a material or something), and Ethan suggested the only accurate way to do this all the way down is to make a door of the material and mount it in a wall then run this type of test (after the guy got roundly and obtusely beaten down by SAC, heh). I can find the thread in my info stash if you'd like.

That said, great testing! I may want to use this stuff for some of my panels, so thank you for leading the way on testing it! This test method is awesome, and would be very useful for whatever sort of fabric was under consideration.

When I chose fabrics, I went to the fabric store with someone else, and not only chose one that I could breathe freely through, but also one that preserves the sound of my voice well when I speak through it. I figure that is a pretty decent fabric store test of AT.

Hopefully I didn't miss this from before: how are you removing reflections from the analysis? Tight (really tight) windows?

And did you use any sort of reflective facing on your chunk-style corner bass dampers?

I placed kraft paper on the front of my bass traps to block mid-hi freq:
Bottom corner traps:


Upper corner traps:

localhost127 05-10-2011 05:19 AM

looks great! did you go with 24" or 34" faced corner chunks?


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