DIY construction methods of hang-able acoustic panels (not fixed frames) - Page 2

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)

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.....

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.

Good job making them and thx for posting!

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.

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.

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.

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!

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]

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

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.

YouTube video showing how these can be moved around.
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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.

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.



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".

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

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

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.....

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"

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;
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 http://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:

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".