DIY Custom-Printed Movie Poster Acoustic Panels - cheap! - Page 4 - AVS Forum
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post #91 of 1529 Old 04-16-2011, 09:49 AM
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Originally Posted by CruelInventions View Post

what do you mean by full frames "that wrap around the sides"?



edge diffraction off frames like those illustrated above when used as broadband absorption panels to kill early/first order specular reflections.
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post #92 of 1529 Old 04-16-2011, 10:10 AM
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Originally Posted by localhost127 View Post

i disagree.

for absorbing early reflections, at least 4" OC703 (or equiv) with 4" air gap. 6" OC703 with 4-6" air gap if you can afford losing a bit more real estate.

you can verify all specular reflections are destroyed with an ETC graph (measured one speaker at a time).

OK... I suppose I need to go with 4"... but unfortunately I have a small living room about 13' x 14' and having a 4-6" air gap would be unacceptable

I will need to live with either a 1-2" air gap.

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post #93 of 1529 Old 04-16-2011, 10:23 AM
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Originally Posted by spike9876 View Post

OK... I suppose I need to go with 4"... but unfortunately I have a small living room about 13' x 14' and having a 4-6" air gap would be unacceptable

I will need to live with either a 1-2" air gap.

4" with as much air gap as possible and you'll be just fine. not trying to scare you away or anything...im not insisting 2" with 2" air-gap won't be incredibly effective...it will. but if you're going through all of the work of building the panel and frame, it is very little effort to add an additional layer of OC703
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post #94 of 1529 Old 04-16-2011, 11:03 AM
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OK. Thanks.

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post #95 of 1529 Old 04-17-2011, 07:25 AM
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I have read this whole thread with great interest, and was wondering if one of the experts could give me some advice on my specific situation:

My listening space is my living room, so I have a simple design goal: "Implement the best possible treatment without negatively impacting the aesthetics".

I therefore guessed that this would be ideal:

* Two (2'X4') black absorber panels (one behind each speaker)
http://www.gikacoustics.com/gik_242.html

* One or two black bass traps for the corners
http://www.gikacoustics.com/gik_244.html

* Three (2'X4') art panels for the back wall

With regards to the art panels I was thinking to use the normal absorber panels (linked above), and just staple the graphic fabric on. I see from this thread that that isn't recommended, and instead I should use the DIY wooden frame + material as suggested by HDvids4all.

Here is a pic of my space:




My questions are the following:

1. Is my guess with regards to what treatment to use a good one? What would you recommend?

2. Is taking a normal panel, stripping it of fabric, and putting my own on, not as good as HDvids4all's DIY suggestion?

3. I see there has been some discussion about putting the panels on stands away from the walls, to create some air in between the panel and the wall. Unfortunately mine has to hang directly on the wall, as one can imagine. Would this negate the effect of the treatment/heavily reduce it? Or are we talking minor differences?

4. How big spacing should I have on the right and left side of the middle panel? (In other words, the spacing between each of the three panels)


Thanks a lot,

M
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post #96 of 1529 Old 04-17-2011, 09:47 AM
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Quote:
Originally Posted by rinnan@online.no View Post

My listening space is my living room, so I have a simple design goal: "Implement the best possible treatment without negatively impacting the aesthetics".

I therefore guessed that this would be ideal:

* Two (2'X4') black absorber panels (one behind each speaker)
http://www.gikacoustics.com/gik_242.html

there really isn't a use for broadband absorption directly behind the front speakers (except for SBIR issues or maybe used to tame some dipole issues), but if you have 5.1, then the front wall can be a first reflection from the rear speakers/surrounds. you can absorb these but dont just randomly put panels behind your speakers without knowing whether you have an issue to address there or not.

use the gik242's at first reflection points:
http://www.gikacoustics.com/education.html#38rule


http://www.gikacoustics.com/education.html#38rule

Quote:
Originally Posted by rinnan@online.no View Post

* One or two black bass traps for the corners
http://www.gikacoustics.com/gik_244.html

the more the better, seriously. you need lots of coverage to be truly effective. stack them floor to ceiling in the corners and if you dont have access to all corners, then put them at other boundaries wherever possible (wall/ceiling boundary, tricorners, etc).

Quote:
Originally Posted by rinnan@online.no View Post

* Three (2'X4') art panels for the back wall

With regards to the art panels I was thinking to use the normal absorber panels (linked above), and just staple the graphic fabric on. I see from this thread that that isn't recommended, and instead I should use the DIY wooden frame + material as suggested by HDvids4all.

you don't need to buy extra frames. just tear off the fabric that comes with the panels and reapply the printed fabric and staple to the wooden frame. it's really not an issue (doubling up the fabric) on the corner bass traps, but you certainly do not want to on broadband panels you place at first reflection points to control specular reflections.


Quote:
Originally Posted by rinnan@online.no View Post

My questions are the following:

3. I see there has been some discussion about putting the panels on stands away from the walls, to create some air in between the panel and the wall. Unfortunately mine has to hang directly on the wall, as one can imagine. Would this negate the effect of the treatment/heavily reduce it? Or are we talking minor differences?

by adding an air gap you are essentially getting a free lunch. e.g, a 2" panel placed 2" from the wall will perform almost as a 4" panel with no air gap. an air gap greatly increases the effectiveness of the panel due (details as to why are probably outside the scope of this conversation). the GIK244s i know have the wooden frame on the back and thus when mounted to the wall automatically provide a 1.5" spacing or so --- so that design works great.

Quote:
Originally Posted by rinnan@online.no View Post

4. How big spacing should I have on the right and left side of the middle panel? (In other words, the spacing between each of the three panels)

if it's in a reflection point, i would place them directly adjacent to each other. you want to catch and absorb all specular energy for as large of a listening position as your requirements call for.
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post #97 of 1529 Old 04-17-2011, 10:59 AM
 
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Originally Posted by localhost127 View Post

is the design requirement to get the room to sound good or to look good?
if you have another solution, then by all means please fill us in.

absorption is surgically applied - it's not like you're coating your entire wall

Is the design requirement to have a room that you can put in people to watch a movie or to have excellent wound but no people to hear it?
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post #98 of 1529 Old 04-17-2011, 11:30 AM
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Originally Posted by cybrsage View Post

Is the design requirement to have a room that you can put in people to watch a movie or to have excellent wound but no people to hear it?

why are you insisting that there are only two solutions and they are of polar extremes of each other?

why do you think it's called 'design requirements' ?
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post #99 of 1529 Old 04-17-2011, 11:34 AM
 
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Quote:
Originally Posted by localhost127 View Post

why are you insisting that there are only two solutions and they are of polar extremes of each other?

why do you think it's called 'design requirements' ?

You are the one who gave the either or statement first. I simply altered your either or statement.

So your question is actually posed to you:'

Why are you insisting that there are only two solutions and they are of polar extremes of each other?
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post #100 of 1529 Old 04-17-2011, 12:37 PM
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Originally Posted by cybrsage View Post

You are the one who gave the either or statement first. I simply altered your either or statement.

So your question is actually posed to you:'

Why are you insisting that there are only two solutions and they are of polar extremes of each other?

oh i see what you did there
>_>
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post #101 of 1529 Old 04-17-2011, 12:46 PM
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Quote:
Originally Posted by localhost127 View Post

it's quite simple - one can always measure via ETC and increase thickness or air-gap until all specular reflections above -20dB within 20ms of original source are destroyed.

I personally wouldn't call the process of adjusting dimensions and gaps on the fly as "quite simple".

Seems to me it would require a fair amount material planning, with possible multiple return trips to the insulation provider (unless you just by a bunch extra from the very start). More daunting... frame-building adjustments to accommodate each new layer of added insulation thickness and bracketing/mounting adjustments to increase air gap sizing as you go along in a step-by-step measuring process, reacting with implementation changes to each new positive measurement discovery.

In a word, "yikes!"

Never having built any of my own, perhaps I am over-imagining the time involved to make these additional changes along the way.


Quote:
Originally Posted by localhost127 View Post



edge diffraction off frames like those illustrated above when used as broadband absorption panels to kill early/first order specular reflections.

Ah, yes.. thanks.

You know, I have a couple bass panels from GIK. They really could do a better job on their website pointing out and showing how their style of frame building can be more effective than the type shown above. With theirs, there is some air exposure to the acoustical insulation on all four sides of the frame. Most pre-fab ones I've seen marketed tend to have the framing style shown above.

I kind of like the styling of these metal frames, available in 2", 4" and 6" depths. There is some side exposure with these too, but still not near as much as what GIK frames provide, however.

Mourning the disappearing usage of the -ly suffix. Words being cut-off before they've had a chance to fully form, left incomplete, with their shoelaces untied and their zippers undone. If I quote your post (or post in your thread) without comment, please check your zipper.
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post #102 of 1529 Old 04-17-2011, 06:54 PM
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Thanks for great replies guys.

To clarify: My space is purely for 2-channel music listening. I couldn't care less about TV / movies (no time for that). As mentioned, aesthetics is a top priority, as it is my living room.

Please correct me if I am wrong, but to sum up:

1. Get 3x GIK242. Tear off the fabric. Staple new printed fabric on. Hang them next to each other on the back wall, with no more than 1 foot spacing on left and right side of middle panel (I hope the spacing is okay, as having them right next to each other would not be aesthetically appealing enough).

2. Get one GIK244. Place it in the top left corner (of the apt. drawing). The top right corner would not work, due to the porch. Other corners are not convenient as seen from the picture.

Unfortunately, I don't think I would be able to go all the way from the floor to the ceiling in that top left corner. Might look a bit odd...


Does the above sound good?



Couple of additional questions:

1. Would you recommend additional panels at other locations, based on the picture of my room and the given the design requirements?

2. Is nothing required on the front wall?

3. Would a carpet be of great benefit? (We have hardwood floors)

4. Does the GIK242 also have the convenient spacing in the back that localhost said GIK244 has?


Again, thanks a ton. I greatly appreciate your help.


EDIT:

I am thinking, if I don't need the panels behind the speakers, the total cost for professionally made art panels isn't that bad. I was thinking this: http://www.acoustimac.com/index.php/...-panels-5.html

How do you guys think that panel compares to the GIK242?


Thanks,

M
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post #103 of 1529 Old 04-17-2011, 07:32 PM
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Epic idea, man! Thanks!
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post #104 of 1529 Old 04-18-2011, 06:26 AM
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Quote:
Originally Posted by rinnan@online.no View Post

Couple of additional questions:

1. Would you recommend additional panels at other locations, based on the picture of my room and the given the design requirements?

2. Is nothing required on the front wall?

3. Would a carpet be of great benefit? (We have hardwood floors)

4. Does the GIK242 also have the convenient spacing in the back that localhost said GIK244 has?


Again, thanks a ton. I greatly appreciate your help.


EDIT:

I am thinking, if I don't need the panels behind the speakers, the total cost for professionally made art panels isn't that bad. I was thinking this: http://www.acoustimac.com/index.php/...-panels-5.html

How do you guys think that panel compares to the GIK242?


Thanks,

M


you can review your room with GIK - that's the advantage of buying from them vs DIY. they should be able to look at your room and give guidance.

as for that acousticmac site, im not sure they understand the products they're selling - as their frames have wooden backings which defeats the purpose of spacing the panel away from the wall. you generally want the backs open so incident energy that has passed through the panel can reflect off the boundary and be forced to pass back through the panel again (increasing effectiveness of the absorber).

as for your questions:
1- for bass trapping, you will need a lot of coverage...one panel is unlikely going to make a noticeable difference in your room

2- you can experiment with absorption or diffusion, but it really depends on the room and your taste. hard to say without measurements. you normally don't blindly apply treatment unless there is a specific problem in your room you're looking to address. even more difficult not being a symmetrical room.

3- the floor is also a first reflection point, and carpet will help absorb the high freq specular energy but will do nothing for anything lower. and because incident angle is not 0* (perpendicular to the carpet), then it will be absorbing even less and the cut-off will be even higher. id say just experiment with and without and see which you prefer...as it doesn't sound like you would be able to apply broadband absorption for the floor reflections.

4- i dont know - have you thought about contacting the manufacture? they should be able to tell you right away. no sense looking for product details from anyone but them.
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post #105 of 1529 Old 04-18-2011, 07:19 AM
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Quote:
Originally Posted by localhost127 View Post

As for that acousticmac site, im not sure they understand the products they're selling - as their frames have wooden backings which defeats the purpose of spacing the panel away from the wall. you generally want the backs open so incident energy that has passed through the panel can reflect off the boundary and be forced to pass back through the panel again (increasing effectiveness of the absorber).

Not to quibble or anything, but the site offers a choice between backless and backed panels. I would second your suggestion about not getting the backing on the panels and spacing them off the wall for better absorption, but there are plenty of people with space constraints that feel they are better served by mounting panels flush against the wall. Ideal? No, but multiple options are never a bad thing.

Quote:
Originally Posted by rinnan@online.no View Post

Is taking a normal panel, stripping it of fabric, and putting my own on, not as good as HDvids4all's DIY suggestion?

No, you would be just fine doing it that way, and your panel would probably be higher quality then the bare frames. My suggestion was mainly for DIY'ers to save a bit O' time and cash since you usually end up paying quite a bit more for a completely finished panel that already includes insulation and is wrapped in fabric during manufacturing.
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post #106 of 1529 Old 04-18-2011, 08:35 AM
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There are a lot of recent good Q's in this thread that are straying from the OP's "DIY Custom-Printed Movie Poster Acoustic Panels" .

I suggest they be taken to the Master Acosutics thread http://www.avsforum.com/avs-vb/showthread.php?t=255432 so other experts there can chime in, plus in general other AVS users can see them in that thread, they will get lost/burried and repeated again if kept just inside this thread.....my 0.02
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post #107 of 1529 Old 04-18-2011, 09:09 AM
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Originally Posted by localhost127 View Post

4" with as much air gap as possible and you'll be just fine. not trying to scare you away or anything...im not insisting 2" with 2" air-gap won't be incredibly effective...it will. but if you're going through all of the work of building the panel and frame, it is very little effort to add an additional layer of OC703

I keep coming back to this question... I had previously contacted audimutesoundproofing.com and today I spoke with a sales person and they are recommending placing 2" acoustic panel (mainly for mid & high frequencies) behind flat wall against my couch and told me that bass trapping are more effective on corners and not much effective against flat wall...

Again, I would like to confirm whether I actually need a 4" bass traping panel against my couch which is flush against flat wall.

BTW, They are running a 20% sale off their acoustic panels with art.

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post #108 of 1529 Old 04-18-2011, 09:16 AM
 
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Maybe I do not understand, but woundn't the sound have to pass through the material a second time regardless of if there was a wooden back or if the material was right against the wall? The sound would simply hit sooner the closer the material is to the wall.
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post #109 of 1529 Old 04-18-2011, 09:49 AM
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Quote:
Originally Posted by localhost127 View Post

As for that acousticmac site, im not sure they understand the products they're selling - as their frames have wooden backings which defeats the purpose of spacing the panel away from the wall. you generally want the backs open so incident energy that has passed through the panel can reflect off the boundary and be forced to pass back through the panel again (increasing effectiveness of the absorber).

I am hanging the art-panels directly on the wall anyways, so the wooden backing would not matter in case i guess. I might have misunderstood, but I thought you indicated that inside the frame, between the wooden back plate and the insulation material, there was a space thus allowing that "air-gap" even when hanging the panel directly on the wall. Would be smart.


Quote:
Originally Posted by localhost127 View Post

1- for bass trapping, you will need a lot of coverage...one panel is unlikely going to make a noticeable difference in your room

I'll skip the bass trapping then.


Quote:
Originally Posted by localhost127 View Post

2- you can experiment with absorption or diffusion, but it really depends on the room and your taste. hard to say without measurements. you normally don't blindly apply treatment unless there is a specific problem in your room you're looking to address. even more difficult not being a symmetrical room.

Does room treatment have the potential of curing too sharp highs and other SQ related issues (given it is not a speaker/equipment problem)? That link to GIK that Localhost posted seems to indicate that it only cures soundstage issues and confusion about what speaker the sound comes from.

It looks like i'll just end up hanging 3 professionally made art panels on the back wall, if there is no point with 1 bass trap, and the front wall is pointless (I will verify this with the store as suggested).
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post #110 of 1529 Old 04-18-2011, 10:01 AM
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Quote:
Originally Posted by spike9876 View Post

BTW, They (audimutesoundproofing.com) are running a 20% sale off their acoustic panels with art.

I compiled this list about a week ago:


Quote:


Absorption Panels
==================
http://www.audimutesoundproofing.com...tive-foam.aspx
Price: $74 (2'X4')

http://www.gikacoustics.com/gik_242.html
Price: $59.99 each (2'X4', sold 3 per box $179.97)


Bass Traps (4" thick)
======================
http://www.audimutesoundproofing.com...bass-trap.aspx
Price: $60 pr square trap (need a couple)

http://www.gikacoustics.com/gik_244.html
Price: $69.99 each (sold 2 per box $139.98)


Printed (Art) Panels
=====================
http://www.soundproofcow.com/acousti...ic-panels.html
Price: ?

http://www.gikacoustics.com/gik_artpanel.html
Price: $280 each (2'X4'. 3-Panel: $840)

http://www.acoustimac.com/index.php/...rt-panels.html
Price: $125 (2'X2'), $687 (3-Panel Art, 4'x2'), $567 (3-Panel Art, 3'x2'), $375 (3-Panel Art, 2'x2')

http://www.audimutesoundproofing.com...l-gallery.aspx
Price: Few bucks cheaper than Acoustimac


Audimute was already the cheapest, but with the 20% off, it definitely takes them far ahead of the competition. I will call them tomorrow.

M
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post #111 of 1529 Old 04-18-2011, 10:28 AM
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Quote:
Originally Posted by spike9876 View Post

I keep coming back to this question... I had previously contacted audimutesoundproofing.com and today I spoke with a sales person and they are recommending placing 2" acoustic panel (mainly for mid & high frequencies) behind flat wall against my couch and told me that bass trapping are more effective on corners and not much effective against flat wall...

you haven't mentioned the type of insulation you're using (the density, the gas flow resistivity)...etc. so it's difficult to have this discussion when we could be talking about porous insulation that clearly will have different characteristics. why don't you ask the vendor selling the product for measurements to backup their claims that their 2" panel will absorb all broadband specular reflection energy - or enough to at least diminish the reflection by -20 to -25dB - if your requirement is to create a reflection free zone? if they're selling a product, then they should have lab tested results for said product.

also, maybe you could ask them to explain how a 2" panel flush against the wall will be able to provide enough absorption of lower frequencies to help mitigate nulls off the real wall (where the distance between the listening position and the rear wall is 1/4wavelength of a particular freq)?

Quote:
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Again, I would like to confirm whether I actually need a 4" bass traping panel against my couch which is flush against flat wall.

ok - you seem to have become confused. just because a panel is 4" thick of rigid fiberglass does not make it a bass trap.

there are two types of velocity based absorbers that we focus on regarding porous material (eg rigid fiberglass). one is a broadband absorber used to absorb a wide range of frequencies ... usually placed at first reflection points to absorb specular reflections so that they do not arrive within 20ms or so of the original signal (you can google reflection-free-zone for more info). the other is a "bass trap" which is located in the corners where the large wavelengths cannot effectively 'diffract' around the panel, to absorb low freq energy sound that functions as a wave.

as a sound wave approaches a boundary, pressure increases as velocity goes to zero. porous absorption works by converting kinetic energy into heat, and thus is most effective at 1/4wavelength where particle velocity is highest. thus, placing your panel directly against the wall where pressure is highest but velocity goes to zero, minimizes the effectiveness of the absorber.

for absorbing 5000hz, the wavelength is 2.7" long...thus 1/4wavelength is 0.675 so if a 2" panel was flush with the wall then this would be ok. however, a 600hz wavelength is 22 inches long .. thus the absorption material is most effective at 1/4wavelength which is 5.5" spaced from the boundary. if you are only putting 2" of material flush against the wall (whose performance is then decreased further as incident angle is not likely to be 0* (more likely 45*)) then you will likely absorb the highs but not necessarily the mids and certainly not the lower end specular reflections. a common issue i think is people lining their entire walls with 1" or 2" of absorption material which can do a great job of absorbing high freqs, but if you're not treating the mids and lows then you're left with a dead and muddy sounding room.

bass traps need to be very deep to be effective (as the wavelengths in that region are much, much longer - and thus, the fiberglass needs to be placed further from the boundary to be effective). by straddling a 4" panel in the corner, you are technically spacing it from the boundary and thus increasing the effectiveness. bass traps usually have a reflective material on the outside to help reflect some mid and high freq energies back into the room. if your corner bass traps were broadband, then they may cause too much mid/high absorption and make the room sound dead. also, dont delude yourself into thinking one or two "bass traps" will make a noticeable difference. you need lots of coverage in the 2D and 3D corners to be truly effective.

it is imperative that you understand how the material works in the first place in order to properly apply treatments. anyone selling treatments should be providing lab measurements of their products, or at least be able to explain how their product works and help you with a solution for your room. that is pretty obvious imho.

ive tried to keep this as high level as possible without going into too many details, but it's recommended to understand how the material works before blindly spending your money and possibly applying treatments improperly. this is why measurements are always a good idea. you don't want to blindly apply absorption unless you have a specific issue you're looking to treat.

if anyone else has a better way to explain, please do.
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post #112 of 1529 Old 04-18-2011, 10:47 AM
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I compiled this list about a week ago:

if you're purchasing product, then you need to contact those businesses directly and direct your questions towards them. you are paying them for a product and that product should include support. if they do not provide that, then maybe you should ask yourself why you are willing to pay them for a product you can DIY for much cheaper.
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I just had a very helpful chat with audimute, where they looked at my apt. drawing etc., and gave some advice. Here is the summary:

1. Diffusion is not needed given my room and the fact that i am not recording music.

2. Panels ar not needed on front wall due to the fact that it is a 2-ch system (like Localhost said).

3. Bass traps are very helpful even though it is just one, in the top left hand corner of my apt picture.


Conclusion:

1. Hang 3x Art Panels on the back wall (behind my couch). 2"-3" spacing in between.

2. Hang 1x Art Panel on the wall above my desk (horizontally)

3. Place one Bass trap in the top left corner



I forgot to ask the following:

If I place a large plant (in-door tree) in front of the bass trap to make it look better, would that have a negative impact on the SQ?


Thanks,

M
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ok - you seem to have become confused. just because a panel is 4" thick of rigid fiberglass does not make it a bass trap.

there are two types of velocity based absorbers that we focus on regarding porous material (eg rigid fiberglass). one is a broadband absorber used to absorb a wide range of frequencies ... usually placed at first reflection points to absorb specular reflections so that they do not arrive within 20ms or so of the original signal (you can google reflection-free-zone for more info). the other is a "bass trap" which is located in the corners where the large wavelengths cannot effectively 'diffract' around the panel, to absorb low freq energy sound that functions as a wave.

as a sound wave approaches a boundary, pressure increases as velocity goes to zero. porous absorption works by converting kinetic energy into heat, and thus is most effective at 1/4wavelength where particle velocity is highest. thus, placing your panel directly against the wall where pressure is highest but velocity goes to zero, minimizes the effectiveness of the absorber.

for absorbing 5000hz, the wavelength is 2.7" long...thus 1/4wavelength is 0.675 so if a 2" panel was flush with the wall then this would be ok. however, a 600hz wavelength is 22 inches long .. thus the absorption material is most effective at 1/4wavelength which is 5.5" spaced from the boundary. if you are only putting 2" of material flush against the wall (whose performance is then decreased further as incident angle is not likely to be 0* (more likely 45*)) then you will likely absorb the highs but not necessarily the mids and certainly not the lower end specular reflections. a common issue i think is people lining their entire walls with 1" or 2" of absorption material which can do a great job of absorbing high freqs, but if you're not treating the mids and lows then you're left with a dead and muddy sounding room.

bass traps need to be very deep to be effective (as the wavelengths in that region are much, much longer - and thus, the fiberglass needs to be placed further from the boundary to be effective). by straddling a 4" panel in the corner, you are technically spacing it from the boundary and thus increasing the effectiveness. bass traps usually have a reflective material on the outside to help reflect some mid and high freq energies back into the room. if your corner bass traps were broadband, then they may cause too much mid/high absorption and make the room sound dead. also, dont delude yourself into thinking one or two "bass traps" will make a noticeable difference. you need lots of coverage in the 2D and 3D corners to be truly effective.

it is imperative that you understand how the material works in the first place in order to properly apply treatments. anyone selling treatments should be providing lab measurements of their products, or at least be able to explain how their product works and help you with a solution for your room. that is pretty obvious imho.

ive tried to keep this as high level as possible without going into too many details, but it's recommended to understand how the material works before blindly spending your money and possibly applying treatments improperly. this is why measurements are always a good idea. you don't want to blindly apply absorption unless you have a specific issue you're looking to treat.

if anyone else has a better way to explain, please do.

Very well said!
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4. Does the GIK242 also have the convenient spacing in the back that localhost said GIK244 has?


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4- i dont know - have you thought about contacting the manufacture? they should be able to tell you right away. no sense looking for product details from anyone but them.

Yes, they do. Their 2" GIK242's have a total depth of 3.5" with that extra 1.5" being the extra hollow depth the framing provides (with 2" fiberglass positioned flush with the front of the panel).

The GIK244's are 4" fiberglass, with a total depth including frame of 5.5". Here again, 4" fiberglass flush with the front and a hollowed out extra frame depth of 1.5" at the back.

They used to have pictures of this on their website and maybe they still do and I'm just not seeing them.

Mourning the disappearing usage of the -ly suffix. Words being cut-off before they've had a chance to fully form, left incomplete, with their shoelaces untied and their zippers undone. If I quote your post (or post in your thread) without comment, please check your zipper.
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post #116 of 1529 Old 04-18-2011, 11:01 AM
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Very well said!

ethan's article does a great job and includes the drawings as well:
http://www.ethanwiner.com/acoustics.html
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post #117 of 1529 Old 04-18-2011, 11:12 AM
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I forgot to ask the following:

If I place a large plant (in-door tree) in front of the bass trap to make it look better, would have a negative impact?

M

If it's deciduous, then yes (I hate raking).
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If it's deciduous, then yes (I hate raking).

Lol. Modified the sentence
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post #119 of 1529 Old 04-18-2011, 11:37 AM
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I forgot to ask the following:

If I place a large plant (in-door tree) in front of the bass trap to make it look better, would that have a negative impact on the SQ?

not an issue for the corner bass traps.
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post #120 of 1529 Old 04-18-2011, 11:42 AM
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you haven't mentioned the type of insulation you're using (the density, the gas flow resistivity)...etc. so it's difficult to have this discussion when we could be talking about porous insulation that clearly will have different characteristics. why don't you ask the vendor selling the product for measurements to backup their claims that their 2" panel will absorb all broadband specular reflection energy - or enough to at least diminish the reflection by -20 to -25dB - if your requirement is to create a reflection free zone? if they're selling a product, then they should have lab tested results for said product.

also, maybe you could ask them to explain how a 2" panel flush against the wall will be able to provide enough absorption of lower frequencies to help mitigate nulls off the real wall (where the distance between the listening position and the rear wall is 1/4wavelength of a particular freq)?


.

I never said that 2" will absorb all reflection energy... My understanding is that these are mainly mid & high frequencies... and not low frequencies.

The rest got a little too technical for me

Really I was going to buy 3 2x4 acoustimac's 4" panels but then was considering audimutesoundprooffing for their sale on their 2" panels... and was thinking if 4" panels are not going to be that effective on low frequencies on flat wall... why not get 2" panels mainly for mid & high frequencies...

It's just that some companies seem to recommend 2" panels on flat wall and others recommend 4" panels... hence my confusion

Fronts: B&W CM8
Center: B&W CM Center
Surround: B&W CM1
JL Audio F112
Integra DHC-80.3
Emotiva XPA-5
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