It depends on frequency range. I bought 2" thick double density fiberglass foam panels - Johns Manville 817 (not installed yet). Sound absorption table shows good absorption at 250Hz dropping to 0.38 at 125Hz. For the lower frequencies 4" might be necessary. Anything helps but rugs or curtains absorb only at higher frequencies. I suspect that if you can hear sound thru the rag holding it in front of you, then sound will be reflected from the surface behind it as well (floor wall etc). 4" panels placed some distance from the back wall would be great but it is expensive and impossible in my living room.
http://www.specjm.com/files/pdf/ci-9.pdf
Assuming that you place speakers on shorter wall, your room will amplify 1125/(2x14)=40Hz |
@Kijanki,
My room multiplies out to amplify 36.75Hz. What table shows how to treat that frequency? Size, shape, density etc. Any recommendations would be appreciated. |
This advice was given to me by Roy Johnson of Green Mountain Audio speakers. If the foam you have is high density foam, like what's used for seat pads of furniture, you'll get very good benefit at the highs and mids if you cut a 4' by 4' piece of peg board in half and make a pair of 2' by 4' panels about 2" apart on the one side by spray gluing your foam to the peg board, then wrap it with a very transparent (easy to see through) fabric. Spray the glue on the peg board, not the foam--that way it doesn't clog the pores of the foam. Hang them on the wall spacing four 1" thick spacers on each panel so the sound may travel behind the them. 2 on each side would require double the materials, but would be highly effective at the 1st reflection points. If your foam isn't high density, go online and buy 2" and get even more benefit--it will cost you about $100-125 for all 4 panels for everything needed. |
I have a 10x11 room and I recently treated my side walls with Vicoustic Cinema Round panels. I am absolutely stunned the difference it made. Please check out my system thread for more details. |
Tom6897, Look at the link I posted. Table shows sound absorption vs frequency. I was mostly interested in taming slap echo and mid-bass frequencies. These panels are glass rigid foam. I've read that organic foam has non-linear characteristic (of absorption vs. frequency, I assume).
36.75Hz is pretty good. As long as room doesn't amplify around 60-80Hz, where many speakers have "hump" it is OK and might even help to reinforce extension. |
IME, absorptive and/or diffusing treatments at the first reflection points can help with high frequency problems. As you go lower in frequency, these devices become less effective. Below 100hz or so, Hemholtz resonators are the only reliable treatments that I've found (other than room correcting EQ schemes).
It's hard to say whether 1" foam will work for high frequency issues until you try that foam in that room. OTOH, it's easy to say that you'd be very unlikely to get any benefits from 1" foam at low frequencies. |
1" foam/treatment will work to some degree, in particular with higher frequencies as noted, just not as much as equivalent 2" foam product.
No way to know what will "sound best" without trying.
I like the "lego" approach with wall treatments. Start with smaller measured amounts of treatment, like 2'X2'X1". Add more or less as needed until best results achieved at primary listening location(s). |
So what's a good place to buy prefab treatment products without breaking the bank? |
Rebbi, GIK makes nice and affordable ones. I use Vicoustic personally. |
So what's a good place to buy prefab treatment products without breaking the bank?
Rebbi If you need foam products I recommend http://nextacoustics.com/. For acoustic panels I have used http://www.atsacoustics.com/ with great success. They made me a custom size panel at a very reasonable price. |
A super cheap way to try if you hear a difference is to simply place pillows on the first reflection points...except ceiling, of course.
I built my DIY traps with fiberglass panels and they work fine for me. Maybe commercial ones would be better, but the physics behind what's going on is pretty basic, especially at the high frequencies these can treat, so I tend to think DIY gets you very close to "there".
Using REW I could not measure any impact on low frequencies by using these or DIY tube traps (ok, a marginal improvement with the latter that was not worth the looks), but did notice a clear impact from using a Helmholtz resonator (at the design frequency, of course). |
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http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dmi&field-keywords=corning+acoustic+panel&rh=n%3A11091801%2Ck%3Acorning+acoustic+panel |
@mapman...which auralex are you using? Any of their basstraps as well?
Any other reasonably priced prefab foam (or any other product) out there that will be effective in treating 1st reflection points? |
Pc, I have three of the panels I provided the link to on my side walls at prime reflection points to two of my main listening positions in teh room.
My OHM speakers are fairly omnidirectional so one can listen with a coherhent soundstage and imaging from most anywhere. In that case one must chose what listening locations to treat for. Its more straightforward when applying in teh case of more directional speakers with a small well defined "sweet spot".
The panels pretty much work as advertised. In my case, I am walking a fine line for best sound by applying the third panel, but I have chosen to lean that way.
Bass in this room, on my basement level with thin carpet and padding on concrete foundation, is quite controlled and excellent. I have dabbled with the idea of trying bass traps just to see, but have not been compelled to actually do it to date. |
Rebbi,
I recall your room having a lot of exposed drywall, and appearing pretty lively acoustically.
Definitely consider the auralex 2X2X1 fabric panels. I put them up in my room downstairs and the wife never complained. BEsides doing their job as advertised, they are also aesthetically quite neutral. |
Check out ATS acoustics web site. I have built several panels using their material. |
Have had good luck using mattress pads I use polyfill over mattress
pad cover with wood frame and fabric. |
I referenced the Nextacoustics site above and want to mention they use the exact same foam used in Auralex products. Pretty sure their web site mentions this and I can attest to this as I have products from both. Also, both companies are located on the north side of Indianapolis. I'm half tempted to go dumpster diving. |
You're going to need broadband absorbers for your reflection points, and DEEP traps in your corners and rear wall. Foam won't do much of anything. Check out the GIK site for info. Lots of good info on the Gearslutz site too. |
I would suggest Real Traps. They can be a bit pricier than some of the others mentioned here, a few of which I tried myself, but in the end the Real Traps are what stayed in my room. The Mini Traps or lower cost Bare Traps might work nicely for side, front, and/or rear walls, but if I were you I would start with bass traps in the corners behind the speakers to see how that improves things. Also, do not treat the rear and front walls simultaneously, one or the other. In a room your size I would not recommend any type of diffusion products. Nearfield listening may actually be your best bet and save you some money. That is what I did in a room your size. |
I can definitely agree with Clio09. I recently added the Mondo Corner traps in my small room and am amazed at the improvement. Everything improved from soundstage to clarity to bass. |
