Noobie questions about audyssey, spl meter, room treatment

It's all about costs and benefits.

You aren't done right until you are satisfied with the results. That may take everything you mentioned, and then building a new room and buying all new equipment.

I'd say that getting SPL meters are a waste of time and effort. If your best results with just Audyssey doesn't do it, you should go directly to measurements with a mic, computer, and analytically software.

Be aware that you are potentially starting on a journey of many steps. Unlike playing musical chairs with DACs or power amplifiers, you will be dealing with real audible improvements.

I agree with Arny that a proper room measuring microphone and the Room EQ Wizard software is a better solution if you really want to know what your room is doing. REW is free, and a good microphone can be had for $50. Though you might also need a better sound card to power the microphone. More here:

Room Measuring Primer
Comparison of Ten Measuring Microphones

Small square rooms have the worst bass problems. Audyssey can help reduce the bass peaks, but it won't do anything for the nulls. It also won't help with "early" reflections which are equally damaging. More here:

Acoustic Basics

--Ethan

+1 to both.

A calibrated mic and cheap (e.g. m-audio) USB preamp will run ~$150. Add the free program REW and you can start making reasonable mesaurements.

I tend to think a lot of people start down that path without any real need nor reason beyond "maybe it will sound better if I buy more toys and piddle".

Of all the toys I can think of, the mic and preamp/interface have the greatest potential for obtaining huge sonic gains but also consuming large amounts of time and money (for acoustical upgrades).

"Vast", you meant to say "vast" amounts of time, right? Maybe that's just me...

There are tons of books and gobs of info on setting up home theaters, and yes a lot of it is based on studio work as that is where a lot of it originated.

Home Depot carries Corning material you can use to make absorbers.

Go to Ethans website and read up; lots of info there! www.realtraps.com -- Look around, read the acoustic info articles, and build your knowledge base before diving in.

I was trying to be polite by avoiding the appearance of hyperbole. I really meant humongous. ;-)

Thing is, in the balance of costs and benefits, the benefits from system tuning and room treatments would be cheap at twice the price, and you can pay more than that with only psychological benefits if you try to improve your system with golden cables, weird amplifiers and magic DACs.

+ a million. Why people spend $20k on a system and hundreds to thousands on interconnects but complain room treatment costs too much I don't get... Of the $25k or so in my system about $3k - $5k is room treatment, not including the room construction itself (floating walls/ceiling on a concrete floor, minisplit to isolate it from the house HVAC). I tthink a lot of folk underestimate the impact a little room treatment can have. From my primordial past life doing live and studio sound I put room treatment high on my list.

I find you can take a pretty modest approach to room acoustics, equipment and system adjustments and obtain great results. If you assume any component is all you need to worry about you will fall short and if you ignore a category or assume things without knowledge you are likely to miss something big. In general the bigger the room the bigger the costs and the louder you want to go the bigger the cost.

I saw someone created their own hanging room treatments with Roxul Safe n Sound comfort batt or the like. They took a light wood made a frame around the comfort batt, then took fabric and wrapped the comfort batt and wood frame to make a nice hanging picture. They then placed these around the room and on the ceiling to absorb the sound to reduce the amount of reflections.

I custom made some treatment for my own theater to hit the room acoustics specification. It can be done. The key thing is to know the room acoustic target for all frequencies and how to achieve it.

Some people are sensitive to some of the chemicals in some materials. It will depend on the person and the treatment. Formaldehyde for example can be in some products. This is not generally a problem, but you can select materials based on sensitives if necessary. I like using natural materials in my theater to avoid problems like this. Most will out gas pretty quickly if they do have some of these chemicals. Some people are sensitive to the materials in PVC projection screens as well.

Most common materials used in absorbers are the same materials used in normal construction and are safe. As mentioned, like most anything new, there may be some initial odor, but that should dissipate quickly.

I don't know anything about foambymail.com. Not all foam material makes good acoustic material. There are plenty of books (and threads on AVS) talking about materials you can find locally. Read up on Ethan's site: www.realtraps.com. He has articles on DIY as well as all the acoustic knowledge. You really want to build your knowledge base a little before randomly buying unknown material and slapping it up any old where.

Most people will have no symptoms from these low levels. That is why they are considered safe. I suspect if you were sensitive to formaldehyde you would already know it.

Here is more info on formaldehyde in the home. http://www.epa.gov/iaq/formaldehyde.html

Here is Owens Cornings position on formaldehyde in fiberglass. http://www.owenscorning.com/worldwide/admin/tempupload/pdf.2-74495-171_FactSheet_E.pdf

I personally would avoid foam if you want a durable product. Most are going to last 10 years before they start to fall apart. It is a messy thing when foam rots.

Yes, I'd stay away from foam. Cheaper and much more effective solutions using fiberglass/rockwool are readily available.

There's many tutorials for easy to build diy panels, all over the web. Ideally, I'd suggest some like (or equivalent) 4" rigid OwensCorning 703, spaced of the wall by 4".

Bass traps in the corners can be superchunk style, or merely stack up loose, fluffy insulation which works best for deep traps and is cheaper yet,...win win!

If you're curious for more details and can't find the info you need, ping me I'll hook you up.

GIK Acoustics, RealTraps, both good we based operations that hand out free info and quality products.


Best of luck.
Edited by FOH - 11/17/12 at 6:02am

Not an inch, thin treatments only create muddy inarticulate sound.

You see thin absorbers only treat the mids on up. Thus creating a dull, lifeless bass thick mix. Ideally, you absorb all or nothing, that's it. Bass trap the corners, if needed treat the first reflection reflection points on sidewalls, ceiling, and oftentimes it's very helpful to treat the area directly behind the speakers too.

1.) Bass trap, most typical residential listening rooms need mucho bass trapping, fortunately the cheapest insulation works the best for this. Thick as possible.

2.) Surgically treat sidewall reflection areas, only as big as needed. This you use rigid, 3lb fiberglass type product, ideally 4" thick, w/4" gap between it and the wall.

3.) From the LP rearward, often a diffuse, scattered soundfield is best. Any bass traps used rearward can have thin plastic or paper covering, thus reflecting MF/HF yet absorbing lows.

I prefer anabsorbent absorbant front wall, and ceiling between the LP and speakers. IMO, these two are nearly a not miss deal. If your LP is too close to the rear wall (within a few feet), then maximum absorption of the surface behind you head is in order. If the wall is farther than that then a diffuse, or scattered surfaces is fine.

In the front, symmetry is key. The spacing around the LCRs needs to be free from anything, and relatively symmetrical on each side. Whatever sidewall first reflection treatment you pursue, you do it only big enough to do the job, and not bigger. For the LP, a 2x2 panel is likely fine. $" thick, 4" off the wall.

Don't apply thin treatments, you're better off without any .... as I stated above, thmerely filters merelyfilter the sound, eliminating all the critical midband and highs, leaving the mud.

Good luck

+1

I think this guy's name is Legion. Good for all of them! ;-)

+453.15926 ;-)

FOH said to stay away from foam, yet you link to a site selling foam?

Interesting that they show sound absorption coefficient greater than 1... I did not think that was possible; need to review the standards they reference. Also note you need a stack of them in each corner.

We have installed Auralex LENRD corner absorbers that look very much like those in our church and I have been very dissappointed in their performance, especially at LF. Be sure to follow the comparison link on that website: http://www.foambymail.com/acoustic-foam-product-comparison.html YMMV.

Home Depot, Lowes, and similar places offer Corning 703/704 that will probably do a much better job for less, assuming you are willing to trim a sheet or cloth over it to dress it up, and mount a couple of sheets (4") 2" - 4" off the wall.

Mineral wool is another alternative, but is harder to work with and sheds more.

Would that work?

Not very well at all, as it's all about thickness off the wall. Upon examining that thing, it's only about 6" deep,... at it's thickest! Not to mention the high price. A 4" or 6" rigid fiberglass bass trap straddling the corner would perform much better and cost much less. This isn't mere conjecture, it's been tested. Yeah, the foam stuff would be great if it worked better, ....then the high cost may be justified. The foam would be nice and handy, easier to deal with etc., but it just doesn't cut it for LF and bass traps.

If you don't want to diy, then look at GIK, or here, or Ethan's products, or these here.

If you want to go all out, the best approach, fortunately also the cheapest, is loose fluffy fiberglass type stuff. You employ very thick approach, covering a corner or an entire wall. Just cut the batts, stack them up. You may need some netting or such to prevent sag and to physically contain everything.

Again, few small HT rooms have adequate bass trapping. The benefits are measurably smoother freq response, and measurably tighter response in the time domain. Subjectively, it yields tight, punchy and well delineated bass. Well worth the effort and seldomly pursued properly.

Good luck

Your concerns are justified. That brand is not as good as claimed, or even as good as "normal" quality acoustic foam. See the comparison here:

RealTraps Product Data

--Ethan