Acoustic Room Treatment

JohnR · « **Reply #100 on:** 3 Mar 2003, 06:15 am »

Hey, cool! How did you decide what to put where?

Can I ask the total $ cost?

Dan Banquer · « **Reply #101 on:** 3 Mar 2003, 01:39 pm »

Oh my, Nathan the cynic gives room treatment the thunbs up. What is the world coming to?

Have any of us thought of the ramifications of Nathan losing his cynical raving maniac edge. Will audiocircle ever be the same? Inquiring minds want to know?

nathanm · « **Reply #102 on:** 3 Mar 2003, 04:08 pm »

Well, I've been reading about room treatment long before I ever got into this stereo stuff. So don't pat yourself on the back TOO much Dan, I didn't get the idea from here!

*nyah nyah!* It's only until now that I spent the money on it. I never questioned its validity at all like I would for other bizarre tweaks. You can get absorbption in one of two ways; fill your room with everyday objects and clutter or buy pricey foam and keep the room relatively free of everyday objects. Everyone knows what an empty room sounds like verses one with stuff in it. You don't even need to be an audiophile geek to understand that a bunch of foam will absorb sound! Heh!

John - There was no set plan, I just spread them out as evenly as possible and stuck the bass traps in the corners. (if I had an extra 6" of ceiling I could've put 4 of them up, but I suppose the building contractor saved a few bucks by making the room shorter than usual

)I'd like to put some on the ceiling as well and possibly make some polystyrene diffusors on the back wall. As far as price goes the grey DST squares are the only things I bought new, those were $200 for 64. Then I probably spent about $500-600 for the LENRDs and the purple wedges. Those I got 'cheap' from Mars Music. This is just a guess, I don't have the receipts handy. Not an inexpensive proposition, but it sure beats that eggcrate look!

The immediate effect is the elimination of flutter and slap echoes. That sound is the most annoying to my ears, so it's nice to get rid of that. Still, between the bare sections of the walls you can still hear a few pings when you clap your hands. That's why I think that ideally, you need more coverage than just a few panels in strategic locations. But that's my taste, I prefer a deader sound. That company that makes those wooden wavy slat things: THAT I am cynical about! And don't they also make some little 2" wood disk that you're supposed to stick on the wall? Hmmm...sounds like trying to stop up a leak in the leeve with a piece of chewing gum. That would work if sound came out of the speakers like a laser beam, but last time I checked it was a pretty omnidirectional radiation pattern!

Dan Banquer · « **Reply #103 on:** 3 Mar 2003, 04:38 pm »

What a relief; and I thought Nathan was losing his edge. I am not clear from your description on what you covered on the wall behind your speakers. Can you please explain that further.

nathanm · « **Reply #104 on:** 3 Mar 2003, 05:03 pm »

Quote from: Dan Banquer

What a relief; and I thought Nathan was losing his edge. I am not clear from your description on what you covered on the wall behind your speakers. Can you please explain that further.

I don't understand the question. The type of foam do you mean? The grey squares are DSTs glued to boards, the purple ones are 2" wedges and the purple chunks are LENRDs. Is this what you meant Dan?

Dan Banquer · « **Reply #105 on:** 3 Mar 2003, 05:15 pm »

Nathan; I was looking for how much of the area behind your speakers did you cover. Did you fully cover the wall behind your speakers or did you leave openings in certain areas on the wall behind your speakers?

nathanm · « **Reply #106 on:** 3 Mar 2003, 06:04 pm »

Oh I gotcha. I will post a pic of the back wall later on. The back wall is about the same as the front. There's 3 purple wedges on the back wall and three LENRD bass traps on the ceiling with an additional column of 3 LENRDs in the back left corner. the right corner has a doorway to a bathroom so it was tricky putting foam there. I'd love to use Venus bass traps, but man are they expensive!

I also tried piling the whole works on the front wall and at the sides of the speakers one time (the live end\dead end thing) but I still didn't like the flutter echoes I got from the untreated walls. I think ideally you could put a checker pattern of foam on the front and slowly fade it into diffusors on the back. That would be cool. I would like to see how it sounds with a whole bunch of diffusors, if it makes it sound spacious or not. Got to get me a hot wire cutter...

Wait a minute...Dan you DID see the picture of it, right?

Dan Banquer · « **Reply #107 on:** 3 Mar 2003, 07:26 pm »

If I may I would like to make a few suggestions. Cover the entire backwall with the standard acoustic foam. Take the wedges off the ceilings and put them in the corners where the rear wall meets the side wall. Then move the spekers a little closer in to the corners. If you have the time and energy to try that please keep us posted. The reason I say this is that typically back wall reflections are the worst, for the treble and midrange. Bass is a whole other ball of wax.

Dan Banquer · « **Reply #108 on:** 3 Mar 2003, 08:49 pm »

This came in to my e mail from Foam by Mail today.

Our color foams are a MVSS 302 fire rating (including charcoal eggcrate),
and our charcoal foams (all other acoustical) is a Cal 117

If anyone can put up a link to find out more about these two standards I would appreciate it.

nathanm · « **Reply #109 on:** 3 Mar 2003, 09:10 pm »

The speakers can't be moved towards the corners because of the doors. I've tried every combination and this is the one that seemed to make the most sense. The doors screw everything up unfortunately. I stood in the rear doorway to take the picture. You can see the knob of the door to the hallway at the right side of the picture. I can't put LENRDs there because of the door. The door opens into the room, not out; otherwise I could mount them on the door itself, but even then it wouldn't be tight in the corner.

I think we may have different ideas of back and front. To me the backwall is the one behind where the listener sits and the frontwall is the one behind the speakers. Is this not correct?

The only way to get bass traps into both corners behind the speakers would be to arrange the system sideways along the longer dimension, but I didn't like this position when I tried it. It makes the room feel smaller. Otherwise I could put the traps against the door and enter and leave the room by climbing out the window!

The Auralex suggestion for the corners is to use a Cornerfill cube and three LENRDs, but personally I think it looks kinda goofy. Framing all the corners with LENRDs would be awesome, but big $.
They do have some panels for that purpose however. Forgot the name.

There's a 40Hz hump in the room and I think it would take some serious treatment to knock that down. And the response really dies off below 30Hz. I would like to know if you can really HEAR those tones under ideal conditions because I've never really heard sines that low in a large room. Maybe they are felt more than heard no matter what. I dunno. They are very quiet though.

JohnR · « **Reply #110 on:** 3 Mar 2003, 09:13 pm »

Geez man, so seal off the doors!

You can cut a small hole in one of the walls so you can get pizza piped in

Rob Babcock · « **Reply #111 on:** 3 Mar 2003, 09:15 pm »

Have you tried EQ to tame the 40 hz peak? My room has two big humps, on around 50 and on about 25 (

). I used a Behringer parametric eq on the low pass to the subs, and it really did the trick.

Just curious. I've read this thread with great interest, as I've been saving up money and researching various acoustic treatments for awhile. Your experience will help give me some ideas where to get started,

nathanm · « **Reply #112 on:** 3 Mar 2003, 09:51 pm »

Ironic, I also have Behringer parametric EQs that I tried EQing the sub with! Seems like everytime I mess with that stuff I end up giving up and taking it out entirely. Maybe I am being too picky. I couldn't seem to get rid of the 40 without weakening the 50 even more, which was already weak. And then there was nothing left over to bump up the 20-30Hz which was even weaker. But I was just doing it by ear with the function generator so... I kinda wish I would've kept the 8024 or whatever it was called, the Behringer digital RTA\EQ device. It's helpful to see the response plotted out like that. The analog parametric EQ is nice, but there's not enough overlap between bands IMO. I will probably end up putting them in my home studio setup where they belong! Heh!

Rob Babcock · « **Reply #113 on:** 3 Mar 2003, 10:09 pm »

It can be frustrating, I'll grant you. Cutting a very narrow slice at one freq can often change the response at an another freq, too. You sometimes have to chase after a flat response for awhile before you get it. I didn't have too much trouble, thought it did take a few days. Unfortunately, I've moved stuff around and added gear since I eq'd, to I really should start over again and redo it. Just laziness that I haven't yet!

I may upgrade to a more potent model, prob the 8024. I'm using the 1124. In one respect, the 1124 is more versatile, as it has ten bands of fully parametric eq, while the 8024 only has 3. But the addition of graphic eq could be interesting to mess with in the bass. I haven't found the need to go with more than 3 bands of parametric eq to fix the low end in my specific room, but other rooms may be different.

Rob Babcock · « **Reply #114 on:** 3 Mar 2003, 10:13 pm »

BTW, I used the Avia & Stereophile test discs in conjuction with a Rat Shack SPL meter (and a pad of graph paper). I would plot, measure & tweak, plot, measure & tweak... it took days. I really wish I had True RTA & a calibrated mic, woulda been faster/easier/prob more accurate. In the end, measuring, plotting & adjusting worked well. I'd listen to some actual music every so many cycles just to be sure the results corresponded to real world music. I'm pretty happy with how it turned out, but again it did take a lot of work and time.

MaxCast · « **Reply #115 on:** 4 Mar 2003, 01:38 pm »

I wish there was a lowner of one of these test kits available.
http://www.rivesaudio.com/software.html#kits

Might make things a little more easy.

JohnR · « **Reply #116 on:** 6 Mar 2003, 05:30 am »

Here's an interesting idea for room treatment:

http://www.halfbakery.com/idea/Audio_20Breast_20Room#1044913093

Xi-Trum · « **Reply #117 on:** 10 Mar 2003, 02:53 am »

Ok guys, I finally go all the foams together. Will post my impressions once I have everything setup.

Xi-Trum · « **Reply #118 on:** 11 Mar 2003, 07:38 pm »

Guys, I finally got everything put together. I got a bunch of 2-inch foams from foambymail and some leftover 8-inch foams from Dannie Ritchie (GR Research). I also got a couple of 4x8 peg boards (cut to different sizes after much measuring and planning) from Lowe's and Home Depot. The foams were glued to the peg boards and the boards were hung on the wall.

For aesthetic (and practical) reasons, I did not treat the whole room. I just worked on the front walls and the front-side walls. For the treated wall, I purposefully left small gaps between the boards. I planned it that way to gain some WAF. After everything was done, I showed my SO the finished project. Her comment: "Nice! The room looks a lot better now. But why didn't you cover the wall COMPLETELY?"

Oh well...

Anyway, here are my impressions of the sound after the room treatment:

Music was a lot more laid back. There was an overall smoothness to the sound. It definitely sounded warmer and fuller with the treatment. I guess another way of describing it is that the sound had toned down quite a bit and made it easier to listen to. Oh yes, imaging and soundstage improved significantly. The speakers seemed to completely disappear. Whereas before I couldn't get the soundstage to extend beyond the front wall (although I kept hearing people talk about it), I have no problem with that now. One area of improvement which I didn't expect was bass performance. For some time, I've been struggling to get that "thumping" bass response. I attributed the problem to the size and geometry (square) of the room. Well, they are only parts of the problems. The room was the other big part. With the room treatment, the mid and upper bass were more much pronounced. As the result, sound was much more balanced and full.

One thing I was worried about with all this treatment was that the room would be dead sounding. Well, I didn't have to. All this improvement came without sacrificing the liveliness of the sound. Like I said before, the music was much more balanced, fuller and smoother. There was a sense of ease about it. "Relaxing" is probably the word if I were to describe it in one word.

I think I could go crazy and add more room treatments. But I like the way it is so much right now that I'm really afraid of disturbing the "balance" between a live room and a dead room.

As for room treatment as a way of improving sound quality? I'm completely in that camp now. For the <$350 bucks I spent on materials (foams, boards, glue, nails) for room treatment, I'm not sure I can get the same return on investment with other equipment upgrades. Besides, I now believe that the equipments are only as good as the room they're in.

Lastly, I have some pics of the treated room. If someone can show me how to post pics, I'd be happy to share them.

Cheers

Dan Banquer · « **Reply #119 on:** 11 Mar 2003, 08:08 pm »

Forgive me, I just can't resist.