Acoustics - They are kickin my butt.

skadarnold · Post by **skadarnold** » Fri May 21, 2004 7:29 am

Ive decided its time for me to put some serious work into my acoustics. I have done alot of research besides the 6 or so hours i put into it ealier today. But, its still throwing me into loops.

The layout of my room is 16x25 with 8 ft ceiling as you can see by the graphic. I built the corner bass traps using mass amounts of fiberglass. I dont know how effective they turned out to be but there is a difference in the room. They are ribbed with 4x1 wood to reflect some of the highs back in. I had hoped they would work well as a broad frequency absorber.

I had a bunch of old 3" wedge foam left over from when i bought the studio. It was enough to cover the entire west wall. Thats shown in the yellow on the left wall in the graphic. I knew this foam abosorbed pretty well down to 500Hz which is why i used it.

There is also Foam Bass traps for the ceiling corners. Which are supposed to be good, but i used them because i had them left over.

The room sounds alright like this, but i know it could be better. The main purpose was to get rid of the paralellism in the walls. So ealier i decided i needed to fix the the paralellism on the north and south wall. I was going to build a false wall to be an easy fix here. But then i started thinking that a slot resonator would work better for that wall. Have it angled to a point in the center of the room extending out to 8". This would absorb down to 200Hz, and would be broad band up to about 450. I thought this would work well, but then i started to wonder if that would be enough for the lower mid frequencies.

So i thought instead of going with the Mini Traps on the east wall. But i was thinking maybe Microtraps would do what i needed on that wall. This also got me thinking about treatment for the ceiling.

First, i wanted to get some opinions on this setup. Would this balance the room out pretty good for the money? What are some suggestions? Second, if i was to go with the Real Traps, which should i get, and how many? I dont understand how it would work unless you covered most of the entire wall. Does 2 Mini Traps on the east wall really help that much especially with the parallel wall? Its just confuses me how that would help that much.

There must be something im not quite grasping so i need someone to elaborate and fix this confusion.

I have a budget of around $1000 - $1500. I would rather keep it around $1000 but if the extra $500 would help alot i would rather spend the extra cash.

This is for the recording room BTW, not the control room.

Thanks a ton everyone.

Danny

skadarnold · Post by **skadarnold** » Fri May 21, 2004 10:29 am

Ethan - What do you recommend as far as the Minitraps go? I was thinking the Micro Traps would do ok for my situation. I need to absorb in the 200-500Hz to balance i believe. How do they work without covering the whole wall? Wont there be spots that will still reflect badly and cause problems. Especially in the center. I could see this working for frequencies around 200Hz, but putting Minitraps on a 25 ft wall vertically? Maybe im just confused about how it works.

I think ill go to the studio tonight and do some analysis with the white noise on your web site. That should give me a better idea on what i need to do. Did i make a wrong choice with the 3" foam on the wall?

Thanks,

Danny

skadarnold · Post by **skadarnold** » Fri May 21, 2004 1:18 pm

Im saddened that i get very little response whenever i post. Am i just asking stupid questions? Im realizing i might be a little slow at this acoustic stuff, because i promise ive read through everything i can find on this about 50 times and its just throwing me in loops.

Anyway, i just got done checking the room modes. I started with the control room even though i wasnt planning on doing anything in it yet. And i was in for a big surprise. That had so many problems i couldnt believe it. Every dip in there was almost -20 to -30 DBs! I realize now that this is very problematic so i should plan on treating this room also. This was my first time analysing a room so it amazed me how much the frequency changed as i even just moved my head.

Heres the modes for the control room.

-70 +125 -174 +195 -223 +236 -262 +275(mild)

I didnt bother writing down DBs for these because they were all huge and obviously needed treating. I practically had to zoom in to see the -70 dip.

The recording room, which is treated better and is much larger, was actually pretty good. All of the dips and peaks were under -10DB from average level except for one. But there were spikes so i went ahead and listed where they were.

-53 -116 +146 +169 -198 +234 -255

The -255 was the deepest of all the dips. It might be the one we really need to fix. the -53 is hard to say because i dont think my monitor speakers really go that low so there was a dip there. The -116 was around -10 DB and it was really rounded. Meaning it wasnt a deep spike but it was rounded that level down to 100Hz to around 130Hz. So i dont know what that means, it would seem to be a problem but not horrible?

Anyway. Thats all i have so far. The control room was set at mix position. The tracking room was set around the center of the room to get an overal effect.

Thanks to anyone who takes a look at this.

Danny

dprimary · Post by **dprimary** » Sat May 22, 2004 5:50 pm

You will have deep modes with this room. 8 ft high 8x2=16 width 8x3=almost 25 the depth. I attached a graph of the Bonello Distribution and mode strengths calculated using a spreadsheet from Jeff Szymanski, along with a screenshot of the first 59 modes. How are you measuring them them?
Symmetry is important in control rooms, you should layout the room so that the left and right sides of the room are symmetrical.

Dan Nelson

Ethan Winer · Post by **Ethan Winer** » Sat May 22, 2004 10:20 pm

Danny,

Sorry for the delay. I'm away at a trade show and I'm sitting in a hotel room typing uncomfortably on a laptop, so please forgive my brevity.

> What do you recommend as far as the Minitraps go? <

Your room is the same size as my home theater, and only the ceiling height is different. You'll need more than two MiniTraps to get good results, and they should go in the corners, not flat on the wall.

> I was thinking the Micro Traps would do ok for my situation. <

Not really. MicroTraps are not really meant to be bass traps, and that's what you need the most. So MiniTraps make much more sense for your room.

> putting Minitraps on a 25 ft wall vertically? Maybe im just confused about how it works. <

If you can wait until Monday, send me an email or call then, and I'll be able to better assess your needs and advise you.

--Ethan

skadarnold · Post by **skadarnold** » Mon May 24, 2004 6:40 am

dprimary - The pictures you posted didnt work. Thanks for the info. Actually i havnt specified the size of the control room yet. It is quite small which im sure is bad. I will get some more information on that also. I was originally just going to work on more treatment for the studio room, but i found the control needed it more.

Also, i guess i should have mentioned that the ceiling is angled. Im sure this plays an important role so i will get the information on that. Its not angled much so i didnt think it would change the nodes much.

Ethan - Thanks for the reply. Sorry if i got a little jumpy on my patience there. I was really eager the other day to get something done with the acoustics and i felt a little pressed on time.

I understand i will need more than two in the control especially. The recording studio room seemed much better because of the bass traps i built. And i wanted to add a few of your minitraps in there to just give it an extra boost. So with the control room, i will probably try and buy at least 6. However, i need to get new monitors along with this purchase, so my budget might limit me to 4 at the moment. I will give you a call later when i get a chance.

Danny

dprimary · Post by **dprimary** » Tue May 25, 2004 3:25 pm

Some broswers can't handle tif images it seems I converted them to gifs they should work now. My thoughts are you might have over done it on the foam. Would you be able to double up some of the foam so it would absorb lower frequencies. Like nest two together and glue a third on top?

Dan

skadarnold · Post by **skadarnold** » Fri May 28, 2004 9:16 am

dprimary - Hey.

Yah i was wondering if i was going to over due it on the foam. But i was thinking i would be able to build things on the opposite walls that reflect highs and absorb lows to balance it out. Thats kind of what im looking for. But thats what i need to know, what do i build? The north wall i would really like to put a slat resonator, or at least some kind of diffusion because of the length of the room. The east wall, opposite of the foam wall, i wanted to put some low fequency panel absorbers.

Ive seen many studios built this way so i knew i could build on it piece by piece.

Like i said, this is the recording room, because of the bass traps i built it really doesnt have as bad as a problem as the control room. I just realize in the recording room that it is a little dull and thats not what im looking for on drums and stuff. But since i havnt built proper diffusion ive had to put in temporary absorbers to tame the obvious. I think a wood floor on one side of the room would too.

Let me know what you think. Thanks a ton for the help.

danny

brandondrury · Post by **brandondrury** » Mon Jun 07, 2004 1:54 pm

However, i need to get new monitors along with this purchase, so my budget might limit me to 4 at the moment.

Well, I spent $1200 on monitors when I first started. Looking back, I should have spent $1200 on Rockwool / Fiberglass and not on fancy monitors, mics, preamps, convertors, etc.

Unless your monitors are broken and what you know about your current acoustical situation, I don't see how you could justify the addition of new monitors at the expense of adequate acoustic treatment.

Then again, I just read that earlier today and repeating it. I don't know what I'm talking about.

Brandon