Studio Sound Treatment

Posted: Sat Oct 05, 2002 10:19 am

James, Fats - We ARE on the same page, glad you clarified the "which wall is which" thing Fats. When I said rear wall, I was talking about the wall behind the mix desk, which if you refer to the walls by where they are in relation to the mix person would be backward. I intended that whole treatment to go on the wall that would be in FRONT of the mix person when they are where they are SUPPOSED to be, facing the speakers.

Also, James, when/if you decide to RTA your room post back here - I saw an article on studiotips.com with some info and a screen shot or two...

Fats, thanks for the vote of confidence - apparently I'm not only studying the right stuff but making some sensible assumptions from what I read; maybe by the time I get to build my own space (looking at a total of 36 x 48 with up to 16' available for ceiling height) I won't screw it up too bad. I was so dumb about this in 1983 I actually thought egg separators on 1/2" carpet pad = soundPROOF. Oh well, at least that room's never had any 10kHz feedback... Steve :=)

Posted: Sat Oct 05, 2002 11:12 am

Quote:

In 1983 I actually thought egg separators on 1/2" carpet pad = soundPROOF.

Well, it's not soundproof but it does make for some trapping and diffusion...Acoustic foam is not a soundproofing material either. For soundproofing we need to get into a whole different approach. This room treatment is to control unwanted reflections and room modes. There should be some attenuation of the sound level but not soundproofing. If the foam were indeed performing a soundproofing function I would think that the absorption would cause an operator to run the monitors at excessive levels, creating problems with the response of the room as you pointed out in your references to "Fletcher- Munson" curves.....Fats

Posted: Sat Oct 05, 2002 11:27 am

By the way DH,
Electric carving knives are very inexpensive. I usually purchase a fresh new one every time I do a foam install. Last time it cost $15. That is less than the cost of 1 piece of foam which I'm sure you will make up in less waste. They may be found at any store that sells toasters, can openers and coffee pots. Out here it's Longs Drugs or Rite Aide....it will save you heartburn and money in the long run. Besides Thanksgiving and Christmas are just around the corner. I can see it now, "What's this gray stuff on the turkey?"...... Very Happy

Posted: Sat Oct 05, 2002 4:15 pm

Haha!!! I love the bit about the electric knife! I will consider that seriously, the holidays are coming...and sooner than we will ready for!

I placed my order today with Markertek, and they say "UPS Ground" which could mean 3-5 business days, depending on when they actually process the order. I also saw a Guitar Center ad today that had the Auralex LENRD traps for $23...I paid $20 at Markertek...I wonder if I should have bought the Auralex ones...oh well...I did not buy any corner traps for the "back wall" yet (behind me when I am in the mixing position), so I guess I can cross that bridge later, since I have to go to Auralex to get the diffusers anyway.

I already have an RTA on my old Behringer digital EQ (I know...I know) that we used to use in our live rig...so when I get all the foam up, I will see if I can figure out what it can tell me! I'll probably need some help here as well. Since this thing is also a digital EQ, I used to use it to set up the room with a "flat response", then I would tweak to taste. How am I to use it in this situation?

Posted: Sat Oct 05, 2002 6:53 pm

DH,
Great! The Auralex foam corner traps are not any better than the other ones available. The only advantage I see in the Auralex products is a choice of colors and cuts. Now, the Behringer EQ / RTA. Does it have a calibrated mic that came with it? If not it will most likely not work for this application. As far as using the eq to flatten the room response, there are 2 schools of thought on this and it has been a thorny issue for years. Some say use eq and some say don't. I go with the don't camp. It induces phase differences and often you create as many or more problems than you fix. I am generally pretty "old school" (couldn't tell could you?) when it comes to audio.....Fats

Posted: Sat Oct 05, 2002 7:37 pm

Look at www.acousticsfirst.com and scope ut sound channels and bermuda traps. Great stuff

Posted: Sat Oct 05, 2002 11:09 pm

Fats, I didn't even mention that we were NOT talking about sound PROOFing for James, I'm so used to knowing what I had no clue about years ago that I may have messed up by not stating what was NOT obvious to ME back then - sorry James if you thought otherwise... Just for the record, sound PROOF keeps sound from getting in or out, while sound TREATMENT or CONDITIONING makes what stays in the room sound right.

I agree on NOT using EQ to flatten room response. First, you don't want it completely flat or it will sound too lite on bass and too bright, and second, that's what the various types of materials with different absorption characteristics are for.

I don't think there's an analog and probably few if any digital EQ's out there that don't induce phase anomalies in a signal if you boost more than 1 or 2 dB - any unevenness in freq response of a room will change the minute you move ANYTHING in the room, so the only practical way to handle these problems is to absorb those freqs more than the non-problem ones. That way there is little or nothing to correct for.

It's a lot like the old statement, "The best way to get rid of noise is don't generate it in the first place..." - If you get your room sounding right ACOUSTICALLY without electronic help, everything you do there will be better sounding, therefore require less tweaking, therefore be even BETTER sounding as a part of the final product.

I have some "live to 2-track" CD's of a group called Flim and the BB's, kind of a slightly Avante Garde jazz group - the liner notes claim on at least one of the CD's that they were recorded to dat real-time and then straight to CD. These things sound great!!! Real dynamics, real acoustics for the most part, real music, real players... you have to listen to these babies at about 90 dB or you completely miss some of the softer passages, and that's not good to do since it's all great. Now there's an impressive way to make a CD, even it it never will get any prime time exposure. Their engineer really must believe in "do no harm" - just one example of the bennys of getting things right in the first place.

'nuff rant, later... Steve

Posted: Sun Oct 06, 2002 9:07 am

Steve,
Hear, Hear and Harumph. Can I get a harumph? (that guy over there didn't harumph).

Posted: Mon Oct 07, 2002 6:34 am

I would never *ever* use EQ for recording/mixing/mastering! When I go back and read my post on the Behringer EQ, I can see the confusion. The Behinger unit is from my old "live" rig for playing out in clubs and such, I have never used it for recording. In fact, I am going to have to dig it out of my huge pile of equipment and dust if off! It hasn't seen light for probably 3 years! For "live" perfomances we would RTA the room (since they are all so different, and most of them suck), have the unit automatically set the EQ to "flat" for the room, then we would adjust the rest to taste. The "flat" setting was used only as a starting point. Again, this was only for "live" performances of my band!

If I adjust the EQ in my studio, I am not hearing what is truly on tape! It makes no sense to have spent a small forutne on "flat" monitors if I am just going to screw with the EQ anyway! Hell, I spent more on my monitors than I did on our big PA High/Mids!!!

Sorry for the confusion there...I absolutely agree 1000% that you should never EQ the room when recording/mixing. I have read posts of those who do however...they usually get flammed pretty badly!!!

Also, I am not trying to soundproof the room. I understand the difference, and have seen sets of pictures of studios under construction...floating walls, rubber insulation, dealing with air conditioning, etc. I will save *that* project for when I win the lottery, and build a dedicated stand-alone studio in some exotic location! Hehe...who hasn't dreamed of doing that same thing??? Come on!!! Be honest!!! Smile

My goal is to get my room sounding the best I can make it, considering it is a pre-constructed room. I know it will never be perfect with the parallel walls and the funky dimensions, so I am just trying to get it to sound decent without breaking the bank too far! Your help has been great so far, and I am making such great progress! I am really jazzed, considering that I have been fighting this fight for a long time trying to decide how to proceed, and instead, getting nowhere! My first big shipment from Markertek is due sometime this week, and I am "chomping at the bit" to get started.

Back to the RTA situation:

I would love to do a before/after snapshot of the room! That would be pretty cool to see the difference that the acoustic treatment makes. With the Behringer unit, I fire it up, (and YES, it does have a reference mic), let the pink noise grind for about 20 seconds or so, and it will genreate the EQ profile automatically for me at that position. I am assuming that I will take reads at my listening position. The system will then boost/attenuate at different frequencies in an attempt to get a "flat" frequency response, is that correct? So how do I interpret those readings?

I guess I could take a quick picture of the spectrum with my digital camera and post them somewhere if you guys wouldn't mind taking a quick look at them and telling me what you think...

Posted: Mon Oct 07, 2002 6:37 am

Oh yeah...and Harumph!!! Smile

Posted: Mon Oct 07, 2002 8:52 am

DH,
The comments re' soundproofing were in reply to Knightfly's comments. As far as th RTA, if it has a calibrated mic that was supplied with the unit (hee hee, he said "unit") then it will be of some use to you in checking out your room..........Cheerio and Harumph!, Fats

Posted: Mon Oct 07, 2002 10:35 am

DH,
I had just woke up when I replied to your last post and I hadn't had my coffee yet. I
re- read your post and here's my 2 cents. Shoot the room with pink noise and then let the RTA do its thing. You will see where the peaks are (where the RTA applied cut and where the dips are, where the RTA's boosting). I would venture a guess and say if you can get the room response within + or - 6 to 8 dB your in the ball park. If not, you need to experiment with moving the speakers and other elements in the room or adding and subtracting treatments until you get where you want to be.....Fats :tu:

Posted: Thu Oct 10, 2002 10:24 am

Here it is Thursday afternoon...and still no UPS truck from Markertek...Grrrrr...Where's my foam??? Hehe...anxious little snit, aren't I?

Posted: Fri Oct 11, 2002 8:35 am

Ya mean foaming at the mouth ain't enough? :=)

Posted: Fri Oct 11, 2002 3:01 pm

Well...my big packages of foam arrived late yesterday afternoon. My wife's first comment was, "You paid *how much* for a bunch of packing material????" <grin> Women! Hehe...

Hopefully tonight I'll get a chance to work on it...

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