Temporary "FAQ"- (was "Complete Section")

cfuehrer · Post by **cfuehrer** » Tue Oct 14, 2003 12:51 am

>As long as only ONE side has the RC channel you are okay

So for my live room, would I make the wall that faces the control room non-RC and the other walls in the room RC, or the entire live room no RC and put RC on the control room?

>Rockwool/Mineral wool is the same thing. Use this in your floors instead of 703

So would it be better to put 703 in the walls or the Rockwool also?

>bought a 15' strip of neoprene 1/2'

Where? I get too much crap when I search for it on the net.

>mounted them to my studs with dryall screws being careful to seat the screw a bit.

As in make it compress the pad a bit?

knightfly · Post by **knightfly** » Tue Oct 14, 2003 1:30 am

"So for my live room, would I make the wall that faces the control room non-RC and the other walls in the room RC, or the entire live room no RC and put RC on the control room?" -

Depends on whether you're also going to have a separate drum booth - if so, the drum booth should get the no-RC walls (except for outside walls, if any) then, if the live room has any walls that do NOT share with the drum room but DO share with the CR, put the solid side toward the live room.

It would help if we knew which plan you've decided on, so we could take it wall by wall...

Insulation in walls needs to be 2.5 to 3 pounds per cubic foot, period. Rockwool or 703 or SAFB's, all will work almost exactly the same.

On the pads, you can either use screws and compress a bit, or (better) use contact cement and glue them to the runners. (You don't know, unless you've done more calculations than I'm aware of, just how much that rubber will compress. ) Just don't use so many pucks that the rubber doesn't compress at least 15% of its thickness, or it won't do any good. Any "spring" is only resilient if it's in the middle of its travel.

If you'll post your final choice in floor plans, I'd be glad to go thru the wall recomendations with you... Steve

giles117 · Post by **giles117** » Tue Oct 14, 2003 1:48 am

Thanks for that which side to put the RC on tip Steve.

I'll make sure I implement that the next studio I build

Why does it matter in the light of a drum booth? Do you loose some db's of isolation? when drums are played? Just curious.

Bryan Giles

rod gervais · Post by **rod gervais** » Thu Oct 16, 2003 2:30 am

I read through the thread here - and you have gotten some real sound advice......... should go a long ways towards helping you........

My only comment - based on personal experience - for the floor i would reccomend a sand fill for the greatest "bang for the buck".

It completely deadens the floor - stops it from acting like a drum head at low frequencies - and the mass is ideal for stopping low frequency transmissions.

Rod

knightfly · Post by **knightfly** » Thu Oct 16, 2003 3:11 am

Bryan, my reasoning on which side gets the RC (and this is nothing I've proven yet) goes like this:

Since stiffer walls stop low freq better, and since drums tend to have adequate quantities of same low freq, and since all published data on walls (except supersoundspoofing.con) says ONLY one side for RC, it just makes sense to me that the side with the most Low Freq stuff gets the stiffest leaf of the wall.

My main concern here would be primarily the coupling between CR and drum room, whether that is the live, or tracking room, or a separate drum booth. I want to be able to set mics based on what it sounds like coming through the speakers, not what it sounds like coming through the walls or glass or common structure.

In fact, in my own personal situation I'm not going to completely "de-commission" my old facility when I build the new one 80 feet away - I'm going to keep the option of having a REALLY isolated room by running Audio/Video/Cat5 between the old and the new, just in case I want/need that extra isolation for something someday. It's hard to beat multi-walls AND 80 feet of air for isolation... Steve

rod gervais · Post by **rod gervais** » Thu Oct 16, 2003 4:22 am

knightfly wrote:Bryan, my reasoning on which side gets the RC (and this is nothing I've proven yet) goes like this:

Since stiffer walls stop low freq better, and since drums tend to have adequate quantities of same low freq, and since all published data on walls (except supersoundspoofing.con) says ONLY one side for RC, it just makes sense to me that the side with the most Low Freq stuff gets the stiffest leaf of the wall.

Steve,,

I would love to discuss this with you further........ tis an interesting concept - and if correct - would actually dis-prove my belief in wall operation....... which is this:

It is the "entire" assemble which acheives the rating - and not a single component.

Although i agree with the philosophy that the stiffer wall (with the greatest mass - I should add that as well) will attenuate the lowest frequency - that frequency has to pass through regardless of which side of the wall the stiff/mass is on - and thus would act the same in either case.

I am open to convincing conversation to suggest this is not correct..... sometimes logic will suffice even without substantiating test data.

Do you suggest that we would get completely different results on STC (or MTC) depending on the source of the test noise? (I.E. : inside or outside of a building?)

Rod

giles117 · Post by **giles117** » Thu Oct 16, 2003 6:02 am

That makes a ton of sense Steve.

Thanks a mil

Bryan Giles

knightfly · Post by **knightfly** » Thu Oct 16, 2003 6:12 am

Now that you mention it Rod, it doesn't seem to tally with accepted fact - you're right, sound control is NOT a "diode" situation - what made me think my comments might be true was the idea that "the best way to stop noise is not to generate it in the first place" - that's coming more from almost 40 years as a tech, though, not from a few years of acoustic study (almost all of which seems to be fraught with contradictions) -

Sometimes it's hard to "turn off" my electronic/mechanical training and "think like an acoustician" (say, didn't the Bangles or one of the girlie groups do a song about that?)

I know, you were expecting more of a fight there - it's your own damn fault for bein' so logical right off the bat.

Still sounds like it oughta be true though, dammit - Oh well, the bright side of it: makes it easier to decide when there are choices about which room gets the better isolation - or does it? What do you do when you have a CR and 3-4 different rooms that share walls with it?

I would think that one way to handle that would be to use RC on the inside leaves of the CR, then any room that shared a CR wall would get solid mounting on its inner walls, except where it also shared with ANOTHER room, in which case... Gee, this is almost as much fun as deciding which of your 35 rack spaces that you can REACH get which 73 spaces of gear...

Given the impossibility of satisfying the "one side only" rule with more than two rooms, I think I would tend to (in those cases) use NO RC in either side of wall sections that conflict, opting instead for double framed, offset stud, multi-layer construction with no two leaves made up the same way.

I'm remembering comments by Eric Desart regarding low freq's and solid walls, and thinking that the improved low end blocking of an ALL solid (but separate framed and offset stud) 2-leaf partition might just average out better in response than one with RC - Eric's comments (and reading I've done) about PERCIEVED sound isolation being best with UNIFORM rejection would lead me to lean toward walls that favor low end TL slightly over STC.

Man, that made me thirsty - anybody up for a beer?

Sooo, whaddaya think Rod - am I back to "think like an Acoustician" yet? Steve

VSpaceBoy · Post by **VSpaceBoy** » Thu Oct 16, 2003 7:44 am

Great discussion! All the little tid bits keep making things more and more clear.

Thanks!!

Ron

knightfly · Post by **knightfly** » Thu Oct 16, 2003 7:56 am

Know what you mean, Ron - for the first 15 years or so, I thought that (in acoustics) as long as you did the OPPOSITE of what your intuition told you, you'd be fine. Now, I've come to realize that that's true only 93% of the time...

MUUUUCH better..

rod gervais · Post by **rod gervais** » Thu Oct 16, 2003 10:47 pm

knightfly wrote:
Now that you mention it Rod, it doesn't seem to tally with accepted fact - you're right, sound control is NOT a "diode" situation - what made me think my comments might be true was the idea that "the best way to stop noise is not to generate it in the first place"
It's true that this is the best way......... but a wall is definately not a diode....

I know, you were expecting more of a fight there - it's your own damn fault for bein' so logical right off the bat.
Steve - I like you just too damned much to want to fight with you......

Given the impossibility of satisfying the "one side only" rule with more than two rooms, I think I would tend to (in those cases) use NO RC in either side of wall sections that conflict, opting instead for double framed, offset stud, multi-layer construction with no two leaves made up the same way.

Well - if the wall isn't a diode - then this really isn't an issue....... who actually created this "rule" ?

I'm remembering comments by Eric Desart regarding low freq's and solid walls, and thinking that the improved low end blocking of an ALL solid (but separate framed and offset stud) 2-leaf partition might just average out better in response than one with RC - Eric's comments (and reading I've done) about PERCIEVED sound isolation being best with UNIFORM rejection would lead me to lean toward walls that favor low end TL slightly over STC.
Well, I would have to ponder that............. I remember - shortly after we completed Power Station - I went back for a walkthrough visit - sort of just checking to make certain we didn't have any problems (i would spot things that the client may not have) ........ and when i entered the lobby - i could hear a guitar playing in the main room......... i was a bit upset because i was thinking that something was wrong with door gasketing..... but when i opened the door it felt like the front of my face was going to be ripped off due to the volume.

The guitar player was the sound tech hired by the company - he was a fantastic guitarist - who had actually turned down an offer from Ozzie Osborn to go on tour so he could take the tech job.

I remember thinking how effective the wall was (along with the rest of the assembly) as i looked at the volume control on this monster Marshall Amp and saw that he had it completely pegged.

So isn't there really a balancing act between the low frequencies and the highs....... and thus an attempt should be made to provide in the wall the best of both possible worlds.

We know that we get a large benefit in STC (150hz - 4000khz) with the use of RC - shouldn't that be a part of the equation as well?

Man, that made me thirsty - anybody up for a beer? Sooo, whaddaya think Rod - am I back to "think like an Acoustician" yet? Steve

Beer sounds good - and you always think like an acoustician - however - the problem is - some of this just isn't logical -

Keep up the good work my friend - these people have a great asset with you here.

Rod

knightfly · Post by **knightfly** » Fri Oct 17, 2003 3:05 am

Hey, Rod - I'm always in favor of recieving kind words, but coming from someone with your background they're even more welcome.

Your comments "So isn't there really a balancing act between the low frequencies and the highs....... and thus an attempt should be made to provide in the wall the best of both possible worlds.

We know that we get a large benefit in STC (150hz - 4000khz) with the use of RC - shouldn't that be a part of the equation as well? "

... Are pretty much what I was trying to say before - If you consider that RC was sort of an "accident" that was later discovered to have benefit within the "speech" range, and that acousticians including Everest have been responsible for the statement I made regarding "uniformity of isolation", (which I probably should have referred to as "uniformity of Transmission Loss") - it just seems to me that, even though RC is used successfully, that a wall might be more easily balanced in TL throughout the REAL frequency spectrum of MUSIC, by NOT using the RC and just concentrating on two separate frames with DIFFERENT characteristics.

Im not sure yet, but it seems like, since lows are much harder to block than highs, that if you slanted a wall's performance more toward the lows while at the same time using 3 different thicknesses of wallboard to control the upper end Coincidence Dips, and NOT gluing layers so that each could have its own NON-coincident resonance, you might just end up with a "super wall" that could keep those "power kick drums" as under control as the ever-popular "man singing with vise-grips attached to gonads" -

Hey, this is fun - I'm already ready for another beer... Steve

rod gervais · Post by **rod gervais** » Fri Oct 17, 2003 4:47 am

Im not sure yet, but it seems like, since lows are much harder to block than highs, that if you slanted a wall's performance more toward the lows while at the same time using 3 different thicknesses of wallboard to control the upper end Coincidence Dips, and NOT gluing layers so that each could have its own NON-coincident resonance, you might just end up with a "super wall" that could keep those "power kick drums" as under control as the ever-popular "man singing with vise-grips attached to gonads" -

Hey, this is fun - I'm already ready for another beer... Steve

Well - you are possibly correct - but - as we all know - ultimately - the only way to prove this one way or another - is to develope a design - analyze it the best that can be done mathematically - and then HAVE IT TESTED................ until then - i (personally) get tense suggesting anything to anyone..........

I am ready as well........... but then again - i am ALWAYS ready...........

Rod[/quote]

knightfly · Post by **knightfly** » Fri Oct 17, 2003 5:50 am

" i (personally) get tense suggesting anything to anyone.......... " -

Right there with ya - I'll be doing a LOT more research on my little "theories" before I deviate from tested designs - I try to remember to caution people that always ask "but what if I just..." that my answers are just (semi) educated guesses.

So far, when people have followed my advice to completion they have been VERY satisfied with the results; just recently a guy in Austin finished a free-standing room following ALL my suggestions, and can't hear the drums at 10 feet away from the outside wall, all on a pretty restricted budget. He's happy; I'm ecstatic... Steve

cfuehrer · Post by **cfuehrer** » Fri Oct 17, 2003 11:21 am

knightfly wrote:post your final choice in floor plans, I'd be glad to go thru the wall recomendations with you.

OK, here's my rendition of John's new awesome design:

I am planning on using Rockwool and just found a local vendor for RC-1