Barts, it's actually a whole lot more than soundproofing. The thing is to make the walls rigid, so that they don't flex in response to sound energy, especially sound from the speakers.
If the walls do flex, they act like exceedingly low grade woofers - woofers made of drywall, responding out of phase. Hence Quietrock 545 with embedded sheet steel. |
Terry, My understanding is that a double layer of 5/8" drywall with Green Glue in between does not vibrate at all. That's not to say that Quietrock is not better, probably is, but I do have a budget. As I have said I will be looking into both. BTW the room didn't sound bad with the old sheet rock. Thanks for the input. I'll let you know how it goes.
Regards, barts
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Don't forget the cost of labour to put up two layers of drywall and slather with green glue, instead of just one layer. If you're not doing it all yourself, that is.
Good luck! |
I used two layers of 5/8" drywall on the room I built, but I couldn't afford green glue so I used an elastomeric carpet glue at about one tenth the price. The green glue might be better, but this carpet glue worked really good, I still have a scrap piece of drywall with the stuff on it and it is still soft and pliable. If you go with two layers of drywall don't get the newer light weight 5/8" drywall it doesn't have the density of the heavy 5/8". My room is so quiet that I noticed I have a slight case of tinnitus that I never noticed before. |
I had an unrelated call with Richard Vandersteen yesterday and we got to talking about the room - talked about a Mutual friend of Our who owns an audiophile record company - super high grade reissues - his quality evaluation/ listening room also included The above in the thread mentioned golden ratio, double layers, air gaps, etc we have been talking about but also S ducting on the air conditioning/ heat ducts as well as the return line.
free pro tip |
I happen to be friendly with Scott Hull, the owner of Masterdisk, grammy winner, chief mastering engineer. At some point he will be coming to my
house for final tweaking (and then I'll tweak it to where I like it). I have listened to some master tapes sitting in the "captain's" chair at the console. Very interesting. Anyway, one of his first thoughts as I picked his brain for a while was "Turn the room upside and fill it with water, then find the leaks". Thought experiment obviously, but it stuck with me.
@invalid Do you have the brand name of the carpet glue, just curious. |
Meant to say:
"Turn the room upside down and fill it with water, then find the leaks".
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I suppose it is time for me to rant.
I think egenmedia is right. The dimensions and design of the room are most important when it comes to bass. I think length vs width should be at least 2 to 1 and width vs height again 2 to one or better. Leave the back wall open. In my house the back wall opens to the kitchen and a hallway. The kitchen then opens to the dinning room. The nearest full wall is 80 feet from the Hi Fi. All the walls including the interior ones have 2 X 6 studs covered in blue board and two coat plaster. Construction glue was used under the blue board but I can not remember what kind. That was almost 30 years ago. The Quietrock does look like an interesting product. If I were ever to build another house I would give it a try. With my system set up like it is there is no nodal behavior that you can consistently measure but there is a lot more to it than the room. One of the best ways to deal with room acoustics is to have speakers that do not throw energy all over the place. Horns and dipole linear arrays have the most controlled dispersion. I personally prefer dipole linear arrays for everything above 125 Hz. They throw very little energy to the sides, up or down and what bounces off the front wall is easily controlled with absorption devices. In order for an array to be linear down to 125 Hz it has to be taller than 10 feet or butte right up to the floor and ceiling. So, in an 8 foot tall room you need 8 foot tall dipoles. ESLs are perfect in this role. The same applies for bass except the array needs to be on the floor right up against the wall into the corners and each driver must be no more than 5 feet away from the next.
I have read many assumptions about "room control" from people who have little extended experience with it or really understand what it is all about. Room control is really not room control. You can not change a room's modal behavior by monkeying around with frequency response. It is digital speaker control. The benefits are that you can digitally equalize your left and right speakers so that they have dead flat and exactly the same response curves as a starting point. Then you do the same for your subwoofers as well as supply the crossover and sinc them in time and phase with your satellites. In doing this the computer is taking into account any frequency response interaction between the speaker and the room in their individual location. No two speakers are identical. No two speakers occupy the same location in a room. Any frequency response differences between channels will muddy your imaging. Once everything is flat you can institute changes that you find beneficial. At normal listening levels I like the treble rolled off so that it is down 6 dB at 20 kHz.
I find flat is too bright. All the processing is done 48/192 and essentially distortionless particularly in reference to anything you might do in the analog domain. But, you can not fix a bad room with digital speaker control. You can manage it to a degree with the right speakers and acoustic treatment but it is always going to be a bad room.
It is absolutely not true that the effect of speaker control can only be advantageous at the listening position and egregious everywhere else.
The benefits are heard throughout the room. Many current systems take measurements at several places in the room.
There are many other advantages of digital system management and speaker control.
Having lived with it for 20 years. I will never be satisfied without this capability. I can instantly remove the sibilance from any recording, bring the treble out in a dull recording and neutralize fat bass. I have programmed dynamic loudness compensation. The tonal balance remains the same regardless of volume. You can make your system sound however you want. You can not get the absolute best bass without it but you still have to have the right speakers and room to get there. You can not get the best imaging without it but you still have to have the right speakers and room. If you have the right speakers and room and are willing to put in the effort to learn how to manage this (steep learning curve) you can make some very appreciable improvements in your system's performance. That includes the analog side of things as well.
If you want to be a digital phoebe and shoot yourself in the foot that is fine also but don't dis it until you have spent at least a year with it. If you are making negative comments on a 15 minute exposure you are doing yourself and others a disservice.
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The way to build a quiet wall is not with two layers of sheet rock. You build quiet walls. These are usually made with 2 X 6 sills and staggered 2 X 4 studs each opposing wall gets it's own studs so there is no direct mechanical contact between either side of the wall. Works great. We build such a wall between the master bedroom and my daughter's bedroom as our bed is right up against the wall. You can jump up and down on that bed till the cows come home and you can not hear a darn thing on the other side of that wall:)))
As for my music room? The system rarely goes below 80 dB and you are never going to hear the AC over that. The only thing I care about are rattles. I HATE RATTLES. So, bring on the construction adhesive and silicone. |
I guess i was lucky or more diligent in my working experiments....
My speakers sound marvellously well in a bad location and in a bad room...
Active device controls and not only passive materials are the key....You can use a computer to compute the nodes where to put the reflective and absorbant materials, but we must use our ears with the powerful active devices to decide how to connect them and with what and where to put them ( different resonators connected to Schumann generators).
Not only that but my 7 inches driver gives so much clear bass that i listen to with my body then a sub was really without interest... I disconnect the one i own, and i purchase it before my experiments....I listen mainly acoustic music....Cello, organ,piano and human voices.... No need of speakers management controls, perhaps to improve my results a bit for sure , but not more....I want to try the speaker mangement controls understand me, but my active room controls are so good that it will be ONLY to optimize what is already more than good...
No sibilant, clear bass, and imaging and decoupling music sound from the speakers.... That are my results....
Cost : peanuts.....
I will not annoy the reader in reexplaining what i said today in an another thread...i already said too much....
:)
« Why do you trust your ears more than a computer? Because we make love together in the old way» - Groucho Marx |
@Chorus - You have 240VAC into your room right? If you don’t mind, how many conductors are there (in conduit?) and what color are the insulation of the conductors please?
I have been following acoustic fields lately.
So much good information coming from so many sources - thanks for this thread, brilliant!
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@tomic601 ....Thanks for that correction re sorbothane.
I'd love to apply the stuff liberally, but the $ involved vs. the sizes I'd like to apply kinda make it unobtainium on a practical level.
If I won a Powerball lottery however, that, and a lot of other things would obviously change in a rather radical fashion. *evil G*
'Scuse the late response...spent the weekend driving 380ish miles....twice. 'Mental road rash' takes a day to recoup from.... ;)
Personally, I've been curious about the use of sheet felt (1/2" thick or greater) as an acoustic accoutrement...any thoughts, yours or the collective? |
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Yyz that’s the company I mentioned, very effective |
People are missing the point of measurement and software and science and listening, they are not mutually exclusive, rarely is one sufficient.
studio six Digital provides a low / no Cost toolbox... start there
avs, felt is not a super broad band absorber But you do see it deployed on a variety of speakers - typically the mid and tweeter. |
@yyzsantabarbara
I note that your article references the Salford simulations. Nice to have company! |
I did something very acoustically low tech this week. It could be a smart or a stupid idea. It was done for my back health and to also get away from my desktop computer while I listen to headphone music. So less A’gon posts by me.
I got a big bean bag that I put up in the worst acoustic location of my small room. Tomorrow, when I get delivery of a 2 channel speaker amp I will be able to test out how great an ideal this was. The room was pretty good before and the bean bag is super comfortable. I may have a conflict. |
Rettinger covers all the ratios.... including the nasty but popular one...
and of course there is a nice page on staggered wall construction, I paid $10 for a deactivated Library copy.... |
One key question to ask is does brand X elastomeric between two sheets of Y constitute a constrained layer - converting some motion into heat ? |
Nice thread, reasonably sane by Gon standards.... |
Good question about matching elastomeric to drywall, Tomic. Another reason to choose something engineered over something contrapted. I use elastomeric to join things that can’t be bought as an engineered unit - like drywall to stud. |
