[MaxCast]

Here is a map of my room which I will be bringing down to the brick walls and starting over. 
It is a basement with two bedrooms above.
Room is 15.75' x 31.5' x 6.95'
Water heat one AC flexible vent.

My first goal is isolation, as much isolation as I can get with out going to a room in a room. 
EDITS:
Sill plate gasket under wall footer.
Caulk wall to floor.
PAC DC-04 clips for walls to joist.
RSIC-1 clips and hat channel. (will loose ?")
Double dry wall. Stager seams.(walls and ceiling?)
Caulk and seal all holes.
Solid core wood/fiberglass door.

Second will be AC wiring suggestions.  I will be adding dedicated lines for stereo, video, general ac, lighting.
EDITS:
Build wood box for outlets.  Seal with caulk.
Separate runs.  Tie these grounds together.

Third will be acoustic.  I can do anything I wish    I plan on corner bass traps, first reflection points (walls and ceiling), front wall.
EDITS:
Keep dimensions large.  I know I'm L=2xW.  I could shorten the length by adding a closet/storage/gear space to the front.

The back of the room got cut off but there will be a book case behind the desk and a closet in the lower left corner.


Any and all advice is appreciated including links, pics, etc.  If you are a dealer/seller you are more than welcome to market in this thread or PM me.


That's it for now. I will be updating as I move along.

[bpape]

Isolation without room in a room:

If you have the height, use Dri-Cor on the floor.  This gives good feel, provides additional isolation, and helps with temperature.  Build the walls on top of this floor.  Use Sill plate gasket under the walls and caulk the wall to the floor.

Frame all walls 1/2" short of joists above.  Use PAC International DC-04 clips to decouple the wall/joists.  RSIC-1 clips and hat channel on the ceiling.  Double drywall and Green Glue between layers.

All openings in the room (switches, lights, outlets, etc.) should be housed inside 3/4" MDF boxes attached to the structure (walls) or decoupled (joists) and caulked to the drywall.  The only penetration then is the hole for the romex which you use caulk at putty on to seal it.

Make sure to use a solid core wood door - not a typical insulated metal exterior door (exterior is fine with the seals but the metal/foam won't block anything).

Plan ahead for as few penetrations into the room as possible.  Building soffits AFTER the room is drywalled and bringing in HVAC and electrical inside those will minimize the intrusions and help with isolation both ways.

That's probably enough to get you started for now.  I have all of the materials you need available except the Dri Core and hat channel.  I'd be happy to put together a materials list of exactly what's needed and the costs involved if you want to go this way.

Inside acoustics:

The room is large enough that we can potentialy build some of the treatments into the room to minimize the visual impact. It will cost a bit of length but you have plenty of volume to play with.  What specifically is needed will be determined by how much of the above you implement and a few other factors that impact the inside aspects of the bare room's acoustics.

Bryan

[JLM]

First is shape, I'd follow Cardias rules for a retangular room.  With your given dimensions, the ceiling height is by far your limiting factor.  But before that, isolation from above will be critical to overall sound transmission and maintaining as much ceiling height as possible.  I'd try green glue (can be found at Hawthorneaudio.com) with an additional 5/8 inch of drywall.  And avoid any ceiling penetrations!  At $17/tube is seems expensive, but not compared to the alternatives.  Adding anything to the floor will just make the room smaller. 

This will bring the ceiling height down to 6.90 ft.  Using Cardias, the width would be reduced to 11.12 feet and length to 18.02 feet (if I remember the exact ratios).  Some of the leftover width will be taken up with the staggered stud walls, the rest can become built-ins for resonators, bookcases, etc.  The studs should vary from 8 to 16 inches, be 2x6s, and support 5/8 inch drywall.  For best results double up the drywall with more Green Glue.  Insulate the wall like you would an exterior wall.  Give the rest of the space up for storage, whatever.

Use an insulated fiberglass exterior door (better than wood) with weatherstripping.  To eliminate furnace noise use fiberglass insulated flexible duct to the room.  Insulate around all the electrical boxes.  These will be tremendous helps.  And Bryan right, minimize the penetrations.

If you can't do battery power or you don't have power abberation issues, run separate 20 amp circuits with 12 gauge wiring to each A/V receptacle.  Wire all grounds together and separate from the rest of the house.  Use receptacles of choice, but any hospital grade (red are the tightest) will do. 

GIK is the best bang for the buck absorption panels, but if you use Cardias you shouldn't need much.  DEQ would be the last step (where I'm at now).  Avoid dimmers on the lights.

Most of the above I've done, except for the double 5/8 inch drywall and the ceiling.     The builder was going to pull warrantee on the entire drywall job for the whole house rather than hange the ceiling drywall using gauge metal "Z" strips.  So with drywall screwed into the bottom of floor trusses (even with fiberglass batts above) there is lots of sound transmission up and down.  Even then, the amount of sonic isolation afforded is spooky and took some getting used to.

[Big Red Machine]

Isolation without room in a room:

If you have the height, use Dri-Cor on the floor.  This gives good feel, provides additional isolation, and helps with temperature.  Build the walls on top of this floor.  Use Sill plate gasket under the walls and caulk the wall to the floor.

Dri-cor is too expensive.  I used 7/16 OSB over 1/4" OC Fanfold and roofing clips to hold the plywood sheets together.  Power nail where needed.  You can borrow my gun.  Then, as Bryan said, you can build walls right on top and use 3" drywall screws to fasten toe plate down.  You get a cushioin and some insulating value.

Frame all walls 1/2" short of joists above.  Use PAC International DC-04 clips to decouple the wall/joists.  RSIC-1 clips and hat channel on the ceiling.  Double drywall and Green Glue between layers.

I used these at about $5 a pop, there is a local dealer:  http://www.kineticsnoise.com/arch/isomax/index.aspx  The hat channel can be bought locally.  HD no longer sells it.

All openings in the room (switches, lights, outlets, etc.) should be housed inside 3/4" MDF boxes attached to the structure (walls) or decoupled (joists) and caulked to the drywall.  The only penetration then is the hole for the romex which you use caulk at putty on to seal it.

I did this in my ceiling, but feel it is overkill in the walls if using green glue and double dw.
 
Make sure to use a solid core wood door - not a typical insulated metal exterior door (exterior is fine with the seals but the metal/foam won't block anything).  why not Bry?  Work pretty darn well I think.

Plan ahead for as few penetrations into the room as possible.  Building soffits AFTER the room is drywalled and bringing in HVAC and electrical inside those will minimize the intrusions and help with isolation both ways.  This is probably the most difficult thing to get right - that is proper circulation of air and low noise at the same time.

That's probably enough to get you started for now.  I have all of the materials you need available except the Dri Core and hat channel.  I'd be happy to put together a materials list of exactly what's needed and the costs involved if you want to go this way.

Inside acoustics:

The room is large enough that we can potentialy build some of the treatments into the room to minimize the visual impact. It will cost a bit of length but you have plenty of volume to play with.  What specifically is needed will be determined by how much of the above you implement and a few other factors that impact the inside aspects of the bare room's acoustics.

Bryan

There are acoustical experts here like Bryan, but I can SHOW you what I did and how well it works because you are relatively close.  I would definitely do a room within a room by lining ceiling joists up inside the floor joists above and using a few hangers if necessary if your distance requires it.  Really does the job all the way with no regrets based on the rooms I have been in done this way.  Everyone is happy - those inside the room and those outside the room.

[bpape]

Boxing the penetrations is absolutely critical - sorry.  You can use 8 layers of drywall, clips, and all the green glue you want but if you cut 12 6" diameter holes in the ceiling for can lights, it's all wasted money as the sound will go right through a thin tin can light fixture.  In the walls, it's the same.  You're going to have most likely at least 10 outlets in a room that size plus a switchbox with at least 3 switches.  Add up all the area of those openings and ask yourself if you'd leave a hole that big in your wall and expect the sound to stay inside.

As for the ratios, to each their own.  ALL rooms have modal issues.  ALL rooms have decay times that need to be addressed.  All one can do is stay away from particularly bad ratios which would cause large issues very low in frequency that are tough to deal with.  You can build a room with 'perfect' ratios but the decay time will still need to be dealt with to a point.  All the ratios are doing is spreading out the modes evenly.  It's doing nothing in the time domain.

IMO, no way would I give up that much width and depth.  The room IS a little long compared to the width but chopping off a couple of feet will solve that issue - not to mention that the width is exactly 1/2 the length (not a good thing - one of those bad ratio things).  The advantages of the additional width alone to me outweigh some additional care being taken in treating the room for a non 'perfect' ratio.

Yes - the low ceiling can be a problem but there's not a lot you can do about it.  If isolation is very important in terms of sound getting OUT (performance wise, sound getting IN is more important), then I'd use the clips and glue on the ceiling and skip the floor.  It's always a tradeoff.

Doors...  It's all about mass.  A metal door with foam (closed cell - terrible for sound absorbtion) insulation is much less massive and will transmit sound much more readily than a solid wood door.  Like I said, nothing wrong with exterior as it provides good seals all around to help with the iso.

Bryan

[Big Red Machine]

Forgot to mention.  85 db in my room will be 52 db outside the double doors.  The furnace is actually noisier and I'm at the limit of the RS meter.

If I had the headroom I would have the room within a room and below the kitchen and laundry room I only am bothered by heavy hi heeled shows occassionally.  Hat channel all around, double 1/2" DW versus 5/8" all around, staggered DW seams all glued, green glued 50% coverage.  6" of insulation in the walls and 10" above.

And I cheat on the electrical.  I run the wires and cut the holes later using rework boxes.  Cuz' setting those boxes beforehand with double thickness and the GG is a crapshoot (for me).  I photograph everything and mark the floor for reference and then go back and cut the holes nice and neat.

I have a complete set of photos of my build.

Ready to start swinging that hammer?!

[Big Red Machine]

Boxing the penetrations is absolutely critical - sorry.  You can use 8 layers of drywall, clips, and all the green glue you want but if you cut 12 6" diameter holes in the ceiling for can lights, it's all wasted money as the sound will go right through a thin tin can light fixture.  In the walls, it's the same.  You're going to have most likely at least 10 outlets in a room that size plus a switchbox with at least 3 switches.  Add up all the area of those openings and ask yourself if you'd leave a hole that big in your wall and expect the sound to stay inside.

Agree on the ceiling with his bedrooms just above that would be a waste not to do this.  But with the loss of energy due to distance travelled I cannot say I experience any less isolation with my electrical boxes in the walls having no boxes behind them.  Buy lots of caulk!!

Pete

[JLM]

I made the mistake of installing six recessed can light fixtures in the ceiling.  Even using IC-AT (rated to be in contact with insulation and air tight) they are just gauge metal boxes.  So I hear every step above.  Fortunately all the walls to my room open to exterior or storage spaces, so no sound transmission via the electrical boxes.

If you want to buy lots of absorption/diffusion panels you can probably solve most acoutical problems.  But IME its a bandaid solution to a problem that can be largely avoided with proper room shape.  Six GIK 244 panels at front/side wall first reflection points and front corners made maybe a 2% improvement in my properly proportioned room.  BTW the primary reason I'm going with DEQ is to replace baffle step and zobel circuits to have a direct amp to single driver connection.  I agree with Brian Chenney and others that DEQ should only be used after the room plus treatments are correct.

With weatherstripping, the door is coupled to the mass of the frame/wall if it latches tightly (like an exterior door should anyway).  Going with fiberglass gives a wood grain look and texture that can be painted or stained.

[MaxCast]

First of all, thanks all for the suggestions 

I don't really want to do the floor.  Green glue is already going to cost me $1500    and I don't want to sacrifice height.

Sound getting out is my first priority.  Bedrooms above.

Is there any benefit by using 2x6 vs. 2x4 in a staggered stud fashion?

Lights will be hanging or whatever.  No cans.  I'm thinking two kinds of light, instant on/bright and ambient/mood different switches.

Pete, the room in a room with nesseled joists is interesting.  I should make plans to stop by your place during the next AKfest.

No, I'm not ready to start swinging the hammer, I'm too scared    Plus, I don't have anywhere to go with the crap that is already in there 

[zybar]

Six GIK 244 panels at front/side wall first reflection points and front corners made maybe a 2% improvement in my properly proportioned room. 

JLM,

I don't see how this is possible regardless of your room geometry or dimensions.

Treating the first reflection points alone would improve things by more than 2% (which I interpet to mean no noticeable change) + you have decay and timing issues that are improved by using products from GIK or Realtraps.

As Bryan, Glenn, and Ethan have stated numerous times, there is always a need for room treatments regardless of the room dimensions.  It is simply that some room dimensions are better than others and will require less work.  I have yet to see or hear ANY room built that can't benefit from room treatments. 

George

[bpape]

I would expect that 6 panels all placed at front/side wall reflections would do little to nothing to help bottom end response which is where most issues are and what 'perfect' ratios are supposed to avoid.  Placment on the rear wall centered, behind the main speakers, and in the corners I suspect would make much more difference in the bottom end response with the same amount of treatment assuming the room isn't huge.

Room dimensions and shape can certainly help avoid slap echo, overlapping modes, push reflections past the listening position, etc.  What they can't do (nor can EQ) is bring the overall decay time curve into the proper range for a given size room for a specific use.  Targe decay time range is much different for a studio control room than for a live room.  Different for multichannel music than for 2 channel, etc.

As for the outlets, that's personal preference.  I'll just reiterate, take 10 boxes each 2"x4" - that's 80 sq inches.  Add in a switch box that's 4x6 and you have a total of approx 104 sq inches.  Would you cut a 10"x10" hole in your drywall and expect a piece of 1/16th" plastic in it to stop sound from going through?  Add in all the other cracks people forget to do (drywall seams, wall plates to the floor, etc.) and you have a much larger problem.

The old addage applies:

"Think of your room as an aquarium.  It doesn't matter how big or where the hole is - you're going to get wet"

I'm just saying that these are very simple things to do that don't cost a ton of money.  A couple extra tubes of caulk, an extra sheet of MDF, 2 hours on a table saw, etc.  If you can get an extra 5-10% isolation for that, isn't it worth it?  It is to me.  An extra few db lower noise floor in the room is free dynamic range, more easily hearing micro-dynamics, subtle tonal details, etc.  The same kinds of things that people spend tons of money on trying to get their equipment to do.

Bryan

[ctviggen]

If you can't do battery power or you don't have power abberation issues, run separate 20 amp circuits with 12 gauge wiring to each A/V receptacle.  Wire all grounds together and separate from the rest of the house.  Use receptacles of choice, but any hospital grade (red are the tightest) will do. 

What is meant by "wire all grounds together"?  It's a violation of code to run separate 20 amp circuits and wire the grounds together, not to mention that you're asking for a ground loop.  But perhaps that not what you mean by "wire all grounds together". 

As for electrical boxes, if you can't box them in as suggested by Brian, you might use these:

http://www.acousticalsolutions.com/products/firestopping/putty_pads.asp

I think boxing in is fine, except when it comes to lots of wires (say, for a projector).  Then it could get rough, as you'd have quite a large hole to route the wires.  It seems you'd still have a large hole in the box, too.

[Daygloworange]

Having been involved in a number of builds (control rooms, isolation rooms for voiceover work etc.) where acoustic isolation was required, I'll echo the importance of what Brian is stressing.

Number one is the fact that your room is exactly half as wide as it is long. That should be changed no matter what.

Air gaps are a huge deal. You lose a lot of STC through accumulated losses.

You want to minimize any breaches in the envelope of your room. If you do require any breaches (electrical boxes, doors, windows, etc), then mass is your best friend. Housing electrical in MDF boxes that are sealed to the drywall and sealed for any holes for wiring are going to lower your STC.

If you've ever been in a room with lower than 20 db residual noise floor, you'll know that it would greatly increase the dynamic range of your playback system, and would be a huge improvement in detail retrieval during listening.

I agree with using a hardwood door if possible. Insulated metal or fiberglass doors will not approach the performance of a hardwood door. Again, mass is your friend. Bigger, thicker than average door stops with wider closed cell weather stripping is cheap and easy to do, and will add noticeable gains in STC. Selaing the bottom of the door woth a door stop is recommended, but if impractical, a  rubber scraper on the bottom of the door is recomended. Double doors (as in, inner and outer doors) has real benefits as well.

Soffit mounted bass traps are a great idea for low frequency absorption, as well as running flexible ducting for HVAC.

For lighting, use track lighting instead of pot lights. Pot lights are terrible for STC.

A really good item you might want to consider using on your ceiling is a product called Symar.

http://www.nrtna.com/index.html

 It comes in thickness ranging from just over 1/16" to 1/2" thick, and you can buy it in rolls. It is most commonly used on floors, but we've used it on walls and ceilings as well with great results.

You could add the Symar to the existing drywall ceiling, and then add another layer of drywall over it. Symar works quite well:

http://www.nrtna.com/pdf/quietdown_manual.pdf

As far as staggered wall construction, the best method we've used is build 2 independant walls (ie. with independant top and bottom plates, thus decoupling the walls from each other), and to not have even spaced vertical studs. The idea being that you have each section of drywall between studs vibrating at a different frequency. If you are doing 2 layers of drywall, do not neglect to tape the seams of the first layer of drywall, even though it will be covered up by the second layer. When doing 2 layer drywall, we would screw down the first layer, then silicone the second drywall to the first, thereby eliminating mechanical coupling.

On the topic of using Eq for correction, it's never a good idea to introduce holes in the frequency response of your playback system. You are attenuating whatever music happens to reside in that frequency range in order to minimize a peak in your rooms response, or to attenuate a ringing.

Bad idea. That's a band aid solution.

There was another thread with a lot of suggestions about building a dedicated room:

http://www.audiocircle.com/index.php?topic=42769.0

Congrats on having the opportunity to build a dedicated room designed for audio Maxcast. It's really not much harder to do than regular construction, just a slighty different approach, and greater attention to details.

The results will be HUGE!

Cheers  

[MaxCast]

For acoustic panels inside the room I am thinking bass traps in three corners (closet in the last corner), 2-3 panels on each side, panels on the ceiling and something on the front wall.  The back wall has book shelves 2'x10'.  Sofit bass traps are undecided at this point.

I will be sealing electrical boxes.  No can lights.  I will be using florescent lights for lighting when maximum lighting is desired and track/lamp/other for listening mode.

Dayglow,  my walls are concrete block with no living rooms on the other side.  I don't see the benefit of using "double walls."  I do wonder about using 2x6's vs. 2x4's???  But then again, why stager the studs if the wall behind it is nothing?  Why wouldn't I just stand off the wall a couple inches from the block?

[Daygloworange]

Dayglow,  my walls are concrete block with no living rooms on the other side.  I don't see the benefit of using "double walls."  I do wonder about using 2x6's vs. 2x4's???  But then again, why stager the studs if the wall behind it is nothing?  Why wouldn't I just stand off the wall a couple inches from the block?

Sorry man, I forgot about the concrete side walls. I was thinking of building room enveloping walls.

I (personally) wouldn't want to use 2x6's on your side walls. You'll lose over 1' of width. I'd rather keep the width of your room as wide as possible in your case.

If you have the option of where to place your door, I would build a wall out from the back wall (changing the depth of your room from it being twice as long, as it is wide) and have a door in it, that leads to another door that enters that area from hall.

Cheers

Cheers

[MaxCast]

Walls...I forgot that the walls are supposed to breathe because of moisture.     It is a basement in Michigan.   



As far as length goes.  I could and probably should add a wall to the front of the room.  We can always use more storage... or a small work shop  aa   No movin the entry door.  It goes through blocks.

thanks again guys 

[JLM]

George,

Part of the answer is that I use single driver speakers with 8 inch cones and no whizzers, so they beam pretty severely.  (That's good for taking the room out of the equation and for being able to "tune" the highs via aiming the speakers, but bad for loss of high frequency imaging/soundscape.)

Another part of the answer is that, although the speakers are rated to below 30 Hz in room, they are a mass loaded transmission line cabinet design, which has a nice slow roll-off that matches room gain.

The final part of the answer is that I use the Cardias layout, which is nearfield and naturally takes away much of the room effects.


Bryan,

Please re-read.  I currently have two panels at the front corners.  I played with several variations, had four stacked in the front corners for months, even tried all of them in corners, but noticed barely an improvement in bass.  Have a slight preference with two at front wall first reflection points, two at side wall first reflection points, and two at front corners.


Bob,

My three dedicated receptacles have the grounding wire run to a separate grounding rod, to isolate that ground from the rest of the house.  This was recommended to me by an electrician/audiophile.


Max,

I'm near Owosso (Michigan), if its convenient please stop by.  2x6 studs would be more than twice as strong and 8 times stiffer than 2x4 studs.  Staggering them varies the stiffness of the drywall.

[Bob in St. Louis]

Hey Rich,
I'm the last guy to ask for advice on this topic, but the first one to ask, "What have you screwed up in your room".

I've got 7 canned lights. Not only do they allow the transmission sound in/out of the room but depending on the db/hz of your system, they can buzz and add their own sounds. Actually this is true of any light fixture but cans are worse.

I have a total of 17 light fixtures on three zones of remote controlled dimming by Lutron. With tube amps I have a varying buzz from the front main speakers when the lights are between...say...15%-95%. All lights off or close to off there's no buzz (detectable). All lights on there's no buzz, but it's a supernova, you'd need sunglasses. I didn't have this problem with solid state.

Listen to Bryan. I've gone "head to head" with him at a few GAS meetings. A constant (friendly) barrage of 'what-ifs' and 'buts' and 'why nots', and he doesn't quiver. His answers are solid and he'll easily give justification regarding his answers. The guy knows his stuff. I've been in his room and seen all the things I coulda/woulda/shoulda....done.    

$1,500 for G.G. !?!? Wait, lemme buy a few shares of their stock first.  

Bob

[Big Red Machine]

WHen you use hat channel the wall becomes "thicker" and you will have more space to work with so 2x4 up against the cement would be my choice.

[MaxCast]

JLM, I do have a customer in Howell and they are due for a price increase maybe I'll give you a holler.
By staggered I mean studs offset from one another.  As I think about it it may not apply to my situation because I don't need to isolate the other side of the wall.  I do like the idea of adding additional studs in between the 16" oc'ers to break up the cavities.

WHen you use hat channel the wall becomes "thicker" and you will have more space to work with so 2x4 up against the cement would be my choice.

I have to use hat channel on the walls?  I thought I could get away without using it on the walls, just the ceiling.