Building a listening room from scratch


Hello all,

I am renovating a 19th Century townhouse in a distressed post-industrial town on the Hudson River.

I will have the 20’ x 30’ attic dedicated to my home studio/office and audio listening area. The ceiling has a steep pitch from the 12’ high center towards the 20’ wide walls, which are 3’ high. To make the building perform to a high energy conservation standard, I have lined the walls with 5.5" of rock wool (which has excellent acoustic insulation characteristics), and the ceilings with 14.5" of rock wool. Except for the three windows situated in a gable and two dormers, and my book and record collections and the audio equipment itself, the floor is the only hard surface, of wide-plank wood. My architect says that I should not sheet rock the walls or ceiling, that I should simply cover them with fire-resistant burlap and I will have a semi-anechoic room, similar to recording studios.

What do you think of this idea?

Thank you all,

unreceivedogma
128x128unreceivedogma
Wow! That sounds pretty neat. Although in the end, you might ease-up on the extensive sound absorption lest the room be too acoustically dead.
Rick
If possible lay some large tile on the floor lest your bass get soaked up by the wood and space below. You ARE going to insulate the walls with something other than burlap right? Otherwise, going to have a monster heating bill.
What about 20 amp service (multiple) for your monoblock amps and power conditioner(s)?
Cool. I am a big fan of using rock wool insulation. I used rock wool in the ceiling and interior walls and 6” regular fiberglass insulation in the exterior walls of my basement listening room. I used sheetrock but floated the ceiling sheets on aluminum brackets to reduce transfer of sound to rooms above. The room has a concrete floor poored over tons of crushed rock, so quite different than a wood floor.

The room is pretty neutral with only a few nodes in the bass region. With a bookshelf running the full length of one side wall and only three smallish windows on the back wall, the room has almost no reflections and treble is a tad reticent below about 50 Decibles. Above that volume, sound is outstanding, with only the reverb of the original recording space presented as well as the speakers can.

I would try setting up your gear with nothing covering the insulation and trying it, and then try tacking up at least half of the space with dry wall, see what sounds better and go all in with that.  Agreeing with Sisyphus51, I am wondering if you really want to approach a full “anechoic” listening space. Also, are there any health issues associated with exposure to unsealed rock wool? Finally, I find having a hard floor with “dead” walls is a good combination, try the tiles suggested above as well.

kn
Dweller, there is 14.5” of rock wool BEHIND the burlap, as described above. The house is being renovated to perform to a high energy standard. On the HERS scale of 0 to 150, with 150 being old existing homes, 100 being new homes, 70 being energy star, this will be a 40. That should cut my energy bill by 75%. The floor is 150 year old wood, we want to enjoy the beauty of it, and save money, so no tile. I will have 20 amp shielded service: how did you know I have a pair of monoblocks? NY Audiolab Julius Futterman OTL 3s, converted to triode and modified with audio grade caps by Jon Specter (Al Cooper’s cousin). 

Knownothing, rock wool is considered to be safe environmentally. 
unreceivedogma
Now, you’ve done it!
On my streaming list for today: "Child Is Father to The Man" - Blood Sweat & Tears and "Supersession" Bloomfield - Kooper - Stills.
Oh! By the way... my room is much too live and needs to be tamed a bit - if I can do it 'on the cheap'!
Sisyphus, I would never indulge in this expense if it were not for the gut renovation.
Had a friend who used his master bedroom for a listening room. It was very large (25 X 35 est.) and directly over the garage. Room had no bass. Hence the recommendation for tile. Sounds like you'll have a killer room!
P.S. Don't ALL audiophiles have mono's at some point? The extra outlets come in handy for actives as well (like ATC) or subwoofers.
Regards
I would flatten the ceiling 9 feet above the floor to a) get rid of the sharp corner for acoustic purposes and b) to allow for space for the rafter air space insulation to empty into, with louvers on each end... instead of a ridge vent.
Dweller:

The floor is supported by 3” x 6” wood joists. The cavities between them are filled with rock wool, to provide a thermal barrier between the two zones.

I’ve never had good bass. I got a second hand 15” Velodyne. Haven’t tried it in my own system, it tested and performed well in the system of the person I bought it from.

G:

i have braces across the ridge ridge but I like the height. I’m gonna keep it. 
Ah! Cork panels might be a solution for my room. I'll have to look into that! Rick
Some of the best sounding rooms I had were in old buildings that didn’t require a lot of treatment, e.g. a large room in an old brownstone in Brooklyn, with wide plank floors and heavy real plaster walls- behind which was lathe and horsehair.
What town are you in? We eventually moved up near Nyack to another old house but are now in Austin, TX (in an old house which is all shiplap planks though the music room has sheetrock- some of the main floor rooms are period recreated wall paper stretched over a muslin like cloth. I have a second system in one of these main floor rooms and it sounds great).
What are the inner wall surfaces (or is it the result of a gut that your architect says don’t sheet rock and simply leave the wall studs in place with the insulation you are describing?
Post removed 
It’s a gut rehab. Left the plaster on the brick wall.  Firred in the walls by 5”, filled in with rock wool. 

In Newburgh. 
I remember you @unrecivedogma. You had an earlier thread about moving your records. You might try what the architect suggests - or other material at some point, since fabric doesn't have to cost a lot and installing it is probably less work and less mess than sheetrock. You could probably come up with an interesting aesthetic using hanging material and could experiment with the acoustics of different materials as well. Last night, we were in a loft apartment here in Austin where the owner, who collected sideshow banners from old circuses, had a massive hanging on one wall. It was very cool. Probably made of canvas, and hand painted many years ago. There is also custom printing on fabrics that you could explore or just 'make some art.' 
whart,

Yes, those records will move into this space.

I’m a painter by training, though I veered into advertising photography and writing thanks to my politics (left of Bernie). I’m thinking just the natural colored burlap for the ceiling, and a deep slate blue dye for the walls.

Building code requires that the material be fire resistsnt, so that limits my options.

For me, the question is how dead do I want the room to be? My old room was full of hard surfaces: wood floor, tin ceiling, brick walls, one wall almost completely glass windows. Now I will be veering in the other direction. I can always harden it up with large framed movie posters hanging on the wall, etc.
Dweller, regarding your comment about laying tile.  I have carpet over plywood subfloor, and it really absorbs the 60-90 Hz region.  That range is down about 12 dB at its max.  I've thought about pulling up the carpeting, putting down ceramic tile over the subfloor, then using rugs over the ceramic tile as needed.  Do you know if  ceramic tile is a good choice or is something else better for the purpose of reflecting bass frequencies?  Do you know of any published references on flooring for listening rooms?
@brownsfan - Sorry I don't have expert info in this area. All I know is my friend had no bass in his room with a plywood floor and a huge cavity underneath. I have profound bass in houses built on a concrete slab. My suggestion for tile is an educated guess but I've got strong feelings it would make a difference.
Dweller, my guess is the same as yours.  I'm guessing that ceramic tile will be more reflective of low frequency information than carpeting over plywood, but I don't really want to run an expensive experiment without supporting data.  If I were to custom build a house, I'd be going with carpeting over a concrete slab.