Building a dedicated listening room

Congratulations on you're new project & I'm sure everyone here is jealous that you are starting with a blank slate.  I'm not sure how deep a dive you want to make on the room but here are a couple of thoughts.  

Number one would be to make sure that you don't wind up with a floating floor in the construction plans.  This will cause all kinds of reverb problems that are hard to compensate.  Something solid below or a lower floor is preferable.  I would put down a hard wood floor and then cover with area rugs to taste to optimize SQ.  This gives you flexibility and you will be able to make adjustments as different sounding equipment inevitably comes and goes.

Take care where the room's windows and doors will be located.

Have the electrician put all of the room's wall outlets on their own dedicated circuit.  15amp should be fine.

Find a Vicaoustic dealer and have them do an acoustic room rendering for acoustic paneling.  They will computer model the optimal absorption/reflection that will make the room sound as well as possible.  I did this and it's the best audio money I've ever spent.  Good luck and cheers.

I will speak for myself. I am sure everyone has their opinions, preferences and personal experiences. I wasn’t until a year ago, when I purchased my current home that I felt that I finally had “my” ideal dedicated listening room. This room is for audio only. I have a separate room for video. Here’s a brief description.

The door is located behind the listening position. All of the walls are (almost) non-resonant brick. The only room in the house with brick walls inside and out. The rest of the rooms are brick outside and sheetrock inside. The foundation is concrete. The audio components are all in a recessed (former closet) located to the left of the listening position so that they don’t protrude into the room. I removed the closet door and put a thin light filtering curtain in its place. This allows for air circulation and also acts as an acoustic panel, while still allowing the signal from the remotes to penetrate and the pretty lights to slightly show through.  I installed 6 30 amp breakers and ran 6 dedicated 10 gauge Romex wires and outlets in the closet.  I duplicated the curtain on the right side, where there’s a window. By pure coincidence, both curtains ended up being symmetrical in relation to the room. I replaced the window with a soundproof window like the ones used near airports. The carpet is not thin or thick and the fibers are dense and very close together. Both the left and right walls are free of any obstructions, other than for the two curtains. All of the media (records, CD’s) is stored to the left and right of the door located behind the listening position. I have 3 recliners in the room. The one that’s centered with the speakers is where I sit and then I have 2 others that are slightly elevated to the left rear and to the right rear of the center listening position. The room leans more toward being live than neutral or dead, which is just how I wanted it. There are two bi amped tower speakers about 4’ from the front wall, 3’ from the side walls and about 8’ from each other. I keep them projecting straight ahead and not angled. There are 2 subs, one on each corner of the front wall. The front wall is bare brick.

Out of all this, I find that the best part is that the components are in the closet and the media is all behind me so that nothing is in between me and the speakers. You are fortunate to have a blank canvas! While your room is in construction, and if I can give you my humble advice, incorporate an opening to the left, right or behind you for your equipment and media, so they don’t get in the way of the sound and preinstall cables and wires in your walls. I couldn’t hide my wires and cables very well because of the preexisting brick walls. As far as any acoustic treatment, you can always finalize that after the room is built, but I would definitely build the walls and ceiling in as resonant less materials as you can afford, as well as a cathedral shaped ceiling and a concrete foundation. I hope that at least some of this helps. Congratulations!

@randypeck  I am also about to start building a dedicated listening room. After a lot of reading I've moved away from the Golden Ratio measurements.  You may find this room calculator interesting:

https://www.acoustic.ua/forms/rr.en.html

Here is the full article.  There is a lot of information here:

https://digistar.cl/Forum/viewtopic.php?t=557

Finally, I encourage you to watch this attached video.  It suggests the room construction used will greatly reduce the need for treatments later.  Really interesting.  IMHO

Best of luck with your project.  And remember, measure twice, cut once.  

When I had my dedicated room years ago I put in a  dedicated 20 amp circuit and ran 10 gauge Romex to three, quad (2 duplex outlets) spaced along the equipment wall. I know that seems like too many outlets, however I saved money by being able to spend less for aftermarket power cords because they could be shorter.  

Good idea from Rick about the Vicaoustic products, however I am not sure you have a dealer in your state.

For floors, 2" x 12" floor joists on pier blocks, spaced every foot with cross bracing, 3/4" plywood for the subfloor. I used wall to wall carpet.

Make sure you have some absorption on the ceiling and walls at the sound reflection points. Don't overdue it, you can always add and subtract later. You really can't judge the sound until your system is setup and dialed in. You also might want to put the room away from bedrooms and rooms where the music might be a distraction to others. A stand alone building would be ideal.  

After 18 months of design work and a major relocation within the design envelope my new home and dedicated room are under construction. I did a very deep dive on size, materials, construction techniques, electrical service, the works. What I learned is that there is no end to the lengths you can go to design the "perfect" room and there is a corresponding limitless amount of money you can spend. 

One thing I can share is be sure to identify your goals. What are you after? I had three goals in mind:

1. Make the room sound good without expensive treatments and without the room looking like an audiophile man cave. I wanted the room to be pleasing to the eye and look like any normal room in a house. (Albeit one with a kick ass stereo system and a bunch of record albums);

2. I did not want the sound to migrate from the room. I want to be able to listen at volume and not disturb my family--any time of day or night;

3. I did not want noise from the house, including from the mechanical systems, entering the room. 

The room was relocated from over the garage to the basement. That was huge. Instead of a suspended floor and wood framing/sheet rock, now I have concrete floors and 2 walls with sheet rock over steel studs (Superior Wall foundation). I was able to land the golden ratio and 9'6" ceilings. 

Ultimately, I only went so far with the wall construction: Staggered studs on walls common with the interior of the house, Rockwool insulation in the cavities on all four walls, two layers of drywall (1/2' and 5/8") with green glue between, walls and ceiling. Entry door with acoustical seal, acoustic putty around all the outlets and switches.

Multiple dedicated lines on the same phase, high quality but not insane outlets (Pangea Premier Series). Siemens panel with copper buses, copper coated ground stake, orange 10 guage wire to the dedicated lines. 

I am working with the HVAC guy to minimize noise from the system and have all the mechanicals isolated in a separate sound mitigating room. 

I could have done a lot more with unlimited funds but was determined to approach this with an eye toward diminishing returns and to not overdamp the room or have it look uninviting. I'll be running Sound Lab stats so reflections are less an issue for the sidewall, floor and ceiling. I'll lightly damp behind the speakers and diffuse on the opposite wall and then experiment from there. 

Fingers crossed I made good choices. I hope this helps you to do so as well!