Building a dedicated listening room

The trend these days seems to be going wireless. My priority would be having electrical outlets close to the ceiling because wireless (surround) speakers still need A/C, and nothing worse than A/C wires running up the wall from low outlets.

Also, a lot of seating options need A/C and floor mounted outlets should be installed under or near seating area.

Good luck with your project!

The best room shapes for acoustics are irregular shapes ones. Symmetrical rooms with parallel walls are sub-optimal due to standing waves. So a box shape room can be problematic even though dimensions fit the classic golden ratio of 1 x 1.6 x 2.56 (height, width,, length). Room treatment can overcome some of these issues.

Concert halls and commercial theaters use the trapezoidal shapes. Houses with cathedral ceilings can be relatively "better" listening environment. However, cuboids are preferable because you can calculate the locations of nulls and peaks whereas with trapezoids those locations will be unknowns. Main objective of room shapes is to break the standing waves. As long as one can work this out, pretty much any room can be designed for a good listening space.

my room is an oval, no 90 degree corners. lots of built in diffusion. the ceiling is also irregular so standing waves don't get supported.

however; it is very important to have an absolutely symmetrical room, if you want your soundstage to approach perfection. otherwise it’s by degrees a mess.

even side to side allows for the musical parts to be complete and located properly with full frequency and the bass connection to the proper part, everything seamless side to side, up and down. it’s how stereo recordings are mastered to sound.

of course very fine sound can be found in rooms that are not symmetrical, but there will be a limit to how fine it can be. when you push it hard it will break down. there is a good reason concerts halls are symmetrical. they can scale without limits. so does my room.

this acoustical headroom I speak of at high SPL’s does require much fine tuning to achieve. it’s not any sort of plug and play kind of thing. took me many years.

The biggest issue to tackle with any room that is dedicated to audio listening is controlling reverb and minimizing delayed reverb. And by that, I mean if you completely eliminate all reverb in a room it will sound dead and lifeless. As an architect I design all kinds of rooms and spaces that have specific STC requirements and none of them use carpets/area rugs as an element to control sound. Ceiling treatment is one of the most important surfaces to consider. Smaller performance spaces have very different requirements than larger concert halls. Even local music clubs that have great live performances, if you analyzed the space, would be non-starters for 90% of the crowd here I imagine because they weren't "designed" to be perfect.

There are ways to treat the ceiling (gypsum board) without resorting to acoustical panels (which are often applied after to correct acoustics). You could benefit from using an acoustical gypsum plaster finish system. Upfront it will cost more than traditional gypsum but it will dramatically help with acoustics. We use this for large areas/performance spaces and other spaces that require acoustical control without "deadening" the space.  Walls can also be built to have a good STC rating for sound transmission (out and in) but you will still want to acoustically treat with properly positioned panels vs an acoustical finish on the walls.

Soft furnishings (area rugs, comfortable seating, drapery) can all have nominal acoustical benefits but the most important aspect of them is making the space comfortable to be in. You want to be comfortable listening to the music vs adopting your body to a single spot in a room.  You should talk to an acoustician about your space and how you want to use it. They should be able to design and specify the material finishes and help with panel placement (where needed). No space can be perfect.

My forever listening room will also be my library/den which means it will be a rectangular room with/ plenty of natural light for daytime activities and a view towards the pond and forest beyond. My listening position will constantly change in that space but I will have a dedicated spot for optimum speaker performance but also won't sweat it too much as the room is for overall enjoyment of what I like to do while listening to music - read, draw, write and purposefully listening as well.

First, I want to thank you all of guys for chipping in with your own experiences and advice.  This is what I had hoped for when I began this thread.  I also hope that others building a dedicated room will find the information here helpful.  

In discussing (many times) this room with our builder he told me he wanted me to be directly involved in the entire process of building my audio room.  Amoung many aspects of the room we discussed, I told him about the dedicated lines using 10 gauge "cooper" wire and he said no problem, he only uses cooper wire throuhout the homes he builds, just not 10 gauge.  He then suggested using a sub panel for the audio room and maybe a whole house electrical filter.   

Though I have not settled on the type of wall and ceiling construction all of your input has given me food for thought.  If you are wondering the room will be on a concrete slab.  

Finally, for everyone beginning a project like this I cannot encourage you enough to do your research.  Over the last three months I have spent several hours pouring over every aspect of building an audio room and Mike, I read your article...twice.  Your pictures really helped me see what is possible not just for acoustics but ascetics too.  It is a beautiful room and I would love to visit you.

One final note.  My wife has always supported my hobby and she enjoys the music just not as much as I do.  She is not only a supporter but a meaningful contributor too.  You should know she is a quilter/sewer/stitcher and will have her own 500+ square foot room...on the other side of the house.  

Keep this ideas and suggestions coming.