Just wondering what forum members think would make the perfect listening room if you could build it from scratch in a home residential setting.
What would be the perfect room dimensions? ceiling/roof height? ceiling/roof shape? wall construction? floor construction? etc etc etc…
You may want to start here
It’s a long thread but there is some really good advice and experience from @Thomas and @PeterR
Or buy lots of different speakers… 
This could be something as simple as something that you found worked for you in a past or present listening room.
A compilation of knowledge and experience of what works and is beneficial.
Try a room mode calculator.
There are a few online, like “amroc”.
It’s a good start point.
EDIT :
Here is a perfectly sized room.
Isnt the perfect listening room, no room at all🤔
I was thinking along the lines of this which is similar to what I already have but would be on the ground floor (concrete floor/brick wall) instead of second story suspended floor and plaster board walls.
The image is fairly/pretty much to scale.
Click on image for larger preview.
A square room is the worst possible.
An 18ft window behind the listening position is also not good.
Trouble is a listening room without a window would be a bit uninspiring and dark.
With the large size of the room and considerable distance from the speakers would it still make a difference to having an 18ft window?
What about curtains or sliding panels to cover windows?
The problem is the size of the window, being almost the entire length of the wall behind the listening position. Windows can of course be treated (with curtains and blinds) but will only partially mitigate their deleterious effect. The good thing about your room is that you are able to move the listening position away from the rear wall and experiment to avoid the peaks and nulls of standing waves.
I would of thought a large room would be good because you wouldn’t get any first reflections.
I suppose you could also use two subs to to avoid/help the peaks and nulls of standing waves.
You will always have first reflections but a large room allows you to pull the speakers away from side walls and therefore delay the arrival of first reflections at the listening point. This is also why higher ceilings are good.
First reflections from the floor can be partially mitigated by carpets and rugs. Side wall first reflections can also be partially treated by positioning furniture in an effort to disperse first reflections. I have a large canvas painting on the wall behind my speakers.
These measures will never be as effective as purpose built room treatment panels/boxes but I am simply not prepared to go there.
Is the general consensus that a flat ceiling or sloped/eves type ceiling (like in the image) is best?
My ceiling is arched, but in the opposite direction to how you have shown yours.
My view is irregular shaped ceilings are better for SQ as they partially disperse reflections but others might disagree.
Yeah have to be very careful here. If you overdesign it to perfection it will sound awful for music but great for surround.
The reason is, a perfect room with no perfectly parallel walls, damped non reflective construction etc. makes it sound like you are an ant trapped between giant headphones. It’s the imperfections of the room that actually create the live in the room sonic illusion.
Consider this:
As such, you need to choose a primary goal and aim for that.
I’m in the middle of a house build and got to design my own room. Nothing stopped me from going to no compromise extremes but I set some rules for myself:
Those are pretty much the dimensions of my lounge/listening room (2.3/4M ceiling), my speakers backing to the glass end (doors and window, with about 1m of wall between them).
Problems:
As already said, ceiling is ‘low’ and square is generally awful. I’ve part improved this by using tall Kallax units to create walls near the speakers, creating dimensions 5M(w) x 6.5M(l). This seems to help.
When talking to GIK, they don’t seem to see glass as a major issue, as it’s porous (in relative terms) but standing treatment panels behind the speakers (in line with them, plus on the rear wall element) helps no end.
I’m also fortunate that I have 3 doorways, 2 of which I leave open, so as to prevent the room getting pressurised.
My speakers (to baffle) are ~2.35M from the rear wall/glass and the optimal seating position is (to centre of chair) ~ 1M, with treatment/panels in behind.
Well a few years back i decided to build MY perfect listening room. But rather than try extending the house i started from scratch with a detached room so i had full control of its design.
When designing this my final goal was for a room that would be for music and have no pretence to be a living room. I wanted a room that would allow me to recreate as near as realistic as possible whatever the source was , be it studio recordings , live theatre , small club and outdoor recordings. Not easy to do but I do believe i have achieved this.
22 ft long x 15ft wide x 9 foot ceiling height. Insulated concrete floor , all walls lined with acoustic plaster board , ceiling of double thickness of acoustic plasterboard. Own mains supply and specified mains cables/sockets.
Designed for symmetry and planned for full acoustic treatment. Did a lot of research into treatment with help and advice from GIK , Denis Foley [Acoustic Fields] and Eithan Winer [RealTraps]. One thing i did find is that even these experts do have different opinions/ideas on treatment. So the final result must allow for personal preference.
Final treatment comprised of 34 GIK panels . A mix of full range , range limited bass traps and diffusion plates.
Building begins
Building complete
View from seat
View from speakers.
Still tweaking but coming together, may never happen but nice to dream and play about with ideas…
Feel free to make any suggestions/recommendations or feel free to post a picture or ideas of what would be your perfect listening room.
Click on the image for a larger preview or click twice for an even bigger preview.
