Jump to content

Building a dedicated audio room

Recommended Posts

Starting this project soon, architect is appointment and a survey is beginning this week.


Essentially ill be building a rectangle ontop of a large garage (2.5 car). The frame is likely going to be steel with a vaulted ceiling that will slope. What im trying to determine in just basic terms is what are the best sizes for rectangle like rooms for accoustics and are raked or flat ceilings best? I was going to have it slope up behind the listening, which would assist in a large solar panel system on the roof sloping from north to south.


Given a steel frame, are there any online resources I can read to assist in ensuring its built correctly? insulation, glues, sound materials, gyprock,  etc to ensure the room is right from the basic outset. I'm not worried about treatments at this stage, just want to get the bones right.


Dimensions are very rough, but its likely going to be approx 7meters long and 5 meters wide. Unsure on heights yet, depends what we can get away with on council



Edited by dastrix
Link to post
Share on other sites

7m x 5m is a great start!

I would make the ceiling as high as you possibly can get away with but 3–3.5m would be good : )

There are literally hundreds  of room builds documented on sites across the world including this one.

I am sure people will chime in soon with a variety of links but if not, Google is your best friend in that regard.



Link to post
Share on other sites
3 hours ago, dastrix said:

What im trying to determine in just basic terms is what are the best sizes for rectangle like rooms for accoustics and are raked or flat ceilings best?

My understanding is that a room that is too uniform can be bad for acoustics due to reflection points.

A raked ceiling may be a good idea worth exploring. 


3 hours ago, dastrix said:

insulation, glues, sound materials, gyprock,  etc to ensure the room is right from the basic outset.

@Marc definitely knows a lot about this.

Worth reading through his build threads.

Link to post
Share on other sites

7x5m is a good size in terms of avoiding cuboid in the horizontal plane. Assuming you plan to place the speakers on the 5m end, with the sloping ceiling it theoretically might provide an uneven ceiling reflection if you want the flexibility of placing speakers across the 7m wide wall, however it may not be audible in reality.


The 5m wall end allows you to have a good 3m equilateral stereo listening triangle with 1m either side of speaker to side walls, which will work for most situations but it may be less perfect for some very wide types of speakers like electrostatic, ribbon or large horn type speakers so retaining an option for that on the 7m wall including an argument for not having the ceiling slope should be considered.


There are heaps of online sites and discussions for best acoustic (acoustic performance) stud wall construction to refer to. 


Also, consider that in an ideal listening room you want be able to use it all day and night while others are sleeping or trying to enjoy there own lives in peace. Therefore in the design, noise reduction breakout (noise nuisance reduction vs listening acoustic performance) to the neighbours and internally, which means higher acoustic grade product panels like single sheet of Souncheck or double layer standard gyprock (double the weight so can studs structurally cope) sealing airgaps and transmission paths like doors, thicker window glass 6-10mm or double glazing if there are any windows and common ventilation ducting treatments (silencing and zone shut off) etc. Modern Building Code energy efficiency performance requirements meaning walls of R3.7 and ceilings of R4 value should take care of the external noise insulation aspects but not the panel material or thickness needed to attenuate noise transmission and not internally between rooms.


Expert acoustic consultant advice may help to avoid the guesswork and errors.

Edited by Al.M
Link to post
Share on other sites

Thanks, yes speakers on the 5 meter wall in this scenario. The room is seperate from the house, so theres no issues with waking anyone up etc - but doubling up on gyprock sounds like a good idea with insulation etc. I have double glazed windows in the house,argon filled and some 10mm glass also in some spots so ill certainly ensure the glazing is adequate.

Link to post
Share on other sites

hi dastrix,

The magic number for the dimensions of acoustic rooms is Phi,   1.618.

1.618 : 1  is known as the golden ratio.    1.6 is close enough, so,   .62  : 1 : 1.6 : 2.6.

So,   about 5m x 8m x 3m is ok.

The idea is to have the resonant frequencies of the parallel  walls tuned differently to avoid harmonic relationships.... the ultimate acoustic disaster is inside a cubical room, where all 3 dimensions resonate at the same frequency. It rings like a bell.

Non parallel walls would be preferable, but builders don’t like that, or carpet layers etc.. but a sloping ceiling is good as it varies the floor : ceiling resonance.

Glass is a big reflector of sound, so use thick curtains (when appropriate) and put fabric cover on the opposite wall.  And of course carpet or rugs on the floor.

Does this all make sense ?   questions welcome.



  • Like 1
Link to post
Share on other sites

We have a dedicated listening / HT room that measures 4.2m x 6m x 3m and I find it slightly to small,  if it was solely a listening room it more than likely would be fine but add a 110” projector screen and it soon becomes a compromise. A 5m x 7m would be my ideal size.

Something to take into consideration is door placement which does impact on set up and acoustic treatment as well.


When the house was built by the previous owners a focal point of the house design was the then dedicated HT room, they had the walls and ceiling packed with sound proofing insulation and the two centre rear wall French doors are solid 50mm Timber with acoustic seals around and between them.
Shut the doors and without the return cycle aircon on I reckon you would eventually pass out from lack of oxygen or heat stroke, they seriously had the room sealed that well.
In theory given the dimensions this room should have worked a treat acoustically but it was in fact seriously horrible, a simple clap test could almost make your ears bleed.
However once it was professionally acoustically treated the difference was staggering, the only thing is the room is that accurate it now shows up every issue my system has and most any change in components no matter how small is usually very noticeable, which is not always such a good thing believe it or not.


Good luck with it and hopefully you will share your room build with us. For what it is worth a often say on here the single most important part of any HiFi system is the room, so having a chance to have a dedicated purpose built room is such a good thing.





Edited by TerryO
  • Like 1
Link to post
Share on other sites

On 19/09/2020 at 6:21 PM, dastrix said:

rectangle like rooms for accoustics and are raked or flat ceilings best?

You'll probably want room for services? Ducting especially - even if you have mini split AC you'll want fresh air return and supplies. Also room for ATMOS?


I'd personally go flat to accommodate anything you don't want "in room"


Everything you need to know about soundproofing can be found here

  • Like 1
Link to post
Share on other sites
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...