Treating an Asymmetrical Room Without Chasing Perfect Symmetry

What to do when one side wall gives you a nice clean reflection point and the other gives you a doorway.

Most rooms are not especially interested in being acoustically convenient. Doors, windows, alcoves and oddly placed radiators tend to arrive long before the speakers do.

One of the more common problems in a small studio is an asymmetrical side wall. On the left, perhaps, there is a perfectly ordinary stretch of plaster where a broadband panel can sit exactly where you want it. On the right there is a doorway, which is useful for getting into the room but slightly less cooperative as a first-reflection surface.

The instinct is often to make both sides look the same. That is understandable, but it is not really the target. Acoustic symmetry is about making the sound arriving at each ear reasonably similar, not forcing the room into a visual mirror image it was never designed to be.

Start with the reflection, not the wall

The useful question is not simply, “Where would the matching panel go?” It is, “What is happening to the reflection on each side?”

A solid wall produces a strong early reflection. An open doorway may produce much less energy returning towards the listening position because some of the sound continues into the adjoining space. A closed door, meanwhile, behaves more like the wall around it. The acoustic picture can therefore change depending on whether the door is normally open or closed.

That is why blindly placing identical treatment at identical distances can sometimes solve the wrong problem.

A practical approach

On the uninterrupted wall, a broadband absorber at the first-reflection point is usually straightforward. On the doorway side, the answer depends on where that reflection actually lands and how the room is used.

If the reflection point falls on the door and the door is normally closed, treatment can sometimes be mounted directly to it, provided the weight and fixing method are sensible. If the door needs to remain untouched, a freestanding panel or gobo can do the same job without becoming part of the architecture. In rooms where the doorway is normally open and already allows a good deal of energy to escape, less treatment may be required on that side than you first expect.

This is one of those occasions where a mirror and a pair of ears are useful, but a measurement is better. An ETC plot can show whether one side is producing a noticeably stronger early reflection and whether the proposed treatment has actually reduced it. It is a much more reliable judge than standing back and deciding whether the room looks balanced.

Do not sacrifice the rest of the room

It is easy to become so focused on matching the side reflections that the larger acoustic problems get ignored. In a small studio, low-frequency behaviour is often doing far more damage than a modest difference between the left and right walls.

So the order of work still matters. Speaker and listening position first. Bass trapping where practical. Then the strongest early reflections, including the ceiling if necessary. The awkward doorway should be treated as one part of the system rather than the room's defining crisis.

There is also a point where further symmetry becomes expensive for very little audible return. A room used for professional mastering may justify more effort than a compact writing or production room. Good treatment is not about winning an argument with the floor plan. It is about getting the room out of the way enough that decisions become easier to trust.

The useful takeaway

If one side of your room has a doorway, do not assume you need to recreate the other wall with treatment. Look at what each surface is actually doing acoustically and treat the reflection that reaches the listening position.

In many awkward rooms, the best solution is not perfect symmetry. It is a sensible compromise that sounds more symmetrical than it looks.