I have diffusion on the back end of my listening room and a mixture of absorption and diffusion on the front wall, in back of my Altec 604 based loudspeakers and this works great. However, my room is large enough so I have the speakers six feet out into the room and my listening chair is about four feet from the wall in the rear of the room, so this works great, with no localization of the loudspeakers in the room, while great tonality and clarity. The side walls are all absorption and that’s been the one constant thing for me in all three of my listening rooms over the years.
One of my YouTube viewers writes:
“Paul, love almost all your videos. but. I think TOTAL ABSORTION behind the speakers is crucial. Reflection behind the speakers is just noise. PERIOD. WORST CASE. A glass window in the imaging space. PERIOD. Sorry.”
This is part of the old live-end vs. dead-end debate in rooms (the actual debate more centers on which end of the room to place absorptive materials). And from the way he is phrasing the question, it makes logical sense. Who wants noise?
The problems with the notion are many but chief among them is this notion that reflections are nothing but noise. In my experience, it is those reflections that are essential to achieving a live sound in the room. Properly managed with a bit of diffusion, it is those very reflections that can help bring a bit of magic to the soundstage.
That said, as with any rule of thumb, it isn’t a universal truth.
There are cases where the dead-end absorption method (or a variation of it) just might be the ticket to better sound. Imagine a smaller room where the main loudspeakers have no room behind them and cannot be pulled out from the front wall. An argument might easily be made that a bit of absorption on the front wall might sound preferable.
My preferred method of diffusion on the front wall (behind the speakers) is really only effective if there’s enough space between the rear of the speaker and the wall.
A bit of experimentation with both methods won’t ta