Sound diffusion panels--do they reduce brightness?


My listening room is still a little too bright
The doors behind the seating area have 2 absorbing panels. It has been suggested that adding 2 diffusion panels in this area of first reflections will cure the brightness. Does anyone have experience with these diffusion panels ?
128x128blueskiespbd
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Blueskiespbd:

Have you tried playing test tones to see which frequencies are the most offending? Sound quality and timbre are usually affected at about 2kHz and higher.

Furnishings:
Try moving the ottoman that sits between your chairs and the speakers out of the room or off to one side. It looks like it could be leather which may be a hard enough surface to reflect high frequencies to your ears thereby adding to the bright sound.

Pictures on walls are typically hung such that they reflect sounds downward because the top of the picture is farther from the wall than the bottom of the picture. Try placing a tennis ball or block of wood at the bottom of the pictures to angle the picture upwards to reflect sound away from your ears.

Equipment:
Speakers have too much treble, or too little bass – a hot tweeter and/or too little bass will create an exaggerated HF thereby throwing the timbre balance off. Try listening to your system using different speakers to see if the speaker’s sonic balance, cross-over or speaker resonances are at fault.

Reflections:
Direction of reflections – front and rear wall reflections are less advantageous than lateral side wall reflections, so absorption on the front wall improves image localization and reduces colouration whereas diffusion on the back wall helps create listener envelopment. You might consider closing the drapes across the front wall window and adding thick absorption (6” thick minimum) and add diffusion above the back wall absorption panels. Also interesting to note is that ceiling reflections affect timbre while side wall reflections affect spaciousness; looks like your ceiling is bare and therefore could stand some 1st reflection point treatment.

Reverberation:
Longer low frequency reverberations help add ‘warmth’ to a room or hall. I guess in theory you could remove your bass traps to lengthen the bass RT60, or better yet keep the bass traps and add higher frequency absorption (e.g. at ceiling 1st reflection points and/or scattered along the side walls) to shorten the RT60 of the higher frequencies.

Let us know how you make out . . .

kevin
Wow lots of good ideas. Will get working on the suggestions this weekend
I did try some other speakers with the same brightness issue. The midtones and bass are good.
Here is something you can try to determined if you have an equipment issue or the brightness is being generated by the room

Warm your system up and give a quick listen to one of your reference CDs that you are very familiar with at your regular listening position (sweat spot)

Now replay the same tracks but go into the room in back of your listening room/chairs and give another listen

If my guess is right when you go into the room in back of your listen room ... the brightness will be greatly diminished because you are not sitting in the direct reverberant field that is aggravating the problem in the main listening position

By going into the other room and listening you remove yourself from the extended/sustained ringing in your main listening room that is being caused by the long RT60 times, Echo Slap, and Comb filtering

If your system still sounds overly bright when listening from the back room ... then you have an equipment issue because you are no longer being effected by the room's anomalies when you are listening from the back room ... it is the equipment that is generating the brightness ... metal dome tweeters ... tube in the pre amp fading or poor match ... etc etc etc

If when you listen from the back room the brightness is greatly reduced then

1 I know What the problem is
2 I know What's causing the problem
3 I know Where the problem is occurring
4 I know how to fix it and your significant other will never realize the you've applied some new room acoustics

Please let us know the results of your listening tests