JBL Speakers Internal Bracing

[Ian Mackenzie]

So explain what it is you are hearing?

Is it a buzz, coloured mid range or something else?

[gbadaut]

Hello,

If I listen to some music, I can hear that some frequencies (I don't know if it is one or several) are louder than normal, strident and unpleasant. It is easier to hear if I turn off the compressions. Some musics are more revealing than others because the notes are played more frequently and are more sustained.

I can hear the same annoying notes if I put one ear on the box panels at some locations. It is very likely high Q resonances that are generated by the box. If it was low Q resonances, it would probably appear more like a coloration (unpleasant but not strident).

I already encountered this problem in the past. It was a DIY box holding a 12" woofer. The box was made with thick MDF and braced with a plywood matrix (like the B&W 800). During several year I thought that the woofer wasn't top notch. But I finally discovered that the box was ringing (even if it was build very strong and eavy). I did a lot of trials to brace and dampen the box. And by chance, I finally fixed it. A part of the matrix was ringing. By damping it, I fixed the problem.