KRK V8 series one - anyone using them? HELP

[groover]

While playing some LF sine waves I noticed a buzz/rattle emanating from the rear panel of my KRK V8s. Definitely not coming from the front of the cones. I torqued all the screws on the front and back but that didn't help the problem.

Anyone encounter this problem with these monitors? (they are about 10 yrs old)

Any ideas on specific things to look for if I open them up other than the obvious loose or broken mountings? (which I wouldn't expect to see happen symmetrically to both monitors)

[Bro Shark]

The fucking gain pot on those is glued to the back panel. Could be that. It's a shit design. Just go ahead and open er up, should be pretty obvious what the culprit is. Careful with that gain pot though.

[groover]

I wonder how diffficult it would be to replace the gain pot with a stepped or detented control? the difficulty of matching levels of the two sided has always bugged me.

[groover]

OK, I finally got around to opening up one of the V8s. The gain pot doesn't appear to be loose, but the circuit board is attached to the aluminum back panel with screws at a right angle, and the ICs are bolted to the panel to act as a heat sink I think. I couldn't find anything that seemed broken or loose, but it appears that there would be a lot of potential for the circuit board and components to cause rattles/buzzing when excited by high energy LF signals.

I have considered a couple of remedies:
1) gluing some kind of damping material to the inside of the aluminum back panel - but would that change the effective volume of the enclosure enough to adversely effect the tuning of the reflex port?
2) removing all the amplifier components and mounting them in an external chassis, and replacing the aluminum back panel with a one made of mdf.

Any ideas? (other than selling them and upgrading, which is certainly an option!)

[groover]

BUMP - I could really use some "crowdsourced" info about these!

The noise in question sounds like a softer version of the noise you would get if you put your lips together in a trumpet embrochure and blow through them (sometimes called a raspberry), and seems to be localized in the area of the XLR combo jack.

[Nate Dort]

BUMP - I could really use some "crowdsourced" info about these!

The noise in question sounds like a softer version of the noise you would get if you put your lips together in a trumpet embrochure and blow through them (sometimes called a raspberry), and seems to be localized in the area of the XLR combo jack.

Is there air leaking out around the jack? Do a smoke test and see if that's the case. An incense stick works well for that. Or a cigar.

[groover]

Oh, a smoke test! I was wondering how to test that suspicion. I was trying to detect air movement with a slip of paper, but smoke is a much better idea! Big thanks! 8~)

Any ideas for sealing if that is the case? The inside of the Neutrik combo jack looks like it was sealed with some black goop at the factory.

[Bro Shark]

Let us know what you decide to smoke.