Open Back 1x12 Cabinet buzz fix?

[Synaptix30]

Hi All,

I recently acquired a 1x12 Open Back Widebody cabinet. https://images.ctfassets.net/m8onsx...6560e54f853a7ea8e72ec1/0.B112W.AB.CO-back.png

When I play a specific note (I think it's B on the low E string), it causes the back panel to buzz. If i put my hand gently on middle of the panel the buzz immediately stops. I tightened all the screws on the back panel, the piece that the input 1/4" jacks are mounted to, the 1/4" jacks themselves, the handle screws. Just to be sure I also tightened the grill cloth screws as well as the mesa logo screws as well.

Any tips on how to dampen the rear panel? Or similar experience with the same cab?

Thanks!

 

[Synaptix30]

Bump.

So it seems like the buzzing is coming from right dead middle of the rear panel right behind the center of the speaker. Also turns out to be a C# from the low E string that causes the most buzzing. C# on the A string even less.

Has anyone had to put some deadening material on the rear panel before to stop the buzzing? Not sure what else to do. I've seen posts from other places about using weatherstripping around the entire panel where it contacts the cabinet. Thoughts?

 

[user 21540]

These things can be really frustrating to fix. Mesa boxes are usually not bad for this though. Can you remove the whole back panel and brefiely test without it to 100% verfiy it is that panel making the noise? I know the speaker jack is there but you might be able to lean the panel on something while you test. Also look to see if you can get a closer fit between the back panel and the cab in any way. Is there any bumpy tolex etc that might be stopping it from fitting in the joint tightly? If no you could try some long strips of compressed fabric wedged between the joint. I have done that in the past and it worked sometimes. Yeah an adgesive type foam strip might also work. Other times what I thought was a cabinet buzz truned out to be a speaker problem -- double check the speaker hasn't been patched in the past. It could ultimately be that the C# frequency is sympathetic with that bit of wood in the panel and that space inside the cabinet itself.

 

[gibsonboogie]

Bump.

So it seems like the buzzing is coming from right dead middle of the rear panel right behind the center of the speaker. Also turns out to be a C# from the low E string that causes the most buzzing. C# on the A string even less.

Has anyone had to put some deadening material on the rear panel before to stop the buzzing? Not sure what else to do. I've seen posts from other places about using weatherstripping around the entire panel where it contacts the cabinet. Thoughts?

The 1st test I would do is to take a rag, cloth, or old tshirt and drape over or clip it to the panel. If that works, I would then try starting with small amounts of damping material. Not too much as that could alter the sound of the cab. As a non-permanent solution I would try taking golfball-sized wads of this stuff and attach it to the inside of the panel with painters tape, (link to damping material) I don't know if this could actually work, but that is what I would start testing with.

 

[bandit2013]

Yeah I had a similar experience with the wide body 112 open back cab. I first thought it was due to a change in speaker as I removed the MC90 and installed an EVM12L Classic. Rear baffle would vibrate tremendously. I had this issue when I converted a Mark V90 head to a combo and loaded an EVM12L in that thing too. Trick was to attach a hardwood brace just below the edge of the rear panel. I believe I used a 1/2 inch or 3/4 inch thick by 1 inch wide piece of poplar wood. That resolved the noise issue. This is the Mark V90 that I modified. I did the same to the 112 cab. I should paint it flat black so it hides better. I glued and screwed it into place.