How to dampen cabinet for tighter sound?

[davey boy]

Just got a new Avatar "Premier Vintage Custom" closed back cab loaded with one hellatone 30 and one hellatone 60. Sounds really nice EXCEPT that it seems to resonate too much on certain bass notes. I'm only driving it with a Peavy V30 and am not cranking the amp. All the screws seem to be tight. Took it apart to check, etc. Very well made as far as I can see. I ended up cutting 1" thick compressed fiberglass (703) which I use as acoustic treatment in my studio and put it on all 4 walls of the cab. Pretty much fixed it but now the cab has less of a lively warm sound. I'm wondering if I didnt' made the mistake by not getting the semi open back version. I was hoping they could sell me that back as well but it's a no go. I'm looking for a tight crunch sound with plenty of low end so I choose the closed back design.

Anyway, I'm wondering if there's a better way to dampen some of the low end resonance. Possibly putting the material on the back panel verses the sides for example. I seem to remember an old marshall cab I had that had some fiberglass on the back panel but can't be sure. I'm still experimenting at this point so am going to take the stuff out, turn down the bass eq and try some more recording. I might be a little "bass happy" right now, who knows. Thanks for any thoughts.

 

[GuitarStv]

Re: How to dampen cabinet for tighter sound?

Try tilting the cab at an angle (between 30-45 degrees off the floor) that should kill a lot of those resonances for you. You could also try elevating the amp on a chair or stool or somthing. Taking your speakers off the floor will remove a lot of the muddy sound you can get from some amps.

 

[JLagoon]

Re: How to dampen cabinet for tighter sound?

I second the tilting the cab solution. However, if you hear this bass resonance through a mic-ed recording, then that's a different problem. Do you have resonance/depth switch on your amp?

Other factors:
Height of pickup poles
Bass knob on your amp

 

[davey boy]

Re: How to dampen cabinet for tighter sound?

Update: It was more of a pilot error thing. Since before I got this cab I had the bass pegged so that when I was playing it through a single 1x12 cab I was getting enough bass. With this Avatar I had to turn the bass WAY down because it didn't need it. I did all the damping stuff before I realized this. The damping really dulled things. Now everything is out of it. There's some resonating on certain notes, not all of them are bass notes. The back panel vibrates. Do people put insulation on the back panel to fix this or are there other tricks? I've tightened the heck out of the screws back there and it's a solid 1/2" sheet of plywood. The kid at Avatar (not Dave) recommended rubber gasket material to put in between the panel and the cab on the seam. don't think that would change anything though. Overall, this thing sounds great and I don't think I'll hear the vibrating when it's close miked or even during a real world live gig situation. I'm just being "ultra picky engineer guy". I haven't used real amps in a long time so maybe this is just par for the course when it comes to closed back cabs. They all resonate a little.