A large number of the posts I’m reading are about people being displeased with the sound of their amps. (too much bass, not enough bass, too dark, too bright, woolly, mushy, muddy, etc, etc) Suggested remedies usually include replacing the speaker, replacing the tube, or adding an external EQ, all of which cost money and, if unsuccessful, extra annoyance.

Voxman frequently reminds us to get the amp off the floor or tip it back, which will certainly brighten/lighten and project the sound, but it won’t clean up mud or add much depth.

I would suggest that anyone unhappy with the sound or tone of their closed back amp try stuffing the speaker compartment with some kind of sound insulating material. Retrobob suggested this to me (http://www.voxamps.com/forum/topic.php?id=3233 for the whole story) and it completely transformed the sound of my VT30, which, to me, lacked bass and was kind of honky in the mids. It now has deeper bass when I need it, and much clearer and tighter sound at all frequencies and volume levels. Some amp models sound quite different than they did before, and IMO, much better.

I used a pillow that happened to be the right size, so there was no cost involved. Just be careful to not let it touch the cone, block any ventilation holes that might be there, or have particles that could get into the voice coil/air gap. Basically, remove the back, add the stuffing, replace the back. Make sure all the screws are nice and tight.

I’d definitely suggest this as a first step, ahead of buying things like speakers, tubes or EQs. If you don’t like the difference it makes, it’s easily undoable.

Retrobob said this has been suggested before (and largely ignored), but I haven’t seen it, so I thought it would be worth putting out there again.

I love the sound of my amp now, and I was quite disillusioned about it before.

Another technique, if you're getting 'ice pick' issues is to use a cone diffuser eg 'Beam blocker' as made by Weber. This 'spreads' the speaker sound more evenly.

http://www.webervst.com/blocker.html

An EQ & or BBE Sonic Stomp can also be useful, even 'direct' (although better through an FX loop)

Just added a pillow(about 12X12) filled with poly fill to the inside of the speaker cavity of my VT15.
Definitely a noticeable difference--for the better! The amp now has a richer sound.
I tested it on all the low gain amp models and the Express Train(my fav) and was NOT dissapointed.
Guitar is a Epi G400 SG. Still have to run the Strat and LP but I'm sure I'm gonna love it.
Great easy, cheap mod. tnx for the idea CRD.
TREW
Dan

I put the pillow right behind the speaker. I think if you put it on the bottom it wont have any affect on the sound.

The goal (at least in part) is to prevent sound waves from bouncing around off the bare wood walls. I'd suggest curving your pillow or whatever you're using around the speaker to block off the back, side, and bottom panels so reflections are minimized or eliminated.

From what I have heard. Stevie Ray Vaughn used to put a piece of duct tape on his grill cloth right over the speaker cone. That is another way to diffuse the sound.

TJ

Interesting, Dan. If you read the thread that I provided a link to, http://www.voxamps.com/forum/topic.php?id=3233
you'll see that it was my VT30 that needed this kind of help, and the reason I knew it needed help was that my AD15VT (with only some 1/2 inch foam inside) sounded better to me. I had treated the VT30 with the same foam, but it hadn't helped.

Probably the smaller cabinets don't need much insulation, but I believe that the larger the cabinet and the more hard surface area for sound waves to bounce around, starting with the 30 watt size, the more damping material is required. And again I'll thank retrobob for pointing that out to me.

Thought this might be interesting so I just tried it on my AD50VT-XL and my AD30VT, and yup, the guy is on to something, there is a change in tone. I originally tried it with a pillow, but it was a pretty tight fit in there so I used some old extra plush carpet I had and screwed it to the bottom and back of the cab...

I *really* liked the change in the XL...more bottom and just an overall more mid range sound...darker sounding...also seemed to hear more definition...it wasn't my imagination because my wife sitting nearby could hear the difference immediately. Sounded less "airy" and had more "punch".

As for the AD30VT, not so sure...I really liked the tone before this mod(unlike the XL) so the jury is out on this one. I had a really nice "middy" tone beforehand, this mod kinda made it *too* "middy"...I think playing with the treble and bass some might make a big difference...note, the speaker and tube on this was upgraded beforehand and that in itself made a HUGE difference in tone(in a good way).

I didn't make any tone setting changes to either amp, it seemed like the XL went the way I wanted with it's current settings but the 30 might need to be tweaked a bit to give it some high end. The good news was this mod is cheap, fast, and easily removable... :D

Oh yah, I only really messed with high gain stuff, didn't test the cleans...

Here's a pic of the XL's, "padding".
http://i31.photobucket.com/albums/c372/alphadog808/DSC00053.jpg

Hi alphadog,
My original dissatisfaction with the sound of my VT30 was around the clean sounds, specifically Strat tones that, to me, were way too middy and indistinct. I was looking for crisp highs, and deep round lows with the neck PU (Hendrix, Gilmour type sounds). I couldn't understand why both the smaller and less powerful AD15VT and my open backed Peavey Valveking 112 sounded so much better. Even with mids turned down and bass and treble turned up, it had no balls. And as I had gotten nice tone playing my bass through the Tweed 4x10 (Fender Bassman) model on the AD15VT (at low volume), I was really disappointed how meek it sounded on the VT30. Stuffing the cabinet fixed all that.
If you rarely use clean tones, you may prefer the tone you have without the stuffing. The reflections off the bare wood may enhance your overdriven tone.
But if you like crisp cleans, the stuffing will help, and some EQ changes and maybe a little reverb may give you back the tone you like for high gain.

When I first got my VT30, the speaker was WAY too icy, so I just cut up a black cotton t-shirt and put it behind the grill. Tone is perfect now - razor blades are gone, and you can't see the t-shirt behind the grill. I experimented with folding it over a couple times until it had exactly the right damping effect, and the grill screws hold it in place. :)