Should I Add Acoustical Batting To My Ampeg B100-R?

[PolkaHero]

I just took a look inside my B100-R combo and noticed it has one inch thick acoustical batting on the bottom and the lower half sides of the inside of the cabinet. Do you think if I add extra batting to the back baffle (and around the two ports) that it would remove some of the midrange "boxiness" I hear with this amp? Seems like I'm always cutting the mids to compensate. Anyone on here done this?

Where would I find this stuff?

[rpsands]

Quilt batting comes in bags at Michael's. Layer it.

I haven't done it with that cab, but I have with others.

It is unlikely to hurt.

Do not use mattress topper. That stuff can just be too much very easily especially memory foam. Recommended for someone who knows how to spot the good stuff and knows how much to use - not recommended for ad hoc use.

[BigOldHarry]

If you aren't happy with the sound of cab, then give a whirl. Try a few different arrangements to see what sounds best.

[rodl2005]

+1 quilt padding or "batting" is it? thats the stuff, I couldn't think of it's name. Works a treat. Staple it in to the rear inside at least.

[PolkaHero]

Originally Posted by rpsands

Quilt batting comes in bags at Michael's. Layer it.

You sure? I checked their website and can't find anything on there. Can't find anything on Sweetwater either.

[rpsands]

Positive. It's where I bought mine, multiple times.

If all else fails, Amazon has it, as does Parts Express.

Amazon.com: Morning Glory Full Low Loft Batting, 81-Inch by 96-Inch: Arts, Crafts & Sewing

You can also use fiber fill if you desire, but it's more permanent since it virtually requires gluing to hold in.

The sheet stuff is my favorite, since you can staple down a couple layers at a time.

At Michael's, you can use one of their 50% off coupons, which is a huge plus.

[steamthief]

Originally Posted by rpsands

Do not use mattress topper. That stuff can just be too much very easily especially memory foam. Recommended for someone who knows how to spot the good stuff and knows how much to use - not recommended for ad hoc use.

Can you digress? I've used 1" open cell mattress topper with great results.

[rpsands]

Originally Posted by steamthief

Can you digress? I've used 1" open cell mattress topper with great results.

It can work. It can also not work. I've seen as many people overdamp their cabs with mattress topper, ESPECIALLY memory foam, as have made improvements.

When working with an existing cabinet, I always recommend quilt batting because it's easier to control the depth and density, and to remove some or add small amounts if needed.

If you're building from scratch you're more likely to have used adequate cabinet volume in the first place, so probably less sensitive to the reduction in volume from super thick mattress topper or something.

So if it works for you that's great, but it's far less forgiving. The super porous open cell egg crate type foam is probably just fine--it's the people who go out and buy a big thick memory foam mattress topper that I worry about.

[PolkaHero]

I finally got around to doing this. I ended up layering some polyester fill to about 1" thick and lined most of the back of the cabinet. It definitely made a difference in the tone: mids not as harsh, smoother, and almost sounds tighter. Not that it sounded bad before, but now the amp sounds great!

[dannybuoy]

Nice to know. I thought that 'boxiness' was generally caused by having a cab size smaller than ideal, and adding extra batting would in theory reduce the internal volume even more. I'm picking one of these up soon, I'll remember to try this if I have issues with the sound!

[billfitzmaurice]

Originally Posted by dannybuoy

I thought that 'boxiness' was generally caused by having a cab size smaller than ideal, and adding extra batting would in theory reduce the internal volume even more.

Extra batting reduces system Q, which helps compensate for a cab that's too small.