Bass drum shell cab, part deaux

Awhile back I built this bass cabinet from a bass drum shell, and loaded an Eminence Deltalite II 2515 into it. I haven't used it much, mainly because the low end just didn't sound right. Mids and highs were sometimes okay, sometimes quirky. So I finally got around to two necessary modifications, and I'm writing my findings.
Here's what it looked like last time:

I found a bunch of this foam packing material at work and lined the interior with it.



This really helped control the midrange goofiness that I was hearing, and didn't make the cab noticeably heavier (forgot to mention that this thing is a single finger lift!). I still wasn't happy with the low end, and someone who tried it out stated that he thougt it might make a good guitar cab.

I tried a number of different port calculators, with a surprising variety of different determinations as to the best port diameter and tube length. In the end, the majority of the calculators specified something around 3 inch diameter and 3 inch length, and I lucked out to find such a tube locally.



I used a hole saw on the back and popped in port tube, which fit perfectly.

Suddenly, the lows have a lot more power and definition, the mids and highs remain clean. It's still not what I would call "great", but it has been useful for me to learn how all these cabinet components work together. What did I learn?

1. A cabinet that isn't big enough for the driver "compresses" the sound in an unattractive manner. For this one to work, it needs a deeper shell.
2. A sealed cabinet is not the best choice for low frequency reproduction.
3. Porting makes a big difference, but takes some skill to get right.
4. Interior stuffing (batting, etc.) really helps clean up midrange definition.
5. PL is better than Liquid Nails for gluing and filling gaps.
6. Sometimes you just have to do it yourself in order to understand what it all means.

Thanks to everyone on TB who's contributed their knowledge and opinion about cabinet construction!

fu22ba55 said:

7. Building a bass cab from a bass drum is so intrinsically rock-donkulous, I don't know why I haven't heard of this before.

My head is spinning now, thinking about what size drums I have lying in the basement.

I wonder if the lugs will line up with the mounting holes on the speaker frames.

Holy Awesome Crap.

Click to expand...

The bass drum shell was a local music store discard. It's a standard 18" x 14", which really is a bit small. I guarantee that the lugs won't line up with the speaker mounting holes. The baffles are 23 " square. Here's a link to my build: