need your help!

[Shpoop]

Hi everyone, long time no talk.

Speaker building has always served the purpose as an escape for me. Since I'm an engineer by trade, that means I actually don't do much optimizing and science surrounding speaker-building (stop judging me!). Instead, speaker building has been more of an artistic outlet for me. That's why I need yalls engineering help!

Three or four years ago I made these speakers out of wine bottles. They look really sexy in person, and I love them:


They actually sound really good too. The mids are great. Though, as you might expect, they lack a little on the lows due to the small size. I am finally getting around to building them an aesthetically-matching subwoofer! You guessed it - a wine barrel!

So I just bought the wine barrel. You'd be surprised how hard it is to find a smallish, not MASSIVE barrel. Anyways, it is 6 gallons, which I think might be a good size for a sub enclosure. So here are the details I have, and if any of you could suggest a driver that would fit in the bottom or top of the barrel and match well with my speakers, both power-wise and frequency response-wise, please please please I'd love your help!

ENCLOSURE:
6 gallons, barrel shaped, white oak. Could be ported or not, so tell me which you think is best.

AMPLIFIER (not sure this matters):
Yamaha HTR-5830 (i know it sucks :\)
80W RMS i think to both the speakers and sub (too little for a 6 gal enclosure? )

SPEAKERS:
Tang Band W3-879S 3"
4 drivers per speaker, 2 pairs wired in parallel, the pair itself wired in series (that clear enough?)
Here are some plots from the manufacturer that the really ambitious might find useful:


So yea I think that's all the info I have. If you have any other questions, please let me know! And I REALLLLY really appreciate any help that anyone can give!