Inexpensive but decent 8" subwoofers

@resveratrol3 note that any smaller sub no matter how good may not be a good match to some speakers and/or room. If speakers are fuller range and not high pass filtered you probably need a larger sub to properly fill in the missing lowest octave. Also the larger the room the larger any sub up to the task properly will probably need to be. A smaller sub running with more full range speakers to start will be a challenge if even possible to blend in properly without merely delivering a big bass bump in the frequency range already covered. That could result in fat muddy bass that also obscures detail in the midrange which is not a good thing.

MK 70B, push pull design. I'm running 2 upfront & 1-MK125 for my surround.. Check all the pos. feedbacks on this brand.

Jamo has a couple of vertical subs that are pretty stylish and inexpensive.

Never heard them though.

Hope you find something you like!

A few years ago I bought a used REL Q108MK2 that's an oldie but goodie...sounds great and has more adjustability than newer RELs. Around 200 bucks.

SVS. They are having a sale right now.