... take a wild guess that this was the BL250??
Exactly right.
It was the first rig I bought when getting back into playing bass after an almost 20-year hiatus. I'd used a GK guitar amp with a couple of 12" JBL plus horn speakers (part of son's DJ set-up) and it sounded great so I was expecting a similar experience. No such luck. I was so disappointed with that.
It was a relatively cheap reentry into bass gear and was touted at the time as being a "made in China" version of their US designs. Never could get that rig to sound decent at gig levels with the single 15" speaker it was relegated to. My plan had been to add it to my Sunn 212 cab or hook up the speaker-only from the Yamaha B50 combo my son had left with me and run a 2 x 15 set-up. Was a shock when I saw it was 8 ohm minimum as that was never mentioned anywhere on any of the spec sheets or I wouldn't have bought it.
I continued to use the GK115blx speaker for years along with an acoustic B410 and as long as I knocked about 2 to 3 clicks off the bass EQ on my first Eden amp (Nemesis RS400) it sounded good. No worries now though, I've moved on to Eden and DNA (David Nordschow Amps) gear now so my GAS has been abated for the time-being.