Hi everyone!
BeoLab 5s work extremely well in small/medium club sound reinforcement, particularly for acoustic and jazz/pop acts. I've been using a pair at a local music school (Indian Hill Music Center, in Littleton, MA) for both rock/metal reinforcement and also the occasional jazz or acoustic evening, in a medium sized recital hall (ca. 250 seats). They sound terrific, the bass correction is an absolute godsend, and (counterintuitively) they are extremely resistant to feedback while also giving the players on-stage a much better sense of the house mix.
There is also a pair of BL5s in a lecture/recital hall at Berklee College of Music, doing hard service for rap/hiphop, jazz recitals, music synthesis demonstrations, and so on. I would love an "industrial-strength" version for such work, but even the stock systems work very well.
Caveat: they will succumb to high-level abuse (I've proved that!), and need a little care when levels in the room exceed 105 dB SPL (I now use a compressor/peak limiter in line with them). And they won't replace a stack of Marshall bass amps.
BeoLab 9s simply don't have eough power for any reasonable reinforcement other than a folk guitarist in a small cafe.
At Sausalito Audio, we've built and tested several ALT equipped guitar amp prototypes, and feel there is real potential there. It's a pity we don't have the time or resource to develop it.
I hope this helps.
Best regards, and Happy Easter! (Be sure to count your Easter Eggs BEFORE you hide them all β this advice from sad experience!)