Yeah, the key word here is bass. Bass takes power and larger speakers than you think you need. The instant you find the bass is getting buried and you turn up a small home rig, bam there goes the woofers in a blaze of glory.

Every single person who has no experience at this makes the same mistake at first. Too small, not enough power. One good pro level 12" 250W powered PA speaker by Mackie, JBL, EV or Yamaha will get you started and $300 should get you a good clean used one. Imho a guitar amp won't cut it because it's set up for guitar sounds not a full range sound which you need for Biab backing tracks. You said how good everything sounds through headphones, those are full range not just for guitar.

For small gigs I use a pair of 12" Electro Voice (EV) powered speakers that I bought used one for $275 and the other $300 but even that is not good enough as soon as I get a crowd of 25 or more if I'm playing bass. They're fine for just my keyboard stuff but not adding the bass. The bass is very difficult. You have to have a robust rig to play bass even in someone's living room as soon as you have other players. For that I use a regular PA setup, two JBL Eon 15's powered by a 500W Peavy amp. You think you won't need what I'm describing but with bass you do. Playing with other people even in your house, you and your friends want it to sound like a real band and the volume goes up. A strong singer even in your house with no mic is louder than you think. I have a 5'8 grand piano in my living room and I've had singers and sax players over. Those people are trained to blow or sing hard with control and can get get really loud. I've had to tell my sax friends to stand a little off to the side because he's blowing my head off and I have to dig into my piano to keep up with them and that's with no amps at all. Believe me about this. Just that pure acoustic volume level will completely blow out what you think are nice sized home studio speakers.

Go into the PA department at any big music store and check these pro speakers out. Those sell new for around $500 or so. And don't be fooled by thinking 10" powered speakers will be good enough. I bought a pair of used 10" Yamaha's many years ago thinking that and no, they were only good enough for monitors right next to me, the keyboard still had to go out through bigger stuff even at low volumes. Fact of life as a musician.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.