Thanks RHarv.

I cabled (usb) a Novation midi controller to the laptop, and, since the laptop has bluetooth, can transmit the softsynth output - through ASIO4ALL - to the bluetooth speaker. (It's separate from the desktop setup, for doodling along with BiaB and perhaps entertaining small gatherings.) But the softsynth response to the controller has intolerable latency, even after tweaking the ASIO4ALL buffers. Not unexpected. So I've been thinking about a usb audio interface, just to improve the latency, not for audio I/O. But the interfaces don't come with bluetooth.

What I wasn't sure about is whether the audio signal, as generated by the DAC in the interface, is sent back to the laptop so that it could be transmitted over bluetooth. Appears the answer is no.

Your mention of an adapter caught my eye, and I see now that there are audio to bluetooth transmitters. They are mainly intended for things like mobile devices (as you suggest), not for serious 1/4" jacks. But I suppose I could adapt one.

From scanning the forums, I got impression a lot of folks use an external usb audio interface with a laptop. Would be interested to hear if anyone has integrated a bluetooth speaker and if so, how they did it.

-Ron