I have an FP-30 and find the speakers generally adequate for home practice. They reproduce the piano tone quite well, but with a bias toward the bottom end (that may be the internal EQ rather than the speakers themselves). As with most of Roland's slabs, they can't cope well if you split the keyboard to play left hand acoustic bass with piano - you get distortion in treble notes. IIRC, the Yamaha P-255 coped much better in this scenario, and even the Kawai ES100 had less distortion with split bass.
I have just edited this post regarding an issue with the way the latest firmware has affected output. The 1.03 upgrade allows you to plug in headphones (or external speakers) and select whether you want the internal speakers to sound. I was getting an over-amplified signal from the headphone output, but having just tried it again, it seems that you need to reset the volume control when you plug in external speakers and require internal speakers to operate at the same time.
This firmware issue has not dampened my enthusiasm for the FP, since it was incapable of speaker switching when I bought it. If you accept it as merely a lightweight substitute for acoustic piano, it does the job well, with a particularly rewarding and rich piano tone. EPs are poor (definitely well below the quality and musicality of those in the Kawais), but the acoustic bass is well executed, and the variable split point is handy. The action is also quite good within the limits imposed by the small case, and key surface feel is very acceptable.
So to go back to your question, yes the FP's speakers are adequate for a modest room and sound quite good for AP reproduction, but can't really handle much more than this.
Last edited by voxpops; 02/15/17 05:02 AM.