I had that problem and started several posts about the sound and tone not being as sweet once you moved away from the amp. I read an article about the acoustic foam "doughnut" placed between the speaker and the speaker grill. It worked! I played my amp at volume 4 tonight with friends in our local pub playing the blues and the tone was just as good at being right next to the speaker and 15ft away. I have replaced the 10" Jensen Alnico with a 12" speaker which I also think helps move more air and helps carry the tone.
Any experience with the Mojotone PR baffles? I want to try a 12" in my PRRI but don't want to hack it up.