I have that setup with the stock HU.. and unfortunately the distortion at high volumes has caused me to re-think my setup. I've sent my radio off to Iron Cross to do a pre-amp output.. I think that will help. However, in the meantime I bought a Biketronics 4180 amp in the group sale and plan on replacing the PBR300x2. With a non-stock HU I think it would be fine. With a stock HU I get too much distortion at high volumes without a pre-amp output.
I think the issue is the multiple amps. If I hook up my phone.. its phone amp + HU amp + PBR300 amp = distortion.
I have used the Rockford Fosgate PBR300x2 since 3 months ago, it has been pretty noisy for me. and I am happy with this
from reading this forum for the past month or so and input received. The bt7.1 can take more power and with the pbr300x2 you aren't providing enoguh. Everyone has different taste if happy why change it.
After speaking with some knowledgeable people here on the forum, I might just wait and change up to 4180 and 7.1s. I’ve been told BT’s amp is better suited for our bikes. Still thinking. You can only expect so much out of two 6.5s and amp… right?