Cap, sorry I wasn't clearer. Your past posts state that (+) mode should not be used with the L1 Classic/Model 1. However, I just assumed that mode was acceptable with an A1. However, upon further reading, I believe the L1 DSP needs to be aware of the B2 in order to use the B2 switched modes.There are two integrated amplifiers in both the Model 1 and the Model 2. One for the radiators and one for the bass bins. They are identical amps in both models. Not sure where you're going with this but if I can help clarify, we'll give it a shot.