BEL 1001 MkIV Power Amp/Soundlab Speaker Synergy?

Isn't the BEL a 50W amplifier? I am going by memory here but, I believe the Sound Lab impedance curve ramps up quite a bit with frequency (or maybe it is with lowering frequency). In either case, a 50W amp may run out of voltage (therefore power) since these amplifiers are generally rated at 8 ohms output impedance. In other words, a 50 watt amp at 8 ohms may only output 25 watts at 16 ohms. It is the rising characteristic that can bite you however, this is likely to only be a problem if the rising impedance is with lowering frequency.

High current is not the only important spec in an amplifier. A good example is the Innersound amplifier. It addresses both high current requirements and high rail voltage requirements (required to maintain high power into rising impedances). Forget about the inrush current. It only means that there is quite a bit of bus capacitance. This is good mind you but, not the only feature that matters.

In the bridged mode you amplifier is likely not spec'd into 4 ohms or less as the amp will not be happy continuously driving power into impedances this low - distortion will be heading north. But, the bridged mode is probably the best mode for the SL due to its impedance characteristics. In the bridged mode you will have decent current output capability coupled with the ability to better drive higher output impedances.

By the way, BEL's are excellent amplifiers. I would stay away from the tricky switchers. I never liked them on SL's (at least the ones that I have tried).