To truly throw the variable out, do you have another amp that is not a Bryston to be hooked with the speakers? Something that gives out at least 100-200 watt, high current?
Btw, I even ran the X-1 and SW-1 that the reviewer said needed 100 watts high current with an older rebuilt Harman Kardon Twin Transformer receiver from the 1970s, I have the receiver rated at 56 watts at 8 ohm but it give grabbed the speakers by the...
I think it might be a good idea to swap the amp and see how it works and btw, also split the circuit, but the amp in a different circuit if possible.