I have 2 system in 1 room, i.e. home theater and music system. I use 2 different power amp. to drive the same main stereo front speaker (Usher Be 8571-II) that have 2 kind of speaker connector on a single connectors (Spade and Banana at the same connector). Now I have to connect and disconnect the speaker cable when to use between those 2 systems. Can I simultaneous connect those 2 cables (1 to banana connector and the other to spade connector) without damage the power amp or speaker or degrading the sound quality of each system? The power amp never turn on together at the same time. Any comments or suggestions? Thank you
Don't do it. It may be OK but (1) all you have to do is turn both on once and you may regret it and (2) there is no assurance that, even in standby, the output impedance of one amp will strongly shunt the other.
1. Get a switch.
2. Use a preamp with a HT-bypass function.