In reply to:
I do hope that someone who knows what they're talking about will chime in here
Just from basic electical circuits theory, by adding additional elements to the circuit, you're changing the load... it won't remain 8 ohms. stacked bananas parallel the load, so the load appears lower from the point of view of the driver. Someone mentioned the example of one amp driving two centers... this appears to the the amp as a single equivalent load of half the original impedance (assuming both centers are matched... 2 parallel 8 ohm speakers look like a single 4 ohm speaker).
Additionally, when there's two active drivers on one load (2 amps, one speaker), unless there's a perfect match of voltage between the two drivers, one will source current and the other will sink current. This may not be an issue if the amp was designed to handle it. Was your amp designed to handle it? If you can't absolutely say "yes", I'd go on the side of caution and not drive both of them into one speaker.
OTOH, My M60s have two sets of banana sockets. They're tied together with metal straps. You can use two amps on this speaker by removing the straps and then each amp drives one set of banana sockets. Internally, they're isolated from each other so there's no current flowing between the amps. It's really that each amp drives its own speaker, but these speakers share a cabinet.
Now we leave my area of expertise and get into yours.
What's the advantage of using two amps on a single speaker? Is it just to get a large amplitude (volume)? I'm not sure of my power ratings, but my amp can drive the M60s, QS8's and VP100 well enough to more than fill my room. Why do I need more than that?
By adding more power capabilities, but listening at the same volume, you'd stay away from the maximum power that the amp is capabile of delivering. Is there less distortion when staying away from the maximum power level? I've seen that distortion in old (like 1940s) amps, but I wouldn't think it would be as prevalent in modern amps. Is it?
Enjoy!
