EDIT - SRB posted whilst I was typing..........
This is info on Passive & Active Bi Wire & Bi Amping - Not 100% to do with the original post, But I hope of use....
1. The "standard" domestic style speaker will have an internal cross over.
Lets consider a "2 way" system, that has Bass and a High Frequency (HF) driver in one cabinet.
This will usually have one cable from one amplifier channel that drives the entire speaker.
This is the most basic and common speaker type. Known as a Single wire Passive 2 way speaker.
2. The next logical step is to "Bi Wire" the same passive 2 way speaker.
Still using one amp channel two sets of wires are run to the speaker.
One for the HF and one for the bass - This requires the speaker to have FOUR terminals on it designed for "Bi Wire" application, You usually have a link wire or link bar between terminals that needs to be removed for "Bi Wire" use.
The advantage of this over option 1. is the reduction of resistance in the speaker cable. It can also be a step between 1. and 3. as he cable can be adapted fo the next step.
3. The next logical step is to "Bi Amp" the same passive 2 way speaker. This requires two amplifier channels per speaker, One to drive the HF and one for the BASS. The signal from the preamp is split and sent to both amp channels, The link wire/bar is removed from the rear of the speaker, One speaker cable from each amp to either the HF or Bass connection. This type of Bi Amping still uses the internal cross over of the speaker. The advantage is that the amp driving the HF does not have the demand of the bass. This is know as a "Bi Amping a passive speaker"
4. The final option is "Active 2 way Bi Amp" system. This requires an active cross over (Bryston 10B). This is placed in the signal path after the preamp but prior to the amplifiers, This Active cross over now splits the full range signal and sends specific frequencies on to each amplifier. Bass to the Bass amp, HF to the HF amp.
This now means each amp is more efficient and dedicated to specific frequencies.
Each amp is then wired to the specific bass/HF driver of the speaker. The speaker for thisapplication should be an "Active speaker" . An Active speaker has no internal cross over. Fully active systems are usually found in commercial applications where the advantage of a high Sound Pressure Level (SPL) is required. There is still an audio advantage in a fully active system. The removal of the speaker cross over allows a more linear response (frequecy vs Impedance) from the driver and more efficient use of power from the amps
Note 1: The active cross over mentioned in point 4. can have additional controls crossover point, slope, gain, polarity - Thats another topic.
Note 2: ALL Bryston amps have the same gain structure so in a Passive 2 (3,4,5...) way system ANY amp could be used for any "way" of the speaker. The more powerful amplifiers are usually used for the Bass.
PLEASE NOTE : Typed in a hurry! So I will need to go back over and check this reads correctly. I also have some pictures which I will add for clarity. I will put this in its own thread over the weekend asthis may be of use to others, I always meant to do this on other forums I am member/moderator.
All the best,