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I have read many articles and done searches in this asylum. What happens to crossovers in each case is not very clear. What happens to a speaker crossover when a speaker gets signals from 2 separate amps?
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Yesterday, I was going to hand-draw a diagram showing the system "chain", but Hornlover's link is much prettier. See his link "... Not quite magic, but close".
:)
When you have a "splittable" aka bi-wirable crossover like that, it means it's a parallel crossover network. Electrically there are independent low and high pass filters, for the woof and tweet respectively.
You can hook individual amps to each set of posts, in what is called a "passive bi-amp" arrangement.
For active bi-amp, you would need to remove/byass the passive filters, and use filters "ahead" of the amplifiers, aka, electronic or "active" crossovers.
Contrary to disbelief, there can be "differences" and "benefits" to passive bi-amping and it's untrue there are 'no differences'. When using dedicated amps to drive each speaker section, the current each amp sees is very different than when one amp is used to drive both.
Cheers,
Presto
A good article on bi-amping is here
When using a passive biamp a speakers crossover is used. Remove the shorting bar that goes between the LF and HF connections and connect each amp to one of the sets of terminals.
I connect this way and it works fine. People will say oh you can't do that as you'll be wasting amp power by sending the full range of sound to each set of terminals. The crossover works on this area. Bass consumes most of the power in the audio spectrum. On my CJ HF amp in my biamp there are peak indicators. My crossover is at 2.5 K. The peaks lights have only ever lit from musical content like snare hits and electric guitar that have a lot of content in the HF spectrum.
The other way to biamp is to connect the preamp to an active crossover. Its a component with line stage circuitry either tube or SS. The crossover is adjusted for the proper points and connected to each amp. It is best to then remove the speakers internal crossover and have the speakers posts connect direct to the drivers. That is of course unless there is a midrange and tweeter or say a two and a half way speaker where one woofer has a much lower low pass frequency.Connecting an active crossover to a speaker where the internal crossover remains one should probably change the crossover frequency by doing some testing as you'd be using two networks.
ET
Passive crossovers my include design components that (1) make the impedance easier for an amplifier to drive, and/or (2) provide equalization to optimize the loudspeakers response, as well as the High pass/low pass circuitry to split the woofer and tweeter signals. These different functions can be integrated into components in crossover. This is what makes converting a passive speaker into a bi-amped active speaker a hit and miss proposition and why most biamped loudspeakers are done by the manufacturer. With a simple crossover it might be OK - but I would recommend measurement capability to get the sound right, to optimize the outcome of the biamps system.
Bi-amping using the passive crossovers offers only the advantage of simplifying the load to the amplifier, missing the advantages of reduces distortion and increased headroom, but avoids the complications. True Bi-amping is for the instrumented audiophile only.
"The hardest thing of all is to find a black cat in a dark room, especially if there is no cat" - Confucius
I fully understand your use of "passive bi-amping", and I don't disagree that the approach works fine. The fly in the ointment is that you're not accomplishing anything other than to make a simple system unnecessarily complicated. Both amps are still fed the full audio signal, and the unwanted part, whether HF or LF, is blocked by the still-present passive crossover components - which are still between the amps and the drivers.While there MAY be some benefit in changing the load seen by the amplifier, you're missing the really important benefits of "true" bi-amping, where the crossover is placed before the amplifiers, so that they reproduce only the frequency range needed for the driver(s) they're connected to. This has several benefits, both sonically and in power/current usage efficiency.
:)
Edits: 06/28/16 06/28/16
And just as importantly the reactive load on each amp is significantly less bad than with passive bi-amping.
I totally agree. If you are going to bi-amp, do it right.
A single two speaker can be bi-amped as long as the crossover high and low pass portions are separate. A three way could also be bi-amped if the woofer portion of the crossover is on one board and the mid/tweeter crossover is on another. I like to use what's commonly called a TD cup with four terminals and straps connecting them. Each separate section of the crossover is connected to its own posts with the straps connecting the whole crossover for single amp use. Remove the straps and connect an amp to each pair of posts to bi-amp. Somewhere in the mix the amps have to have level controls to balance the relative outputs of the high and low pass crossovers.Bi amping can also be done to facilitate the addition of a sub-woofer to an existing speaker pair. This requires an outboard active crossover with high and low pass connections for each amp. Level controls and crossover frequency adjustments are essential for this arrangement.
There is no beer in food, but there is food in beer.
Edits: 06/26/16
The speaker doesn't have a crossover. Each amp is bandwidth limited to be in tune with the individual driver it is hooked up to.
It's a far superior way to do a speaker because each amp only has to drive a voice coil and not a difficult crossover also.
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