[FreedomJazzDance]

Hello to all,

Please appreciate if someone can clarify a doubt of mine, about how works multi amplification with passive crossover.

I understand the concept of how multi amplification with active crossover works, but what about with passive crossover?

For example:

If considering tri-amp a 3 way loudspeakers, with separated power amps, not one multi channel, how the power amps will be connected with the preamp out? the power amp's cables must be unified in order to do that?

What are the solutions?

Many thanks, best regards to all

[audioengr]

Hello to all,

Please appreciate if someone can clarify a doubt of mine, about how works multi amplification with passive crossover.

I understand the concept of how multi amplification with active crossover works, but what about with passive crossover?

For example:

If considering tri-amp a 3 way loudspeakers, with separated power amps, not one multi channel, how the power amps will be connected with the preamp out? the power amp's cables must be unified in order to do that?

What are the solutions?

Many thanks, best regards to all

There are mostly active solutions for this because they sound better.  DEQX, Behringer and others make these.  The crossovers can be precisely tuned and the relative amplitudes tuned.  Optimum crossover filters with zero phase-shift can be used.

You could do your own passive crossover driven by the preamp that delivers three signals to three amps.  The parts for this would be cheaper than those used for passive speaker crossovers because they don't have to carry the power.  It's only signal level.  The impedance would have to be considered however.  Most active preamps will have sufficient current drive, but it would be best if the impedance that the preamp sees did not change during the music signal.  It will with a passive crossover.

Steve N.

[FreedomJazzDance]

Thanks for the reply, I understand the solution of a passive crossover made outside the speakers, what is not clear for me  is: with loudspeakers with crossovers built in, and you choose to triamp for example, how you hook hp all the power amps to the preamp? Via cable unification? Many thanks.

[HAL]

In that case you would need a splitter from the output of the preamp to the multiple power amps. 

Those will be all line level signals and depends on the output capability of the preamp if it will drive more than on power amp.  If the power amp input impedance becomes to low, then an active splitter would be needed. 

If the power amps are different or have different voltage gains, then they would need different signal levels to each power amp. 

[FreedomJazzDance]

Let me see if I understood, assuming we have a pair of 3 way loudspeakers, the speakers have terminals for high, mid, low, and we will triamp this speakers with  three 2 channels  power amps, all cables from the power amps must be connected with a splitter, in order to be plugged at the L and R out if the preamp, that’s correct?

This  triamp Passive crossover is correct?

Many thanks!

[Tyson]

Why would anyone want to passively biamp or triamp?   

[HAL]

Let me see if I understood, assuming we have a pair of 3 way loudspeakers, the speakers have terminals for high, mid, low, and we will triamp this speakers with  three 2 channels  power amps, all cables from the power amps must be connected with a splitter, in order to be plugged at the L and R out if the preamp, that’s correct?

This  triamp Passive crossover is correct?

Many thanks!

No, the output of each amp goes to an individual speaker crossover.  You are splitting the preamp output for each channel into a 3-way splitter to drive each of the three power amp channels.  There are 2 3-way splitters, one right and one left.

Each speaker driver has to have its own passive crossover to work in this configuration.

Tyson is correct that this is not really an optimal solution to a 3-way system.  Active is much better for this application. 

[WGH]

A good start point would be to define your goals and your budget, are you going to be playing in concert halls or a 12' x 12' bedroom? I have no idea how many amps each driver needs, after a quick search I came up with this guess but both the tweeter and midrange look too high:

Tweeters - 15 watts each
Midranges - 60 watts each
Woofers - 240 watts each
Subwoofers - 1000 watts each

Which means if you get three of the same type of say 60 watt amps, then the tweeters will be grossly overpowered and the woofer grossly under powered. Three different sized amps for the tweeter, midrange and woofer will result in a more complex crossover based on each amp's gain along with a complicated impedance for the preamp.

Which is why almost everyone uses a single amp (stereo or mono) to drive a passive crossover network.

[SET Man]

Hello to all,

Please appreciate if someone can clarify a doubt of mine, about how works multi amplification with passive crossover.

I understand the concept of how multi amplification with active crossover works, but what about with passive crossover?

For example:

If considering tri-amp a 3 way loudspeakers, with separated power amps, not one multi channel, how the power amps will be connected with the preamp out? the power amp's cables must be unified in order to do that?

What are the solutions?

Many thanks, best regards to all

Hey!

    I've noticed that you've started a few posts about building system with SET, Tir-amps, Active Xover and now this doubt about this.

   From your other post with tri-amps Fostex driver set up, that's a big system there. Don't know how big is your room or how loud you like to listen to music. That system can fill up a small club for sure. If you are in typical home setting, sitting not far from speaker it will be hard to integrated time alignment all those drivers together. Why so complicated?


  If you really want to have tri-amp system. Why not just buy powered active speaker system? Many Hi-End speaker companies now offer this type of speaker. Everything all built in with amps and drivers all optimized to work together.

   As for myself and my system, I'm the opposite of what you're having mind right now. I have a pair of SET monoblock and Single Driver speaker system. Single power tube directly connected driving a single 6" driver without any xover. OK, fine I admit it... I have a super tweeter that use a single .47uf for xover. 

  Anyway, If you're just starting out in audio and especially DIY audio. I can tell you that don't over thinking things. WGH, is right when he said "... define your goals and your budget..." And one thing I can tell you for sure is that more doesn't always mean better.

  Well, good luck and keep us posted. Audio Circle is a great audio community, you can always find people to help you here.

Buddy




   

[Early B.]

Short answer -- forget about it...

[FullRangeMan]

Lots of wise advices here. He started in the right track with Fostex 208 97dB single driver suited for Frugal Horn dipole enclosure, a hi-end speaker with years of fine tune by Planet10 even being the 208 limited to 14kHz, much better than a xover and a tweeter.

[FreedomJazzDance]

Thank for the advices, HAL explained the hypothetical question, that I made just to understand about how to integrated 3 separated stereo amps, passive crossovers, and preamp.... Understood now, thanks sir.

My system plan is being discussed on another topic, already explained all the drivers that will be used, the speakers plan of construction was shared, as well what I will do first, that will be tell for the speaker's builder to build the passive crossover recommended by the manufacture, and not multi amp at first...

but on that thread, I also telling some doubts that i have, about go active and multi amp, that will be a experiment for the future....

Maybe this another thread caused some confusion... anyway

Thanks guys..