Bi amp question

Rule #1, don't worry about doing something the right or wrong way, as long as it is something that is likely to harm the equipment.

Experiment, if you have an idea, try it and see how it sounds. If you don't care for the result, just change it back to the way it was originally.

Yes, that is true, but if the speaker's internal crossovers are filtering out the part of the signal, it can be workable, but not ideal, as you point out. This wasted power, is not simply discarded, the excess energy has to end up going somewhere, with that somewhere, being converted to heat.

In theory, everything should be gain matched. In the real world, this may or may not be a consideration. As part of my set up, I use commercial P.A. cabinets. A two inch HF driver coupled with a horn, is going to be a lot more efficient, than a 15" bass speaker. Whether active or passive, the level of the HF horn must be adjusted, to match the level of the bass speaker.

Bi-amping is not a new concept, it has been around for decades. In general, it is not used in a home environment. Because, it is not really necessary and while many speaker manufacturer's allow for it, most don't actually design for it, the way Von Schweikert does. In home speakers, you never want to bypass the manufacturer's crossover, as it has been pointed out, the manufacturer's crossover because it is a critical element of the loudspeaker's engineering.

In my home environment, I deliberately choose not to use active crossovers, with the Altec A7's, even though they would be run actively, if run in a modern day P.A. system. I run crossovers, designed by ALK engineering. It took weeks of dialing in the correct HF attenuation to balance the output of the HF horn to the 15" woofer.

Most electronic crossovers, have the ability to adjust the gain on each frequency band that is crossed over. You can use that gain adjustment to compensate for different gain characteristics of the final power amps. You have to be able to tune the output, because the HF and bass requirements of each speaker cabinet are going to be different.

If you are in a dead room, you may need to run the tweeter a bit brighter. If the room is to hot, the HF may appear to be overly bright and may require more attenuation.

Al Klappenberger, of ALK engineering, commenting on the attenuation adjustments of his crossovers "if it sounds right, then it is".

Keep up what you are doing, you gain knowledge by doing.

 

Let's pick up this comment and clarify something. When an amp is driving a high level passive crossover and the impedance goes high where the band is "undesired", then the power is never created. So it then is not wasted as heat.

So to isolate and create an example....if you were driving a bass driver and the music was only very high frequency energy then the amp is not going to be flowing any current and not "creating any power". So no power is being created or dumped in heat in that situation. Pretty cool...huh??

CJ

 

True as Spoken, the more perfect the engineering, the more true this is.

The problem, is that many crossovers are not engineered as well as they could be, so there can be losses.

Which is why, I comment, that in the real world, this is not really a concern and I am fine with the way the OP is doing the bi-amping.

If I wanted to bi-amp his speakers, I would do it the same way.

In today's commercial applications, every thing is converted to digital and the signal can easily be manipulated.

In home audio, if you have a clean analog signal, why convert it to digital to achieve an active crossover? Doesn't make much sense. Much better to split the signal into two power amps and then to the bi-amped speakers.

I have a portable audio rack, behind the TV with two Crown power amps and a Berhing digital crossover. I do not use it in the stereo system, for that reason.

The ALK crossovers use an autoformer on the amp side, which keeps the impedance as a constant load on the power amp. The bass cabinets of the A7's are crossed over at 500-cycles. I don't bother to insert a separate crossover for the super tweeter. I find, despite Altec's specs, that above 6K, the horns start to naturally roll off.

There is a crossover, in parallel with the horns that passes information above 6K to the JBL super-tweeters.

It took me many weeks to find the perfect amount of HF attenuation, but now it has the perfect balance.

I'm from the school, that imperfect crossovers, can really screw up otherwise, superior electronics!

Along with the commercial sub, effectively creating a 4-way system, they are better than anything Altec ever produced.

I'm currently listening to them with a Decware, Mini Torii, that I just replaced the rectification today with 6CA4 tubes and it really sounds sweet. The amp can put out all of 3.9-watts, but very runs over 2-watts, usually not that much.

A little audio science here and there, does serve to benefit the forum and it's members. Right On!

 

I have come to realize that Von Schweikert tends to optimize his speakers and particularly the crossover networks for bi wiring and bi amping

The manual even goes as far as encouraging such experimenting and never once mentions an external crossover.

I am feeling more comfortable and confident about how my system is set up and I'm more than happy with the sound

The other day I was listening to T. Monk alone in San Francisco on vinyl and turned it up. Literally felt like I was there in that (mostly) empty club hearing him play. The piano had such dynamics, presence and tonal realism.

I know piano is a challenging test for any system and I grew up in a house with a Yamaha baby grand and a mother who knew what to do with it.

 

I presume if your speakers have an extra set of terminals that allow for Bi-amping, you can configure vertically biamping by using a preamp
which has Two output jacks and an A+B Output Selector Switch in order to drive the two power amps it would be connected to (one power
amp drives the left speaker, the other power amp drives the right speaker, and the preamp controls the volume level) Its assumed both power amps
are identical models, so no issues with separate Gain adjustments.

My question is: Does this arrangement work with any preamp having two of sets of Output jacks, or does it actually require the A+B Out-Selector?
Without the A+B, I dont see how the preamp can operate both amps together, instead of one or the other (A or B).