To bi-amp or not to bi-amp

[E-Stat]

I have A/D/S/ Sat 7 speakers that are capable of being bi-amped.

While you could passively bi-amp, the connections are really intended for bi-wiring as are many speakers today. They really aren't that power hungry.

ADS Sat Series

 

[grey]

Seems to me more like that article was written specifically to sell Elliot Sound Products. Lots of misinformation in there- like having to disconnect the internal passive crossover network to achieve true bi-amplification. Article itself even then goes on to say that the low-pass & mid/high pass networks are separate- so why? Completely unnecessary to deactivate the internal crossover and substitute it for an external one unless you're dealing with a speaker like the ADS 1290 or 1590 that actually uses a SWITCH on the speaker that decouples the woofer from the internal crossover board in biamp mode and thus requires the use of an external crossover. That article is far more of a sales pitch than a legit discussion of biamping.

Rod is a good dude. Some of it is subjective until you get into the full active parts. How would you write an intro to bi-amp?

 

[Tom Brennan]

There would now be in theory 95 watts available to the bottom verses 70 watts in the ghetto bi-amp attempt. Since the bottom is what eats power how is driving it with 70 watts better than 95?

I knew people who used the extra channels available from AV units to do proper bi-amping of 2 channel stereos; proper meaning using active crossovers. Many enthusiasts think using actives gives an increase in clarity and dynamics and a decrease in distortion and are not bi-amping for extra power. Indeed, IME most people using actives are hornys with highly sensitive speakers and more power is way down on their list of needs.

As for extra power thing, I’m skeptical anyway. Two 50 watt amps used bi-amped to a single speaker are delivering 50 watts above the crossover point and 50 watts below the crossover point. A single 50 watt amp driving the speaker is also delivering 50 watts above the crossover point and 50 watts below it. Now an active crossover eliminates passive crossover loss but many people bi-amp using the passive crossover. Which I think is...well, anyway, they do it. Am I missing something?

 

[Wolverine]

You're saying that bi-amping is not possible with the 806 simply because all channels' power source is a shared power supply? Each channel still has separate amplifier modules that determine how much power is ultimately being delivered to each speaker.

Thanks that was the only point I was trying to make as it related to the OP’s question. Do I believe a HTR is the best method for Bi-Amping? No but a type of Bi-Amping is possible with some HTR’s and if he has one that permits a limited type of Bi-Amping he can at least try it and see if he notices a difference.

 

[Tom Brennan]

 

[grey]

Tom posted another variant known as a PLLXO. I relate passive bi-amping to using portions of the passive crossovers in the speakers.

 

[mhardy6647]

Crossovers (active or passive) at line level make a lot more sense than do high-power crossovers -- but the industry evolved along with the audio consumer domain towards "single" amplifiers (well, stereo amplifiers since the rise of stereo in the very late 1950s), so the crossovers sort of had to go in the loudspeakers.

This said, there have been periodic forays into low-level XOs in decidedly consumer-grade equipment.
Here's an example
Onkyo "Multiac" receiver -- note the separate power amp outputs for woofer, MR and tweeter.

 

[Grenadeslio]

Crossovers (active or passive) at line level make a lot more sense than do high-power crossovers -- but the industry evolved along with the audio consumer domain towards "single" amplifiers (well, stereo amplifiers since the rise of stereo in the very late 1950s), so the crossovers sort of had to go in the loudspeakers.

This said, there have been periodic forays into low-level XOs in decidedly consumer-grade equipment.
Here's an example
Onkyo "Multiac" receiver -- note the separate power amp outputs for woofer, MR and tweeter.

View attachment 1371362

View attachment 1371361

View attachment 1371357

Awesome

 

[Tom Brennan]

Tom posted another variant known as a PLLXO. I relate passive bi-amping to using portions of the passive crossovers in the speakers.

 

[Tom Brennan]

Many hornys bi-amp to mix flavors—often they use a low powered tube amp on compression drivers and SS on woofers. I often did that back in my horny days.

 

[chop_sooie]

View attachment 1371385

Hey you better not call this bi-amping, some people will get pissed.

 

[chop_sooie]

What is the consensus on bi-wiring (i.e. running two sets of speaker cables from ONE set of terminals on an amp or receiver into the TWO sets of terminals on a speaker and using the built in passive crossover?) Any significant difference to be had there?

 

[Grenadeslio]

In before the lock.

 

[Ski]

It doesn't work quite like that. Out of the 140 watts, 70 for the top and 70 for the bottom, the tweeter might use 5 watts meaning the other 65 watts are unused. Now, say the AVR is capable of 100wpc by not using the two extra channels. There would now be in theory 95 watts available to the bottom verses 70 watts in the ghetto bi-amp attempt. Since the bottom is what eats power how is driving it with 70 watts better than 95?

I actively bi-amp my speakers with 150/ch to the bottoms and 150/ch to the mids and tweets. No attenuation needed (but might be done by the manufacturer). Yes, lower frequencies require more wattage, but due to the impedance curve, they get more current which usually implies more available wattage.

 

[grey]

View attachment 1371385

The graphics are very helpful, Tom. The pllxo is the most transparent that I've tried and the finest parts available only cost a few bucks.
I had an oem unit with a pll for the upper frequencies and an active for the lows. The great part of the active portion is that it offers phase adjustment. It was sold with the speakers and I liked it enough to replicate the idea in a Marchand unit.

 

[BigElCat]

Seems to me more like that article was written specifically to sell Elliot Sound Products. Lots of misinformation in there- like having to disconnect the internal passive crossover network to achieve true bi-amplification. Article itself even then goes on to say that the low-pass & mid/high pass networks are separate- so why? Completely unnecessary to deactivate the internal crossover and substitute it for an external one unless you're dealing with a speaker like the ADS 1290 or 1590 that actually uses a SWITCH on the speaker that decouples the woofer from the internal crossover board in biamp mode and thus requires the use of an external crossover. That article is far more of a sales pitch than a legit discussion of biamping.

Wrong about the ADS L1290s. They can't be bi-amp even though there is a switch to decouple the woofers.

The mid and the tweeter are still coupled to the internal cross-over.

The slope, etc, of the internal passive cross-over plays Hell when you impose another slope and cut-off from an active cross-over.

 

[chop_sooie]

Wrong about the ADS L1290s. They can't be bi-amp even though there is a switch to decouple the woofers.

The mid and the tweeter are still coupled to the internal cross-over.

The slope, etc, of the internal passive cross-over plays Hell when you impose another slope and cut-off from an active cross-over.

How so?
I mean, I realize that for all intents and purposes ADS made it that way to sell their proprietary PA-1 amp with it, which has built-in low pass crossover for the woofers and high pass crossover for the mid/tweeter (still coupled to the internal crossover as you said but only using it for the crossover between the mid and the tweeter), but I don't understand why you couldn't simply use another external crossover using the same slope set to the same crossover point as the PA-1.

 

[BigElCat]

How so?
I mean, I realize that for all intents and purposes ADS made it that way to sell their proprietary PA-1 amp with it, which has built-in low pass crossover for the woofers and high pass crossover for the mid/tweeter (still coupled to the internal crossover as you said but only using it for the crossover between the mid and the tweeter), but I don't understand why you couldn't simply use another external crossover using the same slope set to the same crossover point as the PA-1.

You can't have two different crossovers trying to do the exact same thing at the exact same time for one speaker. It doesn't work. I tried it.

I'll post the link here.

 

[BigElCat]

You can't bi-amp the L1290s...probably not the L1090s, nor the L1590s. You would have to uncouple the mid and tweet and install three pair of binding posts.

So why is that switch, marked Bi-Amp on the speakers? Because ADS had the intention of marketing an external EQ box that would work, and then they did not do it.

I found this out the hard way, spent over $1000.

http://audiokarma.org/forums/index.php?threads/rolls-sx45-stereo-two-way-active-xover.779957/

 

[chop_sooie]

You can't have two different crossovers trying to do the exact same thing at the exact same time for one speaker. It doesn't work. I tried it.

I'll post the link here.

Please- cause otherwise I don't understand how the PA-1 amp works at all, since it does exactly what you are saying cant be done.