Bi-Amping Yamaha A-S801

[LPJR]

Hi All, I’m curious to know whether there is any appreciable benefit to bi-amping the Yamaha A-S801 intergrated amp (which is offered through a speaker A+B mode). I have monitor audio bronze 6 speakers - which are fairly sensitive, but could probably always benefit from the extra power.

 

[TLS Guy]

Hi All, I’m curious to know whether there is any appreciable benefit to bi-amping the Yamaha A-S801 intergrated amp (which is offered through a speaker A+B mode). I have monitor audio bronze 6 speakers - which are fairly sensitive, but could probably always benefit from the extra power.

That is NOT biamping. The A and B use the same amps. They are for switching speakers so you can use A or B speakers. You can use both if the impedance of the speakers is high enough, which it usually is not. There is no increase in power. To biamp you would need four amps, and your unit has just two.

Lastly passive biamping is a waste of time.

 

[LPJR]

The AS801 instruction manual provides: “In the case of speakers supporting the bi-wiring connection, the tweeter/midrange unit and woofer of the speakers can be driven independently through connections shown in the following figure, allowing you to enjoy clear mid- and high-range sounds.”

I’ve bi-amped my AVR before (as the AVR had the option to assign 2 additional channels to front speakers). I thought it made a difference.

Is the AS-801 different from the AVR in that sense? In other words, does the AS801 have less assignable amps? Thx!

 

[lovinthehd]

It's mostly about marketing....sells more speakers if they think it's competitive to have the dual terminals, sells more wire as well, so the avr guys came up with feeding the same signal to a pair of speaker channel amps for some weak passive bi-amping. Your integrated amp is equally wimpy as an avr for passive bi-amping, maybe even worse as it only has two sets of amps vs multiple channels of amps in an avr (but in either case all from the same power supply) If you really want benefits simply get a more powerful amp. Real bi-amping is done without the type of passive crossover used in most home speakers, and rather with separate amps and an electronic crossover between drivers.

https://www.audioholics.com/frequent-questions/the-difference-between-biamping-vs-biwiring

 

[TLS Guy]

The AS801 instruction manual provides: “In the case of speakers supporting the bi-wiring connection, the tweeter/midrange unit and woofer of the speakers can be driven independently through connections shown in the following figure, allowing you to enjoy clear mid- and high-range sounds.”

I’ve bi-amped my AVR before (as the AVR had the option to assign 2 additional channels to front speakers). I thought it made a difference.

Is the AS-801 different from the AVR in that sense? In other words, does the AS801 have less assignable amps? Thx!

Yes, you can biwire. But that is the same as connecting the amps with two sets of cables, one to the high pass filter and another to the low pass filter. So they are connected at the amp terminals, instead of the speaker terminals. Again a totally useless and pointless exercise.

Biamping is only of value if you have a preamp which is connected to an electronic crossover rather than a passive one. Each frequency pass band needs to be connected to its own power amp, and the speakers have no crossover connected to them. So to biamp actively you need two amps per speaker and to triamp you need three amps per speaker. You only gain power if one of the crossovers is in the region of 400 Hz or so, which is the power divide frequency.

Basically with these systems you are into either active speakers which contain the electronic crossovers and the number of power amps required, or you are dealing with a high powered large space pro auditorium situation. The other area is advanced DIY. Firms like ATC do offer domestic powerful active speakers, and DIYers like myself design, and construct such systems. There are significant advantages, but it has to be done really well. If we could just get away from amps in receivers and integrated amps, and put amps in the speakers instead, there would on the whole be a great improvement.

 

[killdozzer]

The AS801 instruction manual provides: “In the case of speakers supporting the bi-wiring connection...

Also, something very basic and explained into details in the link HD posted:
bi-wiring = 2 sets of wires/speaker - 1 amp
bi-amping = 2 sets of wires + 2 amps/speaker

If you like experimenting, just be careful to read the manual on the subject regarding the JUMPERS.

As for the benefit, I was also interested in this topic, in what would I gain with bi-wiring. I didn't find anyone here who thinks there's any actual benefit. Some forums talk about separation/cross talk, but I don't think that holds ground in this case as it isn't real separation. The signal is the same all the way to the speaker.

As TLS said, ideally, you would want to first separate what you want to amplify, then amplify it and then send it to the driver you want it to be played with. Nothing even remote happens with two wires.

 

[LPJR]

Thanks all. It seems like the conclusion here is the AS801 is not capable of biamping- even passively- since it only has 2 channels/2 amps.

Whereas an AVR maybe capable (despite people’s opinions of the benefit), because you are reassigning additional channels/amps to the front speakers which can boost the power (theoretically). The AS801 doesn’t have additional channels/amps- so you can’t assign what you don’t have...

Rather, Yamaha is claiming the A+B speaker selector permits biwiring. Which most believe is of no benefit.

Do I have this right?

 

[everettT]

Thanks all. It seems like the conclusion here is the AS801 is not capable of biamping- even passively- since it only has 2 channels/2 amps.

Whereas an AVR maybe capable (despite people’s opinions of the benefit), because you are reassigning additional channels/amps to the front speakers which can boost the power (theoretically). The AS801 doesn’t have additional channels/amps- so you can’t assign what you don’t have...

Rather, Yamaha is claiming the A+B speaker selector permits biwiring. Which most believe is of no benefit.

Do I have this right?

Even an AVR isnt good because it's still the same power supply. Passive biamping period is a waste in 99.9% of the time.

 

[LPJR]

understood. Setting aside the merits of biamping with an AVR, is my understanding/characterization accurate re AS801’s lack of additional channels required to passively biamp?

 

[Swerd]

@LPJR

In amplifiers, there are power supplies and power output devices. The power supply section of an amp has one or more transformers that convert AC power into DC power. The power output devices are usually transistors, one per channel. It may help to think of the transformer as roughly analogous to a car's engine, and the power outputs as analogous to the transmission.

Most AVRs, and the Yamaha 2-channel integrated amp, have one large power supply transformer with multiple wire windings for each output channel. If only two channels are used, the power available from that transformer is available for those two channels. If you set an AVR to "bi-amp" the power goes to four channels. The same applies to the Yamaha 2-channel amp with the A/B speaker outputs. You don't gain any power because that power supply transformer still has the same capacity. Just like in a 4-wheel drive vehicle, switching from 2-wheel to 4-wheel drive doesn't double the available power – you still have the same engine.

To bi-amp, you must (at least) provide additional power supply transformer capacity. The Yamaha manual that you quoted ignores that. Yamaha isn't the only one to do that. That creates enormous confusion, and, in my opinion, does a disservice to owners. It's plain wrong.

 

[ryanosaur]

,because you are reassigning additional channels/amps to the front speakers which can boost the power (theoretically)

Separate from the merits of bi-amping:
The speakers themselves DO NOT see extra power... though the thought of 2x200w=400w would seem to indicate you are doubling/boosting the power to the speaker, what is actually happening is that you are giving a dedicated 200w(potentialpower) each to the LF and HF channels of said speaker: there is no summation of power that takes place.
Personally, I'm in the school of thought that says make certain you have adequate power to cover dynamic peaks, and just use a single amp channel per speaker. The likihood of me turning my system up to true reference level at my LP is pretty low, so even if I listen at -10db, my LP is probably getting -16dB... and my amps have more than enough juice to handle whatever I throw at them.
One last thought, as I WAS curious about this, myself... for a while...
Two speaker designers I have talked too will put dual sets of binding posts on their speakers for bi-wiring. One believes it is useful, but doesn't openly encourage it... in fact you have to order the additional set to be installed. The other gentleman thinks its a waste but does it because its almost expected. A third gentleman I discussed this with is a VP of Regional Distribution for the importer of a well known UK speaker manufacturer: his disdain for bi-anything was humorous and he countered with the proposal that one could put 1000w per channel through their speakers for the absolute best performance (in the way of dynamic headroom), which would be audible according to him.
*shrugs Thought that interesting to share here.

 

[highfigh]

The AS801 instruction manual provides: “In the case of speakers supporting the bi-wiring connection, the tweeter/midrange unit and woofer of the speakers can be driven independently through connections shown in the following figure, allowing you to enjoy clear mid- and high-range sounds.”

I’ve bi-amped my AVR before (as the AVR had the option to assign 2 additional channels to front speakers). I thought it made a difference.

Is the AS-801 different from the AVR in that sense? In other words, does the AS801 have less assignable amps? Thx!

It's an unfortunate trend, adopted by people who wanted to hear an improvement, sold to them by a cable manufacturer, then seen as a way to sell more cable by the other whores.

Amplifiers in integrated amps aren't usually assignable and as soon as they become that, their performance will decrease to the point where they'll no longer be a viable option.

There's one way you can be sure it makes a difference, or not- have someone else switch between the two states, with neither of you knowing when or if it's actually switching. If you know, you're biased. Period.

 

[Irvrobinson]

@LPJR

In amplifiers, there are power supplies and power output devices. The power supply section of an amp has one or more transformers that convert AC power into DC power. The power output devices are usually transistors, one per channel. It may help to think of the transformer as roughly analogous to a car's engine, and the power outputs as analogous to the transmission.

Most AVRs, and the Yamaha 2-channel integrated amp, have one large power supply transformer with multiple wire windings for each output channel. If only two channels are used, the power available from that transformer is available for those two channels. If you set an AVR to "bi-amp" the power goes to four channels. The same applies to the Yamaha 2-channel amp with the A/B speaker outputs. You don't gain any power because that power supply transformer still has the same capacity. Just like in a 4-wheel drive vehicle, switching from 2-wheel to 4-wheel drive doesn't double the available power – you still have the same engine.

To bi-amp, you must (at least) provide additional power supply transformer capacity. The Yamaha manual that you quoted ignores that. Yamaha isn't the only one to do that. That creates enormous confusion, and, in my opinion, does a disservice to owners. It's plain wrong.

Minor correction - Since >99% of solid state Class A/AB amplifiers have differential output stages, there are almost always at least two transistors per channel, and often a larger multiple of two.

I also like to remind people that while passive bi-amping (and even bi-wiring) very seldom improves performance, passive bi-amping and bi-wiring never degrade performance. They are harmless. So while I tell anyone who asks, especially who own AVRs, that it is probably a waste of speaker wire, I encourage them to passive bi-amp if it will make them happy.

 

[PENG]

The signal is the same all the way to the speaker.

Voltage is the same, current from the amp output terminal to the speaker binding posts will be different because current = Voltage/Impedance, and the impedance vs frequency of each branch of the split XO is not same as the combined XO. Current from binding posts to the speaker voice coils would be the same though either way, I guess I am splitting hair but that's the theory and part of the arguments the passive biamp yes camp would make.

Audible or not is a different topic, I would say not, some would say yes (placebo again..)

 

[Swerd]

Minor correction - Since >99% of solid state Class A/AB amplifiers have differential output stages, there are almost always at least two transistors per channel, and often a larger multiple of two.

I should have worded that differently, saying solid state power outputs instead.

I also like to remind people that while passive bi-amping (and even bi-wiring) very seldom improves performance, passive bi-amping and bi-wiring never degrade performance. They are harmless. So while I tell anyone who asks, especially who own AVRs, that it is probably a waste of speaker wire, I encourage them to passive bi-amp if it will make them happy.

Yes, such non-straitforward wiring patterns don't really alter the sound quality of an amp/speaker combination, but they can harm things if wired incorrectly. We've all seen posts from people who (wisely) asked if their bi-wiring/bi-amping scheme was in fact correct, when what they proposed would likely lead to equipment failure. It happens, so I wouldn't go so far as to say "it's harmless".

 

[LPJR]

The responses have been great - super informed, technical!. Do you think the AS801 has the capacity to even passively biamp- as it is a 2 channel amp? Setting aside the effectiveness of course

 

[Swerd]

Do you think the AS801 has the capacity to even passively biamp- as it is a 2 channel amp?

No. Not unless you add an external 2-channel amplifier to the 2-channels of the AS801.

 

[Irvrobinson]

Yes, such non-straitforward wiring patterns don't really alter the sound quality of an amp/speaker combination, but they can harm things if wired incorrectly. We've all seen posts from people who (wisely) asked if their bi-wiring/bi-amping scheme was in fact correct, when what they proposed would likely lead to equipment failure. It happens, so I wouldn't go so far as to say "it's harmless".

You can say that about any speaker wiring, Richard. At least three times in my memory I have helped someone who was disappointed in the lack of bass in their audio or HT systems, only to find that they had wired their L-R speakers out of phase. BTW, all three times that I remember it was people using cheap, clear-jacketed speaker wire with no terminations, and they couldn't or didn't see the printed line on the insulation marking one of the conductors. Even connecting speakers in a conventional manner can be error-prone unless precautions are taken.

 

[mtrycrafts]

The responses have been great - super informed, technical!. Do you think the AS801 has the capacity to even passively biamp- as it is a 2 channel amp? Setting aside the effectiveness of course

Yes, 2 channel amp, left channel and right channel.

 

[killdozzer]

I guess I am splitting hair

Not at all. Thank you.