Bi-Amping Question

[Art_H]

I have a Yamaha RX-V659 receiver, with 7.1.

I want to bi-amp my front left and right. I was hoping to achieve this with the the receiver itself. I don't think this model supports the amp/channel adjustability that is now on current models.

Can I use the 7.1 setting on the receiver and just use the rear L/R for the other end of bi-amping the front L/R?

This would be for 2 ch CD in.

Or are their other settings I could use?

I would also setup a switching system to allow the rears to function as per normal when in surround/movie mode.

Another question, I'm looking to get the Yamaha NS-777 speakers. They are bi-ampable and rated at 6 ohms. What would the individual inputs then be if combined to make the 6 ohms? I know ohms law gets in here, I'm just trying to figure out how they achieve this? I can't see the indiv hookups being 12 ohms to parallel to 6 when together.

What gives??

Thanks

 

[fmw]

Use the search function. You will find hundreds of responses to this kind of post. Someone asks it virtually every day.

 

[Midcow2]

Be careful -don't mess with Ohm's law!

....Yamaha NS-777 speakers. They are bi-ampable and rated at 6 ohms. What would the individual inputs then be if combined to make the 6 ohms? I know ohms law gets in here, I'm just trying to figure out how they achieve this? I can't see the indiv hookups being 12 ohms to parallel to 6 when together.

What gives??

Thanks

If you bi-amp 6 ohms in parallel you get 3 ohms which will load the heck out of most AVRs.

You get 12 ohms when you put two 6 ohm hook-ups in series..

The big question ? What are you trying to achieve?

 

[Art_H]

If you bi-amp 6 ohms in parallel you get 3 ohms which will load the heck out of most AVRs.

You get 12 ohms when you put two 6 ohm hook-ups in series..

The big question ? What are you trying to achieve?

That's what I was trying to figure out, what the individual bi-wiring style speakers would have for resistance on both terminal sets. When the Spec for the speakers are 6 ohms, that must be when both terminals are connected in parallel. Does that mean then that the connectors by themslves are 12 ohms? How are they wired?

I kind of fell silly for asking such a question, but I haven't yet recieved my bi-wire/amp speakers, or I would have pulled out my meter and checked myself. I was more looking for theory on this one too.

What am I trying to achieve? Double the power the speakers for better sound on through the entire volume range.

Thanks

 

[trnqk7]

You're still just limited to the power of the transformer in the receiver and what it can handle-so not really much gain there. But, it hurts nothing to try it and you might be pleasantly surprised.

Parallel resistance works like this:

R1*R2
------
R1+R2

So (6*6)/(6+6)=36/12=3ohms

 

[PENG]

If you bi-amp 6 ohms in parallel you get 3 ohms which will load the heck out of most AVRs.

Not necessarily, bi-amping connection is not the same as paralleling two 6 ohm speakers so it does not mean the amp sees 3 ohms. The speaker itself has to be bi-wirable and that typically means you have the option to remove the supplied links on the speaker terminals thereby allowing one amp to power the HF and another to drive the LF driver (for 2 way speakers).

 

[TLS Guy]

That's what I was trying to figure out, what the individual bi-wiring style speakers would have for resistance on both terminal sets. When the Spec for the speakers are 6 ohms, that must be when both terminals are connected in parallel. Does that mean then that the connectors by themslves are 12 ohms? How are they wired?

I kind of fell silly for asking such a question, but I haven't yet recieved my bi-wire/amp speakers, or I would have pulled out my meter and checked myself. I was more looking for theory on this one too.

What am I trying to achieve? Double the power the speakers for better sound on through the entire volume range.

Thanks

The sections of a crossover are side by side, neither parallel or series. If you put your meter across the HF terminals you will see an infinite resistance, as the tweeter always has at least one cap in series, and a cap will not pass DC.

If you put your meter across the woofer input, you will measure the DC resistance of the voice coil plus the DC resistance of the chokes in series with the voice coil. This is not useful information

In general the HF section has a significantly higher impedance the th LF section. Impedance and resistance are not the same, and impedance varies with frequency and has to be measured dynamically.

If your speakers are two way and one amp is only going to power the tweeter via the high pass crossover section, that is a complete and total waste of time, and of no possible benefit. If you think there is then you join the loonies of audiophile magic land.

 

[TheFactor]

There is a noticeable difference in Passive bi-amping running separate wires to your speakers if they have separate posts for your lows and highs via 4 posts. I experienced definitely more base and possibly better highs. Im very glad I decided to see for my self and strongly suggest you try it yourself. Depending on your speakers and receiver you might be pleasantly surprised when your not expecting any difference from others "opinions". I say try it and if you dont like it switch back .

 

[MDS]

Can I use the 7.1 setting on the receiver and just use the rear L/R for the other end of bi-amping the front L/R?

No. You could only use the rear surround amps to bi-amp the front speakers if the receiver is designed to allow that and lets you reassign the rear surround amps to the front channels.

- When using a 7.1 mode, like PLIIx, you'd be sending the signal meant for the rear channels to the front speakers.

- When in stereo mode, there would be no signal at the rear surround speaker terminals.

 

[Art_H]

The sections of a crossover are side by side, neither parallel or series. If you put your meter across the HF terminals you will see an infinite resistance, as the tweeter always has at least one cap in series, and a cap will not pass DC.

If you put your meter across the woofer input, you will measure the DC resistance of the voice coil plus the DC resistance of the chokes in series with the voice coil. This is not useful information

In general the HF section has a significantly higher impedance the th LF section. Impedance and resistance are not the same, and impedance varies with frequency and has to be measured dynamically.

If your speakers are two way and one amp is only going to power the tweeter via the high pass crossover section, that is a complete and total waste of time, and of no possible benefit. If you think there is then you join the loonies of audiophile magic land.

Good point about the passive crossovers. A lot of my experience comes from the car audio scene where electronic or low level crossovers were the norm. Why is it that passive is 'the way to go' in the home audio setup? What is wrong with having a crossover before the amp? I'd rather not have a 15% loss to the speakers. I do understand that the passive steup in the speakers is simple for the 3 way within and only requires one amp and wire/speaker. But for the insane pricing of some of the 'home' components I would expect that they would have advanced features like multi amps/channel with dedicated multi/wire nice speaker connectors similar to professional speaker connectors. The price of some insane speaker wire would be cheaper to have the conductors made of 24c gold and calling it a day...It'd still be cheaper than some

 

[Midcow2]

Okay now I understand!

That's what I was trying to figure out, what the individual bi-wiring style speakers would have for resistance on both terminal sets. When the Spec for the speakers are 6 ohms, that must be when both terminals are connected in parallel. Does that mean then that the connectors by themslves are 12 ohms? How are they wired?

I kind of fell silly for asking such a question, but I haven't yet recieved my bi-wire/amp speakers, or I would have pulled out my meter and checked myself. I was more looking for theory on this one too.

What am I trying to achieve? Double the power the speakers for better sound on through the entire volume range.

Thanks

The nominal impedance given on a speaker, example 6 ohms, is always is you single connect.

If you are connecting to two separate amp or receiver output channels then each channel would still have a 6 ohm load. That assumes that the circuits are completely isolated and independent. Does you receiver state you can bi-amp? If so then yes you could double the power!

Remember power is logrithmic. If you go from 100 watts to 200 watts you only have an increase of only 30%.

What power do you have coming out of your AVR now? What speakers do you have? Do you know the snesitivity of the speakers; this is how effieicnt they will process power and is usually a dB number from 80 to 100. 80 is very inefficient and a pig for power. 90 is average and 100 is very efficient.

Now, just from a pure terminology stand point.

normal speaker connection equals = wire

Plus voltage======6 ohms======Common
total ohms = 6 ohms


series

Plus voltage=======6 ohms=====6ohms======Common
total ohms = 12 ohms


parallel

Plus voltage=================6 ohms========common
.............................|...................................|
.............................+=========6 ohms=====+

total ohms = 3 ohms.


;;;;;;

now possible bi-amp scenarios


Postive one ========6 ohms=========common
............................|...........|
Positve two =======+...........+=======common

If postive one and positive two are not electrically isolated then the total ohms is as if parallel and is 3. If they are electrically isolated then total ohms is 6.


How loud do you turn up your current AVR or amp ? Is it distorting?

You might want to consider a bigger AMP ( or if you have pre-outs a separate amp) or a bigger AVR. Or you might want to consider replacing your current speakers with more efficient speakers.

 

[TLS Guy]

Good point about the passive crossovers. A lot of my experience comes from the car audio scene where electronic or low level crossovers were the norm. Why is it that passive is 'the way to go' in the home audio setup? What is wrong with having a crossover before the amp? I'd rather not have a 15% loss to the speakers. I do understand that the passive steup in the speakers is simple for the 3 way within and only requires one amp and wire/speaker. But for the insane pricing of some of the 'home' components I would expect that they would have advanced features like multi amps/channel with dedicated multi/wire nice speaker connectors similar to professional speaker connectors. The price of some insane speaker wire would be cheaper to have the conductors made of 24c gold and calling it a day...It'd still be cheaper than some

You have hit a lot of points squarely on the head!

First of all cars. The install is usually custom to the vehicle, and the car is a forgiving environment due to background and being close to the drivers. The drivers are also often separated in space so inaccuracies in speaker hands offs don't shout at you as loudly as they do in the home environment .

The real culprit here is industry "gearing". Everything is geared round these ghastly Far Eastern receivers, which are a low life form among audio components, and should be relegated to the museums pronto, along with tube amps.

The fact is putting the crossover between the amps and speakers is the ideal way to go.

However in the home getting an even frequency hand off at the crossover points is essential.

So the crossover either active or passive, is essentially the heart of the speaker, and has to be custom to the drivers selected, as it has to work with the natural acoustic roll of of the drivers and break up mode peaks etc. So if you want to convert a speaker from passive to active crossovers you have reduplicate the slopes of the passive crossover and any notch filters. Now passive crossovers really limit the performance that would be possible from a moving coil loud speaker system.

Basically the crossovers (active) and the amps need to be in the speakers. The industry seems to have a real problem making this change. It needs to make it though. The problem is consumers wallow in a sea of ignorance when it comes to speakers.

I think you can see that driving a tweeter which will consume milliwatts or at the most a watt or so on peaks from a separate amp via a passive HF filter in nonsense.

If people really are hearing a difference hooking up their receivers that way, then the amps in those receivers are a lot more ghastly than even I thought, and with the current price points that could well be. At the current price points of many of these cheaper receivers, the amps just have to be junk.

Active speakers are around though.

http://www.atc.gb.net/ They sound marvelous.

 

[Art_H]

The nominal impedance given on a speaker, example 6 ohms, is always is you single connect.

If you are connecting to two separate amp or receiver output channels then each channel would still have a 6 ohm load. That assumes that the circuits are completely isolated and independent. Does you receiver state you can bi-amp? If so then yes you could double the power!

Remember power is logrithmic. If you go from 100 watts to 200 watts you only have an increase of only 30%.

What power do you have coming out of your AVR now? What speakers do you have? Do you know the snesitivity of the speakers; this is how effieicnt they will process power and is usually a dB number from 80 to 100. 80 is very inefficient and a pig for power. 90 is average and 100 is very efficient.

Now, just from a pure terminology stand point.

normal speaker connection equals = wire

Plus voltage======6 ohms======Common
total ohms = 6 ohms


series

Plus voltage=======6 ohms=====6ohms======Common
total ohms = 12 ohms


parallel

Plus voltage=================6 ohms========common
.............................|...................................|
.............................+=========6 ohms=====+

total ohms = 3 ohms.


;;;;;;

now possible bi-amp scenarios


Postive one ========6 ohms=========common
............................|...........|
Positve two =======+...........+=======common

If postive one and positive two are not electrically isolated then the total ohms is as if parallel and is 3. If they are electrically isolated then total ohms is 6.


How loud do you turn up your current AVR or amp ? Is it distorting?

You might want to consider a bigger AMP ( or if you have pre-outs a separate amp) or a bigger AVR. Or you might want to consider replacing your current speakers with more efficient speakers.

Midcow,

Thanks for the info. I didn't think they woiuld be elec isolated. You can see mt bewilderment with the 4 speakers bi-wireable and trying to figure out how they are all connected to get the 6 ohms.

Art

 

[PENG]

Midcow,

Thanks for the info. I didn't think they woiuld be elec isolated. You can see mt bewilderment with the 4 speakers bi-wireable and trying to figure out how they are all connected to get the 6 ohms.

Art

I suggest you either get the circuit diagram, or take the manufacturer's word for it. If they say the speaker impedance is 6 ohms and are bi-wirable by removing the links provided then unless they tell you otherwise, it is reasonable to assume the impedance is still 6 ohm to the each amps when you bi-wire. As to how they achieve that it is hard to tell without seeing the circuit diagrams but suffice to say it can certainly be achieved in theory.

 

[Art_H]

You have hit a lot of points squarely on the head!

First of all cars. The install is usually custom to the vehicle, and the car is a forgiving environment due to background and being close to the drivers. The drivers are also often separated in space so inaccuracies in speaker hands offs don't shout at you as loudly as they do in the home environment .

The real culprit here is industry "gearing". Everything is geared round these ghastly Far Eastern receivers, which are a low life form among audio components, and should be relegated to the museums pronto, along with tube amps.

The fact is putting the crossover between the amps and speakers is the ideal way to go.

However in the home getting an even frequency hand off at the crossover points is essential.

So the crossover either active or passive, is essentially the heart of the speaker, and has to be custom to the drivers selected, as it has to work with the natural acoustic roll of of the drivers and break up mode peaks etc. So if you want to convert a speaker from passive to active crossovers you have reduplicate the slopes of the passive crossover and any notch filters. Now passive crossovers really limit the performance that would be possible from a moving coil loud speaker system.

Basically the crossovers (active) and the amps need to be in the speakers. The industry seems to have a real problem making this change. It needs to make it though. The problem is consumers wallow in a sea of ignorance when it comes to speakers.

I think you can see that driving a tweeter which will consume milliwatts or at the most a watt or so on peaks from a separate amp via a passive HF filter in nonsense.

If people really are hearing a difference hooking up their receivers that way, then the amps in those receivers are a lot more ghastly than even I thought, and with the current price points that could well be. At the current price points of many of these cheaper receivers, the amps just have to be junk.

Active speakers are around though.

http://www.atc.gb.net/ They sound marvelous.

I have the Yamaha RX-V659 receiver. Paid $300 new. 100RMS/ch 7 ch.

The reason I bought this receiver was because of the audioholics review that praised the amp section. I am happy with it, and cannot expect too much for $300.

When you mentioned the 'ghastly Far Eastern receivers', are you talking about the standard Asian style receivers? Denon/Yamaha etc?

What is it exactly that you don't like about them?

We agree on the tube amp philosophy. I had to laugh the other day when I found an article about a guy that was trying to isolate his tube amp from the bass vibrations so as to not disrupt the tubes. Tubes are better of usede as light bulbs. Notice how buls are slowly being replaced with LEDs...

I am not doubting anything you say here, but have a few questions.

What are the benefits of passive crossovers over active crossovers?

Why can't/shouldn't the RCA level signal have a passive crossover?

I'm assuming the passive system creates issues with capacitance and impedance.

How about a reciever that is only low level with no internal amplification?

Why doesn't Yamaha have such a model? The Eclipse car deck I have is such an animal. No heat issues for the optical drive system etc. I will admit that it is more likely that external amps are used in the car audio scene.

I will be building an ddesigning my own speakers here shortly. I'd like to hear you points and info on why amp/w speaker is so effective. I may go that route. I wanted to assemble my own amps anyway...

Thanks Again,

I'm not as inept as I may have sounded. So building speakers/amp is not a pipe dream. I'm looking into the required audio test equipment etc and then do a box or 2 before hitting the amp side of things, if i do at all. I'll only do it if I can make something better than I can buy without having to sell my children...

Art

 

[TLS Guy]

The nominal impedance given on a speaker, example 6 ohms, is always is you single connect.

If you are connecting to two separate amp or receiver output channels then each channel would still have a 6 ohm load. That assumes that the circuits are completely isolated and independent. Does you receiver state you can bi-amp? If so then yes you could double the power!

Remember power is logrithmic. If you go from 100 watts to 200 watts you only have an increase of only 30%.

What power do you have coming out of your AVR now? What speakers do you have? Do you know the snesitivity of the speakers; this is how effieicnt they will process power and is usually a dB number from 80 to 100. 80 is very inefficient and a pig for power. 90 is average and 100 is very efficient.

Now, just from a pure terminology stand point.

normal speaker connection equals = wire

Plus voltage======6 ohms======Common
total ohms = 6 ohms


series

Plus voltage=======6 ohms=====6ohms======Common
total ohms = 12 ohms


parallel

Plus voltage=================6 ohms========common
.............................|...................................|
.............................+=========6 ohms=====+

total ohms = 3 ohms.


;;;;;;

now possible bi-amp scenarios


Postive one ========6 ohms=========common
............................|...........|
Positve two =======+...........+=======common

If postive one and positive two are not electrically isolated then the total ohms is as if parallel and is 3. If they are electrically isolated then total ohms is 6.


How loud do you turn up your current AVR or amp ? Is it distorting?

You might want to consider a bigger AMP ( or if you have pre-outs a separate amp) or a bigger AVR. Or you might want to consider replacing your current speakers with more efficient speakers.

You will only double the power if the crossover is at 400 Hz, which is the power divide. In most situations the crossover is 2 to 3 KHz, so the increase in power is infinitesimally small. The only possible benefit is reduced inter modulation distortion. If the amps are properly designed there is no possible benefit from passive biamping at frequencies in the 2 to 3 KHz range. It has to be imagined. So if there is a benefit, then the amps are lousy.

 

[TLS Guy]

I have the Yamaha RX-V659 receiver. Paid $300 new. 100RMS/ch 7 ch.

The reason I bought this receiver was because of the audioholics review that praised the amp section. I am happy with it, and cannot expect too much for $300.

When you mentioned the 'ghastly Far Eastern receivers', are you talking about the standard Asian style receivers? Denon/Yamaha etc?

What is it exactly that you don't like about them?

We agree on the tube amp philosophy. I had to laugh the other day when I found an article about a guy that was trying to isolate his tube amp from the bass vibrations so as to not disrupt the tubes. Tubes are better of usede as light bulbs. Notice how buls are slowly being replaced with LEDs...

I am not doubting anything you say here, but have a few questions.

What are the benefits of passive crossovers over active crossovers?

Why can't/shouldn't the RCA level signal have a passive crossover?

I'm assuming the passive system creates issues with capacitance and impedance.

How about a reciever that is only low level with no internal amplification?

Why doesn't Yamaha have such a model? The Eclipse car deck I have is such an animal. No heat issues for the optical drive system etc. I will admit that it is more likely that external amps are used in the car audio scene.

I will be building an ddesigning my own speakers here shortly. I'd like to hear you points and info on why amp/w speaker is so effective. I may go that route. I wanted to assemble my own amps anyway...

Thanks Again,

I'm not as inept as I may have sounded. So building speakers/amp is not a pipe dream. I'm looking into the required audio test equipment etc and then do a box or 2 before hitting the amp side of things, if i do at all. I'll only do it if I can make something better than I can buy without having to sell my children...

Art

You have asked a lot of good questions!

First of all, at line level you are dealing with high impedances and low voltages. The loss of signal strength from passive components would be prohibitive and introduce noise. At line level you need an active filter. In the analog domain you do it with op amps and you can make a filter in the feedback loop of the chip. You cascade to get the order you want. Remember that phase and time shifts will be the same as for passive.

Now active filters before the amp avoid the interactions between the crossover and drivers and amps. There is no insertion loss and no waste of power from L-pads. Passive crossovers waste 15% of the power at a minimum and usually more.

The amps can be tailored for the frequency response required and the power in that band.

Crossover points below 350 Hz are possible. Crossovers below this point with passive components are highly unsatisfactory.

Also the speaker leads are very short. The length of usual speaker leads have a high enough resistance, when coupled with the inline resistance of passive crossover components to negate the damping factor of amps. This also has an impact on the total bass tuning of the system.

So there are very significant advantages from having the amps in the speakers with active crossovers. With the trend towards digital crossovers that have the potential to solve phase and time problems, then the benefits become even greater.

Now as far as receivers are concerned, I think it is a bad plan to place preamps, and above all signal precessing and decoding in the same case as the amps. Processor chips need a cool environment. There is therefore the need to increase amp efficiency and bias too heavily towards class B operation. These cheaper receiver amps tend to be highly current limited as evidenced by their poor ability to handle four ohm loads and double the power available into a four ohm load. The development of better class D amps will help in this regard, but still the power supply will have to be formidable.

Now there is a good reason that the higher end separates tend to shy away from these auto Eq sytstems.

It is a bad idea. Frst of all it is a myth that you can Eq away loudspeaker problems. You can't. Take a null at crossover for instance, if the auto Eq tries to correct it, the power increases to both drivers, but they are still out of phase and canceling. So the magnitude of the over drive can become immense. The auto Eq program has no idea where the resonant frequency of a tweeter is, for instance, and can inadvertently drive a tweeter to its area of resonance increasing distortion and harshness. There are so many things wrong with this I could be up all night listing them all.

The next issue is room Eq. Nothing says a room has to be Equalized to flat, and it will likely stress a speaker to do so. If you had a couple of instrumentalists in your room and they sound pleasing, then there is nothing intrinsically wrong with the room for the reproduction of music. Rooms intrude when a speaker's off axis response does not mirror the axis response, and the speakers have a poor waterfall plot.

With the long term and current state of microphone technology, the microphones have to be placed closer to the sound source than in the hall where a listener would obtain a pleasing balance. I'm speaking here about classical productions, pop productions are a different kettle of fish. Because of this phenomenon the recording will contain a balance favoring direct sound over reflected sound, where as the listener in the hall will hear a much higher proportion of reflected sound.

So random reflections in a listening room actually enhance a good recording if it is a good room. I and others have noted even a room with a definite echo does not preclude it it from being a good listening room. Auto Eq programs can, and often do spoil an otherwise pleasing room. I see no justification for them at all. Some systems and rooms can be in need of touch up, but I believe this is best done by ear with subtlety. Good loudspeakers will sound their best in the vast majority of rooms with NO equalization.

So in essence those are my objections. Really scarce resources are much better put towards improved basic engineering.

All these "peculiar notions" of the high end distract effort and resources away from solving real and important problems. There are for too many big problems out there to be wasting time on imagined problems.

 

[fmw]

Nicely said, TLS.

If you spend some time studying the pro audio world rather than the myth ridden home audio world, you will learn that active biamplification does a lot of valuable things for sound quality and control of a system while passive biamplification really does nothing useful at all. The problem is that, in order to get an effective biamplification scheme in place, you need to REPLACE the passive network with the active unit. You need to go into the speaker cabinet and disconnect the crossover so that the active one that works in front of the amplifiers can do the job instead. Passive biamplification is simply the convenient home audio way of trying to accomplish what the pros do. Trust me, it doesn't accomplish it. I don't even believe you can buy an active crossover marketed specifically for home use. I could be wrong, but all the active units come from pro audio.

The people who do passive biamplifiaction, love it. No suprise there. However, if you were to set the system up in a way that would allow bias controlled listening tests they wouldn't love it any longer. They wouldn't hear any difference at all. The problem with people's reaction to audio is perceptual hearing. It has fouled up the audio industry beyond belief. But we humans are perceptual hearers and that's the way it is. So the arguments go on and on and on.