Using an AVR for 2 channel. Any benefit with Bi-Amping? Are any bridgeable?

[perpetualglass]

Is it possible to run some of middle and high(ish) end AVRs (Onkyo 818, Denon 4311, Pioneer SC 1522K, in bi amped 2 channel? Is there any benefit gained by doing so? It appears that many, if not most of these amps list their power outputs and distortion levels with only 2 channels running, despite being 7.2/9.2/512.64 capable. In other words, if the supposed output is 140wx9 channels, will using 4 of them amps to power 2 speakers really give you double of the electrical output, in this case 280w per speaker? It seems that the power supply would be the potential power bottleneck, and I'm sure there are others, I'm still pretty clueless to this higher end receiver world. Hell, I still can believe audio auto EQs are somewhat of a standard now.

Are any of them bridgeable?

 

[AcuDefTechGuy]

No real world benefits of passive bi-amping of any kind IMO, although there is slight potential theoretical benefits to even bi-wiring.

Using 2Ch out of the 9Ch will not "double" your power, but it will give you the most power. For example, the $2300 Onkyo 3010 outputs 189.5 WPC x 2Ch into 8 ohms @ 1% THD, but outputs 147.2 WPC x 5Ch and 127.2 WPC x 7Ch into 8 ohms @ 1% THD.



The $1100 Denon 3312:
Two channels driven continuously into 8-ohm loads 1% THD: 143.3 watts
Five channels driven continuously into 8-ohm loads 1% THD: 103.0 watts
Seven channels driven continuously into 8-ohm loads1% THD: 96.8 watts


Keep in mind:
Double amplifier wattage *increases +3 dB of sound
Double number of speakers *increases +3 dB
Double distance from sound source *decreases 6 dB
Halve distance from sound source *increases +6 dB

Doubling the amplifier wattage results in ONLY a 3dB increase in volume ("slightly louder"). Switching from a 50 watt amplifier to a 100 watt amplifier or from a 100 watt amplifier to a 200 watt will only increase the volume by 3 dB as long as you use the same speakers.
In order to double the current volume requires roughly a 6 to 10 dB increase. A 6 dB increase requires 4 times the power! and a 10 dB increase requires a 10*fold increase in amplifier power.

 

[perpetualglass]

No real world benefits of passive bi-amping of any kind IMO, although there is slight potential theoretical benefits to even bi-wiring.

Using 2Ch out of the 9Ch will not "double" your power, but it will give you the most power. For example, the $2300 Onkyo 3010 outputs 189.5 WPC x 2Ch into 8 ohms @ 1% THD, but outputs 147.2 WPC x 5Ch and 127.2 WPC x 7Ch into 8 ohms @ 1% THD.



The $1100 Denon 3312:
Two channels driven continuously into 8-ohm loads 1% THD: 143.3 watts
Five channels driven continuously into 8-ohm loads 1% THD: 103.0 watts
Seven channels driven continuously into 8-ohm loads1% THD: 96.8 watts


Keep in mind:
Double amplifier wattage *increases +3 dB of sound
Double number of speakers *increases +3 dB
Double distance from sound source *decreases 6 dB
Halve distance from sound source *increases +6 dB

Doubling the amplifier wattage results in ONLY a 3dB increase in volume ("slightly louder"). Switching from a 50 watt amplifier to a 100 watt amplifier or from a 100 watt amplifier to a 200 watt will only increase the volume by 3 dB as long as you use the same speakers.
In order to double the current volume requires roughly a 6 to 10 dB increase. A 6 dB increase requires 4 times the power! and a 10 dB increase requires a 10*fold increase in amplifier power.

So then, with the above example of the Denon 3312, by using 4 of the internal amplifiers to drive 2 speakers would yield 206.0wpc vs 143.3wpc by using just 2 of the outputs for 2 speakers? And yes, I'm aware of the logarithmic nature of wattage and SPL, and I think it's wonderful that you post such thorough replies. It really helps feed my addiction.

 

[AcuDefTechGuy]

So then, with the above example of the Denon 3312, by using 4 of the internal amplifiers to drive 2 speakers would yield 206.0wpc vs 143.3wpc by using just 2 of the outputs for 2 speakers?

Nope. Bi-amping won't output more power. You would still get 143 WPC AFAIK.

 

[perpetualglass]

Why is that? It doesn't make a whole lotta sense. I guess I'm wondering if there are any (common) AVRs out there that allow more than 2 channels to be assigned to full bandwidth, in that case, I'm not sure how an AVR could not deliver in the above listed fashion of 103.0WPC x 2 (per side/speaker), yielding 206.0WPC total.


While we're on it. I'm SO MAD that I missed the Denon 4311 closeout that was going on March 25th. I'm in sore need of a receiver that does 2 channel well. I REALLY do not want to spend more than $1,500. Any recommendations? this one might be worthwhile Pioneer SC 1522K for $599.99 at Costco

It's been about 15 years since I last shopped for this stuff, and the quality of most of the newer stuff is JUNK. Even the Marantz 5007 that I purchased and exchanged twice had problems with its' optical inputs. I'm really blown away at how literally lightweight everything is these days and how much must be spent for all of these bells and whistles, without a solid underlying architecture. I'm currently using an Onkyo-9050, and it's underwhelming to say the least.

 

[PENG]

Why is that? It doesn't make a whole lotta sense. I guess I'm wondering if there are any (common) AVRs out there that allow more than 2 channels to be assigned to full bandwidth, in that case, I'm not sure how an AVR could not deliver in the above listed fashion of 103.0WPC x 2 (per side/speaker), yielding 206.0WPC total.

Your math is correct, but the amps will only output what is demanded from them. Theoretically though, you do get more if you push the limit of the amp but not like double, not even close because the tweeter just don't take that much power. In some bi-ampable speakers, the tweeter and the mid(s) are grouped together when you remove the shorting links, so in that case they could benefit more from that added power from using 2 channels per channel, but the tweeter and mid(s) still will not take as much power as the woofer(s) do and the woofer(s) will still be sucking from the same one channel. If you are after more power, you will be better served to pick up a 200WPCX2 amp vs biamping with 4X100WPC. I think that's what ADTG is alluding to.

 

[PENG]

No real world benefits of passive bi-amping of any kind IMO, although there is slight potential theoretical benefits to even bi-wiring.

Using 2Ch out of the 9Ch will not "double" your power, but it will give you the most power. For example, the $2300 Onkyo 3010 outputs 189.5 WPC x 2Ch into 8 ohms @ 1% THD, but outputs 147.2 WPC x 5Ch and 127.2 WPC x 7Ch into 8 ohms @ 1% THD.



The $1100 Denon 3312:
Two channels driven continuously into 8-ohm loads 1% THD: 143.3 watts
Five channels driven continuously into 8-ohm loads 1% THD: 103.0 watts
Seven channels driven continuously into 8-ohm loads1% THD: 96.8 watts


Keep in mind:
Double amplifier wattage *increases +3 dB of sound
Double number of speakers *increases +3 dB
Double distance from sound source *decreases 6 dB
Halve distance from sound source *increases +6 dB

Doubling the amplifier wattage results in ONLY a 3dB increase in volume ("slightly louder"). Switching from a 50 watt amplifier to a 100 watt amplifier or from a 100 watt amplifier to a 200 watt will only increase the volume by 3 dB as long as you use the same speakers.
In order to double the current volume requires roughly a 6 to 10 dB increase. A 6 dB increase requires 4 times the power! and a 10 dB increase requires a 10*fold increase in amplifier power.

This is a tpical highly useful response imho, I love it when it's back with ref data, though we do have to consider how credible such data are and whether there are caveats behind them.

 

[AcuDefTechGuy]

I'm SO MAD that I missed the Denon 4311 closeout that was going on March 25th.

Electroncs Expo was selling the 4311 for $1225 delivered way before that time. Call around and see if anyone still has them for deep discount.

 

[perpetualglass]

Electroncs Expo was selling the 4311 for $1225 delivered way before that time. Call around and see if anyone still has them for deep discount.

I'm talking about the $799 deal from Vann's and Amazon. Once I'm in the $1250 bracket, it becomes easier to justify an ATI or Emotiva.

 

[Swerd]

You're not as clueless as you think .

Is it possible to run some of middle and high(ish) end AVRs (Onkyo 818, Denon 4311, Pioneer SC 1522K, in bi amped 2 channel? Is there any benefit gained by doing so?

Yes it's possible, but, as others have said, there is no audible benefit to be gained.

It appears that many, if not most of these amps list their power outputs and distortion levels with only 2 channels running, despite being 7.2/9.2/512.64 capable.

Yes. The Federal Trade Commission rules require that receiver power ratings show RMS power at 20-20,000 Hz, at a defined distortion level, with an 8 ohm load, while 2 channels are driven. If more channels are in use, you can be confident the power per channel will be less.

In other words, if the supposed output is 140wx9 channels, will using 4 of them amps to power 2 speakers really give you double of the electrical output, in this case 280w per speaker? It seems that the power supply would be the potential power bottleneck…

Yes. I could be wrong, but I don't know of any AV receivers that have more than one power supply shared by all the ouput amplifiers. Let's assume the power supply is large enough to get the job done for all the channels. Using two amp channels for one speaker will not provide more power. The only way to provide greater power is buy an AV receiver that allows adding an external power amp with it's own power supply.

Are any of them bridgeable?

Not that I know of.

 

[AcuDefTechGuy]

I'm talking about the $799 deal from Vann's and Amazon. Once I'm in the $1250 bracket, it becomes easier to justify an ATI or Emotiva.

Dang, $799 for the 4311?

Why didn't Amazon send me an email?

 

[mtrycrafts]

... If you are after more power, you will be better served to pick up a 200WPCX2 amp vs biamping with 4X100WPC. I think that's what ADTG is alluding to.

Absolutely. Tweeters are at best rated to 5 watts to 10 watts and even that may be on the higher end., even in good speakers. Not sure how much the mids are rated for but pretty sure it is far less than the woofs.
So, such a high power amp to them not to mention the music/movie content's power needs to those mids and highs may be way over kill as it will not ever get there but, one may increase the chance of blowing the tweets.

 

[twylight]

OP - just plug them in normal and dont worry about it

 

[perpetualglass]

I guess I should just look at an HK 3490, it seems like the best bang for the buck at the moment.

 

[GIEGAR]

Not that I know of.

A bit of useless trivia: Onkyo TX-NR3007 & TX-NR5007 (2009) and TX-NR3008 & TX-NR5008 (2010) had what they called "BTL (Bridged Transless) Capability". I think we know this as bridgeable. It hasn't appeared on Onkyos since.

The 3008 & 5008 are still great AVRs if you don't need all the latest "new media" support etc.

 

[PENG]

I guess I should just look at an HK 3490, it seems like the best bang for the buck at the moment.

Wait a minute, am I missing something here, why would you go from an Onkyo A-9050 to a HK3490? Do you really need the tuner or the features that the HK has and the A-9050 hasn't? I thought you are after more power. The 3490 may get you a dB or slightly more power, nothing more. The 9050 has Wolfson DACs in them, not sure about the HK. I just don't think that little bit more power will help you. How much power do you need anyway? Or tell us the model of your speakers, room size, how far you sit from them etc., so some of us figure it out.

 

[perpetualglass]

The HK 3490 has the Onkyo 9050 beat by significantly by a much lower price. Therein lies the preference for the HK3490. And the probable better customer service. I still have not been able to get through to Onkyo to ask a few simple questions. If at some point later down the line, I wish to Bi-Amp, it would be nice to run two HK3490s, as I could see a real benefit if the speakers were configured like the current SVS Ultra Towers that I am playing with (sending them back tomorrow). However, the dual volume controls would be a real hassle.


Next in my lineup includes NHT Fours, Aperion Verus Grandes, Gallo Classicos, and if I'm happy with none of the above, then I'll ultimately settle with the Ascend Sierras.

The room is 18x24x8, and no, I do not want bookshelves and a sub, since bookshelves + their stands occupy almost the same space, I find them almost redundant.

After listening to Ed Frias' setup, he did a pretty good job of convincing me of the sound quality and control improvement that is gained by running a system with plenty of headroom. I am not sure if it helps with imaging and soundstage, but it probably does not hurt. Heck, I'm not even sure if the headroom realistically improves bass output and control, but from a pure electrical/physics standpoint, it makes plenty of sense.


Given the pricepoint, it seems that this: http://shop.emotiva.com/collections/amplifiers/products/xpa2 would be a fair contender, even though I really did not want to go that route, initially.

Oh yes, and radio makes no difference to me. Streaming NPR from the internet is not something that requires high fidelity, now that Car Talk is dead.

 

[ski2xblack]

...If at some point later down the line, I wish to Bi-Amp, it would be nice to run two HK3490s, as I could see a real benefit if the speakers were configured like the current SVS Ultra Towers that I am playing with (sending them back tomorrow). However, the dual volume controls would be a real hassle.

The HK has pre-outs. Use with whatever amp you need. Use y-splitters and use the internal and external amps if you wish. No need for two 3490s when one can control the volume to any downstream amps.

 

[perpetualglass]

The HK has pre-outs. Use with whatever amp you need. Use y-splitters and use the internal and external amps if you wish. No need for two 3490s when one can control the volume to any downstream amps.

If only the volume knob still worked on my old Pioneer VSX D511

 

[bikemig]

Why is that? It doesn't make a whole lotta sense. I guess I'm wondering if there are any (common) AVRs out there that allow more than 2 channels to be assigned to full bandwidth, in that case, I'm not sure how an AVR could not deliver in the above listed fashion of 103.0WPC x 2 (per side/speaker), yielding 206.0WPC total.


While we're on it. I'm SO MAD that I missed the Denon 4311 closeout that was going on March 25th. I'm in sore need of a receiver that does 2 channel well. I REALLY do not want to spend more than $1,500. Any recommendations? this one might be worthwhile Pioneer SC 1522K for $599.99 at Costco

It's been about 15 years since I last shopped for this stuff, and the quality of most of the newer stuff is JUNK. Even the Marantz 5007 that I purchased and exchanged twice had problems with its' optical inputs. I'm really blown away at how literally lightweight everything is these days and how much must be spent for all of these bells and whistles, without a solid underlying architecture. I'm currently using an Onkyo-9050, and it's underwhelming to say the least.

The Onkyo 9050 is a pretty nice amp with high quality dacs; the problem you are perceiving may be something other than the amp. In any case, it has pre-outs so you could pick up an emo amp if you're hungry for something more powerful. If all you are doing is listening to music, I don't see the advantage, in your case, to an AV receiver given that you have a nice 2 channel integrated amp with high quality digital inputs.