Using a multichannel amp to Bi-wire/Bi-amp

T

Tradeinstyle

Audiophyte
Any electrical engineers out there?

Set up:
- Yamaha RX-Z9 (running surrounds FRT/REAR)
- Parasound HCA-2205A (running Center and Fronts)
- Center= Definitive CLR-2500
- Fronts= JBL L7's

Current config:
I'm currently using the Parasound to run the center and L7's and it has made a huge difference in the overall impact. So, I'm using 3 channels of the Parasound at present.

Question:
I've considered just passive bi-wiring these three channels as I need better speaker cabling anyway, but my real question is regarding the Parasound. Does it make any sense at all to use the remaining 2 channels to bi-wire the L7's? It seems such a waste to have these channels not being used. So, the technical question is can you split the PRE OUTS for the FRONTS and feed them to 2 different channel inputs on the Parasound and then use the outputs of the 4 channels to bi-wire the L7's? I don't understand the implications of essentially tying two inputs together on the Parasound to accomplish this. I do understand that the same power transformer is feeding the entire amp but each channel has it's own storage capacitors (30,000uF each channel), transformer winding, and output devices so my thought is I would be gaining some power reserve. So, FRT LEFT on the Z9 would feed channels 1,2 on the Parasound and FRT RIGHT would feed channels 3,4. Then channels 1,2 would bi-wire the Left L7 and channels 3,4 would bi-wire the Right L7.

I've read the many threads on bi-amping/bi-wiring and I certainly don't mean to revisit what others have discussed, my main question is will I damage my equipment by splitting the PRE OUT on the Z9 and use it to feed two channels on the Parasound.

Thank you in advance for your advice and expertise.
 
Last edited:
j_garcia

j_garcia

Audioholic Jedi
Any electrical engineers out there?
Not sure why people ask that. It isn't rocket science, it is audio. All you need are ears, not an engineer.

I've read the many threads on bi-amping/bi-wiring and I certainly don't mean to revisit what others have discussed, my main question is will I damage my equipment by splitting the PRE OUT on the Z9 and use it to feed two channels on the Parasound.
No you will not damage anything, but you also already pretty much answered your own question. There won't be a significant benefit either.
 
T

Tradeinstyle

Audiophyte
I need a bit more...

Although I appreciate receiving a reply, I need more substance. I understand that when I split the preamp out there is a signal loss but that may be easily compensated for with the Z9's YPAO. So, what I need to understand better is:

1) What effect does tying the two channel's inputs together on the multichannel amp have on the amp? What is the downside, if any, and why?

2) As stated in my original post, the HCA-2205A is basically 5 amps in one with separate secondary windings for each channels, separate filter caps for each channel, separate discrete devices for each channel. So, with that in mind, if I feed the PRE OUT FRONT LEFT into a Y adapter and then feed those two separate channels on the Parasound, and in turn use those 2 channels to bi-wire the L7's won't that give me additional capacity as I'm adding 30,000uF and a set of output devices in the chain to the speaker.

How would one calculate the effect? I'm an engineer, albeit Software, so I'm looking for a technical explanation as to the effectiveness and pros/cons of such a set up.
 
T

Tradeinstyle

Audiophyte
Technical article regarding this issue.

I can't post the article's link as I'm a newbie to this forum, but here's a selection from the article.

"There is no net system power increase at the speakers assuming the amps have the same voltage rails (e.g. inside an AVR or multichannel amplifier with the same power voltage rails to all amps). If you had a 100 W amp before, passive bi-amping does not give you 200 W to the speaker. You have split the load into two frequency bands, but the net power is the same to the speaker. That is, 100 W to the lows and 100 W to the highs is the same as having a 100 W amp that covers the entire frequency range. It is not the same as driving the speaker with a 200 W amplifier; to increase the power, you need to increase the voltage rails."

Note the caveat, "assuming the amps have the same voltage rails (e.g. inside an AVR or multichannel amplifier with the same power voltage rails to all amps)"

So with the Parasound HCA-2205A, does each channel have it's own voltage rail? The specs elude to that possibility, but again I'm no expert in this area.
 
gene

gene

Audioholics Master Chief
Administrator
Any electrical engineers out there?

Set up:
- Yamaha RX-Z9 (running surrounds FRT/REAR)
- Parasound HCA-2205A (running Center and Fronts)
- Center= Definitive CLR-2500
- Fronts= JBL L7's

Current config:
I'm currently using the Parasound to run the center and L7's and it has made a huge difference in the overall impact. So, I'm using 3 channels of the Parasound at present.

Question:
I've considered just passive bi-wiring these three channels as I need better speaker cabling anyway, but my real question is regarding the Parasound. Does it make any sense at all to use the remaining 2 channels to bi-wire the L7's? It seems such a waste to have these channels not being used. So, the technical question is can you split the PRE OUTS for the FRONTS and feed them to 2 different channel inputs on the Parasound and then use the outputs of the 4 channels to bi-wire the L7's? I don't understand the implications of essentially tying two inputs together on the Parasound to accomplish this. I do understand that the same power transformer is feeding the entire amp but each channel has it's own storage capacitors (30,000uF each channel), transformer winding, and output devices so my thought is I would be gaining some power reserve. So, FRT LEFT on the Z9 would feed channels 1,2 on the Parasound and FRT RIGHT would feed channels 3,4. Then channels 1,2 would bi-wire the Left L7 and channels 3,4 would bi-wire the Right L7.

I've read the many threads on bi-amping/bi-wiring and I certainly don't mean to revisit what others have discussed, my main question is will I damage my equipment by splitting the PRE OUT on the Z9 and use it to feed two channels on the Parasound.

Thank you in advance for your advice and expertise.
You are confusing bi-wiring with bi-amping. Biwiring uses the same amp but uses a pair of cable fed to the speakers top and bottom terminals with the jumpers removed. The amp itself actually sees a very similar load impedance minus some minor changes in cable impedance going from a single to a bi-wire configuration.

Bi-amping is when your using a different amp to power the top portion of the speaker and another amp to power the bottom portion. This is what you're trying to do with the Parasound.

There is NO reason why you cannot split the signal from your Yamaha preamp to the Parasound. The input impedance of the Parasound is very high so it won't cause any loading issues with your Yamaha.

Before doing this, make sure your speakers are capable of being bi-amped. Some speakers can be biwired but NOT bi-amps. The crossover has to physically separate the connection between the top/bottom portions of the speaker to bi-amp. If it doesn't you can seriously damage your amps.
 
lsiberian

lsiberian

Audioholic Overlord
Any positive results you get will likely be the result of the placebo effect. Bi-Amping is really not helpful unless you are using active crossovers which likely would be beyond your expertise.
 
M

markw

Audioholic Overlord
Although I appreciate receiving a reply, I need more substance.
Yes, you do. From the repies you've already received, you don't even kow enough about the subject to even pose an intelligent quetion.

Read more, perhaps full articles on the subject instead of snippets gleaned from bits and pieces of various threads. Perhaps then you can understand the threads in the forums better.

As for forums, lurk more. Then consider asking questions but, if you read more articles and learn enough, you might find you don't have to.

If you had, you would have known that you really can't predict how this configration will sound without doing it.
 
Last edited:
j_garcia

j_garcia

Audioholic Jedi
I can't post the article's link as I'm a newbie to this forum, but here's a selection from the article.

"There is no net system power increase at the speakers assuming the amps have the same voltage rails (e.g. inside an AVR or multichannel amplifier with the same power voltage rails to all amps). If you had a 100 W amp before, passive bi-amping does not give you 200 W to the speaker. You have split the load into two frequency bands, but the net power is the same to the speaker. That is, 100 W to the lows and 100 W to the highs is the same as having a 100 W amp that covers the entire frequency range. It is not the same as driving the speaker with a 200 W amplifier; to increase the power, you need to increase the voltage rails."

Note the caveat, "assuming the amps have the same voltage rails (e.g. inside an AVR or multichannel amplifier with the same power voltage rails to all amps)"

So with the Parasound HCA-2205A, does each channel have it's own voltage rail? The specs elude to that possibility, but again I'm no expert in this area.
The REAL question is what is the goal? In the end, most people don't need that much power to achieve reference levels, so unless you are looking for concert levels, the way you have it connected now should be fine. If you need more power, get a bigger amp.
 

SDrabott

Audiophyte
From what i understood the OP wants to Bi-amp using the different channels of his amp instead of using two different amps.
I also have a multichannel Dared amp, and was wondering the same.
I currently Bi-wired two front speakers using one channel, i have two more channels unused, and was curious if its better to do this:

left speaker highs to left front
left speaker lows to left surround
right speaker highs to right front
right speaker lows to right surround

I can independently controll volume on all 3 channel outputs.

i cannot easily test this setup above because i have the Bi-Wire hard soldered to connect to one channel and split into four banana connectors which hook up to the speaker.

Thanks in advance.

Serge.

By the time im done typing the question it males sence for me to do it but i still consider myself a noobie in audio, so experts are welcome to chime in.

* if youre a smartass, dont tell me to use the search button, i couldnt find the info on here, but if you understand the question and willing to contribute, please do so and my appreciation will have no end.
 
Last edited:
M

markw

Audioholic Overlord
Well, not to be a smartass, OP pretty much gave you a good clue in post four, if you understood it. Now, hit the books to find out how your amp is wired.

In any case, as for any expected results, they were pretty much summed up in several other posts in this thread, particularly since you didn't even bother to list your speakers..

But, as in all things audio, one won't really be sure what ones ears (or imagination) will tell them until one tries. That much should already be clear.

I can say with some authority, though, that it shouldn't matter which channel goes to what speaker terminal.

From what I read, your amp, it has (at least) six inputs and six outputs. I have no idea why you needed to solder anything to begin with, but I guess it's time to break out the ole soldering iron and see what happens.
 
j_garcia

j_garcia

Audioholic Jedi
You cannot biamp via a single channel no matter how many connectors you put on it.
 
P

ParleyW

Junior Audioholic
Any positive results you get will likely be the result of the placebo effect. Bi-Amping is really not helpful unless you are using active crossovers which likely would be beyond your expertise.
Old post, but wanted to add that JBL specifically mentions the sonic benefits of bi-amping. It reduces intermodulation between channels. I would think their engineers would know the skinny. To each his own.
 
highfigh

highfigh

Audioholic Overlord
At any SPL, using two channels for passive bi-amping results in the same benefits as using a single more powerful amplifier, at the same SPL. More headroom, using less of the available power from the amplifiers. Sure, the distortion will be in the range that applies for each channel at that power level, but it's not going to be the same as operating the amplifier at WOT. It's not more power at a given SPL, but the possible SPL at full power is greater.
 
Last edited:
Pogre

Pogre

Audioholic Overlord
Old post, but wanted to add that JBL specifically mentions the sonic benefits of bi-amping. It reduces intermodulation between channels. I would think their engineers would know the skinny. To each his own.
By how much? Can you hear the difference in that reduced intermodulation? Almost certainly not. That's what he's getting at. It's more marketing fluff than substance.
 
highfigh

highfigh

Audioholic Overlord
By how much? Can you hear the difference in that reduced intermodulation? Almost certainly not. That's what he's getting at. It's more marketing fluff than substance.
I'd like to see someone pick out .001% TIM at full output of an amplifier that's capable of more than 10 Watts.
 
P

ParleyW

Junior Audioholic
By how much? Can you hear the difference in that reduced intermodulation? Almost certainly not. That's what he's getting at. It's more marketing fluff than substance.
I can hear the difference in the upper middle range. I can also see differences when frequency scanning the two and comparing with my mic. I’ll grant you the majority of folks wouldn’t notice. I have nothing else to do all day other than listen/compare. However, when bi-amping my RBH Reference SX-T2, nothin. I wouldn’t believe that the JBL guys of that era would pull your leg much. Their engineers were as good as they get. But then again, who cares? I give it a go because I have nothing better to do.
 
Pogre

Pogre

Audioholic Overlord
I can hear the difference in the upper middle range. I can also see differences when frequency scanning the two and comparing with my mic. I’ll grant you the majority of folks wouldn’t notice. I have nothing else to do all day other than listen/compare. However, when bi-amping my RBH Reference SX-T2, nothin. I wouldn’t believe that the JBL guys of that era would pull your leg much. Their engineers were as good as they get.
I do not believe you would be able to consistently pick which was which in a proper DBT.
Then again, who cares?
I would say it's the guy who bumped a 9 year old thread to comment on it...
 
P

ParleyW

Junior Audioholic
I do not believe you would be able to consistently pick which was which in a proper DBT.

I would say it's the guy who bumped a 9 year old thread to comment on it...
Did the new rover land yet? Not the only one spouting on nine year old thread? Suprised you took the time to converse with the little people.
 
Last edited:
Verdinut

Verdinut

Audioholic Ninja
Old post, but wanted to add that JBL specifically mentions the sonic benefits of bi-amping. It reduces intermodulation between channels. I would think their engineers would know the skinny. To each his own.
JBL was mostly relating to powerful amplification at near clipping levels in public venues, not in a home environment.
 

newsletter
  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top