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

Discussion in 'A/V Interconnects, Cables & Power Conditioning' started by Tradeinstyle, Jul 8, 2012.

  1. Tradeinstyle Audiophyte

    Tradeinstyle
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    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: Jul 8, 2012
  2. j_garcia Audioholic Jedi

    j_garcia
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  3. Tradeinstyle Audiophyte

    Tradeinstyle
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    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.
  4. Tradeinstyle Audiophyte

    Tradeinstyle
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    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.
  5. gene Audioholics Master Chief Administrator

    gene
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    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.
    gene,
  6. lsiberian Audioholic Overlord

    lsiberian
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    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.
  7. markw Audioholic Overlord

    markw
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    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: Jul 9, 2012
  8. j_garcia Audioholic Jedi

    j_garcia
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    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.
  9. SDrabott Audiophyte

    SDrabott
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    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: Jun 30, 2013
  10. markw Audioholic Overlord

    markw
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    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.
  11. j_garcia Audioholic Jedi

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

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