Bi-Amping Help

Discussion in 'Archived Threads 2001-2004' started by Craig Ball, Feb 9, 2002.

  1. Craig Ball

    Craig Ball Second Unit

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    I'd like to try and bi-amp my Klipsch speakers using my two Acurus 200x3 amps. Please tell me if this is a good or bad way of doing things, Since my Acurus amps only have one input for each channel I was going to run an RCA from my main out,will say left side for this discussion to a splitter into two of the inputs on one of my acurus amps. So i'd be splitting the signal from my pre-amp ino two channels of my Acurus right? Then remove the binding posts from my speaks and use one of the channels of the amp for the lows and one channel for the highs. Will this work? Is there another way to do it?

    Craig
     
  2. Philip Hamm

    Philip Hamm Lead Actor

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    As long as the speakers are biampable this will work fine. I would recommend trying to find good quality splitters for this applciation.
    Strangely enough there is a post about biamping like this in the newbie section! [​IMG]
     
  3. Craig Ball

    Craig Ball Second Unit

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    Thanks Philip, they are Klipsch KLF-30's and they have two sets of binding posts attached bye a metal bar, I remove the bar and there then bi-wireable/biampable right? As far as the splitter goes can't i get a good quality 1 into 2 cable already made?

    Craig
     
  4. Jason Watson

    Jason Watson Stunt Coordinator

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    Craig,

    If you can not find a good quality "Y" splitter, you can just get a solid "T" with one male and two females. Plug the male"T" into the pre-out of each channel, and run four interconnects of your choice from the females down to the amp. If you are a wire guy,(like me)you might find this easier than finding a "Y" cable you are happy with.

    Jason
     
  5. Kevin McCurdy

    Kevin McCurdy Stunt Coordinator

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    Sorry for jumping in, but I've had this nagging question in the back of my mind regarding this type of bi-amping, and it seemed like a good time to ask.

    If your taking the pre-out from your preamp and splitting it using a y-splitter and then going into two separate amp channels would'nt you effectively cut the signal in half going into each of those amp channels? If so, wouldn't this also cut in half the output of each of those amp channels connected to the Y-splitter?

    Say for example we have a 200 watt amp and 1Vrms input to each amp channel is required to produce 200 watt output at full volume and we split that signal in half using a y-splitter therefore only providing .5Vrms to each amp channel with this input wouldn't each channel only produce 100 watts at full volume instead of 200 watts, or does it not work that way?

    My intention is not to argue the merits of bi-amping, I only want to understand how it works (in easy to understand terminology). Thanks in advance.
     
  6. Craig Ball

    Craig Ball Second Unit

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    Thanks for the "T" suggestion. And Kevin now you've got me worried, I do have two 200 watt amps and definately don't want to split that in half by using a splitter. I just wanted to take advantage of the bi-amping capabilities of my speaks. Is Kevein right about this? Is there a better way?

    Craig
     
  7. Philip Hamm

    Philip Hamm Lead Actor

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    Kevin, that's not correct. The line level signal can be split with no degradation of the signal at all. The signal isn't being "split", it's being "distributed".
     
  8. Kevin McCurdy

    Kevin McCurdy Stunt Coordinator

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    Philip,

    Thank you!

    Craig,

    Sorry, didn't mean to get you worried.
     
  9. John Tompkins

    John Tompkins Supporting Actor

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    Phillip, Maybe you would know the answer to my question. I have the sherwood 9080 amp which I love by the way, anyways its 120 watts per channel, I have it bi-amping with a y splitter to a pair of nht 2.9 {effectivly 240 watts}. I used the test tone to calibrate volume. Now I switched to a single not bi-amped sherbourn 200 watt amp and low and behold when I calibrated I had to turn the denon down from +2 to -2. Thats a big swing in volume. Could it be from the y splitters themselves cutting my volume down or maybe Kevin has a point, not that I dont believe you but Kevins arguement has some merit I beleieve..thanks
     
  10. Ricky T

    Ricky T Supporting Actor

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    John,

    You'd only get the full effective 240 watts if the top and bottom halves of your speakers "eat" up watts equally. I recall some active biamping articles stating that the breakeven point for most speakers is ~ 250-350 hz. Your 2.9s are "split" at 100hz, so the top half is probably pulling more watts than the lower half.

    Craig,

    If your Klipsch are very sensitive (ie, over 94dB), I doubt if biamping will give you an improvement over your current 200 watts.
     
  11. John Tompkins

    John Tompkins Supporting Actor

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    Ricky, thanks for the explanation, but I guess what I was really trying to ask is..If my sherwood is 120 watts with one channel alone say and the sherbourn is 200 watts, and assuming it takes double the power to produce 3 db difference, then why did I have to turn my denon down 4 db when thier was at least only an 80 watt difference ? was it the Y spliter. Also do you know what a recievers pink noise generators hz is ? I always been curious about that..thnaks Ricky or anybody else who has possible answers..
     
  12. Craig Ball

    Craig Ball Second Unit

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    Thanks again Philip, and no problem Kevin, thats why we all ask here right? Ricky my speaks are 102db sensative, if bi-amping wouldn't make a differnce then why make them with 2 sets of binding posts? Don't get me wrong i'm not just trying to trow my money away, because if i did do this i'd still need another amp for my side surrounds, but if it will improve things then i'll do it.

    Craig
     
  13. Ricky T

    Ricky T Supporting Actor

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    Craig,
    Why two sets of posts? Maybe you want a tube amp for the mids/highs and solid state for the lows. Or maybe you have a 50x5 amp, then biamping with two 50 watt channels might be beneficial over one 50 watt channel.
    102 dB?! Wow! My NHTs are 87 dB. 15dB diff > doubling power for each 3 dB > 5 to the 2nd power or 32 times. 200 watts to your speakers, is like 6400 watts to mine! I think your single acurus 200 watt channel is enough [​IMG]
     
  14. Jason Watson

    Jason Watson Stunt Coordinator

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    Craig,

    What cables are you using now? If 12ga. stranded OFC stuff, maybe try a cable upgrade first. As a former Acurus owner,(well actually my A250 still runs my surrounds)I can tell you,power is not a problem with your Klipsch speakers.I am passivly bi-amping my Magnepan 1.6s with four channels of a Powermaster 1000 with good results. However, these are very power hungry/power loving speakers. Your Klipsch, being so efficient may not show the benefits as readily. That is why I am thinking you might find more improvement, for less money, elsewhere. The forward nature of your Klipsch/Acurus combo is very much like my old system(still in the photo that pops up when you click on my little home symbol)of NHT/Acurus. When I swapped cables from 12ga.stranded AR to Audioquest Indigo, it made a very nice improvement. Cheap at the price too!

    Jason
     
  15. ClaudeD

    ClaudeD Extra

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    John said
     
  16. ClaudeD

    ClaudeD Extra

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    Further to the pink noise question, AFAIK pink noise is like white noise, but with an increased level in the (IIRC) high frequencies. White noise, AFAIK, is equal level at all audible frequencies.

    In any case, they don't have a Hz rating as such, since they cover the audible spectrum. Between FM channels on a tuner is one example of white noise, i.e., random noise that includes all frequencies roughly equally.
     
  17. John Tompkins

    John Tompkins Supporting Actor

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    Claude, Very informative post and appreciated, are you sure your not an EE.[​IMG] The ohm change when x-overs are removed is interesting. I agree with you about the benifits of active versues passive bi-amping, but Im not willing are knowledgeable enough to ever attempt active bi-amping. Another thing while were at it, I had the sherbourn 5/1500 bridgeable unit. Most amps seem to rate at triple their 8 ohm value when bridged 100 watts becomes 300 watts. The Sherbourn is interesting in that the amp is rated at 200 watts @ 8 ohms and rated at 400 watts @ 8 ohms bridged, seems curious ?? Just wondering why
     
  18. ClaudeD

    ClaudeD Extra

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    John, Glad you found it informative. Now I'm REALLY hoping that I was accurate [​IMG]
    I'm with you on active bi-amping, at least as far as doing it with speakers that weren't designed for it. Almost all Linn speakers are designed with an upgrade path to active (aktiv in Linnish), and they're my personal choice.
    The ohm change surprised me when I first found out about it, but it makes sense. Two drivers in a cabinet are not so different from two speakers wired together. The impedance of the combination will not be the same as either individually, and depending on whether the circuit is wired in series or parallel, that will determine the resulting combined impedence.
    That pretty much exhausts the extent of my knowledge (and I had to repeat myself to stretch it out [​IMG] ). I have no idea how bridging really works. My only guess is that the Sherbourn is limited by its power supply; was the unbridged rating with only one channel driven? Perhaps you can't fully drive two channels (bridged together) because there's a limited and shared power supply (i.e., not dual mono).
    Claude
     
  19. Brian O

    Brian O Second Unit

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    I have a question too. If by passive bi-amping, arent you eliminating the speaker crossover out of the picture? If so, would that change the speaker characteristics the manufacturer intended?

    I have 3 speakers I am/have bi-amped, Monitor Audio Silver 5 mains and the 10 Center. They are hooked to 2 HK PA5800 5 channel Amps with a Denon 3300 as a Pre/Pro. I am using Y splitters.

    I did have all of those bi-amped, but the left main started shorting out the Amp for some reason. I never did isolate it, but since I quit bi-amping that speaker, it quit shorting and I have just left it that way for now.

    So, my left main is NOT bi-amped where my Center and right main ARE. I have noticed my left main seems to be one or two dbs louder, but I just figured it was because it was in the corner more so than the other two.

    It is tough to say if I really notice any difference otherwise.
     
  20. ClaudeD

    ClaudeD Extra

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    Brian said
     

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