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Thread: Bi-amping 4333A'a but experiencing a problem

  1. #1
    Member MickeyFinn's Avatar
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    Bi-amping 4333A'a but experiencing a problem

    I have recently chosen to bi-amp my 4333A's and I am experiencing a problem that I think originates with my crossover set-up.

    The problem I am experiencing is that the two speaker units are not playing equally (one channel or the other occasionally seems to not be receiving much of a signal). It seems to happen most often with the low frequency drivers.

    Okay so here is what I am using:

    JBL 4333A's
    Ashly XR-1001 crossover
    McIntosh C504 pre-amp
    Dynaco ST70 (35wpc tube amp) for the mid & high frequency drivers
    McIntosh MC2255 (250 wpc solid state amp) for the low frequency - 2231's
    Pioneer CD/DVD player

    I connected the CD player to the pre-amp with RCA cables. The pre-amp is then connected to the crossover with RCA cables by using RCA to 1/4" adapters at the crossover. The crossover is connected to each of the two amps by RCA cables again by using RCA to 1/4" adapters at the crossover.

    Since the McIntosh amp has meters I can actually see that the signals to the left and right speakers are occasionally not equal. And here is what is perplexing... if I fiddle with the crossover, including just slightly tweaking the output level of either channel, it typically corrects the problem... for a while.

    Has anyone ever experienced something like this?

    I am a newbie as regards external crossovers so I am wondering if I am making some kind of lame-brained newbie error here.

    If anyone can help me here I would be grateful for the assistance.
    My biggest fear is that, after I am dead, my kids will sell my audio equipment for what I told them I paid for it.

  2. #2
    Senior Member richluvsound's Avatar
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    Gain !

    Mickey ,

    can you get hold of another crossover to try ..... The Ashley sounds sick .... ! I don't know the Ashley ,but it sounds like a Gain issue. Gain is the thing that matches the input and output signal.


    Rich

    http://www.ashly.com/manuals/xman04.pdf

  3. #3
    Heather [Senorita member] hjames's Avatar
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    Quote Originally Posted by MickeyFinn View Post
    I have recently chosen to bi-amp my 4333A's and I am experiencing a problem that I think originates with my crossover set-up.

    The problem I am experiencing is that the two speaker units are not playing equally (one channel or the other occasionally seems to not be receiving much of a signal). It seems to happen most often with the low frequency drivers.

    Okay so here is what I am using:

    JBL 4333A's
    Ashly XR-1001 crossover
    McIntosh C504 pre-amp
    Dynaco ST70 (35wpc tube amp) for the mid & high frequency drivers
    McIntosh MC2255 (250 wpc solid state amp) for the low frequency - 2231's
    Pioneer CD/DVD player

    I connected the CD player to the pre-amp with RCA cables. The pre-amp is then connected to the crossover with RCA cables by using RCA to 1/4" adapters at the crossover. The crossover is connected to each of the two amps by RCA cables again by using RCA to 1/4" adapters at the crossover.

    Since the McIntosh amp has meters I can actually see that the signals to the left and right speakers are occasionally not equal. And here is what is perplexing... if I fiddle with the crossover, including just slightly tweaking the output level of either channel, it typically corrects the problem... for a while.

    Has anyone ever experienced something like this?

    I am a newbie as regards external crossovers so I am wondering if I am making some kind of lame-brained newbie error here.

    If anyone can help me here I would be grateful for the assistance.
    Frankly, it sounds like dirty pots on the crossovers - and that can be either the Ashly or the speakers, but it sounds like dirty pots in the Ashly ...
    2ch - Oppo981, JoLida502, JBL L200+, KEF 105.4
    HT7- XDA-2, BDP93, 4b NRB, B&K 5ch amp, Vandy 3A, 2Ce, VCC1, TF600 & JBL 4641

  4. #4
    Senior Member BMWCCA's Avatar
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    Since I use a similar setup, including an XR1001, I'd suggest checking your cables, particularly the 1/4" connections and adapters.

    I found discrepancies in the diameter of the nominal 1/4-inch shaft size that caused poor contact. In my case it was the jacks at my Crown amps that were the problem, or rather the "skinny" 1/4" plugs going into those jacks. It seems some modern cables and connectors (read: Chinese-made) aren't as close to English measurements as you'd think and the plugs weren't making continual good contact at the sleeve and caused a hum. If you're using Rat Shack 1/4" adapters you might check to see if they're fitting tightly.

    I actually purchased cables for my pre-amp-to-Ashly run that were RCA on one end and 1/4" on the other, typical of some board interconnects, which fit fine and required no adapters. But the line-level 1/4"-to-1/4" cable I bought for the Ashly-to-power-amp run were the "skinny" ones. I ended up going back to good RCA cables with some older 1/4" adapters that weren't from off-shore just to get a tight fit in the jacks on the Crown. It was a simple solution and something you might look at before you start swapping out your components.

    You might also check to see if you're using stereo phone plugs (1/4" TRS) or mono (Tip/sleeve only) as the ground connection might not be right for your unbalanced amp input. According to the Ashly manual:
    When using a stereo plug or XLR connector for unbalanced input or output
    connections, the signal (-) MUST be tied to ground, or loss of signal level may result.
    Also, I have the Ashly XR1001 (power switch on front), not the later (the most recent being Chinese-made?) Ashly XR-1001 (note hyphen, power-switch on back) so that could be an issue with connectors, too. The XR-1001 has a circuitry change that appears to handle unbalanced outputs differently. Here's the correct manual link to the later unit: http://www.ashly.com/manuals/xr-manual-n.pdf

    ". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers

  5. #5
    Member MickeyFinn's Avatar
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    Quote Originally Posted by BMWCCA View Post

    You might also check to see if you're using stereo phone plugs (1/4" TRS) or mono (Tip/sleeve only) as the ground connection might not be right for your unbalanced amp input.

    According to the Ashly manual: When using a stereo plug or XLR connector for unbalanced input or output connections, the signal (-) MUST be tied to ground, or loss of signal level may result.
    This point strikes me as the possible source of my problem. Here's a photo of the type of 1/4" adapter that I purchased...

    Name:  adapter.jpg
Views: 306
Size:  42.9 KB

    The Ashley manual identifies this type of adapter as a Mono Phono Plug used for unbalanced. And the comment from the Ashley manual above (as noted by BMWCCA) suggests "loss of signal level may result" which sounds exactly like my problem.

    Therefore it looks like I need to buy some balanced stereo 1/4" adapters and try that out.

    Or am I making another mistaken assumption?

    The Ashley manual says, "the signal (-) MUST be tied to ground..." so perhaps the problem is not with the adapters per se but rather that I need to "ground" the signal?

    Considering how easy and inexpensive it is for me to try different ("balanced") adapters I think I should buy some and simply try that first.

    Thanks everyone for your input.
    My biggest fear is that, after I am dead, my kids will sell my audio equipment for what I told them I paid for it.

  6. #6
    Member MickeyFinn's Avatar
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    Quote Originally Posted by hjames View Post
    Frankly, it sounds like dirty pots on the crossovers - and that can be either the Ashly or the speakers, but it sounds like dirty pots in the Ashly ...
    It could be that there is a problem with the Ashly crossover. The one I purchased was a floor model at the music store where I bought it (it was the only one they had in stock and I was impatient).

    And as noted by BMWCCA, the one I purchased was manufactured in China and does have the power switch on the back (which by the way is a horribly inconvenient location for the power switch).

    If I cannot get success with changing the adapters then I will try to swap out the crossover and see if that is the problem.
    My biggest fear is that, after I am dead, my kids will sell my audio equipment for what I told them I paid for it.

  7. #7
    Senior Member 1audiohack's Avatar
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    The adapter in your picture would tie pin one and three together when inserted into a balanced input.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  8. #8
    Senior Member BMWCCA's Avatar
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    Quote Originally Posted by 1audiohack View Post
    The adapter in your picture would tie pin one and three together when inserted into a balanced input.
    Hack is saying you have grounded the (-), as long as the contacts are good. So your adapters are correct for the wiring issue since your amp has no way to accept balanced input anyway. That doesn't mean somewhere along the path the cables aren't making good contact. Of course it might be the Ashly but just make sure the cables snap in snugly and don't have a lot of wiggle-room left in the sleeve contact. Simple to check, particularly if you can wiggle them while the signal is dropping out and see if that makes any difference. Just a thought.
    ". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers

  9. #9
    Member MickeyFinn's Avatar
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    Quote Originally Posted by BMWCCA View Post
    That doesn't mean somewhere along the path the cables aren't making good contact. Of course it might be the Ashly but just make sure the cables snap in snugly and don't have a lot of wiggle-room left in the sleeve contact. Simple to check, particularly if you can wiggle them while the signal is dropping out and see if that makes any difference. Just a thought.
    BINGO!

    It turns out that my problem was in fact a loose cable.
    (How's that for a newbie problem eh?)

    Interestingly, it wasn't at the Ashly crossover where the problem resided. It was one of the connections at the McIntosh amp. One side of the cable carrying the low frequency signal from the crossover to the McIntosh amp was the source of the problem. By wiggling it at the back of the amp, as suggested by BMWCCA, it became immediately obvious.

    Thanks BMWCCA.

    This raises a question though!

    Why do you suppose that when I was experiencing a signal loss (which as I noted above I could visually see on the meters of the McIntosh) that I could correct it by fiddling with the channel "output" knob on the Ashly?
    My biggest fear is that, after I am dead, my kids will sell my audio equipment for what I told them I paid for it.

  10. #10
    Senior Member BMWCCA's Avatar
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    Quote Originally Posted by MickeyFinn View Post
    Why do you suppose that when I was experiencing a signal loss (which as I noted above I could visually see on the meters of the McIntosh) that I could correct it by fiddling with the channel "output" knob on the Ashly?
    Uhh, if one channel had lower level due to a high-resistance connection, raising the level of that channel before the amp would increase the level at the power-amp even with the cable issue. You could have accomplished the same thing with the pre-amp balance control, too.

    Glad you solved the problem.
    ". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers

  11. #11
    Member MickeyFinn's Avatar
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    Quote Originally Posted by BMWCCA View Post
    Uhh, if one channel had lower level due to a high-resistance connection, raising the level of that channel before the amp would increase the level at the power-amp even with the cable issue. You could have accomplished the same thing with the pre-amp balance control, too.
    Doh!
    My biggest fear is that, after I am dead, my kids will sell my audio equipment for what I told them I paid for it.

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