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  1. #1
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    4344 Bi-Amp Crossover Question

    Hello all,

    I'm in the beginning stages of a 4344 replica. While I've read a ton on this forum regarding similar projects and recommendations I'm still at a loss as to what is a good electronic crossover for this setup. Particularly there is mention that if you're not using a JBL 5234(a), or 5235, there is issues with voltage drives and as such other crossovers would need modified? I have no idea what this voltage drive is or means even after trying to research it (admittedly, I'm no expert in speakers or electronics, but know enough to be dangerous. Anyone know thoughts on this? Are these JBL crossovers the ones to get, or is something that is more readily available appropriate or desirable? Particularly I've been looking at the Crown VFX2A. This would be nice as I just picked up a couple of Crown DC300II A's for the bi-amp. I am probably wrong, but these crossovers appear to do bandpass so could they also help with the potential issue of DC leakage at low frequencies (down to 1hz) that these amps can put out when failing, or am I totally off track here?

    Thanks for any insight

  2. #2
    Moderator hjames's Avatar
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    You can start with something simple like an Ashly X1001.
    A number of us went that route - I did with my 4341, Phil did with his 4345 ...
    You can get one fairly inexpensive, its easy to set it for 290Hz crossover,
    easy to set it up with a pair of amps, and if you decide you want something better,
    you can sell it fairly easily and go with something more high end like one of the marchand passives.

    With my system I ran a preamp into the Ashly crossover, which had 2 line level outputs.
    The high split fed an Adcom GFA-555, and the low split fed another Adcom GFA-555.

    Quote Originally Posted by jlwitherell View Post
    Hello all,

    I'm in the beginning stages of a 4344 replica. While I've read a ton on this forum regarding similar projects and recommendations I'm still at a loss as to what is a good electronic crossover for this setup. Particularly there is mention that if you're not using a JBL 5234(a), or 5235, there is issues with voltage drives and as such other crossovers would need modified? I have no idea what this voltage drive is or means even after trying to research it (admittedly, I'm no expert in speakers or electronics, but know enough to be dangerous. Anyone know thoughts on this? Are these JBL crossovers the ones to get, or is something that is more readily available appropriate or desirable? Particularly I've been looking at the Crown VFX2A. This would be nice as I just picked up a couple of Crown DC300II A's for the bi-amp. I am probably wrong, but these crossovers appear to do bandpass so could they also help with the potential issue of DC leakage at low frequencies (down to 1hz) that these amps can put out when failing, or am I totally off track here?

    Thanks for any insight
    2ch: WiiM Pro; Topping E30 II DAC; Oppo, Acurus RL-11, Acurus A200, JBL Dynamics Project - Offline: L212-TwinStack, VonSchweikert VR-4
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  3. #3
    Senior Member BMWCCA's Avatar
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    I'm running the Ashly XR1001 on my 4345s with Crown PS 400 and PS 200. I had previously used the DC300A-II and D150A-II but I prefer the PS-series now. I have two Crown VFX2As but haven't tried them in this system. The Ashly is so easy to use and I find no flaws in this setup so I have no desire to stretch to a Marchand at this time. For the price of best Marchand, I could buy mint in-box 250Ti's.
    ". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers

  4. #4
    Senior Member grumpy's Avatar
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    I am probably wrong, but these crossovers appear to do bandpass so could they also help with the potential issue of DC leakage at low frequencies (down to 1hz) that these amps can put out when failing, or am I totally off track here?
    No. they come before the amp in the chain, so any protection would be between the amp and the driver

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    Quote Originally Posted by grumpy View Post
    No. they come before the amp in the chain, so any protection would be between the amp and the driver
    Thanks for all the feedback guys! Much appreciated. Grumpy - thanks for pointing out a "duh" moment . To that note, do you guys have DC protection after the amps when running these Crowns? One more question. I'm currently building Giskard's passive network for the upper three speakers (see below), one thing I haven't seen about this is it's slope. Again, I'm not an expert. Is his design 12db? If so, do I hook up the Ashly (24db) to the low and low mid woofers (or just low?) in reverse polarity (red to red).

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  6. #6
    Senior Member grumpy's Avatar
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    Yes (12dB/oct in LF low pass and MF high pass), just the low, and reverse the LF leads (or everything else ... your call) if you switch from 12dB to 24dB slopes
    for the LF-MF crossover.

    DC protection? for everything but the LF, you're covered with the crossover.
    If you don't trust the amp, you could put a bigass fuse inline with one of the
    woofer leads. Probably not a popular suggestion, but ok. There are more complicated
    DIY options that could also work

    http://sound.westhost.com/project33.htm

    or there are many available on ebay (that I can't vouch for, and don't use).

    As cool as old amps can be, I have to wonder about hooking up such a unit to nearly unrepairable (now)
    systems without at least getting it properly serviced and checked out... seems awfully risky. Seems like
    someone here had a number or URL for contacting a crown service center that worked on the older gear.

    Sounds like you're having fun, regardless... which is the point

    Cheers.

  7. #7
    Senior Member pyonc's Avatar
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    Well, I've tried both 5234A with factory 4343 cards (300hz) and Ashly 1001. In biamp mode, I use two Crown amps. (According to our forum guru 4313B, JBL studio monitors with 43xx were used exclusively with Crown amps in those days)
    Ashly sounds crisper and brighter to me,
    yet to get the sonic authenticity of the original passive XR,
    you might try 5234A. That's what I heard.

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