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Need help with splitting XLR OUTPUT

Can anyone help me with this question about splitting the subwoofer XLR OUTPUT from my processor to 4 different amps? I am currently using a single XLR. Cable that has a 3 way split from it and concerned about the signal being split again. I only have a Meridian 861 processor that only has a single XLR subwoofer out and I have to send one signal to my pair of JL Gotham subs and two other XLR cables to two separate Velodyne subwoofer amps.
One of the Velodyne amps drives a custom made subwoofer in my rear seat riser and the other amp drive my Buttkickers in the seating. I just added another row of seating and have another row of Buttkickers to drive but am concerned about splitting the single
XLR output signal into 4 different wires. What is the best way to keep the signal pristine or does it even matter that I am splitting it four ways. Should I just add another XLR Y splitter to one of the existing output cables, get another cable that has the single on one side that plugs into the Meridian with 4 cables broken out from it, or use some type of box? The Velodyne amps have RCA passthroughs on them but everytime I have tried to use the RCA input/outputs on anything connected to the Meridian setup I get some type of ground noise so I have to stick to the balanced connections.
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Showing 2 responses by almarg

almarg's avatar
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almarg
9,670 posts
 
DB, again the impedances of the Velodyne components don't appear to be specified, but nevertheless I see no particular reason to suspect that the two-way split would be an issue. The SMS is solid state, meaning that there is relatively little likelihood that it would have an inordinately high output impedance at deep bass frequencies; possible effects on mid and high frequencies would not matter; the fact that the interconnections are balanced minimizes the likelihood of ground loop and noise-related issues; Velodyne recommended the solution; and it appears to work well.

Regards,
-- Al
almarg's avatar
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almarg
9,670 posts
 
The Aphex unit suggested by Tls49 does look like an excellent solution, if you don't mind its cost.

Regarding the original question about using cable splitters to split four ways, it depends on the output impedance of the sub output of the Meridian (at deep bass frequencies), and on the input impedances of the JL subs and the Velodyne amps. Unfortunately none of those impedances appear to be specified.

If you want to pursue that approach, contact Meridian and ask them what the output impedance at 20 Hz is for the 861's sub output. Or, alternatively, what is the minimum load impedance they would recommend that it be used to drive.

Also ask JL and Velodyne for the input impedances of the balanced inputs of those units.

To assure good results, the combined (paralleled) input impedances of the JL subs and the Velodyne amps should be at least ten times as great as the output impedance at 20 Hz of the Meridian's sub output. Or, alternatively, the combined (paralleled) input impedances of the JL subs and the Velodyne amps should be greater than the minimum load impedance Meridian may recommend for the 861's sub output.

The combined (paralleled) input impedances of the JL subs and the Velodyne amps equals the reciprocal of the sum of the reciprocals of their individual input impedances ("reciprocal" meaning the number divided into 1). For example, if the input impedances are 10K for the Velodyne amps and 15K for the JL subs, their combined input impedance is:

1/(1/10 + 1/10 + 1/15 + 1/15) = 3K, or 3,000 ohms

Regards,
-- Al
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