Using some very long balanced Subwoofer cables.

Hi Ozzy,

You mentioned recently in the DEQX thread that you are now using an Ayre KX5 Twenty as your preamp. I see that that preamp provides two balanced outputs and one unbalanced output for each channel.

It is very common for designs which provide two XLR output connectors to simply jumper them together inside the rear panel, and provide both with the same signals. And it is very common for designs which provide both XLR and RCA output connectors to provide the RCA connector with the same signal that is provided to one of the two signal pins on the XLR connector. So depending on the design of the preamp it could very well be that the capacitance of the 75 foot cable will have some effect on the signals received by the main power amp, that are reproduced by the main speakers. The result possibly being small but perceptible amounts of rolloff and undesirable phase shift in the upper treble region, as reproduced by your main speakers.

Stereophile measured the output impedances of your preamp as 78 ohms unbalanced and 156 ohms balanced, which **might** be low enough to make that issue inconsequential, depending on the capacitance of the particular 75 foot cable. But I would suggest that you contact Ayre and ask them if the signals provided to the three output connectors (two balanced and one unbalanced) are driven by separate and independent output stages, or if some or all of them are provided with the same signals.

And if it turns out that one or both signals in the balanced pair of signals that is provided to the rear sub for each channel is/are also provided to the main power amp, you would definitely want to choose 75 foot cables having very low capacitance.

Best regards,
-- Al

tgrisham, millercarbon, almarg,

Thank you for the response.

So, will that long of wire be a problem for my preamp / amp (Ayre KX-5 twenty)? Possibly because of the more capacitance from the additional cable?

I’m thinking no because the long interconnects will actually be connected to the JL sub slave output and is not directly connected to the Ayre.

But then again...?

ozzy

I’m thinking no because the long interconnects will actually be connected to the JL sub slave output and is not directly connected to the Ayre.

Excellent! The sub’s manual makes clear that the balanced pair of signals provided to its "output to slave" connector is buffered within the sub, meaning that the cable connected to that output will be driven by an output stage within the sub and won’t be driven by the Ayre. And that is further confirmed by statements indicating that whatever signal processing is being performed by the sub is reflected in that output. So the concern I cited in my previous post doesn’t apply.

Best regards,
-- Al

Thanks Al,
In addition, the 75 cables are; " the Monoprice Premier Series XLR Male to XLR Female - 75ft - Black - Gold Plated | 16AWG Copper Wire".

So, I'm thinking with 16 gauge wire there will be minimal signal loss.

ozzy

Hi Ozzy,

16 gauge is more than adequate. In fact even 24 gauge, which is sometimes used in XLR cables, would be fine (although I suppose the presumably greater physical fragility of the narrower gauge could conceivably be an issue in your application).

The input impedance of the balanced input of the slave subs is 10K. The combined resistance of the two 75 foot signal conductors in the 16 gauge cable will be 0.6 ohms, which will result in a loss of 0.6/(10,000 + 0.6) = 0.006% of the signal voltage. Which is a loss of about 0.0005 db :-)

Best regards,
-- Al