REL subwoofer cable

Coiling generally negatively affects high frequencies, but this should not be an issue for a subwoofer feed.

Very true. Coiling increases inductance. The series impedance (something like resistance, putting it a little simplistically) which would result from that inductance is directly proportional to frequency, so it should be insignificant at deep bass frequencies.

Apart from the coiling question, though, I would suggest that you try to determine the d.c. resistance, in ohms, of the 25 foot cable length (actually, 50 feet for the round-trip). That would be dependent on the gauge of the cable; if you know the gauge you can look up the ohms per foot in standard wire gauge tables on the web. If that resistance is more than a small fraction of an ohm, it could affect bass damping. If it is in the range of, say, 0.1 to 0.5 ohms or less, then it should be no problem since that would be a very small fraction of the subwoofer impedance.

Regards,
-- Al

Xti16 -- Yes, that will bring some differences of opinion. I'm sure your sonic perceptions were correct, but your technical reasoning is not. The delay of an electrical signal through 35 feet of cable is, roughly speaking, on the order of 100 nanoseconds (a nanosecond is a billionth of a second). Typical cable delays are around 2 or 3 nanoseconds per foot. A quick calculation reveals that 100 ns is approximately 0.001% of a single period of a 100 Hz bass note. I don't think there is any species in existence that could perceive that.

More likely, the changes you heard were due to the lower d.c. resistance of the shorter cable length, which would have nothing to do with the similarity of that length to the length of the cables running to the main speakers.

Regards,
-- Al

Xti16 -- Yes, I respect what you are saying, and conventional, accepted specs certainly often don't tell the whole story.

But I would submit that theorizing that better matching of the cable lengths between the subwoofers and the main speakers is the reason for what you heard is in itself defining a spec. And defining a spec without sufficient testing to establish that it is the reason for what you are hearing.

I can readily envision that a longer cable length to the subwoofers would result in inadequate bass damping, due to increased resistance in the cable. Inadequate bass damping by definition results in less well controlled bass and increased settling time and overhang of bass transients. That would correspond exactly to what you described hearing.

Please take a look at the following paper by Bill Whitlock, an extremely well respected authority who is the head of Jensen Transformers. I happened to just read it today, after it was called to my attention by someone else in another thread here. He explains why and how cables can and do sound different, while at the same time putting into proper perspective the hype and nonsense that tends to pervade their marketing, and what the reasons are that make it possible for that hype to persist. I found it to be one of the best papers I've ever read concerning cable effects, and I think you'll find it of interest as well.

http://wiring.svconline.com/ar/avinstall_designer_cables_critical/index.htm

Best,
-- Al