I know it's against audiophile etiquette, but I just coiled the extra length of mine. Coiling generally negatively affects high frequencies, but this should not be an issue for a subwoofer feed.
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.
When I got my Rel B3 it came with a 35' cable. Hooked it up and after about a month I thought it was sounding good but not great. Then it dawned on me my speaker cables are only 10'. I cut the cable in half and to me it sounded a world better. But a couple of months later something didnt quite seem right. I measured the Rel cable and it was 16' long. Thats when I cut it to 9 ft. Its been well over a year and it sounds perfect. To ME (and NOT everyone will agree) all cables should be within 50% length of the rest of your cables. I can hear the difference IF AND ONLY IF I hear the same lengths first. In other words if your speaker cables are 10' then any other cables driving speakers should be no less than 5' and no more than 15'. I'm sure this will bring some differences of opinion. (Home theater would be the exception because of the delay you can add for the surrounds). To me the bass blends in better. Thats my thoughts and opinions. And I approve this post!!
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.
Hi Al - here is why I wrote that
I have found the technical reasoning is thrown out the window in this hobby. I am an IEEE and there is no reason for why pc's ic's and speaker cables sound so different (better and worse than others). I did just gave my opinion and only my opinion. Specs for really any device cable or cord mean very little to me. I learned the expensive way not to read too deeply into specs.
Also years ago I was able to play with many different lengths of the same cables just to hear the difference. Some people would actually like the different lengths for it does give a slight 'reverb' which most people perceive the room to be bigger. Maybe I played around too much but it was fun with my audio dealer then.
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..
Yes but to me and maybe I have become too critical of a listener but the lowest octaves didn't sound like they were aligned with the rest of the music.
Dont mean to start an argument. I'm just trying to relay what I have experienced in the past using my ears and not looking at specs.
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.
I am using 2 RELs with not only two different lengths but two different cables. One is a standard REL and the other is one from Signal Cable. Both are longer than I need but I have never seriously considered cutting them. I save my obsessing for other parts of the system. The whole question of cables is murky in the extreme and highly system [and listener] dependent. I wouldn't worry about it.
I have found the technical reasoning is thrown out the window in this hobby. I am an IEEE and there is no reason for why pc's ic's and speaker cables sound so different (better and worse than others).
There are plenty of technical reasons that they sound different - an equipment problem, poorly matched gear, poorly designed equipment, ground loops, contact resistance on a mechanical quick connect and many other mundane things. No need to resort to new undiscovered science. Indeed some cables have networks in them and undoubtedly they shoudl sound different. Some ic's have high capacitance and will not perfom well, particularly in long lengths, when used with an underpowered preamp (changing the ic or getting a better built preamp is a valid solution)
I agree that to throw technical reasoning out the window and fiddle around until you get things to work is often the most practical and sensible approach - I use it myself! Sometimes it so difficult to get to the root cause of a problem that is is not worth the effort or expense: often electronic test gear costing much more than the hi-fi system itself may be required and a simple connector contact problem is not always easily reproduced.