Speaker Level Sub Inputs

[Jsmith]

Hopefully someone can clear this up for me. When you buy speaker cable it is always recommend that both the left / right are the exact same length regardless of closeness of the speaker.

 

Does the same logic apply to a sub that uses speaker level inputs? Should it be the exact same length as the speaker cables so the sub receives the signal at the same time? If that is the case, it seems like there may need to be some seriously long speaker cables out there to accommodate for sub placement.

[franky]

According to Jim Smith (no relation to you I'm guessing) author of Get Better Sound, there is a theory that having different speaker cable length for the left and right speakers may not be a problem (see Pg 176). I'd try it out myself but I don't have access to any non-matching pairs of speaker cable. Maybe others can report back what they have found. Personally, I don't know if I'd be comfortable running my system that way but Jim Smith is a lot smarter than me (at least in audio). Regarding the sub, I don't know but considering the above theory, I suspect it may be OK too, especially since you can move it around independent of you mains.

[Jsmith]

Thanks Franky. I have Jim's DVDs (no relation) but I do not have the book. Maybe I will go back through them this weekend and see if this topic does come up.

[wgscott]

I think unless there is a huge difference (100s of feet) in length, the differences, if any, will be negligible (i.e., not detectable via measurement, let alone hearing). With the subs, it probably depends on the wire, but again, it shouldn't become an issue with any normal room.

 

If you are worried about it, just use the same length of wire for both subs.

[Jsmith]

I think unless there is a huge difference (100s of feet) in length, the differences, if any, will be negligible (i.e., not detectable via measurement, let alone hearing). With the subs, it probably depends on the wire, but again, it shouldn't become an issue with any normal room.

 

If you are worried about it, just use the same length of wire for both subs.

 

To make sure we are on the same page. I am not speaking of a pair of subs. Rather a single sub with my main speakers.

 

I believe you have a REL sub as well. If you are are using the Nuetrick connection and yours is like mine, it is about 25' plus long. My speaker wire to my front mains is 15'.

[JohnMH]

From the point of view of any sort of audible timing errors, I don't think there can possibly be any even with quite long runs, since we're talking propagation speed approaching the speed of light reduced slightly by velocity factor of the particular conductor material and cable in question, which is affected by the dielectric properties of the insulation, etc. You're still well over 90% of the speed of light, if I'm understanding correctly.

 

Speed of electricity - Wikipedia, the free encyclopedia

 

However, I'm not envisioning a placement that would require significantly different lengths when using a single sub. I assume the setup would be two L-R speaker cables from amp to sub, then out of the sub with Left and Right speaker cables to mains stereo speakers. Unless you're placing the sub very much closer to L or R main speaker.

 

Playing with a new Velodyne Minivee here. Velodyne recommends placing the sub in the same plane as the mains, I assume for phase coherence. The Minivee only has 0 and 180 degree settings for phase. I see that some subs have continuously variable phase.

 

Personally I would prefer the sub to be centered between the mains, but I'm not sure I can make a rational argument as to why. Obviously many don't do this.

 

Does your sub or other kit details prevent low level input to the sub? That's the way I've been playing with the Minivee so far, using it's internal line level crossover. This seems to be the recommended method by Velodyne.

 

And Jim Smith of Get Better Sound fame strongly recommends using 2 subs for a stereo music listening setup. If I come across another Minivee for the same price I found the first one I will probably jump on it.

 

Anyway, long story short, I don't think even quite large speaker cable length differences will make an audible difference, even if it seems aesthetically problematic. The only real problem I can see with longer lengths is the possibility of picking up more induced noise, but if you're careful about not paralleling near by power lines, unshielded data wiring, etc. it's probably not a big deal.

[mayhem13]

Don't worry about differing lengths of speaker cables, as mentioned above the differences for the sake of signal transmission are insignificant.

[wgscott]

To make sure we are on the same page. I am not speaking of a pair of subs. Rather a single sub with my main speakers.

 

I believe you have a REL sub as well. If you are are using the Nuetrick connection and yours is like mine, it is about 25' plus long. My speaker wire to my front mains is 15'.

 

Yeah, since REL bundles it, you don't really have a choice anyway. My REL is about 3 ft away from my amp and I just use the 25' long cable. Remember, electrons travel near relativistic speeds.

[Audio_ELF]

According to Jim Smith (no relation to you I'm guessing) author of Get Better Sound, there is a theory that having different speaker cable length for the left and right speakers may not be a problem (see Pg 176). I'd try it out myself but I don't have access to any non-matching pairs of speaker cable. Maybe others can report back what they have found. Personally, I don't know if I'd be comfortable running my system that way but Jim Smith is a lot smarter than me (at least in audio). Regarding the sub, I don't know but considering the above theory, I suspect it may be OK too, especially since you can move it around independent of you mains.

Just be aware that with JSmith's Naim amplifier there may be a bigger issue with non-matching speaker cables than with most amplifiers due to their design. Naim amplifiers are usually reported to work best with Naim's NAC A5 cable.

 

I believe it would be recommended to connect a subwoofer to Naim amplifiers via the pre-out connection rather than via speaker connections.

 

Eloise

[Jsmith]

Just be aware that with JSmith's Naim amplifier there may be a bigger issue with non-matching speaker cables than with most amplifiers due to their design. Naim amplifiers are usually reported to work best with Naim's NAC A5 cable.

 

I believe it would be recommended to connect a subwoofer to Naim amplifiers via the pre-out connection rather than via speaker connections.

 

Eloise

 

You are correct that Naim is overly specific about the use of the NAC A5 wire. Currently I am running the REL Speakon connected to the NAC A5 at the amp end. This is actually what the Naim / REL dealer soldered for me. I believe this may be OK since REL claims the sub connect is so minute that it does not pose a problem to the amplifiers. Or I can be trashing my Amp, but hey the dealer installed it and can fix it