Couldn't find the answer to this other than for full-range speakers---so I am wondering if running four differing lengths of speaker cable to four separate subs isn't so critical.
Ideally I want to have a couple of 6 to 8 foot ones and another might be around 12 feet and the fourth around 16 feet. I also should mention that these subs will be hooked up as a single stereo pair (2x 8 ohms wired in parallel per channel).
I was planning to twist/braid one or two pairs of 14 ga. solid THNN copper wire into various length runs but on second thought I may just go with a more standard12 ga. stranded speaker cable (actually DC red/black dual cable in a white jacket sold at my local West Marine) as I am not really able to afford something more exotic.
Will different lengths make much difference in the lows? They'll be crossed over around 59-90 hz as far as I know now and will have their own Crown XLS amp to power them.
Thanks for any info anyone wishes to provide and if I am way off base with this idea I will be happy to stand corrected.
Ideally I want to have a couple of 6 to 8 foot ones and another might be around 12 feet and the fourth around 16 feet. I also should mention that these subs will be hooked up as a single stereo pair (2x 8 ohms wired in parallel per channel).
I was planning to twist/braid one or two pairs of 14 ga. solid THNN copper wire into various length runs but on second thought I may just go with a more standard12 ga. stranded speaker cable (actually DC red/black dual cable in a white jacket sold at my local West Marine) as I am not really able to afford something more exotic.
Will different lengths make much difference in the lows? They'll be crossed over around 59-90 hz as far as I know now and will have their own Crown XLS amp to power them.
Thanks for any info anyone wishes to provide and if I am way off base with this idea I will be happy to stand corrected.
Not really, you'd have to have a pretty significant difference in cable length to start to notice any change in sound. The difference between a 15ft and a 100ft run of 14ga copper wire might be noticeable to a sharp listener, but the difference between 5 and 15 would not be.
The nominal impedance of the subwoofers is also relevant. 8 ohms is relatively high compared to cable resistance vs a 2ohm load.
A 100ft round trip DCR of 14ga copper is approximately .51 ohm. If you've got a 2 ohm load at the end, that will significantly affect both the sound and efficiency of the system. An 8ohm load will suffer a bit, but not to a huge degree.
tl;dr for your short cables lengths I wouldn't worry.
The nominal impedance of the subwoofers is also relevant. 8 ohms is relatively high compared to cable resistance vs a 2ohm load.
A 100ft round trip DCR of 14ga copper is approximately .51 ohm. If you've got a 2 ohm load at the end, that will significantly affect both the sound and efficiency of the system. An 8ohm load will suffer a bit, but not to a huge degree.
tl;dr for your short cables lengths I wouldn't worry.
)This is going to sound very pedantic... That isn't necessarily wrong, but I do take a bit of issue with boiling the issue down to a single number because it glosses over the actual problem. Copper wire runs have DC resistance and a certain amount of inductance. This does two things: it changes the performance of the speaker in both the frequency and time domains, and it causes a decrease in the efficiency of power transfer to the speaker. Both of which can be called "signal loss", but to quantify the two factors together is difficult. At best you can say you know it's too much when you can tell it starts to sound bad. Multiple wire runs next two each other can introduce crosstalk, and the longer the run is the more significant this will become. But no cable of any length is entirely loss-free.
Additionally, the severity of all these problems is also determined by the output impedance of the amplifier and the impedance of the speaker load at the end. Like I said earlier, an 8ohm load is not as vulnerable as a 2ohm load. The ratio of speaker impedance to cable impedance is often talked about in terms of "damping factor". Searching that term will find you some very in-depth discussions.
As for the question of DIFFERENT cable lengths, I don't think it matters much. It won't be causing any crazy issues. I would just avoid any single cable being too long. As wreckingball suggested, I don't think 40' is an unreasonable limit for 14ga before sound quality loss will start to become a consideration if you're looking for a very vague rule of thumb.
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Thanks, guys for the generally OK/good news. The Crown amp can put out enormous power at 4 ohms and that's what I'll present to it with the 8 ohm drivers wired in parallel plus the short cable runs (4ohms or close enough).
Once I'm underway I'll probably shorten the mains speaker cables a bit too---but with those I was concerned about unequal lengths for the different drivers as they are tri-amped---but knowing that cables laying on the floor together can cause crosstalk I best get out the snippers.
Scared at the thought of being tarred and feathered, too
Once I'm underway I'll probably shorten the mains speaker cables a bit too---but with those I was concerned about unequal lengths for the different drivers as they are tri-amped---but knowing that cables laying on the floor together can cause crosstalk I best get out the snippers.
Scared at the thought of being tarred and feathered, too
Speed of electricity over copper wire is appx 280,000,000 meters per second.
280 MILLION METERS per second.
OR
280,000 meters in a millisecond...
OR
280 meters per MICRO Second...
No amount of extra cable in your living room will be noticeable. Actually the amount of cable required to notice a difference would be very noticeable Do you have an extra 280 meters of cable on your speakers to notice ONE MILLIONTH of a second delay? No, you don't.
280 MILLION METERS per second.
OR
280,000 meters in a millisecond...
OR
280 meters per MICRO Second...
No amount of extra cable in your living room will be noticeable. Actually the amount of cable required to notice a difference would be very noticeable
Do you have an extra 280 meters of cable on your speakers to notice ONE MILLIONTH of a second delay? No, you don't.OK, I understand that fine---but my question was based on the impression I've always gotten that (for full-range speakers, not subs) that the length of both L/R speaker cables should be equal as well as as short as possible due to possible phase differences (and potential voltage drop also although that is just my guess).
So apparently the "equal length" cable advice must apply to those who have the most golden of ears, ha ha!
I may be an audiophile but a lot of what is perceived as necessary is simply modern day snake oil, in my opinion. Thanks for chiming in.
Tomorrow I am going to town and will return the 500' roll of THNN I bought at Home Depot and will get ordinary 12 or 14ga. speaker cable instead---I decided against trying to weave or braid solid wire in lieu of soft and flexible stranded speaker cables that will lay flat on the floor.
So apparently the "equal length" cable advice must apply to those who have the most golden of ears, ha ha!
I may be an audiophile but a lot of what is perceived as necessary is simply modern day snake oil, in my opinion.
Thanks for chiming in.Tomorrow I am going to town and will return the 500' roll of THNN I bought at Home Depot and will get ordinary 12 or 14ga. speaker cable instead---I decided against trying to weave or braid solid wire in lieu of soft and flexible stranded speaker cables that will lay flat on the floor.
I have used difnt lengths before & could hear it in time smear of the image, not as sharp as a pair of tweeters in your face but still there. When I equaled up the lengths it all came together. DEQ sub cable for the signal & XLO from plate amps to drivers (I can't say now which wire it was exactly but that it was a heavy gauge one with high x 9's)
Enough can't be said for hardwiring & the quality/purity of the wire your various signals are running through from piece of equipment to piece of equipment. Also the metal in jacks, binding posts, signal wires ends, speaker cable ends, crossover spades & driver spades. Toss in the effect of your wires dielectric & that is oodles & oodles of electrons left bouncing around after a pulse of energy has passed through the system, all of these echoes mess up your image & therefore the control of your amplifier"s" over the movement of your drivers in & out. If you are not on top of these details then all of those echoes are causing a loss of detail that would never allow you to comprehend that there is a difference in wire lengths taking signals different routes to the air & off to your ears. Speed of electrons whether fast or slow will have no perceivable effect through your system if there is such a fog to try & see them through. Keep the lengths as short as possible & yes, good quality connectors are much better than cheap ones but no metal in the way of your signals is by far, far more revealing & so much more affordable
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I've recently changed from a single sub to 2 subs run with a single plate amp damping factor of around 500 @ 4 Ohms with around 60 cm of cable to the speakers. Now with 2 woofers in parallel the cable length is 8 feet and I do perceive a slight overhang I didn't hear before. Removing 7 grams of cone mass loading mitigated this. Subtle but I don't think it was my imagination.
Just cause it can't be measured doesn't mean it ain't there.
Just cause it can't be measured doesn't mean it ain't there.
If it can't be measured, it's not there. Acoustics is not a religious exercise.
I'm with you on this 100%, Z although many tend to believe it is.
Got 60 feet of white jacketed 12-2 stranded marine-grade cable the other day that I will cut once my subs are finished and placed around our living room.
I suspect I will be so blown away by having a truly full-range system again after a few decades that I probably won't notice the slightest measureable difference anyway.
I started pouring the concrete yesterday and will finish the other two today.
Posting pictures in a new thread I'll post once actually up and running sometime next week.
Cheers, Jeff
Experience has taught me not speculation. To let a microphone or any other measuring device dictate your audio reality is akin to putting a steaming nicely laid fecal stool in charge of philosophy at a university. Or putting the tape measure in charge instead of the tradesman. Your ear / brain is highly tuned to impulse response. Microphones do not posess intelligence. Like those who rely on computer modelling alone for speaker & crossover design as it cripples their designs to mediocrity.
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Your experience is entirely speculation. You perceived a difference in the sound, which may or may not exist because you didn't measure it. You speculated that the fact that you changed a wire length from 60cm to 8ft was the specific cause of the possibly non-existent issue. You arbitrarily decided to remove mass from the cone to solve this issue, which I will grant will certainly make a difference in tone. You decided you like the change in tone and deemed the original problem to be fixed.
None of that is in any way scientific, nor will it make you anything more than a more experienced speculator. Don't get me wrong, in the home your audio experience should be the way you want it to be. Any modification you make to your system, rational or not, is good if it makes you happier.
Human ears are sensitive to subtle changes in sound, but they completely fail to quantify what they hear. And frankly your brain is a terrible tool. It's cripplingly susceptible to a number of cognitive biases and logical fallacies, including confirmation bias and false cause as (potentially) seen in your example. In the absence of actual quantifiable data from a measuring instrument, it will simply provide its own flawed, subjective perceptions as "data" and draw meaningless conclusions from them.
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LOL Yup sometimes the passionate & emotional side of my ear/ brain system can actually BE the problem. I agree with what you are saying. But all I'm saying is that to let measurement alone be the arbitar of MUSICAL excellence of loudspeaker system instead of a guide for the very reasons you have outlined above will limit the emotional engagement that separates a good speaker from an excellent one.
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