Does equal speaker length matter? - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 21 Old 09-21-2017, 03:29 PM - Thread Starter
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Does equal speaker length matter?

Does equal speaker length matter? More importantly has anyone tested this?

I need about 8 ft for the left speaker and 12 foot for the right speaker.
I understand at the speed of light my ears won't hear the delay.
There is some talk about impedance and ohms... But does it matter even to an audiophile that has gone through his own blind testing?

I'm looking at either a chance of small difference, or adding loops to a rat's nest behind my AV/TV stand.
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post #2 of 21 Old 09-21-2017, 03:37 PM
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As long as you use black walnut spacers to elevate the speaker wire off the carpet you should be fine
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post #3 of 21 Old 09-21-2017, 04:10 PM
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Originally Posted by gmanhdtv View Post
As long as you use black walnut spacers to elevate the speaker wire off the carpet you should be fine

I use birch cable elevators. Is that ok?
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post #4 of 21 Old 09-21-2017, 04:37 PM
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The Black Walnut ones ----- YMMV
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post #5 of 21 Old 09-21-2017, 05:21 PM
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For reasonable differences in length, it doesn't matter. Now if one cable was 1 foot long and the other cable was 100 foot long, then yes it would matter.
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post #6 of 21 Old 09-21-2017, 05:26 PM
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Quote:
Originally Posted by Speedskater View Post
For reasonable differences in length, it doesn't matter. Now if one cable was 1 foot long and the other cable was 100 foot long, then yes it would matter.
Why? Just move one speaker a bit forward.
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post #7 of 21 Old 09-21-2017, 06:07 PM
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The circumference of the earth is 25,000 miles and the speed of light is 186,000 miles per second.

So even if you lived on the north pole and put the other speaker on the south pole there would only be 7ms of delay, or ~6ft of acoustical delay.

That would make for one very expensive cable, with a very high resistance.

Even at 1ft and 100ft it wouldn't be a problem if the 100ft run was 10awg or thicker.
Is it ideal? No
Would it work? Yes.

More importantly, is having a symmetrical room and room treatments.
In fact I believe trapezoidal rooms are just about the best geometry, as it is still symmetrical, but non parallel (at least for 3 of the 6 boundaries.)
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post #8 of 21 Old 09-21-2017, 07:14 PM - Thread Starter
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Quote:
Originally Posted by BassThatHz View Post
The circumference of the earth is 25,000 miles and the speed of light is 186,000 miles per second.

So even if you lived on the north pole and put the other speaker on the south pole there would only be 7ms of delay, or ~6ft of acoustical delay.

That would make for one very expensive cable, with a very high resistance.

Even at 1ft and 100ft it wouldn't be a problem if the 100ft run was 10awg or thicker.
Is it ideal? No
Would it work? Yes.

More importantly, is having a symmetrical room and room treatments.
In fact I believe trapezoidal rooms are just about the best geometry, as it is still symmetrical, but non parallel (at least for 3 of the 6 boundaries.)
I understand the delay is not a problem, but what about change in impedance?
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post #9 of 21 Old 09-21-2017, 07:33 PM
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Quote:
Originally Posted by AudioQuestions View Post
I understand the delay is not a problem, but what about change in impedance?
Hell, why worry about impedance, just need a bigger amp!!!!! Just ask Marty......................
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post #10 of 21 Old 09-21-2017, 08:54 PM
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Hell, why worry about impedance, just need a bigger amp!!!!! Just ask Marty......................

Big amp(s), you ask?


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post #11 of 21 Old 09-21-2017, 09:08 PM
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Quote:
Originally Posted by BassThatHz View Post
The circumference of the earth is 25,000 miles and the speed of light is 186,000 miles per second.

So even if you lived on the north pole and put the other speaker on the south pole there would only be 7ms of delay, or ~6ft of acoustical delay.

That would make for one very expensive cable, with a very high resistance.

Even at 1ft and 100ft it wouldn't be a problem if the 100ft run was 10awg or thicker.
Is it ideal? No
Would it work? Yes.

More importantly, is having a symmetrical room and room treatments.
In fact I believe trapezoidal rooms are just about the best geometry, as it is still symmetrical, but non parallel (at least for 3 of the 6 boundaries.)
99% joking but REALLY? Speed of light and electron flow is one thing, but once those electrons exit and become sound waves, the much slower .22 miles per second makes a huge difference. :-)
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post #12 of 21 Old 09-21-2017, 10:48 PM
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Quote:
Originally Posted by AudioQuestions View Post
Does equal speaker length matter?
Not in the context of consumer audio in typical domestic sized spaces, assuming you've selected at least the minimum required gauge of (non-crappy) wire.

Quote:
More importantly has anyone tested this?
It doesn't need to be... we have perfectly good formulae.

Quote:
I need about 8 ft for the left speaker and 12 foot for the right speaker.
I understand at the speed of light my ears won't hear the delay.
There is some talk about impedance and ohms... But does it matter even to an audiophile that has gone through his own blind testing?

I'm looking at either a chance of small difference, or adding loops to a rat's nest behind my AV/TV stand.
Audiophiles with the handy combination of hubris, super-human hearing and an immunity from perceptual bias think EVERYTHING MATTERS. Like many things, this doesn't.

Quote:
Originally Posted by AudioQuestions View Post
I understand the delay is not a problem, but what about change in impedance?
Speaker wires present resistance to the flow of current.

Use this tool to determine the minimum wire gauge based on your longest run: BCAE | Speaker Wire Calculator. Then, have a play to see how much difference 8ft vs 12ft runs make to resistance and resulting dBSPL loss. It will be in the order of 0.02Ω and 0.03dBSPL... in other words, the square root of bugger all.

If you're curious, have a play to see what the disparity in wire lengths needs to be to produce a (still inaudible) 0.5dBSPL loss.

Good luck and don't expend too much more mental energy (or money) on wires, cables and everything else that doesn't matter.
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post #13 of 21 Old 09-21-2017, 11:01 PM
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Quote:
Originally Posted by Speedskater View Post
For reasonable differences in length, it doesn't matter. Now if one cable was 1 foot long and the other cable was 100 foot long, then yes it would matter.
Not necessarily Kev. Try the calculator above. A fairly typical combination of 100WPC, 14AWG and 8Ω load only produces a loss of 0.53dB for a 100ft run. You're in strife (just) with 4Ω loads though, but upping it to 12AWG solves it.
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post #14 of 21 Old 09-22-2017, 05:39 AM
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Quote:
Originally Posted by GIEGAR View Post
Not necessarily Kev. Try the calculator above. A fairly typical combination of 100WPC, 14AWG and 8Ω load only produces a loss of 0.53dB for a 100ft run. You're in strife (just) with 4Ω loads though, but upping it to 12AWG solves it.
Yes, the 1/2dB loss can be compensated for. But it will depend on the loudspeaker's impedance curve with respect to frequency. If the curve is rathre flat, then no problem. But if the curve looks like a roller coaster then the long cable channel will have EQ differences.

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post #15 of 21 Old 09-22-2017, 10:51 AM
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Quote:
Originally Posted by AudioQuestions View Post
I understand the delay is not a problem, but what about change in impedance?
Quick answer. Don't worry about it. Not enough difference to matter.

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post #16 of 21 Old 09-22-2017, 06:42 PM - Thread Starter
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Quote:
Originally Posted by Speedskater View Post
Yes, the 1/2dB loss can be compensated for. But it will depend on the loudspeaker's impedance curve with respect to frequency. If the curve is rathre flat, then no problem. But if the curve looks like a roller coaster then the long cable channel will have EQ differences.
Can you elaborate? Because I think the SF olympica 3 has a much lower than the rated 4 ohm on the low frequencies, and much higher on the high frequencies.
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post #17 of 21 Old 09-23-2017, 08:25 PM
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Quote:
Originally Posted by BassThatHz View Post
The circumference of the earth is 25,000 miles and the speed of light is 186,000 miles per second.

So even if you lived on the north pole and put the other speaker on the south pole there would only be (1) 7ms of delay, or ~6ft of acoustical delay.

That would make for one very expensive cable, with a very high resistance.

Even at 1ft and 100ft it wouldn't be a problem if the 100ft run was 10awg or thicker.
Is it ideal? No
Would it work? Yes.

More importantly, is having a symmetrical room and room treatments.
In fact I believe trapezoidal rooms are just about the best geometry, as it is still symmetrical, but non parallel (at least for 3 of the 6 boundaries.)
Quote:
Originally Posted by darknite9099 View Post
99% joking but REALLY? (2)Speed of light and electron flow is one thing, but once those electrons exit and become sound waves, the much slower .22 miles per second makes a huge difference. :-)
(1) Light will travel about 1,300 miles in 7ms. 67ms is closer to an accurate value for light in vacuum.

The signal is traveling using a copper wire at a speed of .7c to .9c so the time would actually be proportionately longer.

(2) Electrons in a DC circuit will flow at velocity of millimeters per hour. Electrons in an AC circuit will have no net flow. Sound in air will travel far faster than electrons in a wire.

https://en.wikipedia.org/wiki/Speed_of_electricity
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post #18 of 21 Old 09-24-2017, 12:29 AM
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As mentioned above, Speed of Light difference between two different Speaker Wire Lengths is of NO consequence. HOWEVER, fol. are the ONLY aspects that CAN result in AUDIBLE differences (NOT copper purity or skin effect, ad nauseum):

Insertion Loss and Damping Factor.....incl. Speaker Size Recommendations:
http://www.audioholics.com/audio-vid...er-cable-gauge
http://www.roger-russell.com/wire/wire.htm#damping

BTW: Do NOT overlook the Ohmic Loss in the Hefty Inductor Coil part(s) of the Passive Crossover feeding the Woofer....which is ELIMINATED for those of us using BI-AMPED Systems with an Electronic Crossover feeding Separate Amps for Woofer and Mid-Range/Tweeter. And to BYPASS the Woofer part of the Passive Crossover INSIDE the Speaker (even though it comes with "Bi-Amp" Terminals), usually requires opening and modifying interior wires. This ALSO eliminates high Woofer currents on the [previously SHARED] Speaker Wires from degrading Mid-Range/Tweeter signals:
https://www.electronicproducts.com/S...lculators.aspx
http://www.audioholics.com/frequent-...ng-vs-biwiring

More Technical Info re Speaker Damping Factor:
Try to keep LESS than 10:1....even better if 30:1 so that Speaker Cone follows Input Voltage with minimal Overshoot/Undershoot:
https://www.google.com/url?sa=t&rct=...POK7rZin1haJKQ

Phase & Freq. Response Variances due to Speaker Wire Impedance Variations at 10+ kHz:
[Minor, much SMALLER than Azimuthal/Vertical Tweeter Pattern Variations....and Human Ear Insensitivity]
https://www.lifewire.com/speaker-cab...rences-3134603

Fol. compares AWG11 Bi-Wire [separate wire pairs to Tweeter and Woofer] vs Doubled Up Wire Pairs to combined Tweeter/Woofer Terminals for a 4-meter (13.1-ft) long cable, showing NEGLIGIBLE impact to Freq. Response or Phase....that's a bit THICKER wire than most people use, but we can expect AWG12 and AWG14 wouldn't be much different:
http://www.empiricalaudio.com/comput...speaker-cables

Note that fol. showed Excellent Freq. Response for IMPEDANCE (NOT related to smaller effect on Freq. Response] for 10-ft long 18-Gauge wire (not so much 24-Gauge) and a WIDE VARIATION for several expensive cables.....but "FORGOT" to show how typical 16-gauge to 12-gauge "Zip Cord" performs [I would expect they would be MUCH BETTER than too skinny 18-Gauge]:
https://www.passlabs.com/press/speak...e-or-snake-oil

Also see my earlier posts on this subject, incl. links to DOUBLE BLIND TESTS:
Ask the Editors: Does Speaker-Wire Gauge Matter?
4 wire speaker connection question

And Roger Russel's entire collected litany of "stuff" on this subject:
http://www.roger-russell.com/wire/wire.htm
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Last edited by holl_ands; 09-24-2017 at 01:42 AM.
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post #19 of 21 Old 09-25-2017, 11:22 AM
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Quote:
Originally Posted by AudioQuestions View Post
I need about 8 ft for the left speaker and 12 foot for the right speaker.
. . . Does equal speaker length matter? . .
No.
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post #20 of 21 Old 09-26-2017, 09:33 AM
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I wrote:
Quote:
Originally Posted by Speedskater
Yes, the 1/2dB loss can be compensated for. But it will depend on the loudspeaker's impedance curve with respect to frequency. If the curve is rathre flat, then no problem. But if the curve looks like a roller coaster then the long cable channel will have EQ differences.


Quote:
Originally Posted by AudioQuestions View Post
Can you elaborate? Because I think the SF olympica 3 has a much lower than the rated 4 ohm on the low frequencies, and much higher on the high frequencies.
Remember that was about a 1 foot and a 100 foot cable.
It only applies to multi-driver loudspeakers with curves that look like a roller coaster. Ignoring the bass-reflex hump.
When Stereophile magazine tests tube amplifiers into their dummy loudspeaker load, you see the same type of response, but in this case it would only be on one channel.

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post #21 of 21 Old 09-27-2017, 09:49 AM
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Quote:
Originally Posted by m. zillch View Post
No.
That was easy!

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