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Tarheel_
07-29-2011, 05:16 AM
I plan to make my own bi-amp speaker cables and wonder about making them equal length or not.

This is a 2 channel setup with the Left speaker only 2 feet from amp while the other Right speaker is 9 feet.

If i make them equal length, then i'm forced to bundle the Left side which doesn't make much sense to me.

Any opinions on this?

JohnMichael
07-29-2011, 05:51 AM
My thought are that different lengths of cables could have different electrical characteristics. The longer the cable the more resistance. Other electrical parameters may change but of course I do not know if it would be audible. I also do not know if the signal arriving quicker through the short cable would be audible. I would think not due to the speed of the signal through the cable. These thoughts are why I keep my cables the same length.

Mash
07-29-2011, 06:32 AM
You can go to a library & find an EE book which will give ohm/meter or ohms/ft for various wires, i.e. 18AWG, 14AWG, 12AWG. Or look it up here:

http://www.cirris.com/testing/resistance/wire.html

You will find that your speaker wires must be of VERY different lengths before your wires plus your speakers offer a significant combined resistance difference w/r/t each other. [Total resistance per channel is wire resistance plus speaker resistance.] And who would want an excessive coil of speaker lying about to be a weak choke?

Magnepans typically offer a mild variation in resistance versus frequency w/r/t their nominal rated value. Cone speakers usually offer a far greater variation in resistance with frequency. But these details will not be very important unless you envision VERY long speaker wires. Run the numbers, the math is easy.

Example: 14AWG is 0.002525 ohm/ft

you have 4 Ohm speakers

left speaker wire is 20 ft and right speaker wire is 40 ft.

Left is [4 + 20 x .002525] equals 4.0505 ohms
Right is [4 + 40 x .002525] equals 4.101 ohms

Tarheel_
07-29-2011, 07:20 AM
good stuff... the speakers are 4 ohm, but with the short distance, i think i'll just cut to the length i need and not worry about the rest.

thx

JoeE SP9
07-30-2011, 11:07 AM
Just wondering, if having equal length speaker cables doesn't matter, why are speaker cables sold as equal length pairs?

Mash
07-30-2011, 11:27 AM
Are you suggesting that speaker wires be sold in sets of: EQUAL LENGTH; one wire 2 ft longer; one wire 4 ft longer; etc. etc.; and then have a nominal set length of 10 ft pair, 12 ft pair, 15 ft pair, 20 ft pair, 25 ft pair.... whew!

You would have 5 x 3 = 15 different sets just for the above.....................

Don't you think this would complicate things excessively and unnecessarily?

Wire cutters are a lot more convenient.... don't ya think?

dwayne.aycock
08-22-2011, 12:13 PM
The signal path from the amp to the speaker needs to be the same. I agree with the other post about the impedence. The longer of thinner the wire, the greater the impedence. Think of a water hose. If you have a hose 10 feet long and a hose 100 feet long...it will take more effort to move water through the 100 foot hose. This is what your AMP sees. If you have a hose 3 inches wide and a hose 1/4 inches wide...it will take more effort to move water through the smaller cable due to restriction. This is what your AMP sees. So optimally a short low guage wire would be best. If you keep the two runs of equal length..... it is better for your AMP and better for your ears. Using unequal lengths will cause you to adjust the balance off center to compensate for the difference. This is the audiophile way.

markw
08-22-2011, 12:20 PM
Just wondering, if having equal length speaker cables doesn't matter, why are speaker cables sold as equal length pairs?It's easier for inventory management and cheaper to package. Plus, there's no audiable advantage,or disadvantage, not to.

Sansui71
08-29-2011, 02:15 PM
The signal path from the amp to the speaker needs to be the same. I agree with the other post about the impedence. The longer of thinner the wire, the greater the impedence. Think of a water hose. If you have a hose 10 feet long and a hose 100 feet long...it will take more effort to move water through the 100 foot hose. This is what your AMP sees. If you have a hose 3 inches wide and a hose 1/4 inches wide...it will take more effort to move water through the smaller cable due to restriction. This is what your AMP sees. So optimally a short low guage wire would be best. If you keep the two runs of equal length..... it is better for your AMP and better for your ears. Using unequal lengths will cause you to adjust the balance off center to compensate for the difference. This is the audiophile way.

I think that you are looking at it wrong. Water pressure does not change because of the length of the hose. It takes the same amount of pressure to get the water to the end of the hose in either the short or the long hose. What it takes is longer to get there. As in the longer the wire for most anything, i.e.( the telephone wire, cable wire) Length versus resistance, or lack thereof.

JoeE SP9
08-29-2011, 02:36 PM
Are you suggesting that speaker wires be sold in sets of: EQUAL LENGTH; one wire 2 ft longer; one wire 4 ft longer; etc. etc.; and then have a nominal set length of 10 ft pair, 12 ft pair, 15 ft pair, 20 ft pair, 25 ft pair.... whew!

You would have 5 x 3 = 15 different sets just for the above.....................

Don't you think this would complicate things excessively and unnecessarily?

Wire cutters are a lot more convenient.... don't ya think?
All of the commercial speaker cables I'm aware of come as a pair of equal length cables. In the past when I made my own I made a pair (or more) of equal length cables.

Poultrygeist
08-29-2011, 03:56 PM
The cable lengths don't matter but don't you mean bi-wiring rather than bi-amping?

Tarheel_
08-30-2011, 04:48 AM
The cable lengths don't matter but don't you mean bi-wiring rather than bi-amping?

I ended up making my own cables from the DIY 6moon article. "White Lightning cables" using outdoor extension white cable from Walmart. $13, I made 4 cables and terminated them with banana plugs.

I use them to bi-amp (not bi-wire) my NHT towers which now have powered subs in them.

While I'm an audiophile, i still don't think much about cable vs sound improvements. I just wanted cheap cable and the fact it matches our room and basically disappears against our baseboard/carpet is a huge bonus. Plus, it looks high-end!

Poultrygeist
08-30-2011, 12:42 PM
Good for you. Since the White Lightning Moonshine cables don't degrade they are as good as anything else and cheaper than zip cord.

Bi-amping can get complicated with two way speakers. How are you addressing the internal crossovers?

Tarheel_
08-31-2011, 05:28 AM
Bi-amping can get complicated with two way speakers. How are you addressing the internal crossovers?

The NHT towers (3 way) are practically made for Bi-amping....I use a NHT SA-2 sub amp which makes it easier. The amp has the crossover, phase, etc. and the tower owners manual clearly states how to bi-amp.

Works great as I use a NAD amp for the upper range and the NHT amp for lower. Really changed the speakers for the better!

Poultrygeist
08-31-2011, 06:49 AM
True bi-amping requires speaker surgery i.e. disconnecting the internal passive crossovers so that it's possible to power the high frequencies with one amp and the lows with another. The crossover function must then be handled by an external active ( electronic ) crossover unit.

Tarheel_
08-31-2011, 09:22 AM
True bi-amping requires speaker surgery i.e. disconnecting the internal passive crossovers so that it's possible to power the high frequencies with one amp and the lows with another. The crossover function must then be handled by an external active ( electronic ) crossover unit.

true bi-amping? You either bi-amp or not....bi-amp means 2 amps driving 1 speaker. Thus, removing the rear speaker jumpers and running a separate amp to each speaker post is bi-amping. The NHT external sub amp allows me the set the crossover, phase, volume, etc. on the bass drivers.

The NHT manual clearly states this...i copied/pasted this from the manual.

"Bi-amplification is the use of two separate amplifiers, one to power the bass drivers and one to power the midrange / high frequency
drivers. This configuration provides greater
dynamic range for both amplifiers, as they
are spared the task of reproducing the
entire frequency range. In addition, biamplification
is a great advantage in home
theater systems, as it turns the passive subwoofer
section of the VT-2 into a powered
subwoofer. NHTís SA-2 and SA-3
subwoofer amplifiers are optimized for subwoofer
amplification and feature adjustable
volume and bass tuning functions,
which allow the user to fine-tune bass
response for an individual listening
environment."

Poultrygeist
08-31-2011, 11:18 AM
This link explains true bi-amping better than I can.

Bi-Amping: Pleasure or Pain? (http://www.gcaudio.com/resources/howtos/biamping.html)

FLZapped
09-11-2011, 05:01 AM
Since you didn't mention it (or I missed it somewhere), I am assuming you are going to use the most common wire size, 12 AWG.

This is one of those questions that has to be qualified. Why? Because there will be measurable parametric differences between a 2 ft and 9 ft cable. The only thing that matters here is whether it will reach audibility.
Simple answer, then: no.

-Bruce

rightaway
09-13-2011, 05:39 PM
i alway try to match wire lenght

Bjorn154
09-27-2011, 07:34 AM
Should not matter too much. I have six foot cables in listening room and also wired to secondary speakers in living room with 30 feet of wire. There is no delay if you may to the secondary speakers when both are on so from atiming point of view it should have no audible effect.