Should speaker cables be equal length ?

Hi All,

How important is it that speaker cables should be exactly the same length ?

If critical, and if wires cannot be measured physically (as when cables runs are embedded in walls), is there a simple means (i.e. not requiring audio lab test equipment) to check whether the cables are same length of not ?

Thanks

 

Not at all. I once ran cables of 1 metre and 3 metres and it made not one iota of difference. Somebody over on HFC did the calculation and concluded that, for an observable difference to occur, one had to be several kilometres longer than the other. This is uncommon in the average domestic situation.

 

Thanks Tones, exactly the sort of answer I was secretly hoping for.

SG

 

I worked it out more precisely,
with a few wild assumptions, the ear should not be able to tell a difference in timing if the cables has no more 500km differance in length.

The signal in the longer cable will degrade more than in the short leading to a quieter less clear sound on one channel.

There is a more direct and more accurate way of finding a solution to this problem that scientific theorising. plug the speakers in....can YOU here the difference?

if not you are ok.

 

Well if you don't mind any imbalances in the resistive and capacitive networks that are your cables, you don't have a problem. If you listen to the Hifi [in the lounge] while your in the kitchen no problem, if you listen off centreand axis to your speakers you probabley wont notice any difference. Otherwise don't do it ....
I always make certain both channels of the amp see the same .....it just makes more sense, no need introducing another variable into the equation.

 

Well another vote for the Zanash point of view. Sure you may not hear the difference, but at least there are genuine issues that might affect it.

The biggest is resistance. Any speaker, but especially a ported one, is affected by resistance. You could measure the loop resistance - connect the far end wires together for measuring with a connector block. then test each loop with any cheap multimeter. The absolute accuracy is not critical, but if one measured 1/2 ohm and the other 1/4 ohm then, yes, there would be a difference in bass output. Probably less than the imbalance from one side of a room to the other [doors, windows fireplaces etc] but more than the effect of the rack you rest stuff on.

 

Well in the Tones example of 1 and 3 metres I would certainly agree. But my stuff is never less than 5 to 15m of cable length away from my amp so that is a different order. If you are going to hide cables in walls such as mentioned, they are probably going to be long. Measuring resistance is an easy check with a £10 meter if you think they are behaving differently.

After the room differences I previously mentioned, I reckon the variability of pairs of drivers [bass, mid, treble] and crossover bits is the next biggest variable. Cable differences, if they are different lengths, would come next.

Even a sceptic like Roger Russell accepts the effect of resistance:

http://www.roger-russell.com/wire/wire.htm

 

Sir Galahad,
If you are still interested to have some entertaining night time reading material, here is one.
http://www.audioholics.com/techtips/audioprinciples/interconnects/SpeakerCablelength.php

 

Thank you all for the input.

As the living room here is quite large, I had two equal lengths of 12AWG zip cord embedded in the walls when we turned the place into an apartment. Not knowing what the final location of the speakers would be, I had a few spare feet extend at each end, but now that I pretty much know where the speakers are (and the kit) gonna be for another 10 years or so, I (and my wife even more than me) want to get rid of the extra coils of wire.

And I'm sure glad I didn't invest in outrageously expensive snake oil speaker wire ...

SG