Equal Length Speaker Cables?

[Russ L]

Why do speaker cables need to be the same length? Isn't this especially hard if you are running a 5 channel SACD setup and your rear speaker is a 25 ft run along a wall from your amp. That would mean you'd need 5 times 25 ft= 125 ft of cable. Some say its important to have same lengths for matching impedance and/or inductance if I recall correctly. This can get pricey especially if the cable is $25+/ft! Even for the front 2 channels. If one speaker is 15 ft away from amp and the other is right next to it or 5 ft away then you need to roll up that extra 10 ft. I even heard rolling up speaker wire can cause inductance problems. :E Any thoughts? -Regards, Russ

[Hdale85]

Here's a question. Have you ever heard a difference in the length of cable?

[Alaric]

Don't some of the better receivers and pre/pros have the capacity to adjust the time phase of the audio signals , so they arrive in a coherent fashion? My music system is seperate from my HT , but my speaker cables (music) are equal length. Probably 'cuz they're sold that way. I never checked the cheesy wire on my HT speakers. :scratchhead:

[whoaru99]

Your wires would have to be different in length by ~200,000 meters to introduce ~0.001 second delay difference.

However, excessive lengths of wire FAR less can introduce RCL losses that can somewhat alter the FR of the system. Probably still talking one or two hundred of feet of moderate gauge wire to do that.

[DL86]

I have different lengths of speaker cable for my set up. I used to run equal lengths of cables previously but the cables broke so I had to get a new set. I honestly could not tell them apart even though one cost 300 dollars and was equal lengths and the other cost 50 dollars and was in different lengths.

[wildfire99]

How about long cables that someone has coiled up to take up the slack?

[kingpin]

How about long cables that someone has coiled up to take up the slack?

I think that is a no-no, isn't it. :T
Cables should never be rolled or coiled up from what I understand. :T

Coiling up cables can introduce a vortex or even a black hole and your speakers and your audio equipment could disappear and enter a whole new Time Continuum. :B :B

Sorry, I just finished a night shift and am a littke looped right now.

Mike

[whoaru99]

How about long cables that someone has coiled up to take up the slack?

The only way you will be truly convinced it to try it yourself both ways.

[Russ L]

Thanx everyone for your input. I get a bit nervous when the audio consultant at my hi-fi shop tells me I'm WASTING MY INVESTMENT of $600 dollars on expensive bulk cable @$17 dollars a foot plus terminations if I don't get the same length for the left, right and center channels. Looks like the consensus here is that it doesn't matter for small differences in length between cables and might cause a problem over very long length diiferences. -Russ

[wkhanna]

I'm surely no expert, but from the majority of what I have read and assuming it to not all be gospel, slight variations in length should have no discernible effect. However, I have 'heard' that less that eight foot lengths can have a negative influence. Of course, the first thing one thinks upon hearing that is the persons motive for saying such a thing, as in...... they might want to sell as much wire as possible.

[wildfire99]

Thanx everyone for your input. I get a bit nervous when the audio consultant at my hi-fi shop tells me I'm WASTING MY INVESTMENT of $600 dollars on expensive bulk cable @$17 dollars a foot plus terminations if I don't get the same length for the left, right and center channels.

Well there's your problem. The laws of physics from our world don't apply in the pocket dimensions of "hi-fi" audio stores, where suddenly special braids and ceramic puck stands and matted grill cloth woven only from the fur of black cats born during a full moon makes your audio system sound 50, 80, even 120% better. Just put those expensive terminations next to your speakers and awe at the sudden increase in richness and air being released from what would ordinarily be cheap plastic cones and wood veneer.

It's too bad really, because hi-fi pocket dimensions can be fun at times. I find that the exchange rate also gets skewed, causing my real world money to be consumed at a 8:1 ratio (8 real world dollars for every 1 pocket dimension dollar), otherwise I would probably get in on more of those deals.

[bigburner]

Why do speaker cables need to be the same length? Isn't this especially hard if you are running a 5 channel SACD setup and your rear speaker is a 25 ft run along a wall from your amp. That would mean you'd need 5 times 25 ft= 125 ft of cable. Some say its important to have same lengths for matching impedance and/or inductance if I recall correctly. This can get pricey especially if the cable is $25+/ft! Even for the front 2 channels. If one speaker is 15 ft away from amp and the other is right next to it or 5 ft away then you need to roll up that extra 10 ft. I even heard rolling up speaker wire can cause inductance problems. :E Any thoughts? -Regards, Russ

Russ,

The longer a piece of wire is, or the narrower its gauge is, the greater its resistance. The greater resistance a speaker cable has the more power is lost between the amp and the speaker causing the speaker to play less loudly. Therefore if you have a very short cable on one speaker and a very long cable on the other speaker, the speaker with the longer cable will be quieter. It is therefore recommended that speaker cables should be the same gauge, the same length and as short as possible. However, unless the difference in cable length or gauge is substantial the difference in volume will be undetectable. Having said that, our hobby is all about achieving audio perfection, so the rule concerning gauge and length is probably a good one to follow.

Nigel.

[littlesaint]

Russ,

The longer a piece of wire is, or the narrower its gauge is, the greater its resistance. The greater resistance a speaker cable has the more power is lost between the amp and the speaker causing the speaker to play less loudly. Therefore if you have a very short cable on one speaker and a very long cable on the other speaker, the speaker with the longer cable will be quieter. It is therefore recommended that speaker cables should be the same gauge, the same length and as short as possible. However, unless the difference in cable length or gauge is substantial the difference in volume will be undetectable. Having said that, our hobby is all about achieving audio perfection, so the rule concerning gauge and length is probably a good one to follow.

Nigel.

With 4ohm speakers and 14awg cable, it would take a ~100ft difference in length to cause an audible difference in power (1dB). ~200ft for 8ohms.

Same for overall cable length. For 4ohm, there's no audible loss for lengths less than 100ft and 200ft for 8ohm at 14awg. 60/120ft for 16awg.

[gd]

I think you need a new 'audio consultant'...

Or at least a second opinion.

If I was you, I'd contact forum sponsor Lex/Doug of Catcables before you spend cable money at the 'consultant'.

Cast my vote for 'no audible difference' unless the cable lengths differ by miles.

Cable is arguably the highest profit-margin item at any B&M retailer.

[Alaric]

[QUOTE]
With 4ohm speakers and 14awg cable, it would take a ~100ft difference in length to cause an audible difference in power (1dB). ~200ft for 8ohms.[QUOTE]

Out of curiosity , who determined that a change of less than 1 db isn't audible?

[littlesaint]

[QUOTE=Alaric][QUOTE]
With 4ohm speakers and 14awg cable, it would take a ~100ft difference in length to cause an audible difference in power (1dB). ~200ft for 8ohms.

Out of curiosity , who determined that a change of less than 1 db isn't audible?

1dB is generally accepted as the Just Noticeable Difference for sound intensity in a normal human ear. There are many exceptions when you factor in reflections, louder levels, higher frequencies, so it is hardly a rule, but more a general guideline.

Just Noticeable Difference

UPDATE: Also know that this number is when measuring a single speaker. When you add other sources with their reflections, it becomes much harder to distinguish a change in intensity in a single source.

[bigburner]

With 4ohm speakers and 14awg cable, it would take a ~100ft difference in length to cause an audible difference in power (1dB). ~200ft for 8ohms.

Same for overall cable length. For 4ohm, there's no audible loss for lengths less than 100ft and 200ft for 8ohm at 14awg. 60/120ft for 16awg.

As I said, unless the difference in cable length or gauge is substantial the difference in volume will be undetectable. We do these things because we strive for perfection, not because they make a difference!

[littlesaint]

...We do these things because we strive for perfection, not because they make a difference!

Preaching to choir my friend :T

I just wanted to give the OP some theoretical numbers.

[Russ L]

I don't want too much of this cable because its thicker than a garden hose. My house will end up looking like a construction site with big loops of cable if the audio consultant has their way. Thanks again for the advice. -Russ

[dknightd]

With 4ohm speakers and 14awg cable, it would take a ~100ft difference in length to cause an audible difference in power (1dB). ~200ft for 8ohms.

The other half of the picture is the "damping factor" seen by the speakers.
Compare the resistance of 100 feet of 14 gauge wire to the output impedance of a "high end" amplifier.

That said, I used to think equal length wires was a good thing. I've since changed my mind (as long as both the length and difference was reasonable).

I think you dealer might be right though, if you are paying $17 per foot for bulk wire you probably not getting your moneys worth. Note I said probably.