Does speaker cable length matter?

[Got2SadowskyNYC]

Bulk cable is cheaper than a finished cable. Speaker cable is cheaper still because you don't have the shielding weave that instrument, XLR, patch etc. have. Ergo, speaker's easier to make.

[zortation]

A really simple test you can do is to touch the speaker cable after playing your rig for an extended period. If it's warm, that warmth is potential output that has been lost because of an inefficient signal path (a speaker cable that is too long or too thin, or both).

[Got2SadowskyNYC]

In the process of making that heat, you're damaging your amp. If you have a tube amp, it's even worse.

And just in case someone doesn't know...


NEVER EVER EVER EVER use an instrument cable as a speaker cable. BAD BAD BAD.

[prd004]

[quote="! Delay in audio cables? What a joke that is. From here to the moon, maybe!

[/QUOTE]

Actually there is a measurable delay. It's been a long time since I was in school but I think it travels at 1,325 feet per second.
(again that number is from memory of a textbook I read more than ten years ago, but if I'm off I'm close)!!!!

Not quite the moon and back, more like Seattle to Los Angeles! :-D

[prd004]

Originally Posted by Bassamatic

Speed of LIGHT, I think you mean.

And being in a coil affecting the sound? Since it is air, I don't think there would be any effect on audio.

Ha! Delay in audio cables? What a joke that is. From here to the moon, maybe!

It IS important however, that it is not too small for the power you are running vs. the length. I know that there are some good charts about this available online. 16 ga. is probably safe and 14 ga. better, but even 18 is fine for a short run.

Actually there is a measurable delay. It's been a long time since I was in school but I think it travels at 1,325 feet per second.
(again that number is from memory of a textbook I read more than ten years ago, but if I'm off I'm close)!!!!

Not quite the moon and back, more like Seattle to Los Angeles! :-D

[Josh Thatguy]

1,325 feet per second is one Hell of a quarter-mile time, plus 5 feet. (5,280 in a mile)

[prd004]

Originally Posted by Josh Thatguy

1,325 feet per second is one Hell of a quarter-mile time, plus 5 feet. (5,280 in a mile)

That's why they call it the speed of sound!

[gumtownbassman]

Originally Posted by prd004

Actually there is a measurable delay. It's been a long time since I was in school but I think it travels at 1,325 feet per second.
(again that number is from memory of a textbook I read more than ten years ago, but if I'm off I'm close)!!!!

You made me spit my coffee over my screen, sound waves throug the air travel at the speed of sound, electricity travels just under the speed of light.
Think about the telephone call a few miles down the road using copper wires, you don't get a 20 second delay in the conversation.

[MikeBass]

No.

[delta7fred]

(With ref to posts #5,6,10)
I know it is a lot of years since I was in college but I seem to remember that a coil of wire like a speaker cable wound up is actually a bifilar coil so will have minimal inductance.

Not that an air cored inductor with so few turns would have much inductance anyway even if it were not bifilar wound.

[MikeBass]

Ok...I was curious.....
If anyone says lenght makes a difference....
Electricity travels about 90% the speed of light.
So, about 883,872,000 FEET PER SECOND.
So your 5' cable.....about 5/1,000,000,000 of a second (five BILLIONTH of a second)....

[Got2SadowskyNYC]

Measureable and noticeable are 2 differnt things all together.

There can be a delay when useing a wireless but the delay happens when the sound leaves the speaker. It's slows down A LOT from the speed of light to the speed of sound.

I don't remember the question being about the measureable delay. I don't think.

[gumtownbassman]

The OP's question was "Does speaker cable length matter".

The propogation delay issue is a factor not even worth concidering.

The coiled cable-inductance will only become an issue if you are amplifying at radio frequencies above 100MHz.

The only issues really worth concidering are cable losses, conductor cross sectional area-vs-length,
and insulation voltage rating.

Don't use shielded guitar/bass input cables for driving speakers, there is not enought copper to carry the load and the voltage rating is typically 50v, where a high powered amp would peak atleast twice that volatage.

Typical speaker cables available off-the-shelf from your music store available at any reasonable length will not pose any problems or cause any noticable deteriation in sound.

[Got2SadowskyNYC]

The main reason to not use an instrument cable as a speaker cable is the shielding.

The copper shielding in a inst. cable adds resistance, but is neccesary to prevent RF interferance. It's the cause of "tone sucking" in cables.

Using a instrument cable that resistance on the amps output is like hooking a firehose (the amp) up to a straw (the cable) and it's a VERY good way to blow the amp up.

The small conductor is not really a big deal unless you're useing high power amps. See if you can find a photo of old speaker cable supplied with a vintage Bassman. It was thiny by today's standard BUT these are relitivly low power amps.

[Razman]

The horse is well beyond dead now, but FWIW I'll add my $0.02.

For most rigs at normal volumes, highly unlikely to be noticeable. I'm pushing four cabs with a SVT6Pro at my church; one of my 12 ga. 3' cables was missing so I was using a 12' speaker cord in its place. I had the extra coiled neatly and set it in my rack under the amp; no one seems to have noticed (including myself) but I haven't done any critical listening tests by A/B'ing both cords. After I recovered said missing cable my OCD is now satisfied knowing that I have four identical 3' speaker cables connecting everything together.

However, when assisting our sound guys with moving our PA around, we always run the same size/brand/type/length cord/cable to our equipment. We've moved to using Mackie powered PA cabs and having signal cables the same length makes an audible difference. And a 100' cord sounds different than four 25-footers daisy-chained together, so we try to eliminate as many connections as possible.

Now can someone help me get this dead horse outta here? It's starting to stink up the place...


Raz

[gumtownbassman]

Originally Posted by Got2SadowskyNYC

The main reason to not use an instrument cable as a speaker cable is the shielding.

The copper shielding in a inst. cable adds resistance, but is neccesary to prevent RF interferance. It's the cause of "tone sucking" in cables.

Shielding adds capacitance not resistance, the shielding has more conductor area than the center conductor in a quality instrument/mic cable.

Originally Posted by Got2SadowskyNYC

Using a instrument cable that resistance on the amps output is like hooking a firehose (the amp) up to a straw (the cable) and it's a VERY good way to blow the amp up.

Never heard of a SS amp blowing up from decreased load, maybe a tube output stage would blow if running open circuit.

[Got2SadowskyNYC]

Yeah. ment cap. Sorry.

New ss amps are more tollerant of this and have protections built in. Designers know that someone's going to do this so they plan for it but they can burn up with long term use and it wouldn't be warrenty work. At the very least you'll shorten the life of the amp.

I had a Crown amp would shut down if you tried stupid stuff.

[Got2SadowskyNYC]

Digital amps are even better at dealing with this.

[fkh006]

Originally Posted by Got2SadowskyNYC

I got the biggest laugh when I first saw the hype about the power cable.

The shorted the better.

Speaker cables should be considered part of the speaker.

Amps have a little known rating called "Dampening Factor". Pro Audio guys know what this is. Basically it's how well the amp controls the speaker below 400hz or so. If you have a long cable it throws this off and you hear it as floppy low end.

This (long cable runs for concert subs) is why Crown has insanely high dampening factors (50,000 in some cases) on their amps and why they are great bass amps.

By comparison bass amps generally have a 500 dampening factor. They expect you to use a short cable.

Sorry, not so.
Damping factor is simply the ratio of the rated impedance of the loudspeaker to the source impedance at a given frequency.
You would need a highly resistive speaker cable to have any significant effect on that ratio.
This ratio typically changes with frequency.
The damping factor is affected to some extent by the resistance of the speaker cables. The higher the resistance of the speaker cables, the lower the damping factor.
In most cases you consider the speaker cable to have zero resistance unless perhaps you are way undersized in your choice of gauge for the power you are applying across the cable.

It's pretty unlikely that the difference between a 3 foot and a 50 foot speaker cable of the same gauge would have any noticeable effect on this.

And for the record Crown amps that I am familiar with have a low frequency damping factor of around 5000 not 50,000 This drops a bit at higher frequencies but usually does not go below 3,000.

[dmusic148]

Originally Posted by JimmyM

I stopped reading once he recommended using ESP power cords, which are grossly overpriced AC cords that do nothing for the sound of the amp. He may make a nice amp, but this power cord thing flies in the face of everything I've ever heard from actual electrical engineers. I've also AB'd one with a $5 cord that came with my computer in a blind test, and could tell no difference whatsoever. Your speaker cable is fine.

He lost me at the second paragraph of page two.
Oh well. I'd still buy one if I had the dough.