Ideal Length for cables?

  • Thread starter Thread starter Dracon
  • Start date Start date
Man, I don't know about this mic forum anymore.

Anyway, length doesn't matter for loZ cables, just use something that's long enough because the amount of connections WILL matter eventually.
 
Dracon said:
Unlike other people who dislike the use of microphone cables (cause they think they are for snobs), I would like to know if there is an ideal length for mic cables?
Is there a lenght in which the signal is best. Sure, I could plug my mic directly into the mixer without a cable, and probably get the least signal dissipation.
However, since I am a snob, I like snooty cables and would like to know which is the best (if any) length when using mic cables. :confused: :o :p ;) :D :rolleyes: :)
Click to expand...

Assuming your cable has good screening, the only thing to think about is cable capacitance. You may have core to core and core to screen capacitances of the order of 100 - 200pF per meter - think of the input of your preamp and cable capacitance as a low pass filter.

With microphone cables this is not such a big deal due to the relatively low impedance inputs. However with instrument cables going into for example a guitar amp with an input impedance of 50k - 1M the capacitance of the cable becomes critical.

I keep my mic cables as short as possible for much simpler reasons-
a) they're easier to coil
b) tidier and less lightly to get tangled
c) less cable on the floor to get stomped on by eejits who think they're indestructable
 
crazydoc said:
I'd think that any induced impedance in a "coil" of this configuration, with an air core, would have a miniscule effect on the current (~1 to ~15 amps) involved. My skill saw seems to be just as powerful with the 100 foot extension cord coiled or straight. :)
Click to expand...

I'll buy that, and frankly admit that my real knowledge of it is scanty beyond the principle.

Now, five minutes later, having done some net research, I have to agree with you.
 
a little trick if you need to make long instrument runs, just use 2 DI boxes. bring it down to a low z and make your 100 foot run, then use another DI box to bring it back up to hi z, and plug into your amp. I have used this a few times when you want a guitarist to be in the control room and the amp to be in the live room, works beautiful.
 
Dracon said:
Sure, I could plug my mic directly into the mixer without a cable, and probably get the least signal dissipation.
Click to expand...
Jumpin' Jehosafat! I'd like to see that!

Personally I think the mic cable is a wonderful invention.

But I think the *real* upgrade in home recording happened with the advent of the AC cable. It is just so annoying having to rip out the power feed from the jack that connects to the power cable and position the device so that I can shove those two wires into the duplex receptacle on the wall.... :rolleyes:
 
jjmanton2 said:
a little trick if you need to make long instrument runs, just use 2 DI boxes. bring it down to a low z and make your 100 foot run, then use another DI box to bring it back up to hi z, and plug into your amp. I have used this a few times when you want a guitarist to be in the control room and the amp to be in the live room, works beautiful.
Click to expand...
Will that work with active DI boxes? Can they work in reverse?

Crazydoc - all of my extension reels say something like 'Current - 13A fully unwound, something else fully wound up', or something like 'Only use fully unwound'. I can't say I totally understand why, but it's there.
 
noisedude said:
Crazydoc - all of my extension reels say something like 'Current - 13A fully unwound, something else fully wound up', or something like 'Only use fully unwound'. I can't say I totally understand why, but it's there.
Click to expand...
Maybe this is why - not induction problems, but simply heat dissipation:
On the subject of heat, most manufacturers recommend against using a cord while it's still coiled up. Although not a common occurrence, if a cord is continually drawing its limit of 15 amps over a period of time, heat can build up in the conductors. The coiled cord can't dissipate the heat efficiently, and the cord's insulation may eventually melt.
from http://www.taunton.com/finehomebuilding/pages/h00010.asp

So while this would hold for power cords, it would have nothing to do with mic cables.

As far as active DI boxes, I'd think anything active is going to introduce noise into the signal, particularly bad at the mic level in the signal chain.
 
Last edited:
boingoman said:
Twenty feet seems to be a nice convenient length to work with.
Two thirties will be fine. If that is long enough. :D
Click to expand...
Problem with two twenty is that if I make two twenty cables, then I end up with two 10' cables as well. :p
Yes, boingo length is the key. I currently have one 20' and it makes it, but I'm a neat freaq (sorta - where it really doesn't count like cables), and like to route them around my door frame, instead of just stepping on them.
Anyway, the current 20' length doesn't neatly come out of the wall right now, so I was looking into a longer run. Hence the question.
 
crazydoc said:
]On the subject of heat, most manufacturers recommend against using a cord while it's still coiled up. Although not a common occurrence, if a cord is continually drawing its limit of 15 amps over a period of time, heat can build up in the conductors. The coiled cord can't dissipate the heat efficiently, and the cord's insulation may eventually melt.[/b]
from http://www.taunton.com/finehomebuilding/pages/h00010.asp
Click to expand...
I agree with you, but holy crap man. What would you be running on a 15amp rated cable (coiled) for so long that you could melt the wire? Now if you tell me you ran a 30amp or 25amp appliance on a 15amp rated cable. Yeah! The cable will begin to melt. The cables are rated to 15amp, but they are really build to 20amp capacity. Even running something at 20amp, on a 15amp cable (even coiled) it would take some time to start melting the cable. You'd have to get that cable a few degrees above 100degrees. That's alot of resistance on the cable, and I'm not sure that it would even operate the machinery.
Anyway, sorry got on a tangent.

P.S. I read that link. Awsome explanation!
 
Last edited:
The problem with really long cables is that the cable gets full...the audio goes in faster than it can come out at the other end. Thus, distortion. This is made worse when the cable has kinks or sharp bends in it. Going back to the original post, my recommendation would be that unless you really know what you're doing, I wouldn't mess with cables. But that's just me :D .
 
punkin said:
The problem with really long cables is that the cable gets full...the audio goes in faster than it can come out at the other end. Thus, distortion. This is made worse when the cable has kinks or sharp bends in it. Going back to the original post, my recommendation would be that unless you really know what you're doing, I wouldn't mess with cables. But that's just me :D .
Click to expand...
LOL!!! Damn! Maybe I need a bigger buffer on my cables. Do you know if Mogami Cables come with bigger buffers? I mean, I am like a first class snob, and I like really snooty (top notch snooty) cables. I don't want overly pretentious cables, just really really snooty cables.
Oh! I know, maybe I can build really, really, really long cables and then build a shortcut for the sound. That way, I have the length I need, but the sound can travel a shorter distance and my cables wouldn't get full. :D :D :D :cool:
 
That's the ticket...now we're talking about buffer-bypass cables...don't get me started on buffer-bypass cables because even I'm not snooty enough for them fandangled rootin' tootin' snootin' bypass cables. :rolleyes:
 
The obvious rule is not particularly longer than you need them, and don't leave the unused bits in a nice tight coil (tight coils are most likely to pick up induced signals. I would work in multiples of 10 feet (3 m) just so you don't have a bunch of oddball sizes.

Oh, and another thing that struck me as 'why didn't I think of that ages ago' was to use a permanent marker to put the length and unique ID on each cable end.
 
Innovations said:
Oh, and another thing that struck me as 'why didn't I think of that ages ago' was to use a permanent marker to put the length and unique ID on each cable end.
Click to expand...

I use color-coded tape on top of the heatshrink wrap (which I have in a variety of colors)--black for 10', nothing for 20', white for 50'.
 
mshilarious said:
I use color-coded tape on top of the heatshrink wrap (which I have in a variety of colors)--black for 10', nothing for 20', white for 50'.
Click to expand...

Oh, god, someone else, good. Mine are color coded by length, according to the spectrum, sort of. You know, ROYGBIV. I use Radio Shack velcro and 1/2' gaff tape.

Red=30 ft
Yellow= 25 ft
Green= 20 ft
Blue = 10 ft
Black= 50 ft
The velcro is for marking the length, the gaff tape (also the correct color) is for numbering the cables. So I have red 1-10, Yellow 1-10, etc. Seems extreme to some, but I can pick any cable end out of any pile of cable spaghetti or in any tight space without guessing.
I am a complete dork. I am going to have to investigate the shrink wrap thing.
Thanks crazydoc for the heating cable thing.
 
mshilarious said:
I use color-coded tape on top of the heatshrink wrap (which I have in a variety of colors)--black for 10', nothing for 20', white for 50'.
Click to expand...
What do you use for your 30' or your 22' or heck what about those 6'??
:D :D ;)
 
You must log in or register to reply here.
Back
Top