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Gear / Technical Help => Cables => Topic started by: mark_ivan on April 30, 2009, 07:17:15 PM
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Need to make some longer mic cables, around 50' each, is there any property of the Canare Star Quad that would make it unsuitable for this purpose?
Alternative wire (available by the foot) that would make a better choice?
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No. Star Quad is perfectly fine for longer runs.
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No. Star Quad is perfectly fine for longer runs.
as long as you don't have to carry it too far. 100ft of star quad is gonna be heavy
JAson
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If you find a reason let me know. I use it for runs that length. It works. 8)
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I've got some 200 ft. starquad- no problem- starquad excels as a balanced mic cable in longer lengths
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Excellent.
Ordered 110' from Newcompass, then read (somewhere?) that it is a high capacitance cable.
Have read that for low level signals going into a relatively high resistance load, high capacitance can create a low pass filter.
I didn't bother to do the math to figure out the frequency at which it would roll off, and probably won't bother now.
Thanks for the feedback!
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(http://www.canare.com/images/L-4E_Freq2.jpg)
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Sorry if this is a stupid question but if that is a log graph, doesn't it appear to indicate that frequencies below 200Hz get sharply attenuated? :-\
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The original question is well justified. At least one of the best-known brands of star-quad cable sold in the U.S. has unusually high capacitance. Cable capacitance forms a simple RC low-pass filter with the input impedance of any preamp or recorder, creating a 6 dB/octave rolloff starting at some (high) frequency; the only question is at what frequency. The higher the capacitance of the cable, the lower the turnover frequency is, and the longer the cable is, the lower it is as well.
With some types of microphones--it may be fair to say "many types" but I haven't tested this myself, so I hesitate to say--there can also be a huge increase in distortion at high frequencies because of the capacitive load placed on the microphone's output circuit. I understand that this applies mainly to microphones that use output transformers--and of course this, too would be a function both of the cable capacitance per unit length as well as the length of the cable.
Being in the U.S. market, the two brands that I've known about for a long time are Canare and Mogami. Unfortunately I don't recall whether one or both of those brands have this problem; I don't have their specs handy, nor the calculations that I made about the effect with long cables. But more recently I was surprised to discover that my engineer friends in Germany made no association in their minds whatsoever between star-quad cable and high capacitance. On checking further, I found that the star-quad cable types marketed over there simply don't have this problem! It's mainly U.S. audiophiles, it seems, who buy the expensive stuff with the worst basic engineering design, and consider themselves superior for it.
That all said, 50 feet isn't very long. The real problems come when you're operating a remote broadcast truck parked outside a venue, with 500' - 1000' cables feeding the mixing board.
--best regards
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The original question is well justified. At least one of the best-known brands of star-quad cable sold in the U.S. has unusually high capacitance. Cable capacitance forms a simple RC low-pass filter with the input impedance of any preamp or recorder, creating a 6 dB/octave rolloff starting at some (high) frequency; the only question is at what frequency. The higher the capacitance of the cable, the lower the turnover frequency is, and the longer the cable is, the lower it is as well.
With some types of microphones--it may be fair to say "many types" but I haven't tested this myself, so I hesitate to say--there can also be a huge increase in distortion at high frequencies because of the capacitive load placed on the microphone's output circuit. I understand that this applies mainly to microphones that use output transformers--and of course this, too would be a function both of the cable capacitance per unit length as well as the length of the cable.
Being in the U.S. market, the two brands that I've known about for a long time are Canare and Mogami. Unfortunately I don't recall whether one or both of those brands have this problem; I don't have their specs handy, nor the calculations that I made about the effect with long cables. But more recently I was surprised to discover that my engineer friends in Germany made no association in their minds whatsoever between star-quad cable and high capacitance. On checking further, I found that the star-quad cable types marketed over there simply don't have this problem! It's mainly U.S. audiophiles, it seems, who buy the expensive stuff with the worst basic engineering design, and consider themselves superior for it.
That all said, 50 feet isn't very long. The real problems come when you're operating a remote broadcast truck parked outside a venue, with 500' - 1000' cables feeding the mixing board.
--best regards
OK that being said, what brands are available in Germany that we are not Privy too?
Thanks,
Michael
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Sorry if this is a stupid question but if that is a log graph, doesn't it appear to indicate that frequencies below 200Hz get sharply attenuated? :-\
It would imply that, but that graph is for 100 meters, which is 300+ feet. One might suspect that a 50' run would be 1/6th as much, but I suspect it's non-linear, and it's a lot less than 1/6th as much... just a gut feeling with nothing to back it up.
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Canare's Star Quad Specs:
http://www.canare.com/index.cfm?objectid=79844442-3048-7098-AFAD046DCA18AAFA
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The original question is well justified. At least one of the best-known brands of star-quad cable sold in the U.S. has unusually high capacitance. Cable capacitance forms a simple RC low-pass filter with the input impedance of any preamp or recorder, creating a 6 dB/octave rolloff starting at some (high) frequency; the only question is at what frequency. The higher the capacitance of the cable, the lower the turnover frequency is, and the longer the cable is, the lower it is as well.
With some types of microphones--it may be fair to say "many types" but I haven't tested this myself, so I hesitate to say--there can also be a huge increase in distortion at high frequencies because of the capacitive load placed on the microphone's output circuit. I understand that this applies mainly to microphones that use output transformers--and of course this, too would be a function both of the cable capacitance per unit length as well as the length of the cable.
Being in the U.S. market, the two brands that I've known about for a long time are Canare and Mogami. Unfortunately I don't recall whether one or both of those brands have this problem; I don't have their specs handy, nor the calculations that I made about the effect with long cables. But more recently I was surprised to discover that my engineer friends in Germany made no association in their minds whatsoever between star-quad cable and high capacitance. On checking further, I found that the star-quad cable types marketed over there simply don't have this problem! It's mainly U.S. audiophiles, it seems, who buy the expensive stuff with the worst basic engineering design, and consider themselves superior for it.
That all said, 50 feet isn't very long. The real problems come when you're operating a remote broadcast truck parked outside a venue, with 500' - 1000' cables feeding the mixing board.
--best regards
how about going from a mixer/sbd > powered speakers
??? what length should you start to worry?
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Mogami have a little calculator on their homepage, http://www.mogami.com/e/cad/mic-cable.html
With some types of microphones--it may be fair to say "many types" but I haven't tested this myself, so I hesitate to say--there can also be a huge increase in distortion at high frequencies because of the capacitive load placed on the microphone's output circuit. I understand that this applies mainly to microphones that use output transformers--and of course this, too would be a function both of the cable capacitance per unit length as well as the length of the cable.
I think that is true too. It is not only a matter of output impedance.
Roger
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(http://www.canare.com/images/L-4E_Freq2.jpg)
This is a designed-in and desirable characteristic, showing rejection of EMI / RFI spectrum interference.
It is the reason for the twists of the pairs in the cable.
My first thought was which gauge were you using?
But at 50'? No worries