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Very long cable runs
Old 1 week ago
  #61
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Quote:
Originally Posted by tourtelot View Post
I am not sure I agree with this. Digital information is just "ones" and "zeros". I can't speak AES-talk on this, but I can't see how glass and copper could sound different. But then again, I could justify spending $2k on a 1m AC cable that I plug into the wall of a 200 year-old church

D.
you're correct, no difference in sound - but with long copper cables, level can drop below specs and destination gear can no longer recognize the asebu signal. dunno about jitter but i assume long cables never help... - fibre got its own issues.
Old 1 week ago
  #62
Gear Nut
 

Quote:
Originally Posted by king2070lplaya View Post
I’d assume crosstalk
I was just assembling a parts list to make some 4-channel analog-over-CAT snakes and was dismayed to read about your testing results, especially since you used S/FTP to reduce cross-talk. (Earlier remarks from Mark Donahue at SoundMirror in various threads gave me high hopes of using this stuff successfully.) What do you think of the notion that cross-talk would be most evidenced when using line level signal, in contrast to mic level?
Old 1 week ago
  #63
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Quote:
Originally Posted by Brent Hahn View Post
Going back to the first post... does this need to be mixed as it goes down? If it doesn't, why not put the recorder near the mics?
Yes as I've (OP) said, that is in all scenarios considered the master recording--the remotely placed pre+recorder, (yes, in a catwalk). The feeds from that to my position down in the church are so I could make some kind of demo mix as well as for archival video. But I still have to see what will survive a real cost-benefit analysis once I get all the facts of the show in front of me.
Old 1 week ago
  #64
You know, I don’t feel qualified to make any objective statements about what was causing the decrease in fidelity, other than to say that there is definitively a difference, and that the CAT signal is deteriorated and noticeably inferior to the shorter signal path in this experiment. I said crosstalk mainly because that’s what I’d heard the primary weakness of a system like this is.

If any of you out there can explain or even refute the results of what I’ve experienced here, I’d love to read about it. I was also surprised and even disappointed in the results, given that the cable’s spec should result in the best results for a system like this.

Tonight I think I’ll string together a 150’ run of Canare -4e6s and rerun the experiment.



Quote:
Originally Posted by DrReid View Post
I was just assembling a parts list to make some 4-channel analog-over-CAT snakes and was dismayed to read about your testing results, especially since you used S/FTP to reduce cross-talk. (Earlier remarks from Mark Donahue at SoundMirror in various threads gave me high hopes of using this stuff successfully.) What do you think of the notion that cross-talk would be most evidenced when using line level signal, in contrast to mic level?
Old 1 week ago
  #65
Gear Nut
 

Quote:
Originally Posted by king2070lplaya View Post
You know, I don’t feel qualified to make any objective statements about what was causing the decrease in fidelity, other than to say that there is definitively a difference, and that the CAT signal is deteriorated and noticeably inferior to the shorter signal path in this experiment. I said crosstalk mainly because that’s what I’d heard the primary weakness of a system like this is.

If any of you out there can explain or even refute the results of what I’ve experienced here, I’d love to read about it. I was also surprised and even disappointed in the results, given that the cable’s spec should result in the best results for a system like this.

Tonight I think I’ll string together a 150’ run of Canare -4e6s and rerun the experiment.
When/if you have the inclination, would you mind posting a few more details about how you conducted your tests, made connections, etc.? I don't at all doubt your ears or observation. It seems that hard data is difficult to come by, whereas anecdotal (and mostly favorable!) observation abounds, concerning analog audio over CAT cable. Mixing COMs seems to be a no-no. I'm just interested in 4 channels of mic level signal, no returns, phantom power.

I hope the OP indulges this little side discussion...
Old 1 week ago
  #66
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Analog crosstalk with Cat5 cables won't be a problem.
With a 100 meter (300 28 foot) cable, crosstalk use -95 dB
with Cat5e it was -100 dB
with Cat6 it was unmeasurable.

this from Stephen Lampen (Belden)
Old 1 week ago
  #67
Quote:
Originally Posted by DrReid View Post
I hope the OP indulges this little side discussion...
I hope they don’t consider it too much of a side discussion, at it seems directly relevant to their topic!

I will run the test tonight with the long Canare starquad run, and make another post with the results of that and with more specifics of how I ran this test.
Old 1 week ago
  #68
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Yannick's Avatar
 

AES/EBU will never get through low cost cable at those distances.
Analog would work.

But the thing that eludes me completely, why is anyone considering spending hours and hours of soldering cables, running cables, going up and down ladders, climbing over rooftops, after the concert repeating all of this in reverse order, after the gig trying to sell kms of useless cable.

???

Just to save a couple of hours of postproduction ?

Some people either have a very good condition, or way too much time on their hands

I would just put a 8ch recorder near the mics, on battery power and hit record 15 min before the concert. That is the way I do it, it actually works !
Old 1 week ago
  #69
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Quote:
Originally Posted by tourtelot View Post
I am not sure I agree with this. Digital information is just "ones" and "zeros". I can't speak AES-talk on this, but I can't see how glass and copper could sound different. But then again, I could justify spending $2k on a 1m AC cable that I plug into the wall of a 200 year-old church

D.
Jitter....is that AES speak ?
Old 1 week ago
  #70
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tourtelot's Avatar
Quote:
Originally Posted by Speedskater View Post
Analog crosstalk with Cat5 cables won't be a problem.
With a 100 meter (300 28 foot) cable, crosstalk use -95 dB
with Cat5e it was -100 dB
with Cat6 it was unmeasurable.

this from Stephen Lampen (Belden)
Hmm. Odd finding in that I have clearly heard cross-talk on Cat5e used as analog snake (with quality baluns) on much shorter runs than 100m.

D.
Old 1 week ago
  #71
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'Using Category 5e/6/6a for Audio and Video Applications'
Steve Lampen

sorry about the strange links:
https://www.google.com/url?sa=t&rct=...vg4a9JYqv84GKS

https://www.google.com/url?sa=t&rct=...64764171,d.b2U
Old 1 week ago
  #72
Ran the test last night and the results were... interesting.

I ran the same stereo audio sample, consisting of a series of CD tracks converted to WAV and imported into Samplitude, through 100' of Canare L-4e6 (one cable for each channel, obviously).

The signal path, for all the tests so far goes: Samplitude -> Zoom F8 DAC/Line Out-> short TA3 to XLRM adapter-> 100' Canare starquad (or LYXPRO XLRF-RJ45 adapter box-> 150' Cat6a cable [link in previous reply]-> LYXPRO RJ45-XLRM adapter box) -> 6' Monster XLRF to TRS cable -> Zoom F8 line input/Preamp/DAC-> Samplitude. I skipped the long middle run for the monster control sample, just plugging the TA3 adapter straight into the Monster cable. Gain adjustments were made on the channel fader in Samplitude. DAW and Zoom were running at 44100 24 bit. I was monitoring on Sennheiser HD600 headphones.

I was expecting the Canare to sound closer to the Monster sample than the CAT6a run, but the results were the opposite. I could always pick the Monster out from the other 2 blind, but couldn't ever accurately differentiate the CAT6a and the Canare Starquad from one another. I felt like there was a difference between Canare and Cat6a when I was flipping back and forth and could see which was which, but blind I couldn't pick them out from one another, so any difference wasn't obvious enough.

There are a number of preliminary conclusions one can draw from this kind of test, though I feel more experimentation is necessary before anything concrete can be stated about the relationship between cable type, length, and integrity of signal. I can say, though, that I am curious to run a test at mic level now between the Canare cables (my usual cabling for microphones) and the CAT6a. And as I was ready to buy a reel of Canare L-4e5c for a more portable set of mic cables, I am also curious to see if other cable options, perhaps Van Damme miniature starquad, would perform "better" than the Canare seems to.

This has been eye-opening for me, and I'm glad I've finally taken the time to run a test like this. I would be curious to rerun this test with a better DAC/ADC, to see if that opens up the gap between the cables even more than the Zoom's humble fidelity is capable of representing.

Last edited by king2070lplaya; 1 week ago at 08:04 PM..
Old 1 week ago
  #73
Gear Nut
 

Thanks for sharing your test and results! Your posts exemplify the difficulty I have in reconciling seemingly conflicting opinions, even within GS alone, on the use of analog audio over CAT. The Belden publications cited above sound (ha!) uniform in their conclusions. Why all the differences? Line vs. mic levels? RF environments? Assuming shielded CAT cabling, other build and length parameters? Devices connected on either end?
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