Which Cables Do I Need? - Page 2 at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > All Things Audio

All Things Audio
Everything Audio, from acquisition to postproduction.


Reply
 
Thread Tools Search this Thread
Old December 15th, 2007, 04:54 PM   #16
Trustee
 
Join Date: Mar 2007
Location: Sherman Oaks, CA
Posts: 1,259
Quote:
Originally Posted by Steve House View Post
Was that sending TC or WordClock from the recorder to the PC?

I've been trying to find more info on Avid and other NLEs ability to do something with linear code recorded on an audio track. Avid does have a Read Audio Timecode tool that will read LTC recorded on an audio track and generate an auxilliary timeline from it. Wondering now if any other NLEs have similar tool? Haven't found anything that would work like that in Vegas or Premiere Pro, is Avid the only one? Anyone heard of any add-ins for other NLE's?
This apparently works for Final Cut: http://www.videotoolshed.com/?page=products&pID=26

I wasn't able to find anything for Vegas or Premiere. But since Vegas is so scripting friendly, I IMAGINE it's a possibility.
Peter Moretti is offline   Reply With Quote
Old December 17th, 2007, 05:49 AM   #17
Trustee
 
Join Date: Mar 2007
Location: Sherman Oaks, CA
Posts: 1,259
Quote:
Originally Posted by Bob Kerner View Post
... After speaking with them on the phone, it seems like having them make a breakaway that has the correct connectors for my camera is the way to go, as opposed to buying a standard one and adding adapters to get down to mini plug size. I'd rather spare myself the aggravation of adapters cables hanging all over the place. Though you might want the adapters and a standard cable if you plan to change cameras in the near future...
Bob, just be sure that the cables going to the HV-20 fits not only its mic input but also delivers a mic level signal, otherwise you'll have to attach an attenuator. I believe most line level to mic level attenuators connect to XLR to mini, not mini to mini. So if you'll be adding an attenuator, then you may actually WANT the cable for the camera to be XLR.
Peter Moretti is offline   Reply With Quote
Old December 17th, 2007, 05:52 AM   #18
Trustee
 
Join Date: Mar 2007
Location: Sherman Oaks, CA
Posts: 1,259
Is there a certain length that should be avoided because its too long a distance for the signal to cleanly travel, or is this really a moot point (practically speaking) with XLR cables?
Peter Moretti is offline   Reply With Quote
Old December 17th, 2007, 11:18 AM   #19
Inner Circle
 
Join Date: Sep 2003
Location: Portland, Oregon
Posts: 3,259
Quote:
Originally Posted by Peter Moretti View Post
Is there a certain length that should be avoided because its too long a distance for the signal to cleanly travel, or is this really a moot point (practically speaking) with XLR cables?
Well, not quite moot for many of us who are doing work in larger rooms. I recently had to go through the math for a 420' run of line level...

There is a formula:
-3 dB Frequency = 1 / (cable length x capacitance per unit length x output Z x 2 x Pi)
for determining the high-frequency cutoff point of a particular cable. Longer cables tend to affect the signal as a low-pass filter (cut off high freqs.) Output Z refers to the output impedance of the source. This effect is known as "line loading", and is all about the total capacitance of the cable. The manufacturer supplies a spec, for example "60pf/foot", pf referring to picofarads of capacitance.

Suffice to say that (using pro low-impedance devices) any pro cable ought to get you at least 100' at mic level and 150' at line level, and usually more.

Radio frequency interference (RFI) is quite another matter, and may occur with any cable length. Here the remedies are: monitor always, balanced cables and circuits, test the cables, shorter cables, longer cables, different cables, move the cables, don't run audio cables parallel to power cables or other metal, etc. which sounds intimidating but in practice only occasionally occurs with pro equipment.

I'd certainly agree with those who've posted above that 25' is a very practical length for audio-for-video in field work.
Seth Bloombaum is offline   Reply With Quote
Old December 17th, 2007, 08:19 PM   #20
Major Player
 
Join Date: Sep 2007
Location: New York
Posts: 388
Quote:
Originally Posted by Peter Moretti View Post
Bob, just be sure that the cables going to the HV-20 fits not only its mic input but also delivers a mic level signal, otherwise you'll have to attach an attenuator. I believe most line level to mic level attenuators connect to XLR to mini, not mini to mini. So if you'll be adding an attenuator, then you may actually WANT the cable for the camera to be XLR.
I went to the shop today. It's easier to use a standard breakaway and adapter than to make a cable specific for the HV20. Would also be unreasonably expensive according to the sales guy.
Bob Kerner is offline   Reply With Quote
Old December 20th, 2007, 02:27 AM   #21
Trustee
 
Join Date: Mar 2007
Location: Sherman Oaks, CA
Posts: 1,259
FWIW, this is the cable configuration I believe I'll need to get the 744T's timecode into one of the HV-20's audio tracks:

LEMO to XLR cable. XLR to XLR attenuator. Mini stereo to two XLR Y-adapter.
Peter Moretti is offline   Reply With Quote
Old December 20th, 2007, 05:40 AM   #22
Inner Circle
 
Join Date: Mar 2005
Location: Hamilton, Ontario, Canada
Posts: 5,742
Quote:
Originally Posted by Peter Moretti View Post
FWIW, this is the cable configuration I believe I'll need to get the 744T's timecode into one of the HV-20's audio tracks:

LEMO to XLR cable. XLR to XLR attenuator. Mini stereo to two XLR Y-adapter.
Looks good to me. Are you going to put a scratch mono audio track on the other channel? Don't forget to slate your takes - I still have my doubts about this workflow doing much for you in terms of streamlining the sync process and it would be good to have slates and a scratch track as a backup. And be sure to experiment with some practice shoots before going out to do it 'for-real' to make sure everything works - really looking forward to reading a report back to us detailing your workflow and experiences in post-production - what you did, what worked and what didn't - when you get the chance.
__________________
Good news, Cousins! This week's chocolate ration is 15 grams!
Steve House is offline   Reply With Quote
Old December 21st, 2007, 02:48 AM   #23
Trustee
 
Join Date: Mar 2007
Location: Sherman Oaks, CA
Posts: 1,259
Quote:
Originally Posted by Bob Kerner View Post
I went to the shop today. It's easier to use a standard breakaway and adapter than to make a cable specific for the HV20. Would also be unreasonably expensive according to the sales guy.
Bob,

Possibly MY BAD.

I believe the HV-20 may be able to accept line level in. It has both an attenuator and a way to manually adjust down the input level.

I'm looking into it more. (I'm just so busy trying to put everything together, that I over looked this feature.)

That said I've seen a lot of posts saying the HV-20's attenuation options are not enough. But I've also read others that say they are enough. So I guess we'll find out soon either way.


P.S. Poking around has turned up that the attenuator probably cuts the signal by 24dB.

Last edited by Peter Moretti; December 21st, 2007 at 12:56 PM. Reason: New info.
Peter Moretti is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > All Things Audio

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 02:28 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network