Another sound question

Don Palomaki · September 30th, 2004, 04:49 PM

MIC level depends on the source: for dynamic mics it is on the order of 0.001 volts (-60 dBV). For a powered condensor mics it is on the order of -50 dBV (say 0.003 volts), some mixers and wireless mics use -30 dBV (~0.03 volts) as mic level, and consumer line level is about -10 dBV (~0.3 volts). Professional line level is typically +4dBU (4 dB above 1 mW in 600 ohms or ~1.2 volts across a 600 load). But you really have to read the specs of the gear in question to be sure. That is part of the reason for level controls and audio meters.

Matthew Cherry · September 30th, 2004, 11:26 PM

<<<-- Originally posted by Cosmin Rotaru :
Is there a real need for BALANCED LINE level? I can see when you get a mic, you get problems on long UNBALANCED cables. But then, how much is the mic signal? about 1mv? or 2mV? And the line level? Isn't that 200mV? The signal to noise ratio being so high on LINE level, do you need it to be BALANCED?! >>>

This was sort of my point. I've honestly been wondering how many of the folks here upset that the XL2 doesn't have balanced line level inputs have actually dealt with them before. But again, I don't have the experience with cameras so maybe something is different.

Yes, if you're running a line-out from a pre-amp fifty yards out, you want to use a balanced cable for a variety of reasons. But ten feet? Twenty feet? I just don't see the need to panic. And to be honest if someone is getting crappy audio in that short a run, I'd look at cable selection, placement or other parts of my signal chain before I blamed it on the cable/connection being unbalanced.

I think part of the problem here is that most of the unbalanced RCA cables people see are the cheap ones that come free with stuff. Yes, they suck. But you can get great (or at least very good) unbalanced cables and they don't suck. Don't lay them next to power cords. If you have to lay them near power cords, don't lay them parallel, lay them at right angles and tape them down. Buy them in various lengths so that you can always use the shortest cable possible. Or as others have said, buy a mixer that is compatible with your camera (mic level out at an appropriate setting).

This really isn't that difficult folks.

Figuring out what the hell you do with one of those 18% grey card thingys - that's hard. ;-)

Matt

Aaron Koolen · October 1st, 2004, 01:10 AM

Sure, I totally understand, but why not get the best signal you can? And when it's pretty much standard fare on camcorders these days to have a line level XLR in it just pisses me off that Canon would not include it.

I'd admit it aggravates me more than normal and that it's exacerbated by the fact Canon has left other features off the camera that I was expecting to be standard. So while it does make the reaction partially an emotional one, but still valid.

Aaron

Cosmin Rotaru · October 1st, 2004, 09:05 AM

Your reaction is valid. But I'm learning about this camera as I'd like to upgrade (from XM2) and wanted to know if it's a big problem (the unbalanced line in) as I'm not very familiar with the audio stuff...
Now I don't think this is a issue to consider (for my POV) when I'll have to decide.

September 30th, 2004, 04:49 PM	#31
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,489	MIC level depends on the source: for dynamic mics it is on the order of 0.001 volts (-60 dBV). For a powered condensor mics it is on the order of -50 dBV (say 0.003 volts), some mixers and wireless mics use -30 dBV (~0.03 volts) as mic level, and consumer line level is about -10 dBV (~0.3 volts). Professional line level is typically +4dBU (4 dB above 1 mW in 600 ohms or ~1.2 volts across a 600 load). But you really have to read the specs of the gear in question to be sure. That is part of the reason for level controls and audio meters. __________________ dpalomaki@dspalomaki.com

October 1st, 2004, 01:10 AM	#33
Aaron Koolen Trustee Join Date: Apr 2002 Location: Auckland, New Zealand Posts: 1,727	Sure, I totally understand, but why not get the best signal you can? And when it's pretty much standard fare on camcorders these days to have a line level XLR in it just pisses me off that Canon would not include it. I'd admit it aggravates me more than normal and that it's exacerbated by the fact Canon has left other features off the camera that I was expecting to be standard. So while it does make the reaction partially an emotional one, but still valid. Aaron __________________ My Website Meat Free Media

October 1st, 2004, 09:05 AM	#34
Cosmin Rotaru Major Player Join Date: Feb 2003 Location: Romania, Timisoara Posts: 453	Your reaction is valid. But I'm learning about this camera as I'd like to upgrade (from XM2) and wanted to know if it's a big problem (the unbalanced line in) as I'm not very familiar with the audio stuff... Now I don't think this is a issue to consider (for my POV) when I'll have to decide. __________________ Cosmin Rotaru

September 30th, 2004, 11:26 PM	#32
Matthew Cherry Major Player Join Date: Sep 2004 Location: Stamford, CT United States Posts: 212	<<<-- Originally posted by Cosmin Rotaru : Is there a real need for BALANCED LINE level? I can see when you get a mic, you get problems on long UNBALANCED cables. But then, how much is the mic signal? about 1mv? or 2mV? And the line level? Isn't that 200mV? The signal to noise ratio being so high on LINE level, do you need it to be BALANCED?! >>> This was sort of my point. I've honestly been wondering how many of the folks here upset that the XL2 doesn't have balanced line level inputs have actually dealt with them before. But again, I don't have the experience with cameras so maybe something is different. Yes, if you're running a line-out from a pre-amp fifty yards out, you want to use a balanced cable for a variety of reasons. But ten feet? Twenty feet? I just don't see the need to panic. And to be honest if someone is getting crappy audio in that short a run, I'd look at cable selection, placement or other parts of my signal chain before I blamed it on the cable/connection being unbalanced. I think part of the problem here is that most of the unbalanced RCA cables people see are the cheap ones that come free with stuff. Yes, they suck. But you can get great (or at least very good) unbalanced cables and they don't suck. Don't lay them next to power cords. If you have to lay them near power cords, don't lay them parallel, lay them at right angles and tape them down. Buy them in various lengths so that you can always use the shortest cable possible. Or as others have said, buy a mixer that is compatible with your camera (mic level out at an appropriate setting). This really isn't that difficult folks. Figuring out what the hell you do with one of those 18% grey card thingys - that's hard. ;-) Matt