Another sound question

Bill Pryor · September 27th, 2004, 12:34 PM

All mixers that I know about can output either mic or line level, but that still is a problem because you're going in through the camera's mic preamp when you do mic in, regardless of whether it's coming from a mixer or direct from the mic.

Rick Step · September 27th, 2004, 12:56 PM

So don't bother with getting a mixer at all when using the xl2?

Greg Milneck · September 27th, 2004, 02:10 PM

NO, this is not true. The purpose of a mixer is so the audio can be properly monitored during recording by a sound technician before sending to the XL2. He can adjust levels without touching the camera. This is always the prefered way to record audio, unless you are simply run-and-gun and using the included camera mic.

The XL2 can NOT take LINE level audio thru its XLR inputs...but it can still take audio from a mixer via XLR MIC level outputs or RCA LINE level outputs.

Matthew Cherry · September 27th, 2004, 10:05 PM

I have to say, I'm a little confused about what all the fuss is about. Now I'm new to the xl2 and have never used a video camera that had xlr inputs before so maybe that's why BUT, I have had quite a bit of experience in music studios and live venues using both mic/line inputs and outputs balanced and unbalanced.

Unless I was setting up a long cable run, unbalanced cables usually just are not that big a deal. Sure the preference will always be for balanced, but I bet if I did a blind test over a short run, and paid attention to some pretty common conventions for laying cable, you wouldn't be able to tell the difference - at all. Now granted, on a long run this can be a problem, but you could always run 99% of the way with a line level balanced cable and convert at the camera (by connecting to an rca adapter). Again, I don't think most of us would ever be able to tell.

Now maybe capturing audio for a film is different that capturing audio for an instrument of a vocalist. Or maybe it's just late and I'm tired and I'm missing something. Or maybe I'm just an idiot....

As far as using an external mixer goes, I would always use one, if I had another person running sound, especially if recording digitally. Remember unlike an analog record you "clip" at 0.0db and in the digital world that means a pretty disgusting sound which is difficult (read impossible) to remove in post. It's sort of like exceeding 100IRE (or whatever that is for brightness) except instead of just losing detail you add nastiness as well. Of course you don't want noise in your audio either (from recording to low) although that's easier to fix. So to maximize your signal to noise ratio, you want to record as hot as you can without clipping. I would recommend that anyone serious about recording audio and willing to employ a sound tech using a mixer seriously think about adding some compression to the signal chain. You don't need a lot, and for dialog you certainly don't need to spend much on the unit, but a little transparent soft knee compression will go a long way to achieving a hot signal without clipping.

Granted with audio you can do a tremendous amount of work while mixing (post) hence the phrase "fix it in the mix" and for anyone running FCP (or other editors that can utilize them) I would highly recommend the Waves pluggins (I use them in Logic and SX as well and they are simply amazing!!). But nothing beats starting with a good signal.

Matt

Lauri Kettunen · September 28th, 2004, 12:15 AM

<<<-- Originally posted by Bill Pryor : All mixers that I know about can output either mic or line level -->>>

I have also a long background in music studios and this is news to me. I find myself now as an "idiot", sorry for my ignorance.

The Sound devices MixPre I own neither has mic output, only mic inputs and balanced XLR line outputs. See, http://www.sounddevices.com/products/mx2master.htm
But the Sound devices 302 seems to have something which indeed looks like a mic output.

Robin Davies-Rollinson · September 28th, 2004, 12:26 AM

If the circuitry is similar to the XM2, then I don't see any problem. If I do a "serious" shoot with the XM2, I always use a professional sound recordist. They plug the output from their filed mixer (yes, we always use mixers) into the Beachtek XLR box, I set the camera audio to ATTN and they send tone at their preferred LINE level and adjust the pots on the camera to suit. I never touch the audio side again for the rest of the shoot. We get perfect audio which has been broadcast (BBC) a number of times with no complaints...

Robin

Jim Giberti · September 28th, 2004, 11:00 AM

<<The Sound devices MixPre I own neither has mic output, only mic inputs and balanced XLR line outputs.>>

Hi Lauri, you're right about the MixPre of course and unfortunately, you only have two choices with it: either get a pair of padded XLR cables to input to the XL2 rear jacks or come out of the tape out with a stereo mini to the RCA Audio 1 ins.

The good news as far the new XLR input/audio section of the XL2 is concerneed is that it performs pretty nicely. I did a few hours of tests in the recoording studio last night through NS-10s and JBL 12/10s, and using the onboard 48v phantom power, XLR gainup off, and attenuation of on that the jacks, I got a good tight signal at an average boom distance using an ME 66.

With the input gain between 10 and 11 o'clock, I got a good average 12db with peaks averaging around 6db. After comparing it to the the line out of the MixPre at the same recorded levels, I was really pleased with the signal to noise of the new XL2 pres. They ain't Focusrite or Neve, but not bad and definitely capable of gettting good sound with good technique.

Nick Hiltgen · September 28th, 2004, 06:37 PM

SO I have a question, let's say you were really gung ho about balanced XLR inputs AND voiding your warrenty, coud you not just go inside the camera and swap the wires from the RCA and XLR connectors ?

Aaron Koolen · September 28th, 2004, 06:47 PM

Assuming you mean route the XLR's jacks to the RCA circuitry there would be more involved because the XLR's are balanced and the RCA isn't. If you just forgot about the cold wire of the balanced line, and just used the hot one you would lose the balanced nature of these inputs.

Of course you'd then only have a unbalanced line level input - no chance for mic.

Aaron

Greg Milneck · September 28th, 2004, 07:55 PM

<<<-- Originally posted by Nick Hiltgen : SO I have a question, let's say you were really gung ho about balanced XLR inputs AND voiding your warrenty, coud you not just go inside the camera and swap the wires from the RCA and XLR connectors ? -->>>

Only if you have a screw loose !

Don Palomaki · September 29th, 2004, 04:45 AM

Many mixers (but not all) offer a balanced mic level output option. This is often at about -30 dBV, give or take and corresponds to the XL series MIC ATT setting. For example the Mackie 1402 does and the economical Behringer MX602A does not.

Also, many offer an RCA consumer line level output, commonly labeled Tape Out that can feed the line inpout level of the XL series.

My observation is that most of the mic preamp noise cleans up when using the MIC ATT setting.

Valeriu Campan · September 29th, 2004, 07:48 AM

<<<-- Originally posted by Lauri Kettunen : Rick, mixers may have a switch between line and mic on input but not on output. -->>>

Lauri,
My Shure field mixer has an output switch for line / mic . I have tested it and it works

Lauri Kettunen · September 29th, 2004, 08:04 AM

Valeriu, yes, my comment was nothing but a sign of stupidity. How come I never came across with a mixer with a mic level output? Quite a coincidence, or then for some strange reason never paid any attention to such outputs.

Cosmin Rotaru · September 30th, 2004, 08:08 AM

What might be a real stupid question:

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?!

I'm not very good to audio. So if someone could explain it to me...

Thanks!
BTW: I think I've read specs on some oudio input (I don't know if that was a videocamera or something else..) with an AUTO switch from mic to line.

Aaron Koolen · September 30th, 2004, 02:50 PM

Mic level (assuming -50dbV) is about 0.003V (3mV) and pro line is 1.2V or 1200mV so it's even a bigger difference than you said. But, it all helps. Why not have it if you can? What if you're in an electrically noisy situation and have no choice - better to get the best audio you can.

Aaron

September 27th, 2004, 02:10 PM	#18
Greg Milneck Regular Crew Join Date: Sep 2004 Location: Baton Rouge, LA Posts: 145	NO, this is not true. The purpose of a mixer is so the audio can be properly monitored during recording by a sound technician before sending to the XL2. He can adjust levels without touching the camera. This is always the prefered way to record audio, unless you are simply run-and-gun and using the included camera mic. The XL2 can NOT take LINE level audio thru its XLR inputs...but it can still take audio from a mixer via XLR MIC level outputs or RCA LINE level outputs. __________________ www.digitalfx.tv

September 28th, 2004, 06:47 PM	#24
Aaron Koolen Trustee Join Date: Apr 2002 Location: Auckland, New Zealand Posts: 1,727	Assuming you mean route the XLR's jacks to the RCA circuitry there would be more involved because the XLR's are balanced and the RCA isn't. If you just forgot about the cold wire of the balanced line, and just used the hot one you would lose the balanced nature of these inputs. Of course you'd then only have a unbalanced line level input - no chance for mic. Aaron __________________ My Website Meat Free Media

September 28th, 2004, 07:55 PM	#25
Greg Milneck Regular Crew Join Date: Sep 2004 Location: Baton Rouge, LA Posts: 145	<<<-- Originally posted by Nick Hiltgen : SO I have a question, let's say you were really gung ho about balanced XLR inputs AND voiding your warrenty, coud you not just go inside the camera and swap the wires from the RCA and XLR connectors ? -->>> Only if you have a screw loose ! __________________ www.digitalfx.tv

September 29th, 2004, 04:45 AM	#26
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	Many mixers (but not all) offer a balanced mic level output option. This is often at about -30 dBV, give or take and corresponds to the XL series MIC ATT setting. For example the Mackie 1402 does and the economical Behringer MX602A does not. Also, many offer an RCA consumer line level output, commonly labeled Tape Out that can feed the line inpout level of the XL series. My observation is that most of the mic preamp noise cleans up when using the MIC ATT setting. __________________ dpalomaki@dspalomaki.com

September 30th, 2004, 08:08 AM	#29
Cosmin Rotaru Major Player Join Date: Feb 2003 Location: Romania, Timisoara Posts: 453	What might be a real stupid question: 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?! I'm not very good to audio. So if someone could explain it to me... Thanks! BTW: I think I've read specs on some oudio input (I don't know if that was a videocamera or something else..) with an AUTO switch from mic to line. __________________ Cosmin Rotaru

September 27th, 2004, 12:34 PM	#16
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	All mixers that I know about can output either mic or line level, but that still is a problem because you're going in through the camera's mic preamp when you do mic in, regardless of whether it's coming from a mixer or direct from the mic.

September 27th, 2004, 12:56 PM	#17
Rick Step Regular Crew Join Date: Jun 2004 Location: Virginia, USA Posts: 62	So don't bother with getting a mixer at all when using the xl2?

September 27th, 2004, 10:05 PM	#19
Matthew Cherry Major Player Join Date: Sep 2004 Location: Stamford, CT United States Posts: 212	I have to say, I'm a little confused about what all the fuss is about. Now I'm new to the xl2 and have never used a video camera that had xlr inputs before so maybe that's why BUT, I have had quite a bit of experience in music studios and live venues using both mic/line inputs and outputs balanced and unbalanced. Unless I was setting up a long cable run, unbalanced cables usually just are not that big a deal. Sure the preference will always be for balanced, but I bet if I did a blind test over a short run, and paid attention to some pretty common conventions for laying cable, you wouldn't be able to tell the difference - at all. Now granted, on a long run this can be a problem, but you could always run 99% of the way with a line level balanced cable and convert at the camera (by connecting to an rca adapter). Again, I don't think most of us would ever be able to tell. Now maybe capturing audio for a film is different that capturing audio for an instrument of a vocalist. Or maybe it's just late and I'm tired and I'm missing something. Or maybe I'm just an idiot.... As far as using an external mixer goes, I would always use one, if I had another person running sound, especially if recording digitally. Remember unlike an analog record you "clip" at 0.0db and in the digital world that means a pretty disgusting sound which is difficult (read impossible) to remove in post. It's sort of like exceeding 100IRE (or whatever that is for brightness) except instead of just losing detail you add nastiness as well. Of course you don't want noise in your audio either (from recording to low) although that's easier to fix. So to maximize your signal to noise ratio, you want to record as hot as you can without clipping. I would recommend that anyone serious about recording audio and willing to employ a sound tech using a mixer seriously think about adding some compression to the signal chain. You don't need a lot, and for dialog you certainly don't need to spend much on the unit, but a little transparent soft knee compression will go a long way to achieving a hot signal without clipping. Granted with audio you can do a tremendous amount of work while mixing (post) hence the phrase "fix it in the mix" and for anyone running FCP (or other editors that can utilize them) I would highly recommend the Waves pluggins (I use them in Logic and SX as well and they are simply amazing!!). But nothing beats starting with a good signal. Matt

September 28th, 2004, 12:15 AM	#20
Lauri Kettunen Major Player Join Date: Aug 2004 Location: Kangasala, Finland Posts: 445	<<<-- Originally posted by Bill Pryor : All mixers that I know about can output either mic or line level -->>> I have also a long background in music studios and this is news to me. I find myself now as an "idiot", sorry for my ignorance. The Sound devices MixPre I own neither has mic output, only mic inputs and balanced XLR line outputs. See, http://www.sounddevices.com/products/mx2master.htm But the Sound devices 302 seems to have something which indeed looks like a mic output.

September 28th, 2004, 12:26 AM	#21
Robin Davies-Rollinson Trustee Join Date: Dec 2002 Location: Gwaelod-y-garth, Cardiff, CYMRU/WALES Posts: 1,215	If the circuitry is similar to the XM2, then I don't see any problem. If I do a "serious" shoot with the XM2, I always use a professional sound recordist. They plug the output from their filed mixer (yes, we always use mixers) into the Beachtek XLR box, I set the camera audio to ATTN and they send tone at their preferred LINE level and adjust the pots on the camera to suit. I never touch the audio side again for the rest of the shoot. We get perfect audio which has been broadcast (BBC) a number of times with no complaints... Robin

September 28th, 2004, 11:00 AM	#22
Jim Giberti Major Player Join Date: Aug 2002 Location: Bethel, VT Posts: 824	<<The Sound devices MixPre I own neither has mic output, only mic inputs and balanced XLR line outputs.>> Hi Lauri, you're right about the MixPre of course and unfortunately, you only have two choices with it: either get a pair of padded XLR cables to input to the XL2 rear jacks or come out of the tape out with a stereo mini to the RCA Audio 1 ins. The good news as far the new XLR input/audio section of the XL2 is concerneed is that it performs pretty nicely. I did a few hours of tests in the recoording studio last night through NS-10s and JBL 12/10s, and using the onboard 48v phantom power, XLR gainup off, and attenuation of on that the jacks, I got a good tight signal at an average boom distance using an ME 66. With the input gain between 10 and 11 o'clock, I got a good average 12db with peaks averaging around 6db. After comparing it to the the line out of the MixPre at the same recorded levels, I was really pleased with the signal to noise of the new XL2 pres. They ain't Focusrite or Neve, but not bad and definitely capable of gettting good sound with good technique.

September 28th, 2004, 06:37 PM	#23
Nick Hiltgen Trustee Join Date: May 2003 Location: Atlanta GA Posts: 1,427	SO I have a question, let's say you were really gung ho about balanced XLR inputs AND voiding your warrenty, coud you not just go inside the camera and swap the wires from the RCA and XLR connectors ?

September 29th, 2004, 07:48 AM	#27
Valeriu Campan Major Player Join Date: Mar 2004 Location: Melbourne, Australia Posts: 223	<<<-- Originally posted by Lauri Kettunen : Rick, mixers may have a switch between line and mic on input but not on output. -->>> Lauri, My Shure field mixer has an output switch for line / mic . I have tested it and it works

September 29th, 2004, 08:04 AM	#28
Lauri Kettunen Major Player Join Date: Aug 2004 Location: Kangasala, Finland Posts: 445	Valeriu, yes, my comment was nothing but a sign of stupidity. How come I never came across with a mixer with a mic level output? Quite a coincidence, or then for some strange reason never paid any attention to such outputs.

September 30th, 2004, 02:50 PM	#30
Aaron Koolen Trustee Join Date: Apr 2002 Location: Auckland, New Zealand Posts: 1,727	Mic level (assuming -50dbV) is about 0.003V (3mV) and pro line is 1.2V or 1200mV so it's even a bigger difference than you said. But, it all helps. Why not have it if you can? What if you're in an electrically noisy situation and have no choice - better to get the best audio you can. Aaron __________________ My Website Meat Free Media