Another sound question
 

We've all heard about the non-line level input of the XLRs...but, there is the possibility that is wrong. Yesterday I spoke with a friend of mine who has regular contact with a Canon rep because the organization has ordered several XL2s. He brought up the audio issue to the rep, who checked on it. The rep claims that the camera detects automatically whether there is mic or line level coming in. If it's line level, ie., from a mixer, the camera will switch over automatically. That's what he said. I only have this second hand and don't know if it's true. I know my friend is a pro and reliable. Could be the rep is full of it, doesn't know, or it is true. I'm wondering if somebody with an XL2 and a mixer might check this out. Should be a simple thing to do...just hook up a line from the mixer to a camera XLR, flip on tone from the mixer and see what happens.

This has been fully tested and is not correct. The XLR inputs are MIC level only.

See thread for extensive info on this subject.

You don't have to tell Bill to see that other thread. He started that other thread.

Yeah, i started it and I'm still in the dark about it. I don't recall seeing anything about anybody actually doing a test to see if maybe the camera does really take a line feed after all. I didn't think of it either till I got this second hand info from the Canon rep. I really would like to know if it's true or not. My natural inclination is to not believe anything any salesman says till I check it out for myself. When I first heard about no line level switches, I was incredulous, thinking it had to be a mistake. So it does make sense that the camera might take care of the issue internally and automatically. That would be very cool if it did. So far, the XL2 is very close to being a terriffic camera for the money.

Agreed. I have serious doubts about the "automatic sensing" claim, but I'd really like somebody to try recording a mic-level source and then a line-level source through those XLR jacks and tell us what really happens.

Sorry, I didnt realize that.
I tested the input....it is MIC level input, not LINE level. I thought I stated that clearly in the earlier thread, but I guess I didnt.

Besides, I have never seen a camera that auto switches between line/mic. It is always a physical switch....I dont see how it could auto detect and switch this.

Regardless, it is MIC LEVEL only!

BTW Bill,
The camera will take a LINE input, but only thru the (unbalanced) RCA connector.

Yeah, I'm aware of the RCA line inputs. Weird to have it on unbalanced but not where you need it. I keep hoping the rep was right.

Since there is a switch in the XLR inputs from MIC to ATTN, wouldn't this drop the input level down to LINE?

Robin.

No, the XLR input is MIC LEVEL ONLY!
The ATT switch is a simple mic attenuator and doesnt even come close to allowing a Line level input.

Let this rest....the XLR input can NOT accept a LINE level without external help.

I own the XL2 and have personally tested this.

I know we are trying to figure out if we have a "line in" and according to the manual (which seems to have some omissions and errors) there is no mention of one. There is mention of a "line out" which I have a question about.

In the audio setup mmenu, there is a setting "AUD. M. SET". And the choices are, "NORMAL" or "LINE OUT".

Page 28 of the manual mentions this setting and references to page 53 for an explanation. However, ther is no mention on page 53 or anywhere else for that matter.

This being the 2nd un/poorly documented item in the manual, no doubt there are more.

Any insight on what this setting is about would be helpful.

Thanks.

Evan

Look at the very bottom of page 53, the last paragraph. This setting simply selects whether or not you want to hear the audio delay when you're monitoring with external gear (audio is always synced to video on the DV cassette).

Oops, User error.

Thanks Chris.

Don't some mixers allow you to switch between line and mic...if you have one such mixer, this wouldn't be an issue. Is that correct?

Rick, mixers may have a switch between line and mic on input but not on output.

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.

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

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.

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

<<<-- 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.

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

<<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.

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 ?

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

<<<-- 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 !

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.

<<<-- 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

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.

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.

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

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.

<<<-- 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

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

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.