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Old May 22nd, 2009, 10:36 AM   #1
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Distortion using Sennheiser G2 w/ ME 2 Lav

Here is a brief audio sample that has an ME 2 through an ENG100 G2 in the left channel as a microphone input on my EX1 and an EX1's built-in in the right channel.

Notice the distortion on the left channel, despite the fact that the signal never came near clipping at any point in the delivery chain. And, while quite meager in level, I don't think there was undue gain introduced (and removed) at any point in the chain. I am not the biggest audiophile to be found in this world, but I can't call this audio acceptable from a hardware as well-regarded as what I have.

The ME 2 was positioned on clothing in the middle of the sternum, and was not being spoken directly into. It had its small mesh cap fitted (when should this be used, and when should it be left off?)

Since this taping, I have watched Guy Cochran's video on the kit and there is nothing to be gained from it in my case.

Is this a quality level one would expect from an ME 2? Is there likely a mistake I am making, or might my ME 2 be a lemony unit?

Thanks in advance for any insights.

tone
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Old May 22nd, 2009, 11:25 AM   #2
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This sounds like an overdriven pre-amp. The transmitter's sensitivity setting may have been much to high or the receiver output overdriving the camera's mic-level input.
The ME2 is not the greatest mic... but usually acceptable. The windscreen would have nothing to do with this. It would also be futile to try to fix this in post.
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Old May 22nd, 2009, 04:21 PM   #3
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Thanks, Rick.

I wonder if I have a bad example of the ME 2 (there's no way this is counterfeit... the construction and packaging are superb). I am fairly sure that the levels were not too high on transmitter sensitivity when I ran the test, as I cannot now with my somewhat greater knowledge get great sound in any controlled test when I can see all three level meters (transmitter, receiver, camera) -- I get the same mild but significant distortion.

tone
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Old May 23rd, 2009, 10:52 AM   #4
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What is the receiver plugged into and at what level: Mic or Line; XLR or 1/8" mini jack? What is the AF output setting on the Recever?
I would also borrow another mic and try it. and/or try the mic on something else that has plug-in power. ie; minidisc or other portable recorder or camera.
If it's still under warranty, Sennheiser USA will certainly repair or replace at no charge.
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Old May 25th, 2009, 01:10 PM   #5
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One thing to consider is that the EX1 has an undocumented, undefeatable limiter. When you calibrate your mixer, match sure that your peaks are at least 4 dB, even 6 dB, below the top on the EX1. It could be you are hitting the camera's limiter too hard. This would explain why your levels seem to be fine.
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Old May 29th, 2009, 03:16 AM   #6
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When I first got my G2 I had problems with distortion. I found that (for most situations with the lavalier mid-chest and a "normal" speaker) that with the "SENSIT" on the transmitter set to -20 and the "AF OUT" on the receiver set to -18, I get the best results.
This is a fair way away from the default settings.
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Old May 29th, 2009, 03:43 PM   #7
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Quote:
Originally Posted by Robin Lambert View Post
When I first got my G2 I had problems with distortion. I found that (for most situations with the lavalier mid-chest and a "normal" speaker) that with the "SENSIT" on the transmitter set to -20 and the "AF OUT" on the receiver set to -18, I get the best results.
This is a fair way away from the default settings.
I use same settings for my PD-170 for the "normal speaker", as you say. I go to -30db on the transmitter (or even less, using pads), with the line output from a DJ mixing board.

Knowing that EX-1 has 2 limiters, I still have to play with my new EX-1 settings for the G2 receiver. Can anyone recommend AF Out (G2 receiver) and Trim level (EX-1 Menu?..) Mic or Line position switch on EX-1?..
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Old June 5th, 2009, 01:38 PM   #8
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I have altered my settings to

Sensitivity = -10 dB or -20 dB (you'll hear the switchover in the new sample below)
AF out to -24 dB
EX1's trim setting is -41dB (the default)

EX1's input level set to have peaks at 50% to 65% of meter.

Here was the old bad audio
Here is a sample of the new

One point of concern is that while the new sounds better, it can be boosted by 14dB before it fills the range. I wonder if this is because the sound cannot really use a 32bit format to its entirety.

Would you say I am in the ballpark for the quality a G2 with its ME2 should be able to deliver?

Quote:
Originally Posted by Iliya
Knowing that EX-1 has 2 limiters, I still have to play with my new EX-1 settings for the G2 receiver. Can anyone recommend AF Out (G2 receiver) and Trim level (EX-1 Menu?..) Mic or Line position switch on EX-1?..
I have my EX1's trim level at -41dB, which is the default. I have not been successful using Line Level (signals were vastly too low), but then again I have not (yet) altered the EX1's trim level.

tone
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Old June 5th, 2009, 02:17 PM   #9
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Hi there,
I just stumbled onto this thread... I've also got an EX-1, and Sennheiser G2 kits (but with Sanken COS-11 mics instead of the Sennheiser ones), and I need advice.
After getting what seems to me to be not very clean audio (interviews mostly), I've become a bit paranoid.
At first I thought that maybe I've been recording at levels that are too high (not knowing much about audio, I jumped to the conclusion that the static-like sound I'm hearing in my editing is clipping). But when I got my camera out and checked audio input levels, I can't think that this has been the problem. I often forget to watch my levels, but I'm sure I've never come close to the red in the Sony meters.

I just called the place where I bought my audio gear to ask for advice re audio settings, and the guy advised me to switch from mic input, which I've been using, to Line input.

On his advice, my transmitter is now set to -10 Sensitivity, and my receiver is set to Level +12 AF Out.

I just recorded a test interview (with myself), and the playback level seems low. I'm pretty sure that low is much better than high, but it still seems too low to me.

Anyway, reading this thread made me realize that I really need the advice of someone who uses an EX-1. The guy in the store might not know an EX-1 from another camera.
I'm not saying he doesn't know a ton more than me, but I'd love to know whether, in my case, I should be on Line level or Mic level.

Any advice would be most welcome. While I'm at it, maybe I could ask about two stand-ups I shot recently... lots of traffic around, but I thought the the lapel mics wouldn't pick it up as much as they did. The traffic is almost as loud as the voice! What do you do in a situation like this? I suspect I could have buried the mics a bit better... is that one's only option?

Regards,
Malcolm
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Old June 5th, 2009, 02:33 PM   #10
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Quote:
Originally Posted by Malcolm Hamilton View Post

Any advice would be most welcome. While I'm at it, maybe I could ask about two stand-ups I shot recently... lots of traffic around, but I thought the the lapel mics wouldn't pick it up as much as they did. The traffic is almost as loud as the voice! What do you do in a situation like this? I suspect I could have buried the mics a bit better... is that one's only option?
Maybe the mic you are using is omni ?
Using unidirectional in this case will help a lots.
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Old June 5th, 2009, 03:20 PM   #11
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Yes, I think you're right... it is an omni mic.
In the average camera person's kit, should there be a little omni mic for interviews in a quiet place, and also a little unidirectional mic for a stand-up outside?
Malcolm
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Old June 5th, 2009, 03:59 PM   #12
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For group or wedding video ... omni will be good choice for sound picks up the groom, bride and also the minister.

For interview, unidirectional will be good, but shotgun mic (not wireless) will be best :-)
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Old June 5th, 2009, 04:21 PM   #13
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"For interviews, unidirectional will be good:"

I beg to differ:

Unidirectional Lavs are normally used for SR purposes, where feedback could be an issue. Not that a unidirectional lav would not work though.

... And interference tube shotguns are usually not the best choice for indoors.
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Old June 6th, 2009, 06:37 AM   #14
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I agree with Rick. Uni lavs are almost exclusively the domain of sound reinforcment applications where feedback control is an issue and are almost never used in video work. If the interviewee turns their head normally during the interview, their voice will go on and off mic if you're using a unidirectional. Lavs for film and video are almost always omni, relying on the higher level of voice to background due to their close proximity to the speaker's mouth to isolate the voice from surrounding noises.

Quote:
Originally Posted by Tuy Le View Post
For group or wedding video ... omni will be good choice for sound picks up the groom, bride and also the minister.
For interview, unidirectional will be good, but shotgun mic (not wireless) will be best :-)
You're not trying to mic the interviewer with a lav and have it pick up BOTH the interviewer and his subject, are you? With a wedding you might not have a choice but for most situations, such as interviews or dramatic dialog, each participant needs to wear their own mic and they should be recorded to separate tracks (never mix lavs in the field). The pickup of excessive traffic noise mentioned in an earlier comment could have been caused by trying to use a single lav to pick up both participants in the conversation, boosting the gain to raise the level of the voice of the person not wearing the mic. You might get away with a single mic for vows in a church where no one else is speaking and there's minimal background noise but not in the field.

A shotgun is a good way to record an interview but you need to have a boom operator swinging it who knows what he's doing. A sole-operator using an on-camera shotgun is an invitation to disaster.

Malcolm and Anthony: You didn't mention the order you were setting the various levels so I don't know if you've done this or not, but you should never try to control the levels recorded in the camera by adjusting the TRANSMITTER sensitivity. Transmitter and recording levels are adjusted separately, transmitter first and then the recording. You always want the transmitter to be fully modulated at the maximum levels possible without it clipping so you first set it up by placing the lav in position on the subject, then as they speak normally adjusting the transmitter sensitivity to get full deflection of the meter, the peak indicator just flickering on voice peaks. Then leave it alone, making all further recording level adjustments with the receiver's AF out and the camera input recording levels. Haven't worked with an EX1 but its specs indicate a line level sensitivity of +4dBu. After setting the transmitter for full meter deflection my first trial would be to set the receiver output to +4, set the camera input to line and its recording level dials to mid-scale (5), then see where speech fell on the camera's meters.
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Last edited by Steve House; June 6th, 2009 at 08:37 AM.
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Old June 6th, 2009, 12:02 PM   #15
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Steven,
thank you for your thorough posting... (I note you're from Hamilton, and I hope you get an NHL team). I notice on a thread on a forum specific to the Sony EX-1 camera that most people use Mic instead of Line Input. Would your same rules apply to Mic Input?
I guess what I was hoping to do is find the best 'average' settings (for the camera and the Sennheiser transmitter and receiver) and then just adjust the volume input knob a bit if necessary up if the interviewee is soft-spoken, and down if the interviewee has a loud voice. And always, I now understand, err on the side of caution (peaking at -10 dB).
What do you think?
Malcolm
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