K6/ME66 distortion problems, but only on EX1 (not on Z1U)??
 

I'm wondering if anybody else has run into this problem: I had a shoot yesterday where I used my normal Z1U shotgun setup (K6 and a ME66 phantom-powered and camera-mounted) to film some kids playing around for a news piece I'm working on. When I get back to review the footage, I hear this really annoying distortion on my shotgun that was never there on the Z1U. Thinking that the shotgun might be broken, I tried plugging it into my Z1U just to double check and it works fine with it, no distortion at all!

The distortion I'm referring to sounds like an electronic buzzing or crackling (not clipping) that goes in and out when the shotgun is either blown by wind, there is a somewhat loud sound nearby, or even if its physically moved to the left and right lightly. I'm 95% sure that the problem is specific to the way the shotgun mic and EX1 are interfacing because I just went in to the office with my old K6/ME66 and told them it was broken and they gave me a replacement, and it does the same thing: works with the Z1U but distorts in this weird way with the EX1. Anyone have any ideas as to how I might fix this? I've tweaked the sensitivity in the sound options menu but that doesn't make a difference.

EDIT: I also have an HVR-A1U as a backup camera. It comes with a dinky little shotgun that works alright. I tried plugging it into my EX1 to see if it was really something wrong with the camera somehow, but the little shotgun from the A1U works fine on the EX1 and does not distort at all, even when I shake it around. So I have no idea why but it seems like my EX1 does not mate well with the ME66...

Sounds like a low-cut filter issue. Try switching the low-cut filter on the ME66 on and see if that improves anything.

There's also a low-cut filter in the EX1 ("Wind Filter")that defaults to off, so try switching that on as well.

Ha! Switching on the low-cut filter on the K6 module fixed it! What I don't get though is, why would it not have to be on when I used it with the Z1U, and now if thats the only way I can use it, aren't I cutting out the lower frequencies? I mean I wasn't crazy about the ME66's sound to begin with (always thought it was lacking in body, especially in all of the bass regions) and now won't it just sound even thinner? Thanks again Eric.

EDIT: Is this problem specific to the ME66 or something? I don't ever recall having to deal with an issue like this after shooting with the Z1U day in and day out for almost two years so I don't see why it would be, but why is it that I have to use the low-cut filter on my EX1 for it to work without distorting? I have been thinking about getting a AT4073a so maybe this will be an excuse to get one, but not if it will have the same issue I'm having right now.

Akira, you're not the only one with this problem - check my posts (and the entire thread) here:

http://www.dvinfo.net/conf/showpost....81&postcount=2

BTW, I'd appreciate if you listened to my short sample and tell us if this is the same kind of distortion you're experiencing. It'd help me eliminate the microphone (Edirol CS-50) from the equation.

Piotr, are you using an ME66 as well? Are we the only people that have experienced this? I wonder if its something wrong with our cameras? Or something to do with specific shotgun mics? Any way you cut it I don't see why this is acceptable from Sony's point of view.

The low-cut won't affect speech too much - and you can boost bass in post. Recording with it on prevents the lows from clipping and screwing up the whole audio track. As long as you get a clean recording you can play with it a little later. But technically, yes, it will make the sound thinner.

Maybe a really good windscreen will help you? The furry ones from Rycote? Then you won't have to roll off the lows at much.

I've never used the Z1U but from what I understand it's audio response is nowhere near flat and it rolls off the lows substantially.

So in the Z1U you had a built-in low cut filter. With your other Z1U mic, you probably had a low cut built in. Only the EX1/ME66 combo did not have low-cut happening somewhere in the chain.

Hmm so its normal to shoot all the time with the low-cut filter on? I was under the impression (having never used it before on my Z1U) that it was only for specific situations, such as very windy shoots.

I assume then that I would also have to use the low-cut on the AT4073a, if I were to get one?

No, I'm using the Edirol CS-50 (which worked great with the V1E, but not with the EX1), or the Sony ECM-763. Interestingly, the latter does NOT distort at all...

It doesn't distort with the low-cut filter off? Or do you have to turn it on as well?

It never distorts - I only use the high-pass filter when the wind is really strong; normally I record the full bandwitdth. Even if there is some wind rumble, there is no additional "clicks" to it as with the Edirol.

Guys, I don't have this camera but I might guess at the problem.

My PD-170 has a problem with distortion and it is because the pre-amp gets overloaded as it is set to handle lower quality mics.

When I plug the same pro mics into my DVC-200, the audio is as it should be, crystal clear.

I don't think a camera should force you to turn on a low-cut setting on a mic, especially a $6,500 camera.

Is there an attenuator setting for the mic input?

Maybe you could adjust for the hotter signal?

I would like to know about this issue as this camera is on a short list to possibly purchase and audio is very important.

Tim,

The audio quality of the EX1 is known to be very good. I don't think the camera is causing these issues, but wind noise that is not being properly filtered.

Akira:

What kind of wind noise protection are using on the ME-66? I always found them pretty crispy anyway, but especially bad without a strong windscreen like the Rycote Softie.

If you're just using the base foam windscreen, I'd put something stronger on the mike, regardless of audio filtering.

Right now I'm just using the stock windscreen, though the amount of physical movement that it takes to make the ME66 (without the low-cut filter on) distort is really very little, not enough to really make wind and air movement a significant factor in my mind. I'm going to do some more experimenting with it today to see if a bunch of stuff wrapped around the mic might prevent the distortion I'm hearing and thereby indicate that it is in fact a wind issue. In the meantime, I just got back from a shoot with the ME66 with the low-cut filter on, gonna see how well the sound can be fattened up in post...

There is something very fishy going on. I think this problem has nothing to do with wind, as I can literally just tap the back of the shotgun microphone and I can hear the weird distortion. If I plug in the short shotgun from my HVR-A1U, I can tap it all over almost as hard as I want and I don't hear any of the distortion I'm hearing through the ME66.

One thought, could it be that the EX1 phantom power is running out of steam when the mic is trying to drive low frequencies into the camera's low impedance inputs. Looking at the problem file Piotr sent me the LF signal didn't look like typical digital clipping.