Audio Distortion - Sennheiser ME66 + K6
 

I am using a Sennheiser ME66 mic module with K6 power module on a Sony Z1E. Using manual settings for audio input and phantom power from the camera.

No problem recording standard volume stuff.

When filming discos I leave plenty of headroom and usualy have no problems but occassionally I get distortion when the DJ speaks over the music. I have looked at the waveform and found that this part peaks at -2db. The rest of the waveform will be around -6db.

Any ideas why this part in particular should be distorted?

(Not sure if i can add a file to this post to let you hear the problem)

You are clipping the input. For loud places you need an inline attenuator. You put it between the cable and your recorder/camera.

This one lets you attenuate by -10, -20, or -30db.

http://www.bhphotovideo.com/c/product/68085-REG/Audio_Technica_AT8202_AT8202_In_Line_Attenuator.html

Actually, you're probably clipping AT THE MIC - the ME66 is FAR from ideal for incredibly loud scenarios. I carry a CHEAP chinese knock-off medium diaphragm condenser mic in my bag for situations like rock concerts, dance halls et al.

Shaun is right. The ME66 is way too sensitive for loud environments. When we bought the two we use (2005ish), Senn. offered all new buyers the opportunity to send them in for a free attenuation adjustment for those wanting to use them in louder environments. In essence, they were offering to modify them to make them less sensitive.

With all the great portable recorders available, you're probably better off using the onboard mics for loud environments. I write this because we've never been able to attenuate these mics enough when levels get too high.

Like I said, an inline attenuator is the tool you need.

Chad: it's my opinion, based on SOLID experience, that it is the CAPSULE that is overloading therefore an attenuator won't solve the problem.

I have owned an ME66 for 8 years (having RECENTLY sold it) and prior to that used one nearly daily since media college back in '98. Again, far from ideal for loud environments.

I suggested the attenuator, David didn't ask for a new mic solution. I figured he wasn't planning on buying a new mic, which he definitely should. I agree, have had a ME66/K6 for 5 years, and I agree that it, or any other shotgun is the wrong mic for either a "loud disco" or a rock show, or any kind of music whatsoever.

David the ME66 is ok for dialog, which is what it is designed for, and it should only be used for outside dialogue really. The ME66 suffers more than most any other shotgun from the hollow/phasey sound one gets in a reflective room. Those slits on the interference tube design of a shotgun don't deal well when a reflection hits them at a different time than the source. The proper mic for indoor dialogue, or roaming around in a club or a show would be a hypercardioid. The AT4053b would be nice. Or for something cheap, the Rode NT3 will do (though it's a cardioid). If all you want is ambient sound and nobody is talking to the camera, the camera mics will do. But if you want to try to focus better on someone right in front of the camera talking or yelling more likely, then definitely a hypercardioid is the mic, as it would reject side noise and capture more of what's right in front of it.

STILL - in any loud environment, be it rock show or disco, any sound person should have a couple inline attenuators like the one I linked above. The mE66 is also very sensitive, and does indeed send a louder signal to your recording device, and it is feasible that it could clip your input, on top of distorting at the capsule. If you are serious about your audio, you want to be prepared to tackle that input distortion when it happens. Since one should have one anyway, you should just try it with your mic, but also just plan on getting a better mic for indoor use.

498.00
http://www.bhphotovideo.com/c/product/642499-REG/Audio_Technica_AT4053B.html
269.00
http://www.bhphotovideo.com/c/product/233750-REG/Rode_NT3.html
429.00
http://www.bhphotovideo.com/c/product/349107-REG/AKG__Blue_Line_Series_Microphone.html

Thanks very much for your replies. I now at least understand what is happening. I do have some in line attenuation built into the Sony Z1 via the menu based input trim which goes to -18db. I will try that first and see what happens as in most cases the mic does cope well.

I will have a look at the mics that you have recommended and purchase one of those for use in loud environments as getting good sound quality is paramount.

Fortunatlely I always use the Fostex FR2-LE Field Recorder during loud events so that I can use the best recording.

This forum is great. Glad I joined.

Thanks again

I've never found in-line attenuators much good with condensers of any type - sensitive condensers that don't have a built in pad distort far too easily, and the attenuator just lowers the level to the recorder/camera - leaving the distortion intact. The flat topping of the waveform is really unpleasant. In these circumstances, I'd just use a dynamic, and if necessary, the in-line attenuator.

For an oppressively loud situation like that, could you just get a cheap SM-58 kind of thing? You wouldn't really have to be "directional"...would you?

The on-camera mic would probably be fine, but particularly on the Sony Z and EX camera bodies, I find that handling noise can make its way through...

Though i suppose if it's that loud in the venue, that may not be an issue...

You need a mike with a higher spl rating. Two good small diaphragm condenser mikes with spl's in the 155 db range are: Sennheiser e914 (about $400) and the AKG Perception 170 (about $140). My thinking is that very loud venues don't require a whole lot of subtle reproduction, just an ability to handle the sound level, and the AKG works very well. One source is sweetwater.com.... in-line attenuators are fine for dropping too-hot line feeds, but as others have pointed out, it's the mike itself that's overloading, if you attenuate the signal you just get an attenuated verson of the distorted waveform the mike is sending out.

The ME66 SPL rating is 125dB, which would be pretty dang ear splitingly loud if you were in a club. The AT4053b is 155dB, which would cover about anything including being right in front of a cranked guitar amp with room to spare.

I agree with elements of all the posters.

"Generally" the mic INPUT will be the first point in the chain that distortion shows up simply because it is often set to be the most sensitive and with the least headroom.

However I do think the ME66 is more prone to distortion than it's SPL spec says it should be. I think it's a by-product of the same problem with off-axis coloration when used indoors in reverberent locations.
Perhaps a kind of "off-axis multiplication" that makes it more vulnerable.

I also agree that in-line attenuators, which are hard to find with any value smaller than -5 or -10 db are often too much attenuation and will bring the signal down too much.

As a first test I vote for changing the MENU attenuation setting on the camera's mic inputs and see what happens.

If that doesn't help, then I also do what many others have suggested and use either a lower output cardioid or hypercardioid condenser mic or a good quality dynamic mic.

There is little point (unless you have the dosh spare and want one) in buying a mic capable of handling the high SPL, simply because it will give you undistorted, distorted sound! What I mean is that the problem with loud sound systems of anything other than really pro spec, is that their quality is bad to start with. Disco DJ systems frequently have very inferior drivers, many have horrible sounding piezo HF units and your new mic will reveal exactly how bad the sound really is! I suspect we've all heard these systems, that sound just about OK when running quietly as background sources, but sound simply dreadful when they turn them up to 11 on the scale of 1 to 10. SM57s and 8s are not at all ultimate mics, but the most expensive microphone will not produce quality sound when it's bad to start with - and most are!

When we do big shows where the talent wear in-ear monitors, we put a microphone on the audience and feed a little of this into the monitor system and a frequent complaint is that it makes the exceptionally expensive PA sound rubbish. I think I'd go so far as to say that I've never heard good quality from any PA system miked up!

Paul. The lack of quality in a source you are recording is no reason to keep using low quality microphones. I would think David wants better mics in general, as that's what any videographer needs. Putting a crap mic on a crap PA definitely sounds worse than a good mic on a crap PA. And you can't categorically say that every DJ has a distorted sound. I've been to many nice shows. It all depends on the people running the gear. The main thing is that even with a perfectly running PA at a decent volume level, the ME66 is the wrong mic. That mic is for outdoor dialogue - not outdoor or indoor music.

Maybe David can't afford the right gear now but I would hope he plans on doing his video production a favor eventually.