Audio Distortion - Sennheiser ME66 + K6

[John Willett]

Originally Posted by Chad Johnson

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.

Audio-Technica AT8202 In-Line Attenuator AT8202 - B&H Photo

Yes - this *is* the most likely cause of the problem and the solution.

Many cameras have the level control *after* the first amplification stage and you are likely overloading this first stage.

You can either have the K6 modified or use an external attenuator. Personally I would use the external attenuator .

Originally Posted by Shaun Roemich

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.

Unlikely - the K6 series work well in loud environments - but the output can be too hot for many cameras in these situations.

Chad has the answer.

Sennheiser *do* offer a version of the K6 with a lower output level (or existing ones can be modified), but the external attenuator, I would say, is the best option.

Very very unlikely that the capsule itself is distorting as it takes a *very* large amount to bottom-out the capsule.

[Shaun Roemich]

John, until such point as I actual hear a SINGLE recording done in a loud environment successfully with this combination, I will respectfully disagree.

Betacams (SP & SX), Sony PD150s, JVC GY-HD200s... I have NEVER been able to get the mic to not distort in a rock or dance room even with pads at my disposal.

[Chuck Fadely]

I have both a standard ME66 and a factory-attenuated one. There's only so much sound pressure a mic like this can stand. In some really loud settings, you need a different mic. In-line attenuators only go so far - if the capsule is overloaded it won't help.

[David Lamb]

Hmmm. Plenty of conflicting advice. Clearly the mic I am using is the wrong one. I will try the least cost option first which is probably to use the camera mic and tweak the mic input levels. If that does not solve the problem I will try an in line attenuator. If all fails then I have no option but to go for a differnt mic. I always use a field recorder with a stereo mic pointing well away from the sound source as back up but would prefer not to have to do this as it is extra set up time.

Thanks for your comments

[William N Zarvis]

I have this same mic set up going into my FX1 for weddings and narratives. I get distortion in loud venues as well, especially when live bands are jamming out - brass is very bad! Although the most curious incident of distortion occured when I was filming a two person scene for a short film in a long indoor hallway (concrete ceilings). I couldn't figure out why some of the actors words were distorting and clipping so bad. I lowered the levels, checked the cables, and attempted to reposition the boom pole. Eventually we got through it. But is was rough. I should go back to that local and see if I can recreate the problem with the same set up to see if it was just some freak event.

Do you guys think this problem is due to the reverb in the tight space of the hallway messing with the mic?

Also, and this is a real stupid question, what is the red recessed switch for above the power switch on this mic? What does it do? There are two symbols on either side of it: a single dash on the left and a bent dash on the right.

Thanks for any info you guys have!

[Chad Johnson]

William the single dash means that the mic is being used with no filters. The bent dash means that you have engaged the low end roll off. This will help if you are getting that low rumble from wind or handling noise.

And remember that the ME66 is a SHOTGUN mic - which means it's not intended for INdoors. The ME66 is one of the especially bad shotguns when used in a reflective area like a hallway. The right mic for indoor use is a hypercardoid. Something like the AT4053b, or the AKG CK93. Even the Rode NT3 will do you though it's a "cardioid, not a hypercardioid). Don't confuse the Rode NT3, with the Rode NTG-3. The sennheiser is a sensitive mic, meaning it puts out a loud signal, which is great for dialogue pickup in the right environment (outside). But it's terrible for music. One mic does NOT fit all situations.

[William N Zarvis]

Chad, thanks for that information! Very Helpful!

[Chad Johnson]

I mistyped when I wrote "ME66 is a SHOTGUN mic - which means it's not intended for out doors."

It's not intended toe INdoors. I just changed the post.

[Steve House]

Originally Posted by Chad Johnson

William the single dash means that the mic is being used with no filters. The bent dash means that you have engaged the low end roll off. This will help if you are getting that low rumble from wind or handling noise. ...The sennheiser is a sensitive mic, meaning it puts out a loud signal, which is great for dialogue pickup in the right environment (outside). But it's terrible for music. One mic does NOT fit all situations.

Another reason for using the filter is that low frequency noise that is too far down in frequency to be audible to our ears will still be driving the mic inputs with a signal. This can be strong enough to overload the input and cause audible clipping even though we can't hear the noise itself. A low-cut filter eliminates that part on the spectrum. IMHO, the filter should be engaged almost all the time, excepting those rare situations such as mic'ing organ pedal pipes, tympani, etc where there actually is important information below 80Hz or so.

[William N Zarvis]

Thanks again guys. So, in your opinion, what is a good mic for getting dialogue outside? I used the ME66 outdoors to record a friend of mine's dialogue while he walked along a sidewalk near traffic. The sound of cars driving by was very prominent and almost ruined the recording of his voice. I see now that was a mistake. What should I have used?

I wish there was a manual for filmmakers wishing to know what types of mics to use in different setups: outdoor - close up and further away, indoor - close up and further away, soundeffects, foley, etc. It would be great if this manual also explained why certain types of mics fail in ceretain situations and why they are not reccomended. Its always nice to know what pitfalls to avoid!

[Chad Johnson]

William the cars were picked up because of the position of the mic. Even if you had a better shotgun mic you still would have picked up cars. If your ears can hear it, the mic will hear it too. Shotguns greatly reduce sounds from the side of the mic, but they don't make that noise disappear.

But if you want a better shotgun, check out the Rode NTG-3 for 700.00. It's much nicer than the ME66.

[Steve House]

Originally Posted by William N Zarvis

Thanks again guys. So, in your opinion, what is a good mic for getting dialogue outside? I used the ME66 outdoors to record a friend of mine's dialogue while he walked along a sidewalk near traffic. The sound of cars driving by was very prominent and almost ruined the recording of his voice. I see now that was a mistake. What should I have used?

I wish there was a manual for filmmakers wishing to know what types of mics to use in different setups: outdoor - close up and further away, indoor - close up and further away, soundeffects, foley, etc. It would be great if this manual also explained why certain types of mics fail in ceretain situations and why they are not reccomended. Its always nice to know what pitfalls to avoid!

As Chad said ... a shotgun mic will pick up sound arriving from inline along its axis. I'll bet you had your mic on the camera rather than booming it. If you did, not only is your talent in the direction the mic is pointed but also anything making noise BEHIND your talent is also in the area of maximum pickup. In addition, you probably had the mic too far from the talent so you didn't have the inverse square law working for you. Getting the mic above and in-front of the talent, aimed down towards his chest, moves the traffic noise into the low sensitivity area of the mic's pattern - the mic is pointed at the ground behind him rather than the traffic. Booming it so it's just out of frame but still within 24 inches or so of his mouth makes the inverse square law work for you, making his voice is proportionally much louder with respect to the traffic noise than it is if the mic is 6 or 8 or 10 feet from him as it would be at the camera. As a general rule of thumb, when the mic is placed properly, the talent should be able to reach out and touch its tip without having to stretch his arm.

Of course, reversing your angle so the camera's BACK is to the traffic would also help.

[William N Zarvis]

Actually, we had a boompole operator (fairly inexperienced) pointing the mic at his lips about a foot and a half away. I was operating the camera so I couldn't see how close she kept it throughout the shot. Since there were two lines of traffic moving parallel to us in opposite directions, the sound of the passing cars was obviously getting picked up pretty well with every drive by - nice Doppler shift :-(

Though the film is several years old now, I think I'm going to get a hyper-cardioid and go out to that same locale and try re-filming it as a sound test. I have some other types of mics so I'll try those as well. Hopefully I can find a nice solution.

[Chad Johnson]

A hyper has a wider pick-up pattern than a shotgun, and they are very susceptible to the slightest breeze. You'll most likely pick up more car sound using a hyper. Really the only way around this is to frame the shot differently, or ADR. Another possibility is to use a lav. But mainly you need to keep the cars behind the shotgun or to the side of the shotgun. Some shotguns pick up more sound from behind the mic than from the side.

Another possibility is to have the actors work with the cars and yell over them, as you would in real life. The end result will be that you can turn your volume down in post, and the cars will be quieter and the dialogue will be understood.

[Jon Fairhurst]

Actually, directional mics also tend to have "lobes" behind the mic, so you don't want the traffic behind you. It's best if the mic is aimed downwards as you wrote. With a camera mounted shotgun, it's best if the traffic and other noise is to the side.

File:Polar pattern directional.png - Wikipedia, the free encyclopedia