Need a good shotgun for high noise ENG environment

[Greg Miller]

Originally Posted by Paul Anderegg

add a little rumble in ANY direction, and it covers those pretty noises.

Back in post #40 you said the rear 1/3 of the slots are completely covered. Are you SURE the mic wouldn't perform better with all the slots open, as intended? It seems possible to me that covering those slots might change the polar pattern and thereby impair LF rejection. I would really urge you to at least test it with all the slots uncovered.

And, BTW, do you have the mic's LF-rolloff engaged? Surely that would help somewhat with the engine/exhaust rumble that's troubling you. (My apologies if you mentioned this in an earlier post and I missed it.)

[Paul Anderegg]

I have since placed it on a JVC HM790, which allows me to mount it with all slots fully exposed, with a windscreen of course. I also have the roll-off engaged, as well as the wind cut on the camera.

It is a much "cleaner" sound source though. I switched back to my Sony ECM680 tonight, and when I keep the level all the way up, it has a very (I notice it now!) obvious hiss to it. The CS3e could be pumped to the max in the same situations and not have anything but louder background, no hiss. I assume that is the signal to noise ration? The CS3e makes my ECM680 sound like an old 1940's record.

Paul

[Greg Miller]

If the recorder and recorder settings are the same, and you hear more hiss from the Sony than from the CS3e, then you are hearing the Sony mic's "self noise." Not surprising that it's worse than the Sanken, considering the price difference.

And yes, the mic's self noise contributes to the overall signal-to-noise ratio (not "ration" ... I assume that was just a typo or auto-correct). (This is sometimes represented as "S/N") However, other things like the recorder's preamp can also contribute to the S/N. But if you're not hearing the hiss with the CS3e and the same preamp (and gain settings) then I'd say you are not hearing noise from the preamp, but from the Sony mic itself.

[Rick Reineke]

I haven't looked at the mics' sensitivity specs, but the Sanken likely has a hotter output and the camera's preamp is the primary noise source (a common issue with cameras and budget recorders).

[Marco Leavitt]

I've got the cs3e and it seems to have a fair amount of self noise. It's not usually an issue unless you are using it in a very quiet location and need to use a lot of gain.

[Jon Fairhurst]

Looking at the sensitivity and noise specs for the CS3e, we get:
Sensitivity: -26 dB
Noise: 15 dB-A

Overall, the sensitivity is excellent and the noise is okay but not great. That's not unexpected, given the multiple capsules and the related complexity of the design.

For low noise, I like to compare the Rode NT1A. Of course, this is a completely different mic. It's big, heavy, and simple with a single, large 1-inch condenser. Oh, and it's a cardioid rather than a shotgun.

NT1A:
Sensitivity: -32 dB
Noise: 5 dB-A

So, it has 10 dB less noise, which is significant, but it's also 6dB less sensitive, which adds up to 4dB more noise. Yes, it's more, but it's impressive given the multi-capsule design.

For some perspective, when we move up to Rode's two-capsule NT2A, the sensitivity is -36 dB and the noise is 7 dB-A, giving up 6 dB to the NT1A and 2 dB to the Sanken.

Looking at the Sennheiser MKH-8070 long shotgun, we get -19 db sensitivity(!) and 21 db-A noise, which is within a dB of the Sanken.

So overall, the Sanken is a valid contender in the overall noise department.

All that said, this is based on specs. Because different mics have different responses, one won't necessarily normalize the volume of two mics at a level that matches their publications. So it doesn't surprise me that Marco finds the CS3e to be a bit noisy in the real world.

Overall, I find specs to be great at eliminating equipment that isn't suited for a particular task. But specs don't necessarily identify excellence.

[Paul Anderegg]

Question regarding maximum input sound levels.

How does this rating work? If I am next to a jet engine for instance, and turn the rec level down as much as possible on the mic, and speak very loudly, how does that max input sound level work itself out? Obviously, the rec level on the camera doesn't affect the mic itself in any way. Is it sort of like dynamic range, the mic will loose the ability to differentiate loud vs even louder sounds?

In my testing, while the background noise levels remain high as my cheap shotguns with the CS3e, the voice quality is higher. That is to say, it sounds nicer, but it doesn't sound any clearer if that makes sense. Same as if it were compared in a quite room, you will hear the voice exactly the same vs a cheap mic, but the Sanken will sound prettier.

Paul

[Richard Crowley]

Originally Posted by Paul Anderegg

Question regarding maximum input sound levels. How does this rating work? If I am next to a jet engine for instance, and turn the rec level down as much as possible on the mic, and speak very loudly, how does that max input sound level work itself out?

The max SPL is the max SPL regardless of exactly what the source of the sound is. A jet engine at 1m is 150dB, and the loudest human voice at 1 inch is 135dB. So It is highly doubtful that the addition of a human voice would make any discernible difference in the jet engine SPL.
Ref: https://en.wikipedia.org/wiki/Sound_...sound_pressure

Obviously, the rec level on the camera doesn't affect the mic itself in any way. Is it sort of like dynamic range, the mic will loose the ability to differentiate loud vs even louder sounds?

Actually, any kind of sensitive microphone (like virtually any condenser mic) would CLIP within the microphone, either the capsule/diaphragm itself, and/or the impedance buffer circuit in the mic. So by the time the audio gets to the camera, its already too late and the rec setting will make no difference.

In my testing, while the background noise levels remain high as my cheap shotguns with the CS3e, the voice quality is higher. That is to say, it sounds nicer, but it doesn't sound any clearer if that makes sense. Same as if it were compared in a quite room, you will hear the voice exactly the same vs a cheap mic, but the Sanken will sound prettier.

It is rather surprising that you find that the self-noise from the Sanken is no better than from your "cheap shotguns". Is the Sanken new? Maybe it is defective.

[Paul Anderegg]

Sorry, by background noise I meant the level of bass type rumble from behind and sides. The self noise level of the Sanken is superior to anything else I own. In a dead quiet room cranking it up my rec level to maximum, I don't think I can make out any discernable hiss, any noise sounds like camera hum/ambience. My cheaper mics have a very noticeable HISSSSSSS like an old analog audio tape when cranked up similarly.

Paul

[Richard Crowley]

To deal with low frequency background (ambient) noise, we typically simply filter it out. Which is why many microphone preamps (and even the mics themselves) have a switchable high-pass (low-cut) filter.

And the earlier the better. If the low-frequency noise is loud enough, it can modulate the signal of interest, and even clip the combined audio signal even though the signal of interest (the dialog, etc) remains at a safe recording level.

[Paul R Johnson]

I don't have the beef about not mounting shotguns on the camera, but in so few shots is the wanted audio on axis with the camera lens. No shots with the subject at frame edge looking in, no two shots with the nice image centre. I really hate the crispness dropping off as people move off centre. In noisy environments, the annoying sounds are usually at the LF end not the HF and the mic collects those really well. Shotguns also suffer badly from wind outside, requiring BIG wind protection. On camera, you might just get away with a hairy sausage cover slid on, but these droop when they get wet - so a bit of rain and down they go. All the problems described in this big topic are well known, and together reinforce the reason on camera is generally considered to be a problem. Not every time, but too many for comfort.

Nobody has mentioned the momentum and inertia problems with a big mic and cover. I broke one of my old JVCs where the mic was in one of the slide on covers, and was damp. I turned very quickly and the mount snapped. Too much force on a small area.

For what it is worth, my old Audio Technica 815 really doesn't like very loud sounds. No idea what the spec is, but I used it on a project with American A10 aircraft and it bottomed out frequently making a quite nasty distortion.

Microphones are not magic. Right tool, in the right place, for the right job!

[Rick Reineke]

"For what it is worth, my old Audio Technica 815 really doesn't like very loud sounds. No idea what the spec is, but I used it on a project with American A10 aircraft and it bottomed out frequently making a quite nasty distortion."
- Way back when, I used to have an 815a (long) shotgun. As I recall it's off-axis response was decent, especially for a long shotgun. I never used it in a high SPL environment. AT's specs state the maximum SPL as 115dB, which is a kind of low..

[Paul R Johnson]

I still have it somewhere Rick, same one. Handy because it could have a battery instead of phantom if necessary. It just hated loud noises - and I guess 115dB could easily be reached with aircraft.

[Marco Leavitt]

Just to be clear, I very much love my CS3e. The self noise isn't generally a problem in the sort of situations where's its directionality excels. Just pointing out that I've been in a few situations where it was an issue and wished I had a CMIT5U available.

[Jon Fairhurst]

Reading the specs, the CMIT5U doesn't look like a low noise king on paper.

Sensitivity: 17 mV/PA, which is something like -32.5 dB.
Noise: 14 dB-A, which is within a dB of the Sanken.

As I wrote earlier, specs don't tell the whole story. For instance, if the noise is pink it might sound good and somewhat transparent. If the noise is focused in one frequency band, it could sound louder than the measured value.

So in the real world, the CMIT5U might be much quieter that the CS3e, but it doesn't win the paper battle.

BTW, if anybody is terribly disappointed in their CMIT5U specs, I'll send you my shipping address. ;)