Anyone Decided on a Mic for the AF100?

Hi,

The camera is rated at -50, and putting in a mic that is -40, that mic will be too -10dB to hot for control. You should put in a pad.Optimally you should have the volume control at about half perhaps a little better than half for best quality audio out of the system. Too low because you didn't put in a pad, the system sounds noisy, too high without a pad you could quickly overload the system and head straight toward distortion. Match the system to the microphone of choice with a pad you will get the best out of the system.

Sort of like wearing shoes that fit.

Best,

Jan
 
Very rarely do I use on-camera mics as the primary audio, but sometimes do use it for sync, or backup.

I have a Audio-Technica AT875R (-30 db) on the AF100 & the audio is hot. On Jan's recommendation I picked up a Shure A15AS with 15/20/25 db Pad, but the sound is still not great. On the HPX-170 the mic sounds much better, even without the pad.

I'm far from an audio expert, anything but, & luckily I usually have a Sound Person feeding audio, however it does seem keeping the pots turned low produces better audio then adding a pad. The AT875R is not a high-end mic, but it does get good reviews.

Regards,
Bern
 
I had not really read this whole thread until now, and am not convinced that some of the info is correct. Maybe I've always done things wrong, but I've owned a variety of shotguns/lavs/wireless mics that have seemed to work fine with every camera I've used them with. Yes, in extremely loud environments I've had issues, but in normal dialog/nat sound they've been fine. Never checked the output reading of any of these mics until now. Until recently I've typically gone direct into my cameras (but I recently bought a SD MixPre that I go through). Anyway, when I did a day of shooting with the AF before my mixer came in and used a Sanken CS3e. Not on camera, but on a boom and direct to the camera (so basically the same in regards to input levels). I just looked at the Sanken specs and it says -28. Anyway, it sounded fine.

So, I wonder if there are ideals, but in practice most things will work (like Jeff said).

Or maybe I'm missing something entirely.
 
I've been using my Rode NTG-2 and under 'normal' conditions has worked fine with the input dials around 5. I recently shot a not overly loud live concert and used the Audio-Technica AT8202 -10/-20/-30 db Pad set to -20 with the on camera dials once again at around 5 as per the on screen levels. Audio came out fine with no overloading or distortion. Yes the 3" pad does make the mic very long or stick out of the camera body quite far but for the frequency I need to use it, it's not a issue for me.
 
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Let's be clear that the NTG3 and Senn 416 spec at a 130db max SPL. In order to get anywhere close to saturating (with
no attenuation), you're going to have to be above 100db SPL at distance .. which is damn loud.

You'll be hard pressed to find a shotgun mic with a sensitivity of less than 20 mV/Pa .. ( ~ -34dBv ). .. Mic
pres are rated from the least sensitive input they support to get to line level. If you go below that sensitivity, you'll
either not be as loud .. or you'll have to get a pre with greater gain to get it to line level. Having more sensitivity means
the mic-pre won't have to apply as much gain .. (which is a good thing usually because it's less noisy).

jeff
 
jmarkham said:
Having more sensitivity means
the mic-pre won't have to apply as much gain .. (which is a good thing usually because it's less noisy)
Click to expand...

Jeff is correct.

I've used Sennheisers, 416 & ME66, for years. Yes, the ME66 is hotter than the 416 so I just turn down the input to 4 and still have plenty of headroom and low noise.

If you add a pad inline and then turn the input up to 6 or 7, you will now DECREASE the headroom and ADD unnecessary noise to the mix.

Jeff said in an earlier post, "The AF100 can work with mic's that have a *minimal* sensitivity rating of -50dbu (setting 1) .. or -60dbu (setting 2). What that means is that when you shop for microphones, you should look for mics that have a sensitivity rating *no worse than* -50dbu or -60dbu".

I believe on-board mics should be used sparingly for ambient sounds only, not critical dialog, and only when you do not have access to a boom.

If I must record dialog without a sound person I use Letrosonic UHF mics set to line level and input directly to the AF100 in the line position, not mic.

Ideally, I use a sound (tech/recordist/guy/gal/person) whenever possible.

Regards,
Scott
 
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Recording digitally with lower levels is actually a good thing (setting -18 dB as your 'zero') if you're planning on multi-track mixing later, since you will lose about 1 bit per -6 dB adjustment in your mix. I think a pad would be a good thing for almost any mic on the Af100
 
DutchFX said:
... if you're planning on multi-track mixing later, since you will lose about 1 bit per -6 dB adjustment in your mix ...
Click to expand...
Depends on what you're mixing with .. Nuendo, Sonar, etc support double precision floats .. so you'll not lose any bits. Protools HD (which we use) has
56bit accumulators and dithers any bit-reduction. I don't get concerned until I get above -6db.

jeff
 
jmarkham said:
Depends on what you're mixing with .. Nuendo, Sonar, etc support double precision floats .. so you'll not lose any bits. Protools HD (which we use) has
56bit accumulators and dithers any bit-reduction. I don't get concerned until I get above -6db.

jeff
Click to expand...

Jeff, do you mix through a desk (or summing box) or in-the-box?
 
In the box. For post, we usually get a large track count .. so summing through an analog desk
would be impractical for us.

ITB is fine... virtually everything you hear on TV and film is ITB .. nobody has the time for analog.
 
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So ... as promised .. here's my experience with the NTG3 going into the AF100 "raw"

Should have had tripods and stands for the mic .. but it's all in the van and I don't feel
like hauling it all out :-)

jeff
ps: in the loud "oooo" section, I lowered the volume to around 3 or so ... I forgot to mention
that in the spoken part.


ntg3.png


Going into the AF100

AF100_in.png


And the volume levels...

at100_level.png
af100_level.png


So .. there's the audio recording from the camera ...

http://techbreakfast.com/af100/AF100_NT3.aif

And a waveform from Protools at the maximum volume recorded.. note: .. it didn't clip

NTG3-oooo.png
 
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So....Jan says you need a pad for best results with hotter mics...Jeff says you don't and things will be fine...snp seems to be saying a pad will even make things WORSE ("less headroom").

Wish I knew who was correct. Anyone else want to chime in?
 
I've written to two audio engineers I know (both former BBC and Abbey Road) about this and will post their response, hopefully later today.

EDIT: I should also say that Jeff's test seems to show that a hot mic can be made to work ok under normal conditions, but not whether a pad will make it better (or indeed worse). There was some system noise, which may or may not have anything to do with the mismatch.
 
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My actual recommendation is to not use the mic-pre's on the AF100 at all .. but to use a line mixer
and go LINE line.

I recommend this guy:

http://www.sounddevices.com/products/mx2master.htm

Like most on-camera mic-pre's, the AF100 micpre is noisy at
higher gain levels.

That said, I stand by my contention that if you don't have a line mixer, you can use
the Af100 mic-pre's with an NTG3 or 416 type shotgun in typical conditions.

If you're in very loud conditions, a shotgun is probably not the best mic choice.

jeff
 
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