What's your strategy for setting gain with wireless?

[Les Wilson]

There's no notion of setting tone and the audio chain has several points of gain and pre-amps. I'm interested to know what strategies are out there for setting gain structure when using wireless. So when you prepare, what do you do?

Any advice or tuning on my approach is welcome:
My camera (Sony EX1r) has a +4db line level so I set input for my Sennheiser wireless to MIC level
Mic (ME2) sensitivity to -18 indoors, -30 outdoors
Set Sennheiser G3 receiver AF OUT to 0.
Set camera TRIM -50
Set camera levels at unity

Also, I'm doing a pro-bono outdoor To Camera bit and there'll be plenty of background noise (cars, ocean, people). Would you drop the mic sensitivity to something like -48, boost trim and handle the noise floor in post?

[Seth Bloombaum]

A conventional approach is to start at the source, setting optimum gain at each stage, ending at the camera or recording device.

Each stage may have its particular methods, some allow monitoring. Allow for some headroom at each stage. Setting optimal transmitter gain (transmitter preamp sensitivity) has the biggest effect on quality, though it's possible to screw it up in any stage.

I use this:
Frequency scan receiver (transmitter off)
Set transmitter freq
Gain transmitter while speaking wearing the correctly positioned mic, and have your on-camera talent do so. Peak about 3/4s up the scale for loud speech (ask them to talk to the back of the room).
Listen at receiver (even if your rec doesn't have a headphone output, try plugging in the phones)
If your receiver and camera will both do line level, set for line level. If not, set both for mic level.
Listen at camera, set cam gain so loud dialog peaks at perhaps -12db, or, if no scale, at the mark.

For this kind of thing it's really helpful to run through the setup at home or office before going out on a shoot. Try your own voice at different levels to get to know your transmitter gain settings for different voices. It's always better to go slightly low in gain settings than to go too high.

Sensitivity setting has nothing to do with the amount of background or ambient sound. The ratio of direct dialog to noise remains constant, no matter your gain settings. Getting your mic closer to the source is the primary method to improve recording in noisy locations. It *does* change the ratio of direct dialog to noise, along with having your talent speak louder.

A little bit of change in distance can have a lot of positive effect, because the intensity of a source varies with the square of the change in distance (inverse-square law). I never studied physics in school, but this is one that all of are affected by... it applies to sound and light.

Once you've done your best with mic positioning and gain staging you are left with whatever tools you can use in post.

[Rick Reineke]

The SK series bodypack transmitter's input setting (sensitivity) is dependent on the microphone's inherent output, AND how loud (SPL) the sound source is. Typically the input meter should go to 75% of the meter range, but this depends on how much headroom is needed as well.. for instance, if the talent is speaking in a steady monotone voice, the input level can be pushed. OTOH, if the talent suddenly screams, if would be lower to (hopefully) avoid distortion.
A good 'mic level' AF output settings for the EM series portable receiver is usually around -6, -12, -18 or -24dB, depending on the recording devices pre-amp gain design. The camera or recorder 'must'. be set the 'Mic'. The EM100 can output line level, but even at the maximum +12dB setting, it's a little anemic for a recording device with a true nominal +4dB line level.

[Nate Haustein]

Is there a benefit to using a lower AF output on the receiver going into the camera like -6 or -12dB? Ive always tended to use 0dB on my G3 set. Thanks.

[Brian P. Reynolds]

Using wireless systems is NOT like painting with numbers..... People often focus on just the settings / numbers, I have yet to find a person talking that you can 'dial' in a voice level.....
There are SO many variables.... Male / Female, Quiet or soft spoken person, Loud or quiet location, Indoors or out doors, etc etc etc.
But as others have mentioned start with the Tx unit and then work your way through the entire system.

[Les Wilson]

@Nate: I've done the same with my G1-G3 units. Always ran at mic level into the camera with AF at 0 thinking that was unity. After reading this article, I'm not so sure.
https://sennheiserusa.happyfox.com/k...-sound-quality

[Les Wilson]

Originally Posted by Brian P. Reynolds

...But as others have mentioned start with the Tx unit and then work your way through the entire system.

The rub comes at the transmitter AF out. With camera gain at unity, you can dial down the AF and dial up the TRIM to compensate and vice versa. How do you decide what AF Out to use?

[Brian P. Reynolds]

Originally Posted by Les Wilson

The rub comes at the transmitter AF out. With camera gain at unity, you can dial down the AF and dial up the TRIM to compensate and vice versa. How do you decide what AF Out to use?

As I mentioned the important one to get right is the 'transmitter' working at the correct level this will give you best signal / noise settings....To high and there is clipping, to low and there is background hiss. As mentioned the settings on the Tx WILL change almost every time unless you are using the same talent on each usage.

Now we get to the Receiver (Rx) the AF output adjustability is there to suit whatever your going into, for example if you are feeding a DSLR camera the Rx output should be a High MIC level this will feed the DSLR with a strong level to minimise the gain needed in the camera that has poor preamps.

If you are feeding a 'Domestic' style handicam style camera then a 'MID level' mic level out would be suitable so the 'auto' gain of the camera isn't really used, this will eliminate 'pumping' in the audio.

If you were feeding a 'Pro' level mixer / recorder like a Sound Devices 633 then line level would be the go as inputs 4-5-6 are 'line only' level inputs, mind you I believe the G3 haven't enough level out to drive this happily.

If you were feeding a small desk audio mixer that has XLR 'mic level' inputs and unbalanced line level inputs then lowering the audio out to mic level would better to used a balanced rather than an unbalanced line input.

So as you can see the output level of a Rx unit may vary from situation to situation.... With no ONE setting being correct for ALL situations.

Like most amps and volume settings on a 1-10 scale the optimum seems to be in the 5-7 range. This must be done with 'Auto Level' turned OFF.


Hope this helps.

[Les Wilson]

Yes, it helps very much. Thank you. Understanding that ying-yang between AF Out of the receiver and the next thing in the chain is clear now. Also clear is control of voice to background noise ratio will to come from mic placement and mic design. Got it.

Searching on the Sennheiser G3 was fruitful because of the discussion of the G3 receiver's ability/inability to drive a Pro line level device (it doesn't for my EX1r).

Anyway, I found an excellent post by Steve House on this topic that came out of the Senny G3 discussion which I'll leave here for those who find this thread later:
http://www.dvinfo.net/forum/all-thin...ml#post1687570

Thanks to all.

[Steven Digges]

A couple more thoughts. As Rick has stated many times the ME2 is a POS mic. Yet many of us own at least one of them (including me). To be specific the ME2 is Sennheisers "kit mic", it is an omni directional general purpose lav. Being omni directional it is "very good at or terrible about" mixing general noise into the spoken signal. As Seth said, one of the solutions is distance. The other solution is to use the proper mic for the job. To keep crowd noise, ocean surf, and seagulls to a minimum a uni directional lav like a cardiod would serve you much better if you have that option.

More and more cameras now have an audio limiter. They are very limited limiters (pun intended). I am a big fan of limiters when used properly. I think it is worth noting here that when doing any form of gain staging make sure your limiter is turned off. During staging it is the first thing that should be turned off and the last thing that gets turned on. If accidentally left on during staging it can create the false illusion that nothing is clipping. Once it is turned on it should not effect your gain staging if everything is set properly. It is there to protect you from all of the variables discussed here. A scream or other sudden loud noise is better "squashed than clipped". It should only engage to save you from the unexpected. It is an insurance device and like all insurance it is something you do not want to use but you need it there ;-)

Rules of thumb for voice level adjustments:
I ask talent to project into the mic in their "presentation voice". Professionals get it right. Amateurs do not. Amateurs seem to have three levels.....normal speaking, louder when you ask for presentation level, and the third one when you hit the red button. The third one is the one that blows up your cans and clips every level you set so carefully!!!

Kind Regards,

Steve

[Jay Massengill]

To add a little more to Steven's comments on camera audio limiters, they can also fool you into raising your input signal too high trying to get a little more level since the meters seem safe from clipping due to the behind-the-scenes action of the limiters.

Once you are consistently pushing your peaks into limiting, all you are doing at that point is successfully raising the level of background noise while squashing your spoken word signal.

If you do this in a room with intrusive ambient noise you will to some degree undo the ratio of a closely placed mic on your subject using a lav or a boom just out of frame.

If you do this in a quiet recording space, then you'll succeed in boosting other unwanted sounds like the talent taking a strong breath between sentences.

[Rick Reineke]

+1 to Steven and Jay's comments.
When I previously stated (more than once) the Sennheiser ME2 "is a 'POS".. perhaps I should be more civil and state: "ok for hobbyist but not for broadcast or film sound".

[Steven Digges]

Rick,

For the record.... I was not picking on you at all. I think you know that. In fact I agree with you about the ME2. It is what it is and you call the truth.

All my other mics are better than the ME2 and If my kit lenses would do every job I would not have a small fortune invested in Canon "L" series glass.

I was just keeping things light but my way of doing that sometimes means I get slapped in the keyboard ;-)

Kind Regards,

Steve

[Les Wilson]

Originally Posted by Steven Digges

...As Rick has stated many times the ME2 is a POS mic. Yet many of us own at least one of them (including me). ...The other solution is to use the proper mic for the job. ... a uni directional lav like a cardiod would serve you much better if you have that option.
...
Rules of thumb for voice level adjustments:
I ask talent to project into the mic in their "presentation voice". Professionals get it right. Amateurs do not. Amateurs seem to have three levels.....normal speaking, louder when you ask for presentation level, and the third one when you hit the red button. The third one is the one that blows up your cans and clips every level you set so carefully!!!

I'm a OMB. Yeah, I have two ME2. I know they're kit mics and looked down upon. Someday....upgrade.

I looked at getting an ME4 but my experience with cardiod lavs is that they are easily susceptible to wind noise and I don't need them that often to justify. I'd rather upgrade my ME2s. Anyway, for this one situation, I thought by turning down the gain at the bodypack, I was hoping to mimick the effect of a dynamic mic that picks up in a smaller proximity. I get it. Not a good strategy. I get everything said here and have re-tuned my audio chain. The G3 does not drive the line level on the EX1r. Maybe Sony just pads the Line level to mic internally. Dunno. Thanks.

Hilarious rule of thumb. Happened exactly like that at Thursday shoot. LOL

[Richard Crowley]

Essentially all camcorders pad "line-level" down to mic level and send our signal through the same input circuit. Some camcorders just reduce the gain of the input stage in combination with a pad. I am reasonably certain that there are NO camcorders ever made with a "proper" line-level input. For that matter most "proper" audio mixers pad the line-level signal down to mic-level. My rule of thumb is that if you can lift it by yourself, it probably doesn't have proper line-level inputs.