Info - Mic Tips

Getting your mic choice and mic technique sewn up can be as important to heard clarity as much as anything else.

Remember, in the days where electret and MEMS ‘condenser’ mics are the norm, they have a very wideband flat response, and very little high SPL tolerence (notably why ‘condenser’ mics, genuine or electret are rarely used as drum pickups bar use for capturing the high-hat or general distant field pickup of drums).

What this translates to, simply, is this -

When you talk too close to a condenser type mic insert, it picks up everything - even really quiet ambient noise you can’t necessarily hear distinctly. It also will rapidly cause a rough compressed and distorted (depending on heard SPL level) output resulting in a garbage or poor input SIG to the audio chain. Definitely not good on analogue, and digital audio suicide by the time the vocoder has butchered it on DV modes.

So at the very least, whatever distance from the mic you’re used to working with dynamic mics, double it and talk at a conversation level - not super accentuated ‘hit the back row of the theatre’ actor style accentuated speech.

Also, don’t set your mic gain at max if you’re told your audio is quiet/thin/indistinct. Using Parrot/Echo on DV or using another radio for analogue (preferably with an assistant and at least one room away) do a test call using your own natural conversation level at a suitable dist from the mic.

If the echo test or what your assistant hears translates as quiet indistinct or distorted or obscured by noise, compensation needs to be done mic and gain settings wise, otherwise leave well alone. Unfortunately, random reports are somewhat subject to what people are used to rather than based on any assessment of any real benchmark of consistent ‘good’.

If you can’t get an assistant, put the earphone output of the receive set into the line-in of a recorder (your PC will do), set to record with the receiver AF gain/volume set where it’s normally at a comfortable low level. Do a test call or two and listen back to the recording.

Odds are, clarity loss in the recording will be due to being too close to the mic (distortion and compression induced) or even if clear but on the high side, you may find excessive or high sibilance in your audio.

High side level can be compensated by knocking the mic gain back a notch usually or holding the mic a touch further back.

If your audio is more sibilant than anything else, and your can really tone compensate, do an old broadcasting trick, talk across the insert.

What happens, without getting overly technical, is what’s heard is quieter but also the effective tonal balance drops from flat response to more low-mids. It’s in your highs in speech patterns where you can be highly sibilant, so if you can reduce that, it’ll help.

On a handheld, such as the FT-70D and AT-878UV, I find with my voice (which isn’t a good match to condenser type mics) holding the radio at half an arm’s length takes care of the level with half mic gain setting. I have a lot of speech impediment sibilant traits, so I also talk side-on across the mic, and Parrot and analog recordings show my voice to be at least telephone clear and uncompressed that way (can’t fix the other vocal stuff with that trickery sadly).

If you’re able to swap mics or replace the insert on a hand mic, do refer to your reference recordings and parrot returns before even thinking about butchery and replacement.

Look at a AF spectral image of your recording on a computer, note where your average and peaks are AF frequency wise.

This will guide you towards what response characteristics you need to look for in a replacement insert.

For example, where hand mics and base mics go, a response on the LF side of the curve in common Shire mics suits my voice. So that helps me decide on what insert to use and/or replacement mics for base use.

It helped a lot with getting consistency across SSB/FM, all DV modes I’ve tested, as well as where I picked it up from, in my broadcasting world ventures.

Remember, just because perception of a MIC’s intended use doesn’t discount it as useless for you. It’s better if it’s halfway suited ti your speech than a mic that really poorly delivers a good reproduction to the audio chain.

The input is so much more critical than people give credit to, as it will definitely effect what’s heard. It’s not the most critical factor, but it can lift your audio into real clarity if it’s combined with good techniques.