Low Cut (frequency) switch- how and when

[Jonathan Levin]

I've got a low cut switches on my mic and also on the mixer I am playing around with. And scratching my head.

From what I've read, the low cut switch helps if there is wind, or some kind of ambient noises.

I've noticed on the mixer side if I switch the Low cut to "-----" the sound is much warmer, boomier. I kinda like that. With it in the /¯¯¯¯ sound a little thinner, for lack of a better term.

The switch on the mic, same effect, but not nearly a pronounced.

So if you have a mic with a switchable low cut, I'm guessing you would keep that in the off? or --- and on the mixer switch to on? /ˉˉˉ, not not have both set to the same?

Normally when I switch on the mic, I just go all the way from OFF to /ˉˉˉˉˉ.

So on or off for:

Indoor interview
Outdoor interview
Recording ambient

Thanks so much.

Jonathan

[Gary Nattrass]

it all depends, some low cuts on a Mic can be in between the capsule and the op amp so can be more effective at preventing low frequently buffering or rumble.

They all tend to be 80 or 90 Hz but may have different shelving this should be in the spec. personally I tend to keep the 80 Hz filters on all the time with my mixer but use the Mic one depending on what I am recording and if it is needed to prevent any handling or wind buffering noise.

it can be hard to hear the effects but a good set of headphones will help and whilst there are no hard rules I tend to leave the Mic ones on my capacitors on all the time but have 80 and 160 available on my mixer but with a smooth shelving so they tend to just cut very low rumble or wind noise.

[Jonathan Levin]

Thanks Gary for this and other posts.

Just to make sure I'm on the same page, which is on, ----- or /¯¯¯¯ ?

[Richard Crowley]

Please tell us specifically what microphone you are asking about. If you are talking about experimenting with your AT822, please note that until you get it connected properly, you will never see "typical" or "normal" results with it.

The straight line symbol indicates that the response is "flat". In other words, the low-end is NOT rolled off.
The line with the left ("low") side bent down designates that the low frequencies are rolled off.

Under "normal" conditions, it is probably better to keep the low frequencies CUT (filter turned ON). While you CAN filter out low frequencies during post-production editing, it is very possible that strong LF noises (as from wind) will generate such high audio levels that it will affect how the rest of the spectrum is recorded. It could influence your auto-level settings, or it could even overload the mic preamp. So unless you are recording something with a significant low-end (steam engine, flamenco tap dancing, mondo pipe organ, etc.) roll off the low frequencies and save yourself some potential grief.

[Jonathan Levin]

Hi Richard.

How did you know I might be referring to the AT 822 ;-}

OK. So it seems that keeping it on may not have consequences. Cool. And thanks for clearing up on (left bent line) and Off (flat line).

Do most mikes have the low cut filter option switch or is my AT stereo mic an exception. And this gets back to my other question: if the low cut is ON on the mic, should it be redundant to also have it on on the mixer, or does that introduce trouble? Or is it on one or the other?

Again, I am re-thinking and need to figure out what to invest in some mic equipment sooner than later.

Jonathan

[Jon Fairhurst]

When recording full range sounds, such as music, indoors on a fixed stand, record with the flat setting. When recording outdoors or on a handheld boom, you want the low cut setting to cut wind and handling noise.

When recording a person with a high voice (child, woman, tenor), you can probably leave the low cut active at all times. Recording a person with a deep voice for a movie trailer or radio promo is best done with the flat setting.

I prefer adding the cut at the mic, rather than the recorder. The further upstream, the better as it keeps large spikes from distorting things downstream.

It's really a trade off. When cutting the low frequencies are you cutting bad sounds (wind/handling/plosives) or are you cutting good sounds (bass drum, chest voice...)? When you have both, it's a judgment call for the audio engineer.

[Jonathan Levin]

Thanks Jon!