When do I use the low cut filter?

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Indyreel

Well-known member
I just bought an Oktava Mk012 Mic (film edition) and it came with a low cut filter. Does anyone know when I should use it? i.e. would I use it when recording indoor dialogue? or would that be unnecessary for a quiet setting?
 
ou should use the low cut (high pass) filter when you have ambient noises like AC or other objects that can produce low freq tones... What is the freq is the cut off? Most of the time vocals are not in the range of the cutoff anyways, so its good practice when recording voice.
 
But if I use the low cut filter when in a quiet environment, would that be unnecessary? I'm thinking that if I want to record the voice in all of its clarity, that I should NOT use the low cut, as long as there are no ambient noises present.

It this correct thinking or flawed?
 
I guess you dont need the low cut for this situation, i dont like to say this but if it turns out wrong you can cut it off in post...

But i would left a low cut on just for the verry low frequency that you dont want enneways ( like gain noise )
 
You can record without the low-cut, and if it turns out you need it just apply a "hi-pass" filter to the audio in post. Set the cut-off to 80.
 
While its true that you can always apply a high-pass filter in post, there are a number of situations where it would be better to record with a roll-off. If a sudden bit of bass (eg. a wind gust, a bit of handling noise, etc.) causes the mixer or recorder's limiters to kick in (or worse yet, cause the track to overload), then you'll be stuck with the results even after you roll off the bass in post.
 
Indyreel said:
But if I use the low cut filter when in a quiet environment, would that be unnecessary? I'm thinking that if I want to record the voice in all of its clarity, that I should NOT use the low cut, as long as there are no ambient noises present.

It this correct thinking or flawed?
Click to expand...

There is very little to virtually no voice information in the frequency range the high-pass effects. About the only time you should not use it is when recording music or bass-heavy effcts like explosions.
 
Steve House said:
There is very little to virtually no voice information in the frequency range the high-pass effects. About the only time you should not use it is when recording music or bass-heavy effcts like explosions.
Click to expand...

I agree with this... especially with the Oktava... which is extra-sensitive to wind and handling noise.

Try a little test on your own... mic'ing yourself and a couple friends with and without the low-cut in place... see how much difference you can hear when you play it back. If you can't hear much difference (I expect a very slight extra fullness w/o the low-cut... SLIGHT... not really noticeable)... then I'd use the low-cut all the time... unless you're specifically recording something that includes low bass... as Steve said.

When you're booming dialog or working outdoors... a low-cut filter is free insurance.
 
If your not in a VERY quiet studio there is always "ambient noise". I record classical concerts and usually have the low cut in at 80. The building has a rumble in it from??? (the AC is off for shows) and I end up having to do it in post anyway. Even for most FX recording with the Oktava I leave the cut off in, you start picking up garbage you have to remove later anyway. I'm doing at the mic pre so it's pretty easy to A/B if I have doubts. Never used the inline one. Are you sure it's a roll off and not a pad? Oktavas ship with a 10dB pad (or most do anyway) and I have only seen the roll off as a separate purchase. You also haven't mentioned how steep and at what freq. the roll of is. The most common is around 80Hz and that is what folks are talking about when they say use it all the time. Some are a lot higher and that is more of a special situation use. I wouldn't use a roll off over 120Hz or so on a regular basis.
 
During record, you can easely do a low cut of about 80Hz. Everything under that is rumble, dust, not needed.

You can also cut some of the high frequenties to reduce noise sounds.
 
As an FYI to any readers... doing a low-cut at the mixer isn't the same as doing a low-cut at the mic... Most good location mics have a 80hz (or so) low cut option, at the mic... this saves the wind and handling from ever getting into the rest of the audio chain.

Cutting out an overload from the mic... before it gets into the recorder... doesn't do much to clear up the total audio that came in with that rumble, other then removing the bass-end.

If anybody has a 120hz cut filter... I wouldn't use that too often... what I've been talking about is the 70-80hz low-cut... which affects little beyond wind or handling.
 
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