Topic: Setting Bass Roll Off

[Tim]

The last moe. show I saw (february?) was super bass heavy.

[plucks]

I had the rolloff on during the Trey show on monday and wished I had kept em on the whole time!  Oh well, that's what comparisons are for.  I would rather have the bass be a little lower on the recordings and turn up the bass during playback if need be.  It seems that the boominess factor decreases a little this way.  Which is exactly what happened on Monday
Phil

[F.O.Bean]

why risk something in the field, when it can be fixed post........not worth it to me either, and i own 480's.....

bean

Hi bean and All,

The ability to "fix in post" is compromised because you have already sacrificed the additional headroom, and more importantly, given up the resolution (ie. bits), due to the lower level of the mid and high content of the audio.  A rough examples follows.  I would appreciate hearing some further expansion/correction on this from anyone with a deeper understanding of digital audio:

Basically, each bit represents 6dB of dynamic range.  If you are using a 16-bit recorder then you achieve 16-bits only at 0dBfs.  From 0 to -6dBfs, you are only utilizing 15-bits.  This is where we typically let our levels peak.  Now, if the extreme Low Frequency 6-12dB hotter, and we plan to take it out in post, we should roll it off when recording so we optimize our levels (and resolution) based on the level from the mids and highs that we will be keeping.

A fun way to hear the impact of various HPF setting is by taking the line out of your playback deck into the input of your pre-amp.  Set the pre-amp at it's lowest gain setting and connect the outputs of the pre-amp to your receiver/pre-amp in your listening system. (Warning: initially keep levels low on your receiver/pre-amp as the level coming from the microphone pre-amp could be quite hot) Now, play a few different recordings, especially something that is quite bass heavy and something else that is already light on bass.  Switch through the various HPF settings on the pre-amp to observe their impact.

because the 853's cannot handle the same SPL level as most mics and you run the risk of distortion, which cant be fixed post.

However, depending on the design of the microphone and pad, this may not help.  If the pad/HPF is not between the capsule and the pre-amp section of the microphone, it will only reduce the LF going to tape.  If, on the other hand, it is between the capsule and pre-amp, and the pre-amp is clipping, then the use of a pad or HPF could help significantly.

Happy Recording Everybody,

Marc

mark,
  you have a WAY GREATER understanding of this than i shall ever have.....but due to my love of bass, i shall NEVER use that pad, altho, i will give it a try, just once.......i am sure i couldve used it in a few cases, but i LOVE the transparnet sound of the 480's......and pad at all to me would compromise this......IMO....

thanks for the informative statements, mark, and glad you gave me a better understanding of bits, persay......

also, is this the same w/ 24 bit?

bean

[Marc Nutter]

Hi diskobean and All,

The issues are the same at 24-bit but you have better resolution so it's easier to give it up in post and not as critical to retain the highest levels possible when recording/tracking.

As for the pad and High Pass Filters, a pad should be flat across the entire frequency range.  The reluctance to use a pad is based on the fact that it will change the impedance seen by the microphone (if using it on a pre-amp).  A HPF is specific to a given frequency (ie. 75Hz), about 1/2 an octave above the elbow (ie. 112Hz), and everything below that.  

If you are happy with the results you are getting from your system and don't feel like mids and highs are being buried in thunderous bottom-end, there is no reason to use a bass roll-off.

Happy Recording,

Marc

[Marc Nutter]

Hi All,

Several years ago, a friend shared the following technique for determining if you should use bass roll-off.  

If you feel the bass in your chest, it is a good time to use a bass roll-off (high pass filter).  Usually a very gentle one --6dB/Octave at 50Hz or 75Hz is adequate.  

Just hearing nice pronounced bass, without feeling it, doesn't usually necessitate a filter.

This is kinda cool since it involves the whole body, not just the ears...

YMMV.

Happy Recording Everybody.

Marc

[John R]

Hi All,

Several years ago, a friend shared the following technique for determining if you should use bass roll-off.  

If you feel the bass in your chest, it is a good time to use a bass roll-off (high pass filter).  Usually a very gentle one --6dB/Octave at 50Hz or 75Hz is adequate.  

Just hearing nice pronounced bass, without feeling it, doesn't usually necessitate a filter.

This is kinda cool since it involves the whole body, not just the ears...

YMMV.

Happy Recording Everybody.

Marc

good yardstick, marc

jr

[F.O.Bean]

great way to determine, marc.......you told me that YEARS ago, and i still remember...... just never used it cause the pad is on my mics, not a sound ya wanna hear on any tape....

bean