[sdiy] Low Pass filters and musically useful frequency range

[Chris McDowell]

Mixing and mastering engineers will definitely filter out everything below about 30 Hz, and often some above that too. The bass you really feel is in the 70-90 Hz range, so most energy below that just contributes to rumble and “muddiness”. Everyone should experience this sometime! Make a track with analog synths and big drums, then put a steep high pass on the master and sweep it around. The good stuff gets nice and tight when you remove that rumble. 

But I doubt that was the aim of the high pass in that circuit. I’d bet it was set arbitrarily low, out of the way of audio entirely but still blocking DC. 

On May 6, 2014, at 2:32 PM, Pete Hartman <pete.hartman at gmail.com> wrote:

> TOTAL swag follows :)
> 
> I was watching a video on production techniques a couple weeks ago,
> and the guy doing it recommended for bass setting up a HPF to keep the
> lowest of the low end from muddying up the sound.  Not explicitly
> said, but I was guessing "on audio playback that couldn't reproduce it
> well".  He was using a moderate Q as well so there was a bit of a bump
> for the low end in that.
> 
> Keep in mind, I'm merely repeating what he asserted; though his video
> did seem to demonstrate a tighter bass sound by doing so, I have no
> authority with which to agree or disagree :).
> 
> Could the reason be related to this concept at all?
> 
> Thanks
> 
> Pete
> 
> 
> On Tue, May 6, 2014 at 2:11 PM, David Ingebretsen
> <dingebre at 3dphysics.net> wrote:
>> The basic question revolves around the output stage of the Moog 914 fixed
>> filter bank and the fact it incorporates a highpass filter with a cutoff
>> around 40-60 Hz depending on how you want to define the -3dB point.
>> 
>> Questions:
>> 1. As a general proposition and in a purely subjective context, what is the
>> lowest frequency that is musically useful?  At some point most waveforms
>> start to sound like clicks and pops. Subwoofers can pound your
>> proprioceptive system and add a useful effect I suppose but "how low can you
>> go" and still be musical?
>> 
>> 2. Why would Moog add such a high pass filter to the 914? I can see blocking
>> DC, but why worry about 10 Hz getting through? Does it have to do with being
>> musically useful? I don't think this high pass filter was in the 907, so why
>> add it to the 914?
>> 
>> Thanks
>> 
>> David
>> 
>> 
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy