If the low cut is something that's built into the mics then that's a different story. As I said, if the low end is distorting at the microphone that's an entirely different situation.
Leonard's mics are 2-piece...there's the mics, which then connect (via a 1/8 jack) to the "battery box"....
Leonard's lo-cut is a version of his battery box, with a 3 way lo-cut switch built into it.
the real funny is that he admitted to me he built my mics with bunk batch of wire...yet even though I sold a dozen pairs of them for him in the 90's, he'd not replace my pair with bunk wire "at cost", and instead told me tough titties.
sooooooooo, when they shorted a THIRD time, a half-roll of black electrical tape later, ,and I isolated the short by de-facto hard-wiring the mics to the box (or, the tape has been holding the wires in place in a 'black ball of tape' since the late 90's.)
so, no, the lo-cut is not built in, it's optional, however, in my situation, it is "built in", as should I ever take that tape ball apart, the mics are toast.
hands-down it's easily the best option I ever selected as a taper....not even a close second in terms of "taper aid".
the easiest way I can explain it is this:
prior to using the low-cut, pretty much everything to the left of 250hz would bounce up to, if not thru +12dB, that's 40hz, 63hz, 98hz, 160hz and 250hz....way too bassy, and while some of that bass could be trimmed, it just dominated the tapes.
however, ,when using the lo-cut, those levels would bounce to around 0dB, which, in conjunction with the attentuator of the D6 ***allowed me to set the recording levels higher, which made the mids and highs shine thru the lows'.***
or, instead of the peak meter being dictated/dominated by 'rumble rumble rumble', those nasty bass levels would be reduced to a point where I could get a much brighter capture, sans distortion.
when shifting to the R-09 in '08, and the DR-2D in '11, the R-09 low-cut was garbage (as the mics in the R-09 were garbage), but the DR-2D one, I will occasionally use the built-in one ***with the internals only*** (depending on what is being recorded), but not with the Sonics or the Church mics. (nee: externals)
it was a bit of a different learning curve in setting the levels, but once dialed in, it's been pretty smooth sailing.
or, as gutbucket said:
A good reason to engage a HPF filter is to enable sufficient mid and high frequency signal level to the recording medium. This is (was) more important to do this when recording to analog tape which has far less dynamic range than digital recording, as well as a less-linear response across other frequencies as the tape becomes oversaturated prior to clipping. If the recording medium could capture the full range of all frequencies at any level, we would not need recording gain controls nor high-pass filters to make recordings which aimed to accurately reflect the frequency balance and and loudness of the live event.* This may bring to mind similar discussions about recording level and recording 16 or 24 bits. As it is, digital recording currently allows us to get away with not needing to engage a high pass filters most of the time in order to get good usable full-spectrum signal recorded, yet we still for the most part tweak the recording gain depending on what we are recording.
I'm far from an expert, but at the same time, I'm not a dummy when it comes to figuring out how to make a recording sound good with my "lo-fi equipment". the lo-cut is in-effect built-into the Sonics via black electrical tape, and the mics will officially have been in service for 25 years at the end of this year.
the black rubber coating has completely come off of the earbuds (and they too are now covered with black electrical tape).
they look like garbage.
but they still get the job done....or, I've never had a desire to 'upgrade' them, as they still make pretty good tapes.