$LPFRolloff for SNDINFO (Low Pass Filter rolloff)

[Zanieon]

I've been wondering if the version of FMOD that ZDoom uses (also OpenAL now) supports the Low Pass Filter, because if it does, would be nice to make use of it to give more depth in sounds, especially when used in conjunction with reverbs.

My intention about it is that adding a $LPFRolloff to SNDINFO which is possible to control where the Low Pass Filter starts and where is ends, or in case where it starts the cutoff and where it is full low frequencies only. I know this can be simulated by using two sounds, the main sound with all frequencies and another with only 100Hz, however this creates overbass ingame causing a unwanted effect but still using two sounds for such simple effect is kinda hacky and a waste of a mod's space.

I did this image to explain better what i mean when applying a LPF to a sound.

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The entire red circle is the normal Rolloff of the sound
The orange disc is where the LPF starts acting, where that 1000 radius is where it starts it's cuttoff and the 1200 is fully low frequency only.

My thought on management:

If the LPF max radius is greater than the normal rolloff max radius nothing happen because the volume of the supposed sound is zero since it's out of the normal rolloff. (by logical sense this is a bit obvious and not be treated as a bug anyway)
If the LPF max radius is shorter than the normal rolloff then all the remaining space between the max radius of LPF and the max radius of normal rolloff applies total filtering.
By default LPF is unactive to any sound unless it's usage is properly defined by a SNDINFO to a sound (for better compatibility with vanilla feeling, so unless you apply a $LPFRolloff to a sound, nothing happens)
The LPF is subjected to the same Sound Curve defined in the $rolloff of the supposed sound