audiophile low pass filter

Yes, I see. A riddle.

What is the air speed velocity of an unladen swallow?

Everything.

and what does this have to do with the original post about low pass filters???

It does amaze me the "audio engineers" that I have conversed with seam utterly ignorant of the following truth

frequency recorded = (frequency input) mod (sampling rate/2)

Dnewhous, this thread is a waste of time unless you clearly state what you are hoping to accomplish, Unless you clearly state what you hope to accomplish with this filter then any advice given is worthless. You give a tiny tidbit of information and then scold Jwmazur for offering advice on what he can only hope to guess is your intent.

Statements like this

After looking into this a little more closely, it appears that what I'm looking for is referred to as a "digital mastering processor." It incorporates a low pass filter with the ADC. See, for instance, the Drawmer DC2476.

The piece you refer to has multiple functions so we can only guess what problem you are trying to solve.

Either come clean with the details of what your system is and what you hope to improve or stay at home.

I meant low pass as I stated. Jwmazur, speakers have absolutely nothing to do with this thread.

Off topic aside: You can do high pass for rumble in the digital domain.

After looking into this a little more closely, it appears that what I'm looking for is referred to as a "digital mastering processor." It incorporates a low pass filter with the ADC. See, for instance, the Drawmer DC2476.

Are you sure you want a low pass? It is more common to need a high pass to block low frequency rumble.

Check the link below. I use this type in a high pass application to keep my main speakers from seeing anything below 100Hz. I don't suffer anything by using them. They came at the recommendation of the speaker manufacturer.

http://www.partsexpress.com/webpage.cfm?WebPage_ID=3

Good luck.