I posted this in the technical forum, on a two-year-old thread talking about FMODs, but thought I'd ask here as well.
I'm researching these inline filters and wondered if anybody is using them, and if they're happy with the results.
I'm after upgrading my two-channel setup and am looking at tube or tube-hybrid preamps to replace my Emotiva USP-1. The problem is that I love the built-in high-pass/low-pass analog bass management feature in the Emotiva. Running LSA-1 Signature monitors and a Salk Songsub, high-passing the speakers at 50hZ and the low-passing sub at about 52hZ. This sounds worlds better than running the speakers full range and using the sub's crossover to blend it in, not because it's a more seamless blend, but because I have a horrid room peak at 40hZ and another at around 31hZ, and sending everything below 50hZ to the sub, where it can be equalized by my Anti-Mode 8033, makes for nice tight bass. Putting the peaks right back into the room, coming from the speakers, muddies everything up.
So, the thinking is: a 20Hz FMOD filter and a 30Hz stacked with a 3dB attenuator between them to make a 24dB/octave 50Hz high-pass filter for my speakers, placed between the preamp and amps, and a full range signal sent to the sub, which has a 24dB/octave variable crossover. Now I don't need the bass management feature of the Emotiva.
The concern is: Signal degradation.
Do these things pass the frequencies above their designated roll-off point cleanly with no loss of detail and/or dynamics? That is the question.