Active analog splitter?

Biwiring has nothing to do with what you are talking about, so I'll assume you meant biamping. Its kind of hard to give an answer without knowing what your system is. Unless you are using 2 identical stereo amps, or an amp that has 4 channels, and have them configured vertically, I wouldn't bother. Its more trouble than its worth.

Yes, sorry, I do mean bi-amping. My DIY customized front speakers have a 12" bass drive that has its own connector. I have some hearing loss for low frequencies and bi-amping has historically worked very well for me because I can simply increase the volume for the bass drive.

On my Rotel unit, it has 4 Zones so this isn't an issue. I simple connect the Front out to the Zone in and connect Zone 2 and 3 to separate amps. Each zone's volume can be individually adjusted.

Long story short, now that I have the NAD t757, it has only 1 zone so I must somehow split the front signal so that I can connect it directly to an amp and the Zone input at the same time.

A cleaner solution would be to use an EQ to recover frequencies due to hearing loss. Another member on AG has some hearing issues and ended up getting a Behringer 24/96 digital EQ, and is very pleased with the results. One of those goes for about $300-$350 new. I have one myself that I use for poor recordings. If you don't need digital, you can get an analog dbx for around $200.

Its just something to consider.