use both LFE and Line in connections with 2 amps?

I own the Rythmik L22 sub which has the two RCA input options: the LFE and also the L&R jacks. Are both ready to receive a signal when cables are physically plugged into both inputs?

Currently my AVR sub out goes to the LFE in. I would like to purchase a stereo integrated amp (possibly a used Hegel H160, or Musical Fidelity M5si) that has a home theatre bypass input and add that into my HT system. I want better sound quality for stereo music. And since I have the sub, would also like to utilize it for music playback also.

When using the AVR, the stereo amp would power my front L&R speakers. and the sub would receive the LFE signal sent from the AVR.

When listening to stereo music, the AVR would be powered off. Can the variable stereo pre outs from the new stereo amp connect to the stereo line in jacks on the sub so that I could play music using the sub?

Unfortunately, I would not be able to high-pass my stereo RAAL Towers, but if the crossover on the sub was set low enough I'm guessing this could work well.

Does this hookup work? The subwoofer would play in both cases, irregardless of which amplifier was sending the signal?

Why not use the receiver for music and stay with the LFE rca connection? That'd solve a lot of your issues right there...

Yes, you can use the AVR subout to LFE for movies and the integrated subout to Line In for music on the Rythmik subs.

This has been confirmed by Rythmik as I asked because considering the same set up.

Either this or a variant via my miniDSP (AVR out to input 2 on minidsp, music preamp to input 1 on minidsp). MiniDSP outputs to subs lfe-in (most likely as can do bass management in the miniDSP, and set up different configurations for music and movies).