IMO, there is no way to make the transition to wireless without sacrificing sound quality. That being said, if you must, or want to experiment, it all depends on your system. If you have a pre-amp that is feeding your amp with an extra set of outputs you can feed from there. If your amp have line level outputs (the blue RCA's on the Rachel) those could be used as well, as long as your wireless system is not looking for low frequency input.

Many possibilities...

Why don't you post your gear chain (list of system components) and lets poke around and find out.

Yes, it appears the only realistic option is to add a wireless hookup since I can't run a rca line across the room.

Now becomes the question which wireless system to buy?

I have a Wiim Ultra that has a sub control within its software. I hooked the sub directly to Wiim Ultra because I can control all the variables like volume, crossover points, phase and delay from the app RATHER that hooking directly to the Decware Rachel. I set the subwoofer to BYPASS since I was controlling it from the app. I hope I did everything correctly so far. The only thing that confuses me is how to sync the delay from the main speakers and sub so that they are time-aligned. Also, would appreciate anyone with knowledge regarding how to set the corss-over point for my Klipsch La Scalas. I read somewhere these go down to 50htz? So I should set the sub crossover to begin producing sound BELOW 50htz?

I don't have any of that fancy audio spectrum app stuff you are showing me. Can I download that app on my iPhone so that I can test my room?

The iPhone microphone would be the weak link for this approach but I use “sonic tools” fairly regularly. Knowing it is off due to the microphone but useful for comparing changes.