Splitting line level out from preamp, versus using 2nd set of outputs

Dynacohum,  I think your idea is better than mine. As the signal runs it would hit a female rca at the start of my splitter.  Leg one and leg 2 split.  Leg one could be very short, and would end in male rca to connect directly to the high frequency amp.  Leg two could either be long enough to reach the low frequency amp, in which case it would also end in male rca terminations, or it could also be short, and in such case would have females on its terminus. 

Should have said Mulveling and Dynacohum. Great suggestions guys.

What if I plugged the male end of the Audioquest 1M to 2 F metal splitter into the back of amp 1, then ran incoming signal into one of the two F connectors, with the second F being used to feed the signal to amp 2?

Morrow audio makes whatever cable you need, splits, varied lengths, whatever connector you need.  They have a range of cable types for every budget, often having substantial discount sales. 
I’ve several of their interconnects and have found them reasonably priced and perform very well.  I’d avoid the splitters and get something made to suit without spending big bucks. 
apparently they’re currently moving their facility so orders are a bit delayed however.  
 

I have used rca f connectors off one amp into another and daisy chained multiple amps. Amazon ,parts express ect .good luck with your project and anjoy the music.f connector on the back oof one amp short rca to other amp.it is shorter than a y connector.