Audience 1+1 with subwoofer

I am in the process of replacing my trusty Gallo Ref 3.5 with subamp by an Audience 1+1 V4 (plus potentially 2 SVS 3000 micros). This will give me the opportunity to compare the Audience 1+1 combined with the subamp section of the Gallos to the Gallo Ref 3.5 incl. the subamp. As the Gallo subamp allows me to choose crossover frequency etc.; it should be possible to achieve a reasonable result for an overall comparison. I will use a Radio Shack sound level meter for coarse adjustements of subamp to rest of speakers.

Has anybody any ideas or experience about:
- best crossover frequency 
- use of a hi-pass filter for the Audience (and if yes after preamp or after amp)

I use Quobuz, for serious classical listening a Shelter 90X with a VPI Super Scoutmaster, Shindo Masseto and a Audio Mirror Set amp.

Thanks for helpful input

hhhans