Full agreement with Sugarbrie - you want a fair amount of "underlap". You might want to start with the crossover point close to half an octave below (or perhaps even a bit lower) where the mains start to rolloff. Trying the REL Strata with my Dunlavy SM-1s (-3dB somewhere in the mid-40s), the best crossover point seemed around 32Hz. In your system, you would need to be even lower, so it seems unlikely that the ACI would integrate as well as the REL, even though the ACI rolls off faster. You might have a slight suckout from setting the crossover in the mid-20s, but it won't degrade the sound of your Thiels.
subwoofer setup problem
I am trying to mate an ACI Titan II with my Thiel 22. The Thiels go down to 30 hz but the lowest crossover on the Titan is 35hz. Thus, there is an annoying overlap in frequency. I am considering several possible options and would appreciate some input. They are (1) get a REL sub whose lowest crossover point is 28 hz. (2) get an active crossover and cross my mains at a higher point. (3) use a passive 65hz filter between my preamp and amp that ACI has.
The passive filter is the cheapest route but will it do more harm (to the sound of my thiels) than good?
Thanks
Greg
The passive filter is the cheapest route but will it do more harm (to the sound of my thiels) than good?
Thanks
Greg