This sounds like looking to create a problem where there is none. Your speakers go down to 26Hz and were designed to work that way — including the drivers that are custom made by Ref 3a — and you wanna cut them at 100Hz? And why in the world would you want your subs to be working up to 100Hz with near full-range speakers that cost $10k??? This sounds like a potential big step backwards to me, but I guess anything is at least worth trying.
Do No Harm ... well the least harm anyway
I want to insert a high pass filter between my preamp and amp (both Benchmark) so I can limit the frequencies going to my full range speakers (Ref 3A Nefes II) to over 100Hz with a 24 db/oct. slope. The 3 possible ways are passive, active, or digitally (A to D then D to A where this is done through software). I am seeking opinions on which method would be the least intrusive to the original signal (ie. best sounding). Thanks for any replies.