Low-pass + high-pass?

I've been using a pair of KEF Ref 1s 4th order low-passed at 80 Hz to subs.  I have a passive Marchand 4th order high-pass 80 Hz filter that I could use between the Ayre 5/20 series preamp and amp -- Ayre tech says the balanced passive filter will do no harm, but discourage inserting an active filter.  My question is whether I should high-pass or let the Ref 1s run full range?
Ag insider logo xs@2xdbphd
In my experience with my speakers, both ESL and dynamic, there was a benefit to not running the mains full range and using a high pass filter to just send 100 Hz and above to the mains. As you know, I use an active crossover 100 Hz, 4th order, 24 dB slope for both high and low pass.

I can't see why Ayre would have some concerns about an active crossover, really good ones won't do any harm.

Clio09, Charles Hansen had advised against inserting a Bryston 10B active high-pass filter between the KX-5/20 and VX-5/20.  Nevertheless. I tired it, and found that it indeed colored the sound, some of the Ayre sense of naturalness was missing.  According to the tech at Ayre, Gary IIRC, that should not be a problem with the passive balanced Marchand filter, nor was it when I tried it previously.  I'll reinsert the high-pass filter.
Dbphd, we have yet to find any passive filters that won't compromise the sound of a great high resolution system.

The Kef Ref 1 can play loud and do not really benefit from removing the strain of the bass from the speakers unless your room is huge or you listen very loud if you have enough power the Kef Ref 1 will play very loud.

We run ours without any crossover in line with the speakers and dial in the subwoofer to add pressure to the Ref 1's output.

You won't loss one iota of clarity and you still get great bass, without losing any detail.

Dave and Troy
Audio Doctor NJ Kef Ref dealers