Need a good high-pass Xover for Sonus REL

And I join Arni and second the "disasgree" vote. I just went thru this discussion in great detail on another thread and offline. Let the Monitors' bass roll off naturally. Measure it if you can -- at what frequency does the bass START to fall off in volume, and at what frequency is its volume down by HALF. Set the sub's upper limit (where it STARTS to roll off) 10 to 20 Hz BELOW the half point frequency of the main speaker rolloff.

Here's an example:

Let's say the monitors' bass SPL (sound pressure level expressed in dB) starts to fall at 80Hz (at whatever you measure the SPL) and it's half as loud (ie down in SPL by 3dB) at 60 Hz. Then for starters, you'd want to start the sub roll off at approximately 40Hz (an equal amount the other side of the 60 Hz midpoint frequency) -- this is assuming the sub is putting out the same SPL at 40Hz as the monitors are putting out at 80dB.

The object is to have the two curves cross at 60Hz at half their SPL so that when added together the two curves form an (ideally of course) flat line.

IMO, and in that of the people at REL apparently, there's no reason to "clip off" the low end performance of the monitors. Doing that shouldn't make them "work better" if they've been designed well to begin with.
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Thanks for the info! I think I just neeed to tweek the REL's crossover a little.

Greetings
If you want to take the system up to the next level
The Vandersteen 5A High Pass units are the most transparent and simple solution you will find.
This is a big advantage with no downsides.
By high passing your system your amps distortion lowers dramatically cleaning up the whole system while not doubling up the bass frequencies. Once you experience
this level you will wonder why Rel didn't design it into
their subs in the first place.
Cheers JohnnyR

Greetings
If you want to take the system up to the next level
The Vandersteen 5A High Pass units are the most transparent and simple solution you will find.
This is a big advantage with no downsides.
By high passing your system your amps distortion lowers dramatically cleaning up the whole system while not doubling up the bass frequencies. Once you experience
this level you will wonder why Rel didn't design it into
their subs in the first place.
Cheers JohnnyR