Help finding a subwoofer

I was using a set of SEAS Froy3 speakers and added a pair of 18" woofers crossed passively about 85 Hz designed by the SEAS designer(a friend) and the improvement in openness , detail and clarity was overtly noticeable even thoughthe Froy3 was already very good. Of course being designed by the Froy3 designer the crossover between the speakers and woofers was custom designed for just this case.

I do understand the lack of a high pass when the high pass is generic and not a special design for the speakers and woofer. It's easier to integrate without the high pass but you pay a price for this flexibility.

I believe in not altering (DSP etc) the signal. It adds distortion.

No it doesn't. CD digital output into a DSP offers the ability to exactly tailor the XO frequency and slope to match the drivers, something that is extremely difficult with passive XO. Additional benefits are minimum phase, time alignment, room correction and precise driver control as damping factor is preserved at Fxo instead of being ZERO with a passive XO.

99% have never heard a correctly timed, phased and crossed-over multi-amp system. Shock and awe are the usual reactions when they do. Poorly recorded multi-mic compressed one dimensional recordings are exposed as the dreck they are. Comments like "That's one of my favorite recordings and it sounds so lifeless compared to ..." 

Thank you for those great responses.

Ieales do you mind to elaborate on what you meant when you wrote preserving the damping factor at crossover frequency if that is what you mean with Fxo 

I want to spend 1500 us used in two subs.