External Crossover

On the advice of SVS I changed my setting on my subwoofers from 50 hertz to 63 hertz. In addition, I turned the volume up. The change opened up the soundstage, more detail, better /more defined bass. Not a night and day difference, but easily heard. Now I'm looking into purchasing a JL Audio CD-1.
Two questions:
1. Are there other external crossover units that I should consider?
2. Should I expect similar results as when I changed the low pass filter from 50 hertz to 63 hertz with the external crossover?
1. Bryston and DSPeaker.
2. Cannot say because I do not know your system or why this adjustment accomplished what you describe.
Post removed 
I use a Behringer DCX 2496 modded by Audiosmiles, over in the UK. Best $1k crossover you can get.
Bob and Cerrot,

Thanks for the response. I've already called HSU and left them a message. I will follow-up tomorrow.
IMO, the first question you need to figure out is whether you want to go analog or digital. Digital XOs offer many advantages, but some folks don't want to there. DSP of low frequencies (including digital room correction) offers IMO the opportunity for a huge improvement in sound, particularly for those using subwoofers who can also benefit from improved integration of sub and main speaker.
I talked to HSU today and they told me, "an electronic crossover would be of no benefit to my system due to the fact that I'm using a Integrated amp."
Post removed 

I have a Jeff Rowland Continuum S2 and it has 1 pair of balanced and unbalanced outputs. It has 2 pair of balanced and unbalanced inputs, as well as a bypass input. I told HSU what I had, he said he looked it up and adding an external crossover wouldn't benefit me. Maybe someone with more technical knowledge could explain why an external crossover wouldn't work with my integrated amp. My subwoofers are SVS SB13 Ultras.
Post removed 

First and foremost let me say thanks for taking your time to answer my post. My thoughts were an external crossover would provide more adjust-ability; thus making it easier to blend the subwoofer with the main speakers. So yes, my plan was to filter the lows totally out of the mains to prevent overlap...at least that's what I thought an external crossover would enable me to do. I knew my subwoofer has a low and high pass filter, but I thought an external crossover would provide more flexibility. Now I understand that I don't have the option of using an external crossover...thanks again!
Post removed