RonRizz

Typically not necessary (or wise) for low freq. drivers. Overlap can cause cancellations of certain frequencies. Try gapping your xovers between Sub and Woofers...
Example: 63hz LP on Sub, 80hz HP on woofers. No freq or crossover is set in stone. your vehicle may display gains or dips anywhere on the spectrum. keep tweaking little bits at a time until you find what works for you.
If you have the capability to do so, I like to save my Base tune to one preset, copy that to a second preset, and tweak on the second. Once I feel Im satisfied with tune #2, switch back to the base and compare what improved/what got worse, ect.

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P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals