I have a pair of passive subs that I would like to pair with some speakers that I'd like to run full range. These speakers reach about 35Hz or so. Any recommendations on an affordable active crossover that would be flexible enough to offer variable low pass settings for this application (say as low as 30Hz) but be really useful in future monitor/subs combinations I might have in the future using both high & low pass? I don't want to drop a boatload of $ on this but would like some versatility and decent quality. Thanks in advance!