Is there anyway to split the signal between subs? I have an 8" subwoofer that is flat to about ~27hz, and i want to incorporate an adire tempest 15" to cover the duties below that. How would this setup be possible without buying any expensive equipment? my receiver does have decent bass management and has mcacc and crossover points of 50/80/120...etc. but that is only good for one sub. is there any inline crossovers i can put between each sub to filter out the frequencies?