Mixing Different Sub Sizes

[James Scullin]

Hello all, I hope I have this post in the right place.

I want to first apologize in advance if I'm not understanding a fundamental issue with my question.

I know mixing different sub sizes is apparently wrong. In all my searching on the internet I cant seem to find out why/ how to overcome this.

Here is my issue. I have 2 OA 18s tuned to 28hz, and they dont py much over around 70 hz.

So my thought was to have the head units sub line low passed at ~120hz, have the 18s amp low passed at 70hz, and add a pair of 12s (or something) high passed at 70hz.

That (to me) would make sense. I have heard some things about phasing, and subs canceling each other out, or the 18s outshining other smaller subs, and at this point I wanted to ask the forum that i have followed for a long time (but never became a member of for some reason).

If it helps here's my system:

'05 Suburban

2 250 amp alts

3 3100 xs batts

all knu wiring

2 pair re audio xxx 6.5 components

each pair powered by a jl 360/2

2 pair of infinity kappas

powered by a jl 360/4

2 OA 18s

powered by a hifonics brx 1600/1

ANY help would be greatly appreciated! Thanks

[Rev. Wrath]

If you're trying to get your subs to play higher, try tuning them higher. 28 seems a bit low. Maybe you could get it to blend a little better tuned around 32-35ish? that's where I'd start anyway.

[OrionStang]

Those XXX's should be able to cover your 70 and up range easily. Either your settings or your install is lacking.

Don't add a second set of subs. If you can't figure out why the RE's arent' hanging, you can add a dedicated midbass driver to the kicks or something.

[SIDE SHOW]

v8 motor at 2000rpm will sound total different to a 4cycliner motor at 2000rpm, same as an 18inch woofer playing 70hz tone will sound different to a 8inch woofer playing the same frequency. (box depenent)

if your missing mid-bass (add a midbass woofer or two) not a sub