2x15" Below BMS 4590

The basic ported 12s and 18s can sound good in a small to med hall but will never kick and punch like Whitenoise's horn loaded system. Horn loading adds approx. 5 dB. Large horn subs or a stack of med horn subs give a feeling to the music that ported boxes will never have.  VECTORSONICS 

I would stay away from horn loading your 12 inch drivers as you will need a very deep enclosure to get low enough to meet the 18's. As the length of the horn denotes hz cut off. Maybe you would need nearly 1M deep. Could do folded horn but then it won't get high enough to meet the 4590 's! The only other way is horn loaded and port but the design is more difficult and you can end up with a lot of cancellations. Going 15 inch enables you to get down to 80hz and so you can cross lower to your 18's. IMHO 18 inch reflex sound the best when crossing below 90hz. 80hz ideally.

How are they above 370Hz? Can they stretch out to 500hz with some eq?

There is no fold in what i have on mind, i need to build one ant try :-)

No you start getting reflections creep in over 380hz. Think you'd be hard pushed to get 90-500hz range at the spl. a super deep box no foldings maybe.

4590's will go down to 370hz in a big enough horn however.

Like this one I'm doing :)

FYI I spotted this in Rogs FAQ regarding 2x12" vs 2x15" and thought it was partly relevant to the thread.

http://www.speakerplans.com/index.php?id=faq9

Rog wrote: This brings us to front loaded vented boxes. You could use two 2 x 18" reflex boxes per side and have two 2 x 12" and 1" compression driver on a horn in reflex cabs or ideally two 2 x 15" and 2" compression drivers on a horn in reflex cabs per side with the 2 x 18" reflex bass cabs underneath. This arrangement would not be as loud as the horn system descried above, but it would sound a lot better when used in small venues. You would also get a lot more low bass from the reflex bass cabs unless you used around 6 or more bass horns per stack.

Edited by vertx - 29 May 2017 at 11:13am