help with 4th order blowthrough for 2 zv4 18s

[plexlove]

Ok so i have spent days now researching and cant really seem to find a straight answer!

I have an avalanche that im gonna build a blow through 4th in the bed....have 40cubes to work with but need room at the tail gat for my batts and amps. So lets just say 30 cubes.

I have a few questions....im planning a 3to1 ratio, subs will be reversed to help with cooling.

Id like to know thoughts on cubes sealed? Also ive read this going both ways but is a 4th efficient? Read about 20 forums last night saying they were very efficient (doesnt make sense to me since its sealed) and read and 20 saying they werent efficient! Which is it lol

Same with frequency response...hundreds of people say they r one not wonders (including almost all audio site..12v.com) then all the builders say they will do great on a full range tuned to 42to46...which is it? Lol

My setup is 2 northstar 170ft batts, kinetik 1600 under hood, 4 runs 0 gauge, 2 300amp alts, 2 rub1.2500d amps running at .5 strapped giving each sub close to 3k.

So my efficiency needs to be good!

Goals....pure spl and move air.

I got solid hair tricks of 2 15 sundown x's on 2k so this should get nasty.

Thanks in advance for any help...oh, and please, PLEASE, if u feel the need to say something dumb about my amps not doing 3k then dont bother posting...been over this 100s of times and tired of hearing...numbers r posted all over. Just had to say that because everytime i ask a question some idiot smarts off bout them then myquestion never gets answered, just turns into a "whos the bigger idiot" thread!

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[dbjunior 10+ year member]

4th orders can be efficient. Anything over 2to should be,good but the higher,the ratio the narrower the bandpass. Your 3to1 should be possible in 30cu. Less port area will give more low-end extension but lower output higher up, Try for half cone area.

 

[plexlove]

Ok...well let me ask u this...i originally wanted to do a 6th order but read someone saying the zv4 wouldnt work well but just now read a few diff forums and according to them it would work perfect...so which do you think would be better for my goals?

I know the 6th will be more efficient but what about space?

Id absolutely LOVE to build a nice 6th.

 

[plexlove]

Also....on a 6th should i go parralel or series? Id think parrelel would work best and from what im finding, size shouldnt be an issue.

Know of any GOOD enclosure designers on here i could contact?

 

[oxsign 5,000+ posts]

You have anymore info on the box you had with the 2 15"? Right now I have 4 15" in a 6th in my Avalanche, but looking to go down to 2 15" since I need some of my bed back.

 

[undone1 10+ year member]

Also....on a 6th should i go parralel or series? Id think parrelel would work best and from what im finding, size shouldnt be an issue.Know of any GOOD enclosure designers on here i could contact?

RAM Designs - Home..

have had excellent results with his designs...//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[plexlove]

Cant remember my build exactly but im pretty sure it was a tad over 9cubes before displavement, 45s and bracing build into the midgate opening...midgate removed. Center slot port tuned to 32hz and if i remember right it was about 104 port area. They werent even moving half way and id get a good hair trick.

Seats down or up it didnt matter.

 

[plexlove]

Ok upon further research it looks like 6th is out due to qts being WAY too high....but then again the qts for this sub also calls for it to be in a sealed enclosure so idk.

So im just gonna do the 4th so if anyone can just give me an idea of sealed cubes per sub i can get the rest just fine.

I just have no clue how to figure that!

 

[plexlove]

Ok 12hrs straight reading forums and doing complicated *** math and ive come up with this.... 2.75cubes per sub sealed 19 cubes ported...will come out to roughly 16.5 after displacemnt for subs, bracing, and 45s....subs reversed and tuned to 40hz, 250" port area...should get down in the low 20s easy.

Any comments/suggestions about those specs?

 

[dbjunior 10+ year member]

Sounds good