2 18s 4th order help or oppinion

[joshy629 10+ year member]

shirink it a couple cubes? and add another 8inch aero. and you think it will be alot louder?

 

[813thumper 10+ year member]

ok wow lol. right now you are tuned at 30 hz. that is really really low for a 4th order. what i would do is shrink your sealed chamber by at least 2 cubes and put a huge 45 in the opposite corner of your box from the subs to eat up some of the ported side. and i would suggest adding 2 more 8" ports about 8" in length.

so:

6 cubes sealed

14-15 cubes ported

4 8" aero ports 8" in length

puts you at about 43-45hz and 200sq" of port.

 

[RAM_Designs 5,000+ posts]

shirink it a couple cubes? and add another 8inch aero. and you think it will be alot louder?

Yeah, shrink it down to 5-6ft^3 at first. Right now with 16ft^3(asusming before port displacement) and two 8" ports 13" long, you're tuned to ~32hz. Add a third 13" long aero and you'll raise the tuning to ~40hz...which is still pretty low for a 4th order bandpass. You can add another aero and raise the tuning to the low to mid 40's if you want. Those two things should give you a good amount of gain. The smaller sealed chamber will also allow the subs to mechanically handle more power.

 

[joshy629 10+ year member]

good god. lmao. that is alot of work. haha well tuned to 30 peaking at 28 hahahah sooo crazy but the lows are pretty cool. it was def worth the experiance. but i will make the changes...eventually. lmao im out of money and its insurance time. but i will shirnk the sealed and round corners with some sono tube and fiberglass

 

[joshy629 10+ year member]

they dont seam to move as much as they should. would adding more port cause less compression on the subs allowing more movement

 

[galacticmonkey 5,000+ posts]

To get your peak note up and score up, add another port, maybe two. I'd also shrink the sealed chamber way down. Shoot for about. 5 cubes sealed.

 

[joshy629 10+ year member]

will do guys. thanks so much. i just dont know when that will happen. lol

 

[galacticmonkey 5,000+ posts]

Just cut a 280in^ hole in the front of the box an make it about 6" deep. Would be real easy to do and you would only need a few small pieces of scrap wood to do it.

 

[joshy629 10+ year member]

Doesn't adding more port in a ported box tune it lower so why does more port in a 4th order tune it higher? Just asking

 

[duanebro 10+ year member]

adding more port area (not length) will up your tuning. I'd add two more ports just like what you have. But uping your tuning will hurt your low end power handling. shrinking the sealed part of the box will help that out. I'd guess your peak will be about 45 Hz. Anyone have a guess as to where his peak will be? LOL

Duane

 

[snoopdan 5,000+ posts]

uhm, IMO you should be experimenting with large ported enclosures first before attempting a 4th order.

For example, my 24 cube ported enclosure tuned to 32 hz does 149.1 at the headrest with a 1400 watt autotek amp. When I slap on my 5kw Atomic, im in the low 155's... Sometimes, a big ass box just works.

 

[joshy629 10+ year member]

ted to do a 4th order. Its what I wanna work with. Flat walls are loud. I jus want something diffrent

 

[galacticmonkey 5,000+ posts]

adding more port area (not length) will up your tuning. I'd add two more ports just like what you have. But uping your tuning will hurt your low end power handling. shrinking the sealed part of the box will help that out. I'd guess your peak will be about 45 Hz. Anyone have a guess as to where his peak will be? LOL
Duane

Its a sealed chamber in the back, so the power handling will be pretty much the same.

 

[Ronny 10+ year member]

Not enough port, sealed chamber is a tad large too.

 

[GeekSquad 10+ year member]

Move the batteries to the front and put the subs as close as possible to the back of the vehicle and dynamat the hell out of the rear hatch! lolz Good looking system though!