ported box for two sa15s limited space

[blkvenm97]

hello as the title states I have fairly limited space and I want to somehow someway make a pair of sa15s work. I really like the sa series and have been wanting to try them for a while. i was about to pull the trigger on sa12s coming up in the near future but with my space I believe it to be possible to actually go with two sa15 considering my build and wants and needs but I want some more oppinions on if this is a good idea or not. I am working with a 2003 ford focus svt hatchback...it is a 3 door hatch and the max demensions I came up with when measuring (these measurements are with the two plastic trim peices on either side removes that cover the rear seatbelts on top) are 39.5 wide by 22 inches deep (will come up to about the top of the seat with the spare tire and carpet etc already removed) and 19.5 inches top to bottom...or in my case front to back since I will be going subs up port up. I have a pair of rockford p3 12s sub up port up now they sound good like they but ive been wanting to switch to sa's for a while and I have really always wanted 15s. I don't want just one Id really like to make two 15s work unless it just cannot be done with a decent box. I have fooled with my box calculator app on my android all day and tried it with aeros and just couldn't seem to get it right while still having enough port area. And when I fixed the port area it was tuned too high. I would like it tuned 33-34 hertz....33 being the number I'm really after. I came up with a design that is 39.5 wide 19.5 top to bottom (or front to back subs up port up) and 22 inchs deep (or tall in my case) and it's slot port with a 5 inch wide port that is 18 inches front to back (tall) and 29 inch port length. According to my calculator it comes out tuned to 33.01 hz and with a new volume of 6.04 and after sub displacement itd be 5.7 (2.85 per) with 90 square inches of port (14.9 sq in per cube)....and this seems to be right where it needs to be just a hair under recommended specs on volume but this will be running off a crescendo b2k or a sundown scv2000 or q1-2200d from sq (havn't decided between the 3 year but leaning towards the b2k) and will be tuned with a dd1` that I am also purchasing so no worries there. I figure a little less cubes with the power I'm sending them would be ok but will this box get loud and sound good doing it and will it moves plenty of air and smash lows? Does this seem like a good design? I listen to alot of rap and I want it to slam ecspecially on lows but still sound good with hard rock, classic rock and metal when I listen to those as well. When i'm jamming in my car i'm 75-80% rap but I want the other music I listen to to sound good also. am I on the right track? and if not can anyone help me design a box for two sa15 to fit in this space? I really wanna make dual 15s work if i can. but if it's going to sound like **** i'll just roll with the sa12 I need other oppinions. I will go with slot or aero just as long as it works. Don't really want any aeros that stick out from the box but if it's not sticking out alot and it would work i'd be willing to give it a shot. thanks so much

Michael

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[blkvenm97]

would two sa15 or a single zv3 18 work best with the space I have? I messed around with some specs and came up with 5.42 cubes after displacements for a single zv3 18 with 90 sq in of port and 15.87 per cube tuned to 31.97 hz. I came across a good deal on an saz2500 and I'm trying to work out a deal on getting it as we speak so if i do that will be what powers either set up. which setup would sound better and which would get louder? i don't have plans to compete but I would like a decent score on the tl if i ever decide to meter it for fun. I'm more concerned with having an all around daily ground pounder that gets loud and sounds good doing it and digs low and sounds good on everything ecspecially rap music. So it's either two sa 15s in 5.7 cubes net tuned to 33 with 15 sq in of port per cube on an saz 2500 or a single zv3 18 in 5.42 cubes net tuned to 32 with 15.87 sq in of port cube also ran off an saz2500 at 1 ohm. thanks for any help

michael

 

[LosIsATool 5,000+ posts]

One 15, 2 12s, 3 10s. That's all you should do

 

[blkvenm97]

i also just thought of the idea of potentially inverting the sa15s that way the full 6.04 cubes of air space would be there for the taking. that gives them 3 cubes each tuned to 33 hertz with right at 15 sq in of port per cube. I realize that's towards the smaller side of the spectrum but putting over 2kw of power to them wouldn't this be ideal anyways? I've read alot of stuff online about the sa15 doing good in 3 cubes, which is what sundown recommends anyways. thoughts? I'm not totally against going with sa12s I really like them but I'd love to have some sa15s so I'm trying to make it work lol

 

[LosIsATool 5,000+ posts]

If you want the best use of space 15s won't work for what you are looking for. I would do a Z15 and call it a day

 

[blkvenm97]

yea I see what you are saying. ***** having a small car makes me wanna trade for an suv lol. What about a z18? I figured out a way to get 5.4 cubes after displacements tuned to 32 hz with just under 16 sq in of port per cube. that's 1.4 cubes over what sundown recommends and I'll be feeding it pretty decent power. Not opposed to a single z15 but a single z18 would be even better (and louder lol)

 

[blkvenm97]

maybe jacob will chime in with some food for thought on this haha

 

[LosIsATool 5,000+ posts]

A 18 will be peaky under 6 cubes net. We went 7 with a Zv3 and it dug low and flat.

 

[LosIsATool 5,000+ posts]

On a BC3500

 

[blkvenm97]

a box with 39.5x22x19.5 demensions and six 4 inch aeros 18 inches long (leaving them 4 inches off the backwall mounted flush) gives me 7.21 cubes before sub displacement with 10.46 sq in of port per cube with aeros that would be enough port area wouldn't it? 75.4 sq in total. that would come in at 6.87 cubes after displacement for two sa15s or I could invert and get 7.21 cubes. would this be aight? just trying to exhaust all my options and two sa15s are really calling me but I don't wanna do it if the box is crap. thanks for the help

michael

 

[blkvenm97]

to my understanding since aeros are more efficient you don't need as much port area as with a slot port correct me if I'm wrong I'm by no means an expert (obviously) lol

 

[LosIsATool 5,000+ posts]

You are right. 8-12 is good. Lower for more flat and better roll off. Higher for more peak and less bandwidth. Inverted should work well

 

[blkvenm97]

tuning comes in at 33.46 on that last idea btw

 

[LosIsATool 5,000+ posts]

That's fine. You will be able to pick up 25hz good. Should play 30-60 strong.

 

---------- Post added at 03:31 AM ---------- Previous post was at 03:30 AM ----------

 

Can you do 2 6in ports?

 

[blkvenm97]

the problem is it's going to be taking up all of my space so the subs and ports will have to all be mounted on the top side so I've got two 15 inches subs plus six 4 inch aeros to mount and the measurements on that side will be 39.5x19.5 that is a very tight fit. I'm not sure if it would work or not is do you or anyone else on here have some sort of modeling program where i could model it up to see if that would work?