Box Recommendation for 2 SA-12 Ported in s10 Blazer

[bosco2023]

Ok, I was working up a box for a Re sx 18 when the eBay seller decided to bail
out and not ship my sub. So I bought 2 new sundown audio sa12's. Im gonna be
powering them with a hifonics 2000d at 1 ohm. Which realistically with my 200 amp alt , 1/0 wire, and 2 agm's in rear should net me 1600-1700
rms. The subs are going in a 02 s10 blazer fired up and port rear/Up. Tuning I
don't know, Maybe 32-33 hz. I listen to alot of lil boosie, webbie, waka, ti and
music like that with occasional colt ford and newer country. My max dimensions
are 23" high, 23" deep and 37" wide. 23" deep allows me 8" from box to tailgate
with rear batteries. I have 3/4 mdf already and will be doubling the top baffle.
I like the side slot port as I can build that pretty easy. Bottom port is a
little more difficult. Also a cut sheet would be awesome. Thanks guy in advance.
Ive also been looking at aero ports for ease of build. I read on another thread
about 1.75 cubed per sub and a single 6'' port. You guys are the pros here. Ive
built but not designed about a dozen boxes over the last 15 years, just havent
tackled it in a while. I wish i understood the box calculators better.


Thank you very much

Rich

[Joe X]

So here is a suggestion:

Enclosure Specifications:

Fb = 33 Hz
Vb = 3.6 ft^3

External Height = 17 in
External Width = 37 in
External Depth = 18.25 in

Port Width = 3 1/2 in

Cut Sheet List:

* All Dimensions in Inches.
* Wood Thickness is 3/4 for all Parts.

External Enclosure Parts:

2 x Top & Bottom (3 parts) = 37 x 18 1/4

Left & Right Sides = 16 3/4 x 14 3/4

2x Front = 16 3/4 x 14 3/4

Back = 37 x 14 3/4

Shared Port Internal Assembly Parts:

2 x Front to Back = 15 x 14 3/4
2 x Extension = 7 7/8 x 14 3/4

Assembly guide (generic dimensions):

- The 45s if you want to do them are 2 1/2" wide except the one/ones inside the port, if you want that let me know.

- The port needs 3 1/2" of free airspace in front of it for proper operation.

- Setting your amp's subsonic filter to 27Hz is suggested.

[bosco2023]

Thank You very much!

[bosco2023]

Yes I would like the dimensions of the divider in the back of the port

[Joe X]

Yes I would like the dimensions of the divider in the back of the port

So the dimensions depend on what how you smooth the corners in the turn, you just should make sure of the width of the port at the turn, take a look:

So 1/2 of the port width is 1 3/4", if you have any other questions let me know.

[bosco2023]

Hey Joe, I really appreciate the box design. I have one more favor. Can you do the same specs on box but ported to the drivers side. Not sure on which I want to build. All the 45's make me nervous as I have a shitty jigsaw..Ha. I think id have to really mess with the two pieces inside the port. If I can get my buddy over here this weekend with his good skilsaw, then I will be ok. If he has to work, then im on my own. lust let me know now if im pissing you off.

Rich

[Joe X]

Not bothered at all, the thing is that small subs up/port back port vertical to the side boxes can have unloading issues which can result in bottoming out, lower power handling on the driver(s) unloading and eventually damage to those driver(s) overtime, take a look specially the pic at the end:

http://www.stevemeadedesigns.com/board/topic/154640-subs-not-playing-correctly/

Instead, I suggest to just round or slant the ends of the port and the corners at the turn and avoid the 45s:

Some people think boxes will do even better without the 45s and I have seen very successful outcomes in boxes without them.

I could still try to do the sided port box if you really want but I wouldn't recommend it.

[bosco2023]

Thank you very very much. It's nice to get a straight answer. As far as the port side sub unloading issues I know exactly what you mean. Good info Joe. I also appreciate the info you gave me for the single re sx 18. Unfortionately, the eBay seller was a scammer and never shipped mine or the other 10 he had for sale. 160 shipped new, I should have known better. The sa12's d4 I bought from skar for 130 shipped each new with warranty

[bosco2023]

I will build the box and port then do the 45's on Sunday when I can get the saw. Here is an idea for you to think about. Does the divider on back wall at the port throat if you will have to be angled like that? Can it be a half round as in maybe 3" PVC cut on half long ways and glued to back of box allowing that clearance you were talking about at the back of the port? Sound crazy? Don't know if that 180 degree half round would act as a speed/air bump and cause turbulence instead of acting like a ramp with the 2 mdf pieces

[Joe X]

Hope paypal took care of that as they are supposed to.. sorry. PVC cuts have been used before as an alternative to 45s, the deflector at the turn can be done with PVC, the important thing is that the area of the center duct splits evenly to each side, if it is not, the box will fail, if it can't be done for all practical matter perfectly is better not to do it. As before rounding every corner inside the port is important as well.