Would someone please double check this port size for a box I've made

[Raymief]

Vehicle 1995 single cab Dodge Ram 2500

Drivers: (2) JL 10W6

Amps: (2) Alpine 500.1

Box inner dimensions: 49"L x (7"top 11"bottom)W x 18.5"H

Box is about 4.5 cubic feet

I will gain match the amps.

i tried to do the math and came up with 36" of 1.5" single slotted port size. I don't know much about tuning and Hz and would love someone to double check or recommend what size/type port and driver placement. I like loud bass and listen to everything. Thanks so much in advance!

[Triticum Agricolam]

So the port is 1.5" wide, but how tall is it? The full 18.5" internal height? What frequency are you trying to tune to?

That box seems pretty big for a pair of 10"s.

[Raymief]

I was going to go with the whole 18.5", but I really don't know what I'm doing and have a hard time learning from only reading info from the Internet. JL recommends 36Hz I think? Here's from JLs ported enclosure recommendations:

0.75 in / 19 mm

Front Baffle Thickness 0.75 in / 19 mm

Volume (net int.) 0.75 cu ft / 21.2 L

External Width (W) 22 in / 559 mm

External Height (H) 12 in / 305 mm

External Depth (D) 10.75 in / 273 mm

Internal Slot Port Width (SW) 1.25 in / 32 mm

Internal Slot Port Height (SH) 10.5 in / 267 mm

Internal Slot Port Length (SL) 30.625 in / 778 mm

Port Extension Length (EL) 17.25 in / 438 mm

Tuning Frequency (Fb) 37.89 Hz

F3 36.0 Hz

Enclosure Notes

EDIT: I wasn't using any of this information when I started building the box. I got the dimension idea solely from the room behind the seat of my truck. I was under the wrong impression that bigger meant better .....ha

[Triticum Agricolam]

Looks like JL recommends a tuning of 38 hz and a net box volume of .75 cu ft. Depending on the music you listen to you may want to tune lower and make the box a bit bigger, however how you have the box now its WAY WAY too big. You need to shrink your box down quite a bit, I'd shoot for around 1 cu ft of net volume per sub. To do this I'd probably make it shorter, this will have the side benefit of decreasing the aspect ratio of your port. You will need to tweak your port area and length too once you get your box size down to a more reasonable number.

I'd strongly suggest you get everything planned out how you want it to be before you cut any more wood or glue anything else together.

[Raymief]

Thanks for the good advice. I have an idea to better fit the enclosure in my truck that will adjust the volume to 1 cubic foot per driver, but the idea consists of separating the drivers. Do you recommend the drivers share the same port or do you think separating them won't make much difference?

I love the work you've done. The enclosures on Facebook you have made are meticulously flawless. I see you using slotted ports and the tube ports... I read the thread comparing the two- do you suggest I use a tube or slotted port?

Thanks for taking the time to give me so much input

EDIT: added a rough sketch of what I'd like to do. But should the skinny middle section be blocked off to separate the drivers? could I use that spot for the common port? If I remembered how many cubic inches per foot correctly then I have 1.3 ft in each section and that's excludes the skinny center section. I can easily make that smaller if you think 1.3 is still too much room. I want as deep of bass as possible out of 10" woofers...

[Triticum Agricolam]

Thanks for the compliment, I'm glad you like my work!

So as long as they both have an appropriate amount of port area there really isn't going to be any performance difference between round and slot ports. What makes them different really is their implementation. Different port style will work better or be easier to use in different situations. Since you are building a truck box, either type will work well. A lot of people will use a round port and fire it to the side, though you can do the same thing with a slot port too.

It will probably be easier if you don't separate the chambers and just use one port.

I think you can probably get away with 1.3 cu ft of net airspace per sub, but I definitely would go any more than that and I hope your amp has a subsonic filter on it. I'd recommend tuning lower too, 30-32 hz would be good. If you can fit a 6" round port, that will work well. You could use a piece of 6" pipe or 6" concrete form tube, the form tube will be cheaper. If you want to use a slot port I'd suggest using no less than 30 sq in of port area.