[loycribbssr]

So can I close up the rear port and port it out the side making it long or maybe leave it out the rear & turn the port on the inside in the front of the box to make the port longer?

 

[Destarah]

Caustic is correct, the sub you have @ 700W tuned to 28Hz will dig deeper than the pair of SD-4 sealed ... the following model shows your current setup in red, the 2 x SD-4 sealed in blue and your Level 3 tuned to 28Hz in green. Let me know if you need any help understanding what the graph represents (we are all learning, that is how life works)

 

[Destarah]

Yes, but if you only make the port longer you will hear the air rushing through it. You should make it wider (3x5 and a length of 43")
Changing the size of the port (3x3 to 3x5 for example) changes the length it needs to be for a given tuning frequency.

 

[Caustic]

And the green looks pretty nice. Not peaky, smooth and definitely extends lower.

I'd pull the box, remove the sub and see what I could do from the sub hole. Would probably be easier to mimic the dimensions of that box and make your own box. 60 bucks for a sheet of birch, 6 bucks in glue and you have pvc already

 

[Destarah]

ah yes, the plumbing!
you could get 28Hz by using a pair of 3" conduits 42" long ... that would be hella easier to build ... and remember the conduits can stick out of the box as much as you need

 

[loycribbssr]

So mimic the box or do I make it a little bigger and how would I place the plumbing lol. Nice little pun there. And I do appreciate all the help/info.

 

[Caustic]

Like it's so easy to find space for 84" of 3" pipe in and under seat box 🤣🤣

If you made a box along the whole area you could get about 2.3 ft³. You only need like 1.5ft³. 84" of 3" port will consume about .36 ft³ and the driver is probably close to .1 ft³ itself so you'll be left with a net 1.1ft³ after

I'd shoot to put the sub on the passenger side and the port firing to the drivers side

 

[loycribbssr]

I can probably make the box an 1 1/2 - 2 deeper, front to back if that would help

 

[Holmz]

Once you start going under 30-Hz, it might make sense to consider:

SLAPS-M12 - EarthquakeSound.eu

www.earthquakesound.eu

Sometimes Amazon has them for ~60-80$

Obviously a port is cheaper for a plumber, but there is some ease in tuning a PR, that may be worth considering.

 

[Caustic]

I want to try a PR myself... got some reading to do on them

 

[Destarah]

Ironically, an under-seat box in a truck is about the easiest place to cram in 84" of 3" pipe lol. Consider the box you have - 3x3 square port that is 12" long. Assuming 3/4" material for interior port walls that is taking up 0.1 cuft. 84" of 3" pipe takes up 0.4 cuft (accounting for outside diameter) so if your box is 36" long and 7" high at the front (I am guessing from the pictures you posted) adding 2" of depth would get you the extra space you need to fit the ports inside.

 

[loycribbssr]

Here's what I can do if I build a new box. And if building new is it still best to go ported?

 

[humandrummachine]

Why not flip up a seat and put your sub in about 2 cu. ft. ported to 28-32hz.

 

[loycribbssr]

Why not flip up a seat and put your sub in about 2 cu. ft. ported to 28-32hz.

Don't want to loose seating capacity.

 

[humandrummachine]

I dont think you're going to get what you want using underseat boxes and DC subs because they are meant for big ported boxes. The best advice was probably to get that SI sub.

 

[Caustic]

Ironically, an under-seat box in a truck is about the easiest place to cram in 84" of 3" pipe lol. Consider the box you have - 3x3 square port that is 12" long. Assuming 3/4" material for interior port walls that is taking up 0.1 cuft. 84" of 3" pipe takes up 0.4 cuft (accounting for outside diameter) so if your box is 36" long and 7" high at the front (I am guessing from the pictures you posted) adding 2" of depth would get you the extra space you need to fit the ports inside.

The boxes for the silverados are typically 4" tall on the back side and 6" or tall on the front inside due the middle hump in the floor.


A 3x5" slot could be made along the front wall and exit the side

 

[Caustic]

Don't want to loose seating capacity.

I hear ya man. I would love a 15, like an ultimax or HO 15, but it would require losing at least 1 seating position and that's not in my wheelhouse yet.... yet 🤣🤣

 

[loycribbssr]

I picked up the adapters, etc that I need to put 2 - 3" pvc pipes 42" long, capping off the existing port or starting one of the pipes there. Just gonna raise the seats for now & stick them on the outside the easiest way possible to see what it sounds like. If I like it I'll build a new box with the proper ports built in it & I can cap the holes I drill for the ports in the current box & give it away or trash it lol.
Will report back as soon as I can.

 

[Caustic]

I like this idea. Not too intensive/time consuming and it will give you a good idea of what is possible

 

[loycribbssr]

I like this idea. Not too intensive/time consuming and it will give you a good idea of what is possible

Would aiming one to the left side & one to the right be good or should I try for something different