So, I did an experiment and found space to mount two 6 5 speakers in each door of my 94 pickup. I want to add subs behind the seats, but I'm not sure how I want to go about it.

I have a pair of Rockford P2-8's which I can BARELY fit, but I dont like the idea of firing directly into the seat...I'm a big guy and like my leg room!

Currently thinking about down firing skar 6.5 subs, amp centered on back wall, between bucket seats, I listen to a lot of rock, alternative, metal and country.

What do you guys think? 8's or 6's

(will be installing skar 600.5 amp, 60w×4 4ohm and 300x1 4ohm)

 

Without firing into the seat is a tall order in a single cab. For subs, I would use the largest speakers that would fit. I’m in the same process in my 81 4x4 and have decided to mount an underseat sub on the back wall between the bucket seats, firing forward. Most have a volume control cable that can be mounted anywhere. That might help in deciding the right fit for you

 

A regular cab Toyota Pickup is a pretty small space, so you really don't need massive sub-woofers.

How much bass do you want? Just enough to give a rich, full sound (the way I prefer to listen to my music) or do you want panel rattling thumps?

Dual 6" sub-woofers would be probably ideal for me.

The other "less subtle" option is to just put a sub-woofer box in the passenger side floor, which gives you lots more options for subs, but not desirable for most people who actually want to use the passenger seat, or for theft reasons.

 

I'm trying to get a clean punch sound, not so much boom. I had the two p2-d2 8 in the smallest recommended box according to Rockford, sounded like they were being suffocated by the seat, or maybe I didn't set the amp right, didnt sound clean.

with a fiberglass back (forming to the rear of cab, MDF face n sides) I estimate around 0.4-0.5 cubic feet behind the seat, I dont know if I can set the full size 8s in there.

 

After some thought and visual aids, I'm going for the downfiring option! I borrowed a sub from my dads C-20 project, and it fits nicely.

Rough placenent of 6.5 sub

Side view behind seat, pleanty of room for possibly bigger box!

My experimental speaker placements. Sound ordinance 6.5 component paired with SO coax, 55w rated each, crossover hidden behind panel under arm rest

 

I fixed my ghetto power situation, and installed 4ga power and ground from my 2nd battery, located in the bed of the truck. Hopefully I can find an indoor shop soon to build me a box and get some cable management done!

Cab ground for 2nd battery, also serves amp ground. Using 10-32 threaded insert for mount. Removed and replaced cab plug with grommet for pass through


Final dress if power cables, left the loop to pull amp for maintenance later on, will be using different amp

 

Got a break in the weather, decided to get busy building! Being small speakers, I don't anticipate much flex while using 1/2" MDF, but I made a recessed baffle that is 1" thick and should hold strong! made four baffles, two with 7" holes, and two 5 7/8" holes, laminated a 7 on top of a 5, gain 1/2" extra clearance on the floor of vehicle while having a good strong mounting surface. In the process of making two boxes, one behind each seat, with an amp rack in the middle. Yes I could use the middle to add volume and go ported but the truck is the road warrier! The only thing kept under my seats is books, lost tools and hidden beer money! Plus, I learned that forgetting about your monster energy drink behind the seat overnight in the winter causes your amp to get all wet and gross.....whoops....

8"x16" boards (x4) two get 7" hole, two get 5 7/8" holes. Measuring the center for the speaker holes, will hide some under body panel, so left an inch on back side, measured 7.25 from front and door sides for center.

using Dremel tool to cut the holes, works great with thinner materials, going slow, bit overheats quick.....

using drywall screws to hold cut out in place, this keeps the cut out and center straight while finishing cut.

Passenger side outline completed, ready to work on the fiberglass back! speaker will be about 1" from the carpet, bit closer than I wanted, but seems to be the only place it'll fit without sacrificing leg room!

So......failures so far:
LOTS of trimming of baffles to sit where I want them, I forgot that the passenger side "hump" is taller/wider to accommodate fuel tank will have to massage the corner there just to make sure the sub doesn't make contact.
...speaking of making contact......I test fit a speaker, which fit PERFECTLY!! so perfect in fact the rubber protector around the magnet will make contact with the face board, but BARELY. like, I can get a feeler gauge in there, and it will clear if I cut a hair off with a knife, but I don't think it's necessary and I'm going to leave it be. Hole should move 1/8" toward the rear and would fit nicely!
rogue nails are from me putting one side of baffle too high on one side....had a heck of a time finding out why it wasn't square......good job me...
put ZERO thought into the amp rack, it will go in the center but I forgot to think that one through, I will likely end up putting a 11.5"x14" board in there to make everything one piece, fiberglass the edges for strength, this piece will mainly serve as a mounting point to cab.
not really a fail, but i have noticed more differences between the driver and passenger walls, I don't think the two boxes will have much (if any) difference in volume. I plan to use an acoustic tuner (band geek tools.....go trumpet section!!!) to get both boxes referenced, should be fun!

 

So the amp I got from skar was DOA! I sent it back and they decided to refund my money rather than replace it.....kinda strange to me.

So after some planning and consideration I am upgrading to Rockford amps. This is a bit more expensive than I wanted but should be higher quality!

Note: i already own the R2x500 and only had to get the 4 channel amp to complete the system.

Stereo: JVC KD-X560BT *had to drill out dimples on toyota stereo mounts*

Rockford amplifiers:
R2-500x1 (500w x1 @2ohm)
R2-500X4 (75w x4 @ 4ohm)

Sound Ordinance door speakers:
P-67CB 6.75 component speakers (rated 55w 4ohm)
P-67B 6.75 coaxial speakers (rated 55w 4ohm)

MESA :
6 channel rca cables
Rca y cable

Skar:
(X2) EVL-65 6.5 subwoofers (rated 200w dual 4ohm)

Hopefully I'll get some time this weekend to install the amps and hear my stereo finally!

 

You could've just bought a shallow subwoofer than fits under the seat.

https://www.crutchfield.com/S-XFBLLX...SAAEgLp_vD_BwE

 

I'm aware of the powered subs, but I loved the feeling of the 400w 8" subs I used to have in there, and my original goal was to get a similar system with a cleaner sound and more leg room. I believe I can achieve this by having the smaller subs free of obstacles, and not being muffled by the seat.

This IS an experiment, if It gives someone any ideas cool! If it's a fail I'm learning something new!

 

I got everything powered up and playing, super happy with the result!!

the subs clear the floor panel at full extension, nothing is rubbing, and they sound much cleaner than previous setup.

Box view with mid/high amp installed, made an angled base for sub amp to fit properly behind center console.

Both amps installed in final position

Driver side clearance

Reference measurement to back wall for seat position

Reference measurement to firewall for seat position/leg room

I'm going to run this for another month, and will pull everything out when its warm enough to paint everything and make the box look pretty, clean out my interior, and fix some more items!

with this setup I get a nice kick, good low end response (for the rock/metal I listen to), and clean at higher volume.

Hopefully i gave someone ideas on what can be done in a single cab, and maybe someone help me improve what I started! Had fun with the experiment!