Subwoofer in an Access Cab... The Right Way

This is a quick little thread showing you how to fit a 10'' subwoofer under the rear seat of a 1st gen access cab. This has been done before but really hasn't been covered in detail.

These trucks have no room whatsoever, so I had to get a little creative and throw it in the passenger side storage compartment, with the amp under the seat. This actually turned out pretty good, and sounds fantastic, but does get a tad annoying if you are constantly hauling more than 3 people around. If I could go back in time I would have just bought this. But if you are on a budget, the way I am about to explain is the way to go.

Here's everything you need. A shallow mount sub and amp of your choice, 1/4" MDF, some wiring (copper if you want the best sound) and, most importantly, a decent amount of sound deadening mat. Generic works fine,

$30 Noico 80 mil 10 sqft car Sound deadening mat, Butyl Automotive Sound Deadener, Audio Noise Insulation and dampening

here's where I got mine. Also going to need some stainless hardware, and some felt and spray adhesive, and fiber filling. I had an old amp laying around, and everything else cost me about $200.




First step is to cut the MDF to the size of the storage compartment lid. Then cut the hole in for the sub. After you have the cuts and sized perfect, you can cover the MDF in felt or carpeting. I got mine from JoAnns. Also, if you want be a little bit extra, you can get some foam tape and put it around the bottom edge for a better seal.



Now here comes the hardest and most time consuming part. After pulling back the carpet, you will see that the "compartment" completely littered with holes. YOU HAVE TO COVER EVERY SINGLE ONE WITH THE SOUND TAPE IF YOU WANT THIS TO SOUND GOOD. There are gaps everywhere, even towards the back where you can't see. Use a pencil and poke around to find all the gaps. Fill them with the sound deadening tape. This is honestly the step that made me regret doing this whole thing. However, if you have the time, and have limited budget, this is still the way to go.



Now I ran my wires to the other side of the truck, because I only had a power cable long enough for the amp to be under the drivers side. You can really run it to either side, under the carpet, then under the plastic trim, and out to wherever it needs to go. There are countless videos on YouTube that can help teach you how to wire a sub and amp. Just give yourself a little slack.


Now you can start putting everything back together. Carpet gets tucked back in under the the floor trim, and then pack the compartment with fiber filling. The filling makes the subwoofer operate like it is in a larger enclosure. Connect your wires to the actual sub, and then use your hardware and screw down the MDF. You can use the existing holes, and drill a couple more if you want.



Here's the final product. I ended up taking the grate off because it was digging into the seat when it was down. Now I just turn the sub off if I have people sitting on it. Turned out pretty decent, and the sound is great. Most importantly, it looks like it somewhat belongs there. No exposed wires or any other loose ends. This was my main concern when beginning this project, and is why I took the extra steps to make it come out better.

 

Nice work. Thanks for taking the time to write this up.

 

Good content. As someone who went with the Q-Logic dual 8 setup (pics of my install), but I'd love something more like this.

Some questions for you, if you have time:

As far as airspace goes, what is your actual vs. recommended on the sub?

Is there a reason you didn't under-mount the sub on the bottom of the MDF so the cone has more cone travel ....

Or any reason you didn't under-mount the baffle board inside the compartment vs. outside ...

Or under-mount the baffle board and the sub for extra-extra throw and allow the seat fully down?

I realize you're sacrificing airspace with any of these steps, but you can easily remove the metal cage, so bolting the baffle to the cage and/or under-mount would be no big deal if your 10" sub was made shallow-mount and-or shallow overall profile as-is.

 

It's hard to see in the pictures, but the bottom of the compartment is angled. I thought about mounting the sub or the wood under instead of over, but there is absolutely no room. Even with it mounted how I have it, the end of the sub is like 3mm from touching. As for airspace, I did this about 4 months ago, so I don't remember exact numbers, but the weird shape of the box made it hard to measure. I am pretty sure it was something close to .75cu ft. The sub states it needs 1.0-2.4 cu. ft. to operate properly. But even with the lacking space, it works just fine.

 

That's the hard part of putting a 10 in there. I've been eyeballing the Infinity shallow 10 and the JL shallow 10, they only need 3.25" depth I think, where the Polk is closer to 4.25"

 

You can always add poly fill to disrupt the air behind the driver to simulate larger airspace for your sub. Cheap fix. More info from the most neutral voice I can find : https://www.crutchfield.com/S-Edxy5rMaZpV/learn/loudest-car-subwoofer-faq.html#14

Also, something else you can consider, we used this to give a flush-mount appearance: Cut the hole in your baffle large enough the sub cage and mounting flange will slip through it Then cut an MDF "donut" with the inner diameter perfect to mount your sub, and outer lip large enough to glue it in and fasten to the underside of your baffle. This will buy you depth as thick as the MDF you chose, usually 1/2" - 7/8" depending on what you chose. You may not have much lip at the north and south.

I went with two Kicker CompRT 43CWRT81 which require a little less than 2.75" depth. Sadly I looked at their 10 and it's looking like it's 3-7/16 mounting depth.

I really think 8s are the sweet spot for access cabs. I'd prefer a single 10 or 12, but I'm not complaining with two DVC 8s. My HD900/5 arrived a few weeks ago and 4ga wiring supplies should be here in before December, hopefully I can finally get around to getting them wired up.

 

Not to thread jack but...

Good choice, I have an RD 900/5 waiting to go in. Around the house stuff has been getting checked off little by little and that project might start in December as well if I can get my garage cleared out. Will be interesting to see different builds around two similar amps. I have some tricks up my sleeve for the sub.


I ran a single 12 for over ten years and regretfully with age comes the "what the hell am I doing trading a seat for a sub box" question. Besides my wife doesn't let me bump so I pulled it out last year.

 

That one was a Hanging Curveball.

 

Pulling out isn't a viable solution for ... wait, what were we talking about?

Ultimately, space being a premium is why I ended up with this 8" amplified MTX that I never ended up installing in my Camry. Despite being brand new/unused, I can't even sell for 1/4 what I paid for it, it's sad, this specific unit kicks. Sad times. But I sold off my older (but near-mint) JL amps to bmf and an old PG power grid that netted half what I needed for the new HD900/5. I'm in the same boat with house stuff; I'm hoping to start my install by mid-ish December. I think I'm installing the amp under the passenger seat, I need to think through how I'm going to mount it. Maybe I'll come back to this thread later and post mine to show other options.

 

I went with the Q logic and Alpine drivers. Really feel like this is plenty for most music. I made a grill that is not in the picture below but is just a piece of wood that goes across and allows someone to sit in the seat and not dig into the cone.

 

I am looking into this type of set up as well. Did you have to do any cutting or trimming to get this to fit or is it essentially plug play right into that storage area? Thanks.

 

Basically plug and play other than some carpet slicing to get it to fit. I am very happy with the setup. I also added a wooden brace across the top of the sub because when a passenger sits in the rear seat it sags enough to hit the sub. I could not find any premade covers that worked so just some scrap wood did the trick.

 

Interesting. Last time I tried to build an MDF box and fitted it inside instead of using fiber filling. It worked but I got a bad vibration when I turned it up, so I returned the 10" JBL sub and tossed the box I made.

Never revisited it since with tinnitus my ear can't stand even moderate levels of low bass for a long time. Although it was fun to pulling up next to a ricer with a wing in the back at a light and blare the opening to "Enter Sandman" where you got the full effect of the bass.

 

I ended up going with pretty much same setup as @1stgenike utilizing a 10" JBL. Sounds pretty good and zero rattle on my truck though I didn't do the sound matting but i also don't have it cranked as I'm not 20 anymore haha.

The grill - i am also looking at that grill but specs indicate it's about 1 5/8" in height? Does that sound right? I'm thinking this is too high as the sub itself is already higher than the original cover. Are there any other recommendations for a grill?

Thanks.

 

I actually ended up just taking the grill off because it was definitely too tall. It really dug into the seat when it was down, so now I just turn the sub whenever I put the seat down.

What I thought would be the best plan would be to build something like this, that goes over the entire sub area and fits the seat bottom when placed down. The seat will not lock in the down position with this idea, and it will sit about an inch higher than the single jump seat when both are down.


Basically two 1/2 inch thick triangle supports spread as far as possible, with angles that allow a sheet of 1/2 wood to be placed on top and not hit any park of the sub. Add some carpeting to make it fit in. (Also I spelt towards wrong lol)

I figured this would be the answer to the sub still working best while the seat is down, and allow the seat to have a full platform to lay on so the leather isn't creased. I rarely have more than 2 passengers in my car, and I went back off to school, so never had time to actually make this, but I don't see why it wouldn't work.

 

Great idea and thanks for that. I thought of something like that as well but I was more going to just cut out a template similar to the subwoofer template but with a larger opening and then getting one of those flatter grills for protection. Guess it's another project...

 

How is the sound with the seat down? Does that hinder the performance of the sub? What if you have a gap between the seat and the sub? I figure if you have an air gap then the sub should work as intended with no issues. I was thinking you can mount the wood inside the enclosure and mount with some T-nuts and spacers to lower the sub further into the enclosure. By doing so the seat wouldn’t touch the sub. Does this math make sense? I don’t know please correct me if I am wrong.

 

What a great idea and project write up. You do good work, and the write up shows it!
Having just redone my audiosystem on my AC, I can appreciate the work you have done!
Thank for your post!

 

I believe they are called type R. I recently replaced the 6.5s with new stereo integrity 6.5s which match my SI tweeters. I spent about 3 hours giving the DSP a tune yesterday and this system rocks!

 

There are 3 ways when it comes to doing things:
1) The right way
2) The wrong way
3) The Mamba way
This is the latter

A traditional 10 cannot be under-mounted as the magnet will touch the floor. With everyone mounting theirs above the cover, the seat gets in the way. I built a cover that flush mounts the 10 using the trim for the storage opening. This allows the 10 to fit and the seat to close without touching the 10. I didn’t have enough solid material from the confiscated taco box to build a cover so I just screwed 2 wood strips to the side to support the seat. Very happy a hides nicely. I mocked it up first using the busted 10 and then swapped in the good one.

 

I'm gonna take a wild stab and say you can absolutely undermount, but you need a shallow-mount sub. There are plenty on the market! But cool all the same!

 

I just use the free to me stuff

 

Reading comprehension > Me.

I can't get past pretty pics sometimes

 

We all like pics

 

I dunno, that @bmf4069 guy, I don't think he likes pics much.

 

I couldn't find a good meme to respond with.