My New Subwoofer Install

Hello All,

On Saturday I finished installing my new subwoofer. Now this isn't normally a big deal, but there is little space for a sub enclosure in a supra and even less space when you have an aerotop as the roof is stored in the boot. In fact, there is no room in the boot when the roof is stored away in there.

After seeing what Lee (SRD) did with the space in the spare wheel well on Jamie's car, I decided that I'd ditch the spare myself and build an enclosure in there.

Before the sub, I had my rainbow speakers (FL, FR, RL and RR) running from a Kenwood Amp. I decided that I wanted to stick with Rainbow for the speakers and purchased a Rainbow 12" Hammer sub. To power the Sub, I purchased a second Kenwood Amp.

In order to get the required volume in the sub enclosure, I came up with a pretty tricky solution that would provide the required air volume but also be easy to remove if necessary.

The first thing to do was remove the boot trim and the stock subwoofer enclosure:

I used the existing bolt holes to mount a square section of MDF. This will be where the enclosure will be fixed to for stability. As you can see from this picture, the main obstacle in building the enclosure is the hump (technical term!) for the spare wheel, which also houses the fuel pump below.

The first thing I did was construct what would become the new base of my boot space. I did this using a cardboard template to ensure the fit was right before I cut the shape out of the MDF:

Without much margin for error, I cut a hole for the subwoofer to sit in. This area sits above the largest space within the wheel well (bottom left as you look at it from behind the car). I did want to mount it to the top right, but there just wasn't enough room for the 12" sub.

I couldn't afford to build around the hump, as the enclosure wouldn't have the required volume of air, so I decided to utilise it as a wall of the enclosure (sort of).

So I measured and cut what would be the base of my sub enclosure:

Which fitted as so:

Utilising a sheet of 3mm thick rubber, strong adhesive, flexible silicon and 13mm staples from my nail gun, I created this seal that would sit around the hump. When the sub is dropped in to the wheel well and pushed down, the rubber forms tight seal around the hump. Sort of a like the action of putting a jonnie over the helmet

The next step was to construct the rest of the enclosure. Using lengths of MDF I had cut at a local timber merchant (to ensure perfectly straight edges), I constructed the rest of the enclosure:

And this is how the enclosure sat in the wheel well:

I added a terminal box to the side of one of enclosure walls to ensure easy of removal when necessary:

Silicon sealed from the inside:

With the enclosure complete, I placed my new boot floor over the box and transposed the sub hole onto it (the enclosure is slightly larger than the boot floor as it sits underneath the plastic boot trim – again, so it can be removed easily enough when necessary).

This photo shows the sub hole in the enclosure, along with the wiring and the silicon seals around the joins:

And now with the boot floor on:

And the final step was to mount the sub and wire everything up (this was done by my auto electrician).

As my Kenwood head unit has a pre-out for each speaker, everything is controllable via the head unit. So the sub can be turned off and the levels can be altered when it’s on (I’m still trying to get around it all). I’m really pleased with how it turned out. The sub is rather powerful, so I’ve set it changed the gain to something like -7 decibels for general use, which seems to have tamed it to a level where it adds a bit of thump but not enough to p!ss the general public off.

Nicely done

That's a pretty impressive install, Matt. Nicely done

Looks good, but i bet its weighty.

Great work!

I'm looking at doing a similar install on mine as I also have the roof storage to think about

Nicely done. I'm never sure whether I want to lose my spare wheel, but I appreciate the appeal and the work that has gone into this.

Is there room for another next to this one? Or is the enclosure too small?

Looks good, but i bet its weighty.

That stock subwoofer enclosure isn't light to be fair, but it's not light no. The sub is heavy on its own, let alone the enclosure.

Nicely done. I'm never sure whether I want to lose my spare wheel, but I appreciate the appeal and the work that has gone into this.

 

Is there room for another next to this one? Or is the enclosure too small?

It's a tough one about losing the spare wheel, but I'm not actually too sure how much use the space saver actually is in my case. It's questionable whether using a spacer on my car will result in the body work being dangerously close to the pavement. Thankfully I've never had a flat in the 6 years of ownership.

As for a second sub. I don't think another 12" like mine would fit in. Even if it did the enclosure space would be on the small side for it. With that said, two 10" subs would probably work? Due to the obvious difficulties, I don't know the exact air volume in there, but it's approx 30 litres.

That looks good Matt.

When I eventually get round to doing mine, I definitely want the spare wheel back in, as forking out another £400 at the side of a motorway doesn't appeal much.

I'm going to put two Raptor 6" subs in where the stock sub normally goes. I've removed the plastic enclosure area, and they could easily go into that space in a tailor-made box. The amp would either sit between, or in the spare wheel area.

Garfy has the Raptor 6 subs in his Supra, and they have an unbelievable stunning deep bass sound.

good write up and nice build mate - i like it when people go and try things themselves, i wouldnt know where to start

Great install, but you need matching amps

That looks good Matt.

 

When I eventually get round to doing mine, I definitely want the spare wheel back in, as forking out another £400 at the side of a motorway doesn't appeal much.

 

I'm going to put two Raptor 6" subs in where the stock sub normally goes. I've removed the plastic enclosure area, and they could easily go into that space in a tailor-made box. The amp would either sit between, or in the spare wheel area.

 

Garfy has the Raptor 6 subs in his Supra, and they have an unbelievable stunning deep bass sound.

good write up and nice build mate - i like it when people go and try things themselves, i wouldnt know where to start

Cheers Jamie. There was a lot of head scratching to be fair, but it all seemed to come together as I got stuck in. Half of it is having the right tools I think.

Great install, but you need matching amps

Thought someone would pick up on that I've had the multi channel amp for a while (far one) powering my corner speakers and they don't make that model anymore. If it's any consolation, they're both Kenwoods!

Great work Matt !

Looks great , buy those halfords repair kit spray.

Perfect timing I was fixing to get stuck in some fibre glassing but this is much more efficient and less messy..! Excellent...! :-)

buy those halfords repair kit spray.

What for, Jazz?

What for, Jazz?

Your tyres incase of a puncture

Your tyres incase of a puncture

Ah!

What for, Jazz?

I think he means for tyre repair.

The blow out in mine was around 4", and started to shred at the rate of leptons I was going, so no spray was going to repair that, unfortunately.

Your build is very nice Matt. I've currently got that kind of thing in my car, but I won't go on a long journey without my spare, which has to sit on the back seat. Nice.

Very nice, love those curtains too.

that looks great matt how many hours did it take you?

Great boot build wish i had the skill to do something similar as really like that

If you want, you can buy fibreglass sub boxes from the states that still allow you to keep your spare wheel in the aerotops, either single or twin 10" subs. That is what I did (although I still chucked my spare wheel as I had to find somewhere for 3 amps and the distribution blocks as well )

If you want, you can buy fibreglass sub boxes from the states that still allow you to keep your spare wheel in the aerotops, either single or twin 10" subs. That is what I did (although I still chucked my spare wheel as I had to find somewhere for 3 amps and the distribution blocks as well )

Linky?

Linky?

http://www.ebay.co.uk/itm/TOYOTA-SUPRA-FIBERGLASS-SUB-BOX-ENCLOSURE-2x10-MAGICBOX-/350284875164

They do a single sub box too, pricy I'll admit but mine fits perfectly and was really well made, delivered quick from the states too. Its an option if you want to have something custom but haven't got the skills to fibreglass (I haven't!!!)

Not really sure. Actual build time didn't take that long, but planning and getting materials etc was time consuming. The hardest bit was getting the shelf / boot floor right. If you had everything to hand you'd get it done in a day easy