UD Sub Install Guide

[stargazer30]

Hi Everyone,

I've created this how to help anyone wanting to install the Under Dash (UD) Sub on the UK MR2.  The instructions that come with it are Illustrated by our friends over the pond and are for LHD cars so basically they show the wrong positions for the brackets and it makes the job much harder than it needs to be.

I'm using one of NathanMR2's UD boxes here and the associated hardware supplied by him.  For those who missed it NathanMR2 is making/selling the boxes on his thread here; http://www.mr2roc.org/phpBB3/viewtopic.php?f=36&t=34566

So before we get going why do you want to even want to buy and install one of these? £80 box and a 6.5" Sub costing £100 - meh!  s:mrgreen: :mrgreen: s:mrgreen:   Well I've tried several MR2 Sub installs ranging from big subs to little ones, active ones, different box locations in the rear bins etc.. This is quite simply the best one yet by quite a margin.   s:bowdown: :bowdown: s:bowdown:   The reason is the location and the fact it fires up into the dash, which means its takes advantage of something called corner effect.  This means more bass from an 8" sub, but more importantly it means decent bass with the roof down.  Every install I've done to date suffers and looses bass badly once the roof goes down, but this one thanks to the location of the box still works.

So heres the Sub box.  I asked Nathan to send one uncovered as I prefered to cover it myself, without the felt you can see the work needed to build one of these, they're fairly complex given the shape, all the fittings and drill positions needed.




First job is to strip off all the hardware and cover it up.


Given its shape I couldn't do it with one bit of felt, I had to use two. The first bit does the top side and back.


Then the second does the other sides.   Next add the hardware back on.


Note the box needs to be filled with fibre wool (which is supplied) I just took it out for the pics.

Heres the Sub I've used.  Its a unbranded ebay Sub for £30.  s:flame: :flame: s:flame:    Its no JL but it has a decent magnet on it, a high RMS rating and extends into the mid bass range well.  The JL sub would be better though.


Next the Sub goes in the box.  Theres an oversized washer and long bolt that needs to be added (from the inside out) before you put the sub in as described in the instructions.


Okay now its ready to go in the car. From here on in you can follow the instructions that come with the sub but use my photos to show the correct bracket positions.

1. The first job on the car is remove the knee panel.  This is pretty easy just be careful unclipping the OBD port and alarm LED.
2. Remove the drivers side plastic trim on the sill, I didn't I just clipped it up at the end
3. Remove the kick plate as described, again easy.

Okay heres a pic of the footwell before the install.  That big void is going to be filled by the sub.  The red box is the BCM which will be moved.


4. Carefully unplug the BCM and unbolt it, put it aside.

5. Next we need to relocate this relay on the right hand side


It takes a bit force but it will pop out.  Then I unclipped both relays from the plastic housing and tie wrapped them in the kick plate space out the way.

6. Now Install the long metal bracket.  Look up and you'll see the long metal bar with 2 x 10mm nuts on long bolts.  Ignore the instructions the bracket goes on the far right hand side nut here.


The bracket faces toward the driver and needs to be angled like shown so its facing toward the door slightly.  Tighten it now as you won't be able to later. It is easier if you leave this a little loose in order to get its positioning correct before doing it up. Providing you have a long reach socket you should be able to reach to tighten while everything is in situ

7. Next add the speaker wiring to the sub box.

8. Mount the BCM to the sub box, the holes are pre drilled.  Like this.


9. In the pic on the instructions it shows the other larger bracket mounted to the box near the BCM, this is wrong it doesn't go there.  Instead mount it to the base of the box near the edge.  The screw and hole are already there as in the pic above.  Don't tightening it much yet. It is far easier to connect the bracket to the car (where the BCM unit was) and do it up tight before you lift the box into place

10. Unclip the spring off the brake pedal, don't worry it goes back on.

11. Now have a cuppa tea as the next bit can be a pain!

12. Okay you have to lift the sub box into position now. It will be a tightish fit but with it correctly angled it will go in nicely. Be careful not to catch your sub on anything when sliding it into place  The sub faces up into the dash, the BCM faces the drivers side door/hull of the car.  The long bolt is going to go through the hole where the brake spring was like this.


The long bolt goes in first, then angle the box up into the cavity.  The long metal bracket at the front should locate onto the shorter bolt on the now front facing side of the box.  Like this..


This is tricky but if you have the brackets right it'll go.  Make sure the top of the box is pretty much touching the metal bar the long bracket is bolted to.  If its too low the knee panel won't go back on.

This was my first attempt at it and its too low, notice the bolt and bracket, in the pic further up its higher.  This pic is a good one to show the box mounted from a distance though.


The larger bracket should locate now where the BCM was initially bolted to like this..


13. Once your happy its located correctly, tighten up all the bolts up on the brackets and the screw in step 9. Remember to put the brake spring back onto the long bolt!

14. Plug the BCM back in.

15. Run the wiring through the kick panel space and door sill trim.

16. Now you just need to replace the knee panel and kick trims you took off.  The knee panel needs a little bit of the plastic trimming off as in the instructions.

Job done!   s8) s8) 

Finally heres my old sub.  The box was about the same size as the UD box and its the same sub (just a black one)  Doesn't sound nearly as bassy though!

I had tried this box with the JL sub and it rattled the **** out the rear bins   s:lol: :lol: s:lol:

[nathanMR2]

Thanks to stargazer30 for the write up  s:) s:)  After the time taken to build the boxes i hadnt had chance to do as he has done so this should hopefully help people out.

I hope stargazer30 doesnt mind but ive added some more information in red and tips to help out as ive had these in and out the car a few times.

As ive mentioned before for anyone whos a little worried about fitting and you can get to me im happy to help with your install

[Anonymous]

Nice, do you have any photos of how the UD looks when in?

Do you have any more of these for sale? I would be very interested in one...

[manchestermatt1986]

Im thinking of doing this, does the bass feel more one sided in the car thou? as in the drivers nodding there head away but the passenger cant hear/feel it as much?

[stargazer30]

I'm thinking of doing this, does the bass feel more one sided in the car thou? as in the drivers nodding there head away but the passenger cant hear/feel it as much?

In a word No   s:lol: :lol: s:lol:   The human ear can't locate sounds below 80hz, thats why you only have one sub in a home cinema setup but have 5 speakers.  Infact you don't actually hear the sub as much as you feel it.  Thats why its such a git to do bass in an MR2 as once the roof goes down the sub is fighting a loosing battle as it has no enclosed cabin space to pressurize.  The UD box in this thread is as good as it gets as it uses the enclosed space under the dash to get around this.  So net result is tight, punchy bass roof up or down.

Oh to revist this thread I recently upgraded my ebay sub to the 6" JL (thanks Nige   s:P s:P  ).  The JL sub hits harder than the cheapy ebay one I had been using, really impressed with it.

[dansage]

Just installed one of these with th JL sub and have to say its pretty awesome!

[pill20]

Ok I want one!! Lol any still for sale ??

[pill20]

Ok I want one!! Lol any still for sale ??

[no1trancefan]

i want one too

[ais]

i want one too

markiii had been producing them - this one may be(?) still for sell in the private sales:
 l viewtopic.php?f=37&t=42940 l

I have one so can vouch that this is the best bass solution

[trickyD]

Can this go I the how to section please? Took a while to find it