Subwoofer in a Miata?!?!?

jersey_emt

Member
:
04 MSM #1089
Yeah, it might sound crazy, but I want to put a small sub & system in my Miata. After researching, I've decided against putting a sub in the trunk, because (a) it supposedly sounds like crap, and (b) I don't want to lose 0.75 cubic feet of trunk space.

A popular option is to install 2 small (6-8") free-air subs on the package shelf behind the seats. I've decided against that because I've never heard a free-air sub that sounded good enough. Plus the install looks pretty daunting, you pretty much have to take a good portion of the interior apart. I want something I can work on a bit at a time, the free-air sub install pretty much has to be done all in one shot.

Here is my plan:

Take out the spare tire and build a false floor for 2 amps (one 2-channel for front components, one single-channel for the sub). Yeah, I'll lose the spare tire, but not any trunk space. Works for me.

Build a custom sealed box for (1) or (2) 8" subs, placed on the package shelf behind the seats. I would have to remove the windblocker for this to work. No big deal. The speakers on the windblocker suck, and the sub box would function just as well as a windblocker.

I only have about 6" of depth available to not interfere with the top. I don't want the box to be too tall to not block rear visibility. The windblocker looks to be about 10" tall (it's about 11-12" 'tall' but it is angled back a bit). I wouldn't mind going a *bit* taller than that, but lets say the box will be about 12" tall.

The box would be the width of the car minus ~6" on each side, this is to allow for a rollbar install in the future.

Most 8" subs I've looked at require 0.3-0.5 ft^3 of volume in a sealed box. I think I may be able to pull off having (2) 8" subs, but I have no problem using only one if space doesn't permit. If it's close, I could always put some polyfill in the box.

Now, I'm not concerned with ground-shaking output, just something to 'fill out' the bottom end. This is why only (1) or (2) 8" subs will suffice for this.

I was looking at Kicker CompVR's, and Polk/MOMOs.

Anyone have some advice? Or is my plan ridiculous and stupid?
 
Last edited:
I like both subs you mentioned, You may even be able to fit the new JL w1 series as they are shallow mount. AE makes a very shallow sub too.


However, if its a 94-97 miata, then the work has already been done for you.
http://www.jlaudio.com/stealthbox/miata.html
I didn;t know if perhaps this was for a different miata then your MSM.

Can you take a few pictures for me so I can get some ideas?
 
1sty said:
I like both subs you mentioned, You may even be able to fit the new JL w1 series as they are shallow mount. AE makes a very shallow sub too.


However, if its a 94-97 miata, then the work has already been done for you.
http://www.jlaudio.com/stealthbox/miata.html
I didn;t know if perhaps this was for a different miata then your MSM.

Can you take a few pictures for me so I can get some ideas?

I saw that JL stealthbox but unfortunately this is for my MSM. I also wanted the subs to be facing foward, as I am thinking about putting my car into a few shows this fall or next season. Yes, I know having an exposed audio system is questionable for a convertible, but I have an idea to hide them when I want to....some matching carpeting, with the 'Miata' logo embroidered on, with velcro attachments to cover the front of the sub box.

I'm going to take some pictures & measurements this weekend and let you know.

Any advice or suggestions is much appreciated :)
 
Last edited:
12" = way too big. The total height of the box needs to be 12". MAYBE 13". Even a 10" sub is cutting it pretty close, hence my decision to go with 1 or 2 8" subs.
 
Don't know how much room you have in the passenger footwell, but a trick I've used in a few convertibles was to build a fiberglass enclosure in the passenger footwell and up under the glovebox, leaving room for movement of the glove, with the lower edge of the box going rom the bottom of the footwell up at and angle to the lower edge of the glovebox, sort of like a triangle. I've done this quite successfully on old Porsche 914s and a few 911s, as well as some older MGs. Best part is that it becomes almost invisible when done. You do lose a little foot room in some cases so you have to see if you have the space for it.
 
6W0 requires .175 cuft. I've got mine in a FG box almost double that size and it thumps incredibly for the size. 2 or 3 ofthose would be pretty good for a vert and could be easily hidden.
 
LOL. Well, if you get a flat, you'll have some good thumpin' to listen to while you wait for the tow-truck!
 
I saw several Miata's at the MOM meet last tear in Toronto with subs in the drivers footwell, like Greg S mentioned. It lets you run a real sub.
 
jersey_emt said:
I saw that JL stealthbox but unfortunately this is for my MSM. I also wanted the subs to be facing foward, as I am thinking about putting my car into a few shows this fall or next season. Yes, I know having an exposed audio system is questionable for a convertible, but I have an idea to hide them when I want to....some matching carpeting, with the 'Miata' logo embroidered on, with velcro attachments to cover the front of the sub box.

I'm going to take some pictures & measurements this weekend and let you know.

Any advice or suggestions is much appreciated :)

Yeah, don't do that.
Build the subs down firing but with 2 windows cut into the box so you can see the magnets and mirrored plexi under where the subs fire toward so you can see the cones. You can then build covers to hide it all when not showing so window shoppers are non the wiser.
 
1sty said:
Yeah, don't do that.
Build the subs down firing but with 2 windows cut into the box so you can see the magnets and mirrored plexi under where the subs fire toward so you can see the cones. You can then build covers to hide it all when not showing so window shoppers are non the wiser.

Why have them down-firing opposed to front-firing? I would assume because the drivers would be only about 20" from my head, but I figured I could adjust that using the gain on the amp.

Unless there is some other reason?

This will be my first custom box, so I was trying to keep it simple. Of course if there is a really good reason why I should go with downfiring subs with windows, then I'll go for it.
 
2 reasons, one nothing can puncture them accidently and no one can see it while its parked. You don't have to do plexi, just do a plan box that is carpeted. This way when you go to shows, you will have basicly hidden bass that no one can see.
 
I was behind a Miata today that had subs. My system wasn't on yet and I could feel them pounding in front of me. Days like today make me wish I wasn't too tall for the Miata.
 
I just put my Jl 10w3 sub and 250/1 mono amp in my msm. I put it in the trunk and used a truck box (.65 cubic feet) and it works pretty well imo. I may build a box so I can mount the sub level with the trunk floor by taking out the spare tire. The sub hits as hard as in my msp so I would not worry about putting it in the trunk.
 
maybe you could mount a small box to the roof of the trunk on the inside if it is one large enough.
 
a friend of mine installed this..maybe not a good solution on a NB, because of the glass rear window...
pict0013.jpg


another solution..

http://www.miata.net/hakuna/subspeak.html
 
Last edited:
Having owned a '94 Miata until this Feb, I can sympathize with your delima on the subwoofer for a Miata. I originally tried to Rockford 8" subs in a custom box on the parcel shelf of my '94, but with the top down at speeds above 35 mph I couldn't hear it. I was really disapointed, so I took it out and abandoned the idea of having any bass in my car for a while.
Then I tried a footwell sub using a cheap ($35 shipped) MTX off ebay. I figured if it sucked, I only wasted $35 and some time making a simple box. So I made a small box for it, stuck it in the car, and it kicked a$$. I only got to use it in the winter time with the hard top on, but it really pumped out a huge amount of bass for such a small speaker/enclosure. I was impressed, and happy to have bass. Don't know how it would sound w/the top down @ 80mph, though, 'cause I traded it in before the weather got nice. You could give it a shot....
My old cardomain site
 
i knew a guy that molded an 8 into his center console(into the side if it so the speaker was facing the passenger leg area) of his 914 I think it was could that be possible for the miata
 
Back