Here’s something I’ve not had in decades and never in a Miata – bass. Some of my past cars had stereo systems. But since buying Sharka in 2000 I’ve been in tiny speaker land.
Tiny speaker land really isn’t so bad.
One day I was kicking back, browsing forums, and I came across an ad for a footwell speaker box. I realized that I almost never have a passenger in a Miata with me, and when I do, she’s not even 4′ tall and her feet don’t touch the ground. And it’s gonna be a while before they do touch.
Visions of speakers filled my head.
Bucky is the car being modified this time. Sharka usually gets all the love, but Bucky seemed to be eager for some stereo upgrades. Bucky is sort of my daily driver since I drive the little guy most days and drive Sharka roughly twice a week. I figured I’d get more use out of a stereo upgrade in Bucky.
The above shots are quicky “before” pix. Stock footwell, stock trunk. Nothing special.
This footwell subwoofer box comes from a guy named William, who I’ve known for damn near all of my Miata driving days. He was a member of the Yourmiata.com forum (The Darkside) back in the day. I spent all of my hours there. We’ve chatted a lot over the years. I should have bought one of these sooner.
William has been making these footwell sub boxes for years. It’s just something he does in his free time. He has no store front. You can find him under “black roadster” on most of the various Miata forums and I’ll include better contact info at the end of this post. The sub box went for roughly $150 shipped at the time of this blog post. It comes without speaker or amp.
March 2018 update
You can now order a footwell subwoofer box of your own straight from William! Go to miatabox.com to claim yours.
The box is really impressive to me. I know next to zero about building speakers or boxes or matching speakers to boxes or… well… anything about car audio. I’m truly NOT the person to be writing a car audio review, but I’m doing my best.
Anyways, the footwell box is sized to fit the NA and NB left hand drive Miatas. Mine fits in my NB perfectly, which is something I was ever so slightly worried about. They have small differences in footwell shape.
It comes with wiring, polyfill, and terminals. The box volume is .26 cubic feet. Polyfill increases the effective volume (or so I read). The front edge is carpeted.
It’s lovely, really.
I asked William for help matching a sub to the box. He sent me back a ton of links and info. In one email he more than doubled my subwoofer knowledge.
I will save you from a half-winded explanation of subs, sizing, and other such stuff and just give you the details.
I used a Rockford Fosgate P1S4-8 8″ subwoofer in this box. Mine is the 4 ohm version. It’s sized for a .2 to .3 cubic foot sealed box, so it’s perfect for the Black Roadster footwell box. It’s a 200 Watt RMS speaker, so it needs an amp that puts out something in that neighborhood (so I read).
And the little footwell box and RF sub work very well together. The sub mounted into the box with no problems at all. I highly recommend the pair.
I grabbed this 4 gauge wiring kit from amazon. It’s a “New England Providore” 20 foot 4 gauge kit with RCA and speaker cable. I’d link but at the time of this blog post it’s out of stock.
Decent wiring. Stranded copper with nice rubber insulation. Very easy to bend, crimp, and work with. I’m pretty happy with it.
The tiny silver brick on the spare in this shot is my amp. Seriously. THAT tiny thing is a 600W amp! Back in my day, an amp of any power rating was the size of a brief case.
It’s a Kenwood KAC-M3004 amp. 4 channel, 600W max, bridgable. At 4 ohm bridged it puts out 150W per channel. So it’s sized well for my little 200W sub. Or at least that’s what I read and am attempting to blog here.
If you’re interested, google it. There’s a nice youtube of this amp on a dyno putting out some incredible numbers. It’s underrated from the factory. The dyno example put out 730 watts. That’s… insane. This tiny phone sized thing? Yeah. Technology.
I looked all over the trunk and settled on the fuel hose cover as a mounting spot for the little amp. I wanted to put it in the passenger side tunnel, but that seemed a little hard to access. I still might shove it back there, but for now it’s mounted on the fuel hose cover.
Nice thing about mounting it here – I can easily find a replacement cover if I want to remove the system or move the amp. No permanent holes were drilled. It’s not often that I can say that about any given Miata project.
Wires. I cut them, I crimped them, I mounted them to the car. Nothing much to say about it. I used one of those hammer crimpers for wires above 8 gauge. Just a cheap one from amazon that I ordered with the wiring. It didn’t make the prettiest crimps, but it worked!
I could have probably done a better job making the wires pretty on that amp install. Alas. It’ll give me another Miata project a few months in the future. I need to look at some pretty amp install pix.
The footwell box wedges in there solidly. It does indeed take away foot room. My legs don’t stretch out in the passenger side anymore. But the box also comes out easily and can fit in the trunk for a quick trip with a passenger.
With the floor mats installed the sub just disappears. I love this! Stealthy even if you’re looking dead at it.
Now, the several hundred dollar question: how does it sound?
It sounds great. The amount of depth this little sub adds to any given song is truly impressive. It’s very clean bass too. I’ve got things tuned to not really distort. It sounds fantastic.
There’s even bass with the top down while driving at freeway speeds. THAT is something you rarely get from a trunk mounted sub. When the top goes down, your bass goes away. But with the footwell sub, your tunes stay rocking.
I’m really impressed by this upgrade. I should have done it a while ago. I just didn’t take the time to think who my passengers usually are. For the next 5 or 6 years, my copilot won’t have a problem with leg room.
If you want to get one of these footwell subwoofers, reach out to William. He’s…
–black roadster on Miata.net ClubRoadster MiataTurbo, MazdaRoadster and other forums.
–blackroadster96 on Facebook
–blackroadster on Instagram
and can be emailed at blackroadster96 at yahoo dot com.
Thanks for the box, William! And for all the help finding a speaker and amp for it.