Performance-tire Subwoofer

Around 5 years ago I started building DIY-speakers and at some point I got bored of cube-shaped subwoofers and decided it's about time for me to have something really unique. Since I had a pair of used high-performance tires (315/30 ZR18!) I thought I'd give it a try. Unfortunately I built the subwoofers a few years ago and didn't picture every small step. However you should be able to get a good understanding of the process :-)

Step 1: What You Need

First of all, the shopping list:

- 1x Used high performance tire (the wider/bigger the better!): ~ free, if you kindly ask a tire-store

- 2x MDF/wood plate (depending on the tire diameter): ~5€

- 1x sikaflex glue: 5-10€

- 1x Mivoc AW3000 12" Subwoofer: 50€

- 1x Mivoc AM80 (80W Amplifier): 90€ (or any other subwoofer amplifier)

- 1x any Speaker-Terminal: 5€

- Screws

- 1x expanding foam: 5€

- optional: carbon fiber or carbon fiber optic foil

- speaker cable

Tools:

Power Screwdriver, gloves and a jigsaw (or even better a router with a circle-tool)

Step 2: Planning

Depending on your tire you should have a volume of around 30-40 Liter for your subwoofer which is suitable for the Mivoc AW3000. I've build different versions (closed and vented cases) of the tire subwoofer and with the Mivoc AW3000 I preferred the closed version (which is also easier to build). I did simulations before the build, but unfortunately didn't save them. If you want to do the math: the AW3000's parameters are available here.

Step 3: Build!

The buid itself is rather simple (see fotos).

1.) clean the tire

2.) Use the jigsaw or router to build the adapter plates for the speaker and the terminal

3.) Force the plates into the tire

4.) Use the screws and the sikaflex glue to mount the plates to the tire

5.) (not pictured): Use the expanding foam inside the tire to give additional strength to your speaker. Otherwise it might 'wobble' under power ;-)

6.) mount the speaker and the terminal and connect everything with speaker cables

Note: you might also mount your amplifier on the back of your subwoofer, but in my case this would have decreased the inside box volume so I devided to have the amp as external device and keep the subwoofer passive.

Step 4: Enjoy!

Be warned: People will immediately recognize you are a crazy gearhead (That's the male version of the crazy caat lady I suppose)... :)

Step 5:

Comments

[Shah syed Imran]

Tell me about the performance,
Is it better than the wood or mdf

[BlackieL]

That is an awesome idea bro! Thanks!

[gregg miller]

Too Cool!!! These will draw a comment no matter where they are! I found this site while looking online for a box calculator and I am hooked! I am blown away by the quality and craftsmanship I see evident in every project. I am recovering from a Ischemic Stroke "bad one" and I feel that if I'm careful I can feed my creative monkey and rehab at the same time. It might not turn out perfect, but I'll try not to destroy too much material in the process. It just happens that I am a Car Audio enthusiast and I have several sizes and types of sub woofers and amps at my disposal. I've got a burnt out Hoosier drag slick tire and some 1/2" and 3/4" MDF lying around 3/4" for the baffle and 1/2" to line the tire with as this sub will be in the 500 watt range. I first cut the 1/2" into 5"x 11" pieces to line the tire on the inside of the tread and used great stuff foam, latex gloves and manual hand power to smooth and place all the panels it took two days as I had to let it dry and setup before rotating for the next set of panels. It came out solid and I am sure it will perform well I then used some 1/8" medite and foam wearing gloves once more...

What a mess!!! I haven't got any on the outside of the tire yet but I'm sure I'll meet my expectations on that. Day 3 I've let it all dry and it is very strong but at this point the darker side speaks... Why not use that 12" over there? No not that one , the other one with the really big magnet! "What"I say... the Power Acoustic MOFO12X... why not, it really is a cheap sub and I'm gonna put it in a tire after all...

I begin by measuring the tire inside and cutting a 1/2" MDF strip then cutting it into 3" sections, a lot of them. I don latex gloves and begin placing the sections into the tire, allowing them to set before placing the next few. As the tire rotates I realize the sidewalls will also need some work. After all the sections are in I cut some 1/8" medite to cover as much of the sidewalls as I can. I then let it dry awhile, and cut the back circular panel and decide to brace between the sidewalls as well so I cut some 2"x 2" studs to length. Once dry I force the sidewall braces into the tire and foam in the rear panel using silicone on the bead and 1.5"drywall screws to pull it tight. I then put on a fresh set of gloves and use foam with a small piece of spatula shaped wood to smooth out and fill any irregularities internally. The tire needs to dry at this point so in the morning I check and it is solid. I then use some fleece strips and polyester fiberglass resin to secure the braces, as I wait I just pour some into the tire and rotate it to spread it around. I've added enough resin to coat the medite on the rear sidewall, back panel and outer circumference of the tire but I've got about a quart left so I cut up another sweatshirt, soak the pieces in resin and use my gloved hands to layer the front sidewall with fleece. I then let it dry again, be patient is all I can tell you. I cut the baffle put a bead of silicone on the tire bead and tightened it down with 1.5" drywall screws (8) and flipped it over, I then traced a terminal cutout template onto the rear panel and cut it out. I poured the remainder of the resin onto the back of the baffle while tilting it all around to spread it... I'ts a heavy object at this point, let me tell ya. I carefully tried to cut the port through the tread section, foam, MDF and all that resin. I then forced a 4" x 11 pvc into the hole with a silicone bead to seal it.once that was done I installed the terminal and then cut the speaker hole after it all dried and wired up then mounted the driver on the baffle. I've got some more MDF and I cut 2 ea in a "C" shape with a flat bottom elevated 5.5" off the floor to the bottom edge of the tire I've traced with the tire leaving 1" clearance to accommodate the Shiruken ST-BT20 i pulled out of an old dead Yugo of mine. I've kept it fresh for 3 years on the trickle charge and it is collecting dust but still fresh. I lay it sideways under the big Hoosier with the port at the 4 o clock position the battery terminals face rearward where my old Hifonics ZRX1216.1D is mounted. I finish the pedestal with front to rear bracing 1'X4" square pine glued and screwed. At this point I stop and take pics again before mounting the amp on the back panel using 1.5" drywall screws with rubber grommets and washers.Then I connect the amp to the battery running the remote wire through a toggle switch mounted on the face so I can turn the amp on and off. Oh darn it !!! I have to cut the pedestal to access the battery and hook up the charger! At this point I weigh it at 96 lb without the driver mounted this thing is a beast... I grab the car keys and go to Harbor Freight to get a charger, I grab a $40 10/2/50 amp charger which will be fine, I'm never going to draw 80A for an extended period anyway..."that's what the car is for!" this will be used with my SMSL Q5 and bookshelf 2-ways in the garage. I run home hook the speaker up at 1 ohm, drop it in, screw it down then hook up the battery charger and flip the switch to 50 amp charge. Before I say what happened let me say this, I had a stroke, it does affect your memory, reasoning and motor skills. I plug in the Rca's then turn it on...OOPS! The dusty garage has an undiscovered dust layer in the rafters..." I never turn the car up due to neighbors " and the neighbors across the street who barely tolerate my hobbies as it is decide enough is enough and stand in front of their house voicing their silent disapproval while I'm trying to set my gain levels. Once I got it leveled off ... A 20 x2 SMSL Q5 does the job well but the tire is in another class...is thing is a 2.25 ft3, 110 lb monster what was I thinking? A MOFO 12X may not be a audiophile driver but it will certainly get very loud.The amp is around 600 WMRS and it is enough. the driver may be able to handle 1500 watts but I don't think my house can, I know the neighbors can't. The local PD is across the street discussing the situation with the neighbors who apparently called them. I've been oblivious, and crankin' it up...oops! This is not the first time I've gotten a noise complaint and since the police observed this happening they had no choice. A $175 downer to the end of the week! The tire sub is big and ugly and LOUD!!! I think I built a winner, just a little excessive. it really is just an 2.25 ft3, 4" ported tuned to 34 hz enclosure wrapped in a tire and sitting on a battery hooked up to a car charger. But it is a thing of beauty,and beauty is in the eye of the beholder. Let me just say after viewing the projects posted, I really don't think I will be posting posting pics! The foam was a mess and I cut the port hole without reversing the drill to burn through the rubber and cord. The MDF baffle has resin all over it and since my motor skills are diminished, all my cuts are beautiful. If this done by a competent DIY'er, with all his faculties .... it could be beautiful, mine just sounds beautiful !

[Wolfbane221]

These would make some sweet shop speakersa

[aimzzz]

They certainly would... That would be better for the speakers than sitting in my storage room as well :D

[Gl0ckage]

Where did you spray the foam? Wouldn't it reduce the volume inside the tyre?

[aimzzz]

Yes it does reduce the volume. It is a trade-off between volume and stiffness. If you don't intend to use the subwoofer for high volumes you can neglect the foam and benefit from the bigger volume. If you want to listen to higher volumes, I'd recomment the foam.

[Gl0ckage]

So the foam is placed where? In the outer ring of the tyre? As the stuff I used gets everywhere. Thanks. Also i have given you my vote for the competition!

[aimzzz]

Yes, I tried to place it in the outer ring.

[soy_bean]

freakin awesome