Introduction: 5 Speaker Car Head Unit Boombox

Picture of 5 Speaker Car Head Unit Boombox
I built this 20+ pound monstrosity in 2005 for my Mother who was working in a noisy industrial environment and needed some audio umph to enjoy her tunes. I had built a couple of boxy rectilinear 80's style portables to wrap old car stereos and speakers in before and wanted to design something more sleek and sophisticated. I also wanted to incorporate some beefy industrial utilitarian elements hence the expanded metal grills, exposed screws, and unfilled brad holes.

Alas I only have a few poor quality photos of this build that don't show all of the construction details but I shall endeavor to describe the process. UPDATE: I was able to get some fresh photo's showing more details! 


Cabinet Dimensions
  • Length= 24"
  • Height= 10"
  • Depth= 11.5"
  • Pyle PLCDS200 AM/FM CD Cassette 50W X 4 Channel Head Unit
  • 2X 5.5" Goldwood Woofers
  • 2X 1" Dome Tweeters
  • 1X 6.5" Dual Voice Coil Subwoofer
  • 120VAC to 12VDC 9A Switching Power Supply


1 - 8' 1 X 12 Pine
1 - 4' X 4' X 1/4" Pine Plywood
1 - 5/8" Hardwood Dowel
Wood Screws
Wood Glue
4- Cabinet Feet
3 - Port Rings
Car Head Unit
2 - 5" to 6" Woofers
2 - 1" Dome Tweeters
1 - 6.5" Dual Voice Coil Subwoofer
1 - 120VAC to 12VDC XA Switching Power Supply
Speaker Wire
2 - 6" Expanded Metal Speaker Grills
1 - Telescoping Antenna

Table Saw
Router & Bits
Drill & Bits
Pneumatic Brad Nailer & Air Compressor
Tape Measure
Sand Paper

Step 1: Make the Front & Back Plate

Picture of Make the Front & Back Plate

  1. Crosscut two 24" lengths of 1 X 12.
  2. Choose the straightest long edge to ride against the rip fence and rip the 24" blanks down to 10" in width.
  3. Measure for component placement then draw the layout on the front plate and determine the location for the 2 cabinet partitions.
  4. Measure for speaker port & access panel placement then draw the layout on the back panel, then transfer the partition locations.
  5. Butt the bottom edges of the front & back plate together with the inside facing up making sure the ends are flush. Using a router equiped with a 3/4" straight cutting bit & a straight edge guide clamped to the blanks mill 1/4" deep dados to accept the partitions on the inside of the plates.
  6. Layout the radius on the ends of both plates then use your router equiped with a straight cutting bit and a circle cutting plate to cut the radii in successively deepening passes until cutting through. Using this same router set up cut the holes in the front plate for the 5.5" speakers.
  7. Using your router equipped with a rabetting bit with guide bearing rabbet the radiused ends on both plates on the inside to accept the bent plywood panels. Using this same router set up mill appropriate recesses around the speaker holes to accept the speaker flanges. Also with this set up mill the recess for the access panel in the back plate.
  8. Using your router equipped with a 3/8" radius round over bit with guide bearing round over the outside corner of both plates.
  9. Cut the opening for the head unit in the front plate using a jigsaw.
  10. Use a drill equipped with an appropriate bit or holesaw to make the holes for the tweeters. Use this set up to make the holes in the back plate for the speaker ports.

I added a small recessed panel between the tweeters that I had planned to install a headphone jack and other goodies in, but as you see the panel is blank.

Step 2: Make the Partitions

Picture of Make the Partitions

  1. Determine the desired finished outside depth of the cabinet, subtract 1" from this measurement and crosscut 2 blanks from the 1 X 12 stock.
  2. Rip both blanks to 10" in width.
  3. Measure for and machine appropriate dados and rabbets in the partitions to accept the bent plywood ends and bottom panel.
  4. Assemble the chassis by fastening the front & back plates, and partitions together using glue and brads.

Step 3: Make the Bent Plywood Panels

Picture of Make the Bent Plywood Panels

Cut the Panels  

  1. Use a sewing tape measure that can conform to curves measure from rabbet around the radius to rabbet for the length of the bent plywood panels. Cut 2 panels of 1/4" plywood this length by the depth of the speaker compartment openings rabbet to rabbet.
  2.  To allow the plywood panels to bend cut kerfs on the inside every 1/2" at least 1/8" deep perpendicular to the radius.

Bend and Fasten the Panels

Successfully bending the panels can be challenging, here's what worked for me. Prepare the panels prior to fastening them to the chassis by thoroughly wetting the outside surface with water and let it soak in for a few minutes. This helps make the wood more supple and flexible. Apply glue in the rabbets that accept the panel. Insert one end of the panel into it's rabbet and brad that edge in. Start slowly forming the panel into the radius rabbets bradding as you go. If there's allot of resistance or you here cracking sounds rewet the surface.

Step 4: Make the Subwoofer Enclosure

Picture of Make the Subwoofer Enclosure

I installed the sub inside the center compartment underneath the head unit firing down through a port in the bottom panel. I built an appropriate sub-assembly and enclusure with pine cleats and 1/4" plywood.

Note.The cone of the sub that I used sags a little due to gravity which allows the voice coil to overextend when driven hard causing some distortion.

Step 5: Make the Remaining Panels

Picture of Make the Remaining Panels

Recessed Vented Top Panel

I wanted a recess at the top to fold the handle into and decided it would be aesthetically pleasing and electrically beneficial to vent this panel. Measure the opening and decide on a gap pattern then cut appropriate strips of 1/4" plywood and glue and brad them at both ends to pine cleats pre-drilled with screw holes to attach the panel to the chassis. I also glued a piece of speaker grill fabric to the inside of the panel.

Bottom Panel

Cut a 1/4" plywood panel to fit and drill an appropriate subwoofer port hole then pre-drill screw holes for mounting.

Back Panel

Cut a 1/4" plywood panel to fit then pre-drill screw holes for mounting.

Folding Top Handle

Make the handle from an appropriate length piece of hardwood dowel fastened with screws to 2 strips of scrap hardwood counterbored to accept the dowel.

Finding the cabinets loaded center of balance is tricky. I initially attached the handle at the midpoint from front to back only to realize after the cabinet was loaded, that the front would tip down when being carried by the handle because most of the weight is toward the front. Your handle will need to be attached offcenter toward the front, it will take some trial and error to find the sweetspot. Once I did I installed 1/4 - 20 threaded inserts in the partitions and through bolted the handle.

Step 6: Apply a Finish

Picture of Apply a Finish

I recommend lightly sanding all exterior surfaces prior to finishing and then tacking off the dust. I used a rag to apply a couple coats of danish oil, followed by 2 coats of satin polyurethane.

Step 7: Installing the Electronics

Picture of Installing the Electronics

  1. Insert the head unit and fasten it.
  2. Choose an appropriate placement for the power supply in the center compartment and fasten it.
  3. Drill appropriate holes to pass the power cord, and speaker wires through.
  4. Following the wiring diagrams that came with your components, wire evrything securely soldering, nutting, or crimping the connections together then use ties to neatly route them.
  5. Fasten the speakers.
  6. Install the expanded metal speaker grills, and the top, bottom and back panels.
  7. Install the cabinet feet.
  8. Install the speaker port rings.
  9. Install the radio antenna.

Note. I connected both the left and right outputs of the rear channel to the dual voice coil subwoofer. The tweeters are connected in parallel with the front channel woofers through a simple inductor & capacitor crossover network. Also I insulated all of the the speaker compartments with poly fill.

Final Thoughts

This thing sounds great and has some serious window rattling power for an um....semi portable jambox. Unfortunately the CD player and cassette deck failed due to a combination of poor manufacturing and exposure to a volitile environment. The radio and amp still function and it works well with an external input.


Asek Solo (author)2016-02-02


jprussack (author)2014-08-16

Well done!

technovative (author)jprussack2014-08-16


rwneto (author)2013-02-10

awesome. just i looking for. congratulations!

technovative (author)rwneto2013-02-12


detinu77 (author)2013-01-26

Ghost Dog would be proud, nice build.

technovative (author)detinu772013-01-27

Ghost Dog, cool flick, one of my favs. I think my build is a little bit nicer than his though. ; )

kdf.inc1969 (author)2013-01-23

ive got a car radio that doesnt have the connections from the back. would it be possible to wire it up to work like this? thanks

technovative (author)kdf.inc19692013-01-24

I assume you mean that there is a socket that accepts a wiring harness connector, as opposed to individual wires exiting the radio? If so it is still possible to use the radio but you will either need to get a matching connector with wires, or connect individual wires to each pin manually. If you have identifying information for the unit it's likely that you can acquire a matching connector harness from a business that specializes in automotive audio eqipment like Crutchfield. If it is an OE factory installed radio then you could probably find a matching connector in a junk vehicle at a salvage yard. To connect individual wires to each pin you would need to know the pinout sequence, which if you're fortunate may be labled on the unit.

bigpig (author)2013-01-23

Absolutely beautiful.

technovative (author)bigpig2013-01-23

I appreciate the compliment.

VertDude (author)2013-01-22

Pretty sweet radio.........good job my friend!!

technovative (author)VertDude2013-01-22


hohum (author)2013-01-21

way COOOOOL!! looks great, superb job on kerfing the wood,, great looking finish>>>>

technovative (author)hohum2013-01-22


ggardner7 (author)2013-01-21

I love your design for the car radio .Could you do this with a CB Radio ?

technovative (author)ggardner72013-01-21

Thanks, yes you can power a CB radio with the same kind of AC to DC power supply.

ggardner7 (author)technovative2013-01-21

Sweet I am going to do one with a old liberty Cb all silver
I will send you pics

Eh Lie Us! (author)2013-01-20

Wow. Great work. Can you expand more on your connections from the radio to the power supply? I'm good with the wood work but useless when it comes to electronics. Thanks.

technovative (author)Eh Lie Us!2013-01-20

Thank you. The reason that I didn't specify how my build is wired is because those details are uniquely applicable to the radio & power supply I used. Typically however the power wires for most modern car radios are yellow = key on power, red = constant 12V, and black = ground. In this scenario you would connect the yellow, and red wires to the + terminal of the power supply, and the black wire would connect to the - terminal of the power supply. Ultimately the best practice is to refer to the wiring diagrams/instructions that come with your components to ensure proper connection.

Eh Lie Us! (author)technovative2013-01-21

Rock on! This helps me a lot. Thanks again.

RadGlobe (author)2013-01-21

what an awesome piece of work...thanks!!

technovative (author)RadGlobe2013-01-21

My pleasure, Thank you.

PtrkLnk (author)2013-01-20

I have a bunch of old speakers of all sizes and a lot of other audio stuff. I am going to try and build something like this with it.

technovative (author)PtrkLnk2013-01-21

Go for it, come back and share your build with us when you do.

Mr Joshua (author)2013-01-20

Excellent work! The enclosure looks fantastic!

technovative (author)Mr Joshua2013-01-21

Domo Arigato.

ozzman39 (author)2013-01-20

Awesome wood working skills i could do the radio end but the enclosure would look like crap lol

technovative (author)ozzman392013-01-21

Grazie, you can do it!

popmircea (author)2013-01-20

A few months ago i was buildind a similar construction for use under one cabinet in my kitchen's family. I constructed a box from a melamined PAL, i used a switching power supply from 220V AC to 12V CC. My car stereo is PNI 8209 and for the speakers i use some used for computers. I suppose that someone sollen my idea :) ... but i am very glad !

technovative (author)popmircea2013-01-20

Yeah you caught me, I stole your idea....NOT! :) Your build sounds nice though.

onemoroni1 (author)2013-01-20

ROCK OUT AND ROCK ON! Very nice build. I can understand the failure of the CD/Tape by the vibration at high volume, but looks great.

technovative (author)onemoroni12013-01-20

Thanks, this beast was inundated with highly consentrated ultra-fine plastic dust for several years and I think that coupled with poor quality manufacturing led to the CD & cassette failure.

Gordyh (author)2013-01-20

A work of art ;-) Just wondering if you put rechargeable batteries in the radio, would your power supply be able to recharge them?

technovative (author)Gordyh2013-01-20

I appreciate the compliment. 12V lead acid batteries really need an applied charge voltage of around 13.8V to charge efficiently, so no the fairly consistent regulated 12V output of a switching power supply wouldn't do well charging a 12V battery.

randomray (author)2013-01-20

Hey , sweet job . It's really nice of you to make this for your Mom and then share the design with us .

technovative (author)randomray2013-01-20

Merci, it's my pleasure.

bethmwl (author)2013-01-20

I really like your design. I've wanted to use auto components outside of the auto and had no idea how to do so. Being more mechanically inclined than electrically, i had no idea you could get such a power supply. I will be on the lookout for decent, yet unused auto audio pieces and would like to give this a try. I think you exceptionally well with the design also.

technovative (author)bethmwl2013-01-20

Thanks, 120VAC to 12VDC power supplies are readily available, you just have to choose one with enough output power for your head unit. For example if the head unit is rated at 25W X 2 channels output you need to devide 50/12 = 4.2 so the minimum current output rating of the power supply should be 5A.

modemotions (author)2013-01-20

I love the idea, would you be able to help me make this portable... as in self-contained rechargable battery run?

technovative (author)modemotions2013-01-20

Because we are using a head unit designed for 12VDC automotive use the power supply indicated can be omitted and a small 12V sealed lead acid battery that will fit inside the center compartment can be used to power the head unit. However if you use a high power head unit a small lead acid battery will be depleated fairly quickly. To recharge the battery you can purchase an appropriate manufactured charger, or if your comfortable with electronics there are numerous open-source circuit designs for simple chargers available on the web.

agis68 (author)2013-01-20

reminds me the Jeep radio boombox of 90's

scavanger (author)2013-01-19

I've thought about building something similar. I was going to build just a simple utilitarian plywood box, but your radio makes me want to put a little more effort into the case design.

Nice work and design.

technovative (author)scavanger2013-01-19

I get allot of inspiration from what others have shared, so it's gratifying to learn that something I've shared may inspire someone. Thank you.

stevemoseley (author)2013-01-18

Nicely done. Love the woodwork on this.

Danke, thanks for taking the time to comment.

fretted (author)2013-01-18

That's a damn good looking radio if you ever play fallout it kinda looks like one of those radios in the game ....

Great Ible too !

technovative (author)fretted2013-01-18

Gracias, no I've never played fallout but it's cool my design looks similar to a radio in the game.

SlickSqueegie (author)2013-01-17

Very nice job all around!

Thanks, I appreciate the compliment.

About This Instructable




Bio: Exploring the cosmos one synapse fire and one mouse click at a time.
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