How To Build Your Own Boombox

(Researched and written by Kyle Macdonald of One Red Paperclip fame):


If you don’t want to troll church basements hunting for the perfect boombox and prefer a proactive take-no-prisoners set-up-a-boombox-factory-in-your-hotel-room kind of lifestyle, then building your own boomboxes is probably right for you.

Take note: 12V rechargeable batteries and 12V car stereos will be your best friend. The beauty of sticking with 12V systems is that 12v is the worldwide standard for audio systems in cars and boats so there’s a pre-existing global logistical and supply chain for this stuff.

All you need for a bombastic DIY boombox is 4 simple elements:
– Audio source (amplifier)
– Speakers
– Music Source
– Power Source (battery)
– Charger


AMPLIFIERS:

Car stereos are cheap and plentiful but your best bet is to just buy a new T-Class amp from China on eBay or AliExpress. Search for “Lepai amp” or similar. These can cost as little as $8 apiece when bought in quantity. Ignore all the wattage ratings; just hook them up to any old speakers and experiment (at your own risk/peril). T-Class amps are mind-blowingly powerful for their size.

Lepai AmpAmps with FM TUNERS are essential for DDP use. There are work-arounds that use phones or other external FM tuners, but our experience is that smartphone-like circuitry causes a quarter-second delay that’s enough to get your boombox out of synch and create an unbearably annoying echo.


SPEAKERS:

Thrift shops sell old “mini system” stereos for like $10 and the detached speakers are perfect for building custom boomboxes. Party-proof the speakers by fastening them inside plastic jerry cans or other ready-made boombox receptacles. Literally any speaker will do (don’t overthink this; the average “golden age” boombox had very poor stock speakers)

red-paperclip-boombox


MUSIC SOURCE:

If not using FM, just connect your phone or ipod via 1/8” or RCA cables, bluetooth, etc.

1_8" _ USB CablesPOWER SOURCE: (batteries)
You can recharge 12V batteries hundreds (or thousands) of times for pennies on the charge; making it a much simpler, more affordable, and environmentally-friendly option than normal C and D cells. If you’re primarily hosting small-scale DDPs and rarely losing boomboxes, then a rechargeable DIY boombox fleet may be your best option.

red-paperclip-boombox-many

The DDP has exclusively used 12V sealed lead acid (SLA) batteries because they’re cheap, available everywhere and can be recharged 300 times without losing much battery juice.

We suggest 7-9Ah (Amp Hour) SLA batteries as the bare minimum capacity to power a large DIY boombox for an entire Party. The higher the Ah, the longer the Party lasts, but SLA batteries get pretty horribly heavy once you exceed about 15Ah. If you’re paying more than $2 per Ah for SLA battery power then you’re paying too much.

BONUS LEVEL:
We highly suggest experimenting with other battery types such as LiFePo and other emergent technologies. Sealed Lead Acid sounds archaic like a coal-driven steam engine and while that’s cool and all, lead and acid probably aren’t the best things to deal with all the time. The DDP expects battery technology to evolve very quickly in the near future.

*ACTUAL SAFETY WARNING*

The reason all factory-built boomboxes rely on 1.5V C and D cell batteries is because a 1.5V battery alone is not enough to heat up wires or cause a spark or start fires.

BUT A 12V BATTERY CAN (AND WILL) START FIRES IF YOU CONNECT THE BATTERY TERMINALS IMPROPERLY OR ALLOW BOTH TERMINALS TO TOUCH THE SAME PIECE OF METAL.

ALWAYS COVER 12V BATTERY TERMINALS WITH FAR-TOO-MUCH ELECTRICAL TAPE AND DON’T LET INEXPERIENCED PEOPLE WIRE HOMEBREW BOOMBOXES.

AND NEVER LEAVE 12V BATTERIES LYING AROUND WITHOUT THE TERMINALS COVERED. EVER. IF YOU DON’T HAVE ENOUGH TAPE, THEN DON’T BUILD A 12V BOOMBOX OR TAKE IT INTO BATTLE.


CHARGER:

Battery Tender Jr. is an inexpensive, high-quality 12V charger that we highly recommend!

Battery Tender Jr

Note that you will ruin SLA batteries if you let them fully discharge or let them sit for long periods without being charged (as they slowly discharge on their own). SLAs also take a long time to charge with a small charger and you may want to keep them plugged in at all times to maintain the batteries and ensure your boomboxes are always in “go” Party status.

PRO TIP:
Wal-Mart and other faceless national chains have interesting lawnmower-type 12V batteries with large amounts of Ah for low prices if you plan to build large wheeled boombox systems and Amazon.com also has excellent ground-ship deals on SLA batteries.

MEGA PRO TIP:
Get a full-size 12V car or (better yet) deep cycle marine battery, a 300-watt inverter and a 200-watt powered PA. Rig it all up and it’ll be WAY louder than you can imagine.

It’s gonna weigh 75-100lbs, so put it on some sort of wheeled contraption like a bike or dolly or bike trailer or Radio Flyer wagon or wheelchair and you’ll be rocking out to Hot Tracks for at least 10 hours. Easily as loud as 30 boomboxes with more Turbo Bass than allowed by law (Illegal Bass).

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(This information is featured in the soon-to-be-released Official DDP Field Manual– an authoritative guide to Capital-P-Partying and creating your very own DDPs!)

5 Responses to How To Build Your Own Boombox

  1. Gary says:

    Hmmm not really sure- sorry! Maybe try asking on a car audio forum?

  2. Lindsay says:

    Hi,
    Great projects! I’m building a car stereo boombox, but have hit a snag. I’m using a 12v AC/DC plug inside the box and connecting to either battery with clips or to mains with a 12v adapter. However, the problem I have is the inputs. There are two, one for direct battery power and one for the ignition. I only have one input and if I put both to the plug I get a power surge pulsing buzz. Could you possibly advise me how to overcome the issue of the two power cables from the head unit? Of course, it won’t work if they are not both connected. Many thank yous in advance.

  3. NIloy says:

    Such a cool and awesome stuff. Thanks for it

    I also have t class amp which is Lepy TA2024A+. I keep it store room for a long time. It’s time to make something new with old.
    Again, thanks for it.

  4. Stephen says:

    You boys are doing the lord’s work.

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