portable bluetooth boom box for a teenager

[poboy]

I built this for my 14 year old daughter on her birthday. She wanted one of those Bose Bluetooth and I got one to listen but was not impressed. So a home-built it was. I had built car sub (out of MDF) so I thought this would have been easy. Was I wrong.

Took me 3 months (I made 3 different enclosures) and $300 in parts.

Sub is a Tang Band 5.25 subwoofer from parts express tuned to 60Hz with internal volume of 200 cubic inches. This is an excellent sub for auto use as it can reach down to 35 Hz.
Left and Right are modified internals of the Klipsch ProMedia 2.1 satellites.
Amp is a 100W mono sub I got from Amazon.

The L and R are driven by a Sure Tripath 2x15W; Bluetooth 4.0 is by Sure that I got from partsexpress.

Batteries are 4 of 26650 A123 LiFePO4 (2.3 aH) with a BMS to prevent thermal runaway.
RGB LEDs are from Amazon as well as a noise sensitive LED controller with remote.

Material is birch plywood 1/2 inch with aluminum flats to brace the front baffle. Dimensions are 18 wide by 7 high by 7 deep and 13 lbs.

First is the video: https://www.youtube.com/watch?v=OakXTW-ZEm0

[wassp223]

Re: portable bluetooth boom box for a teenager

Nice work! I like the stained wood. I did something similar on a bluetooth boombox build. Also bravo on going the battery way, I wanted to keep cost down and got overwhelmed with the logistics of making it battery powered and rechargeable. The LED's are a very cool touch.

How did you do the metal grill and where is that material from?

Were you able to get the full 200in/cu sub enclosure volume with all those parts inside?

I would spray paint the port black to make it blend with the drivers nicely.

So how does it sound?

[Paul Carmody]

Re: portable bluetooth boom box for a teenager

Thank you for showing the inner cutaway. I have been wanting to do a boombox with the W5-1138 for years. I have a bunch of variations sketched up, but nothing I could quite settle on. Seeing yours gave me a new burst of inspiration.

[JoshuaC2U5H]

Re: portable bluetooth boom box for a teenager

Thanks for posting! I'm about to make two Bluetooth boxes and hadn't even thought about trying to incorporate a subwoofer. Juices flowing! I can't see the pictures at work, but from the YT video it looks awesome. That metal grill you bent up is clean!

[poboy]

Re: portable bluetooth boom box for a teenager

Nice work! I like the stained wood. I did something similar on a bluetooth boombox build. Also bravo on going the battery way, I wanted to keep cost down and got overwhelmed with the logistics of making it battery powered and rechargeable. The LED's are a very cool touch.

How did you do the metal grill and where is that material from?

Were you able to get the full 200in/cu sub enclosure volume with all those parts inside?

I would spray paint the port black to make it blend with the drivers nicely.

So how does it sound?

GRILL - The metal grill is the Parts express one. I used an 18 inch bending brake from Harbor Freight to bend it. Cutting it was a pain with a tin snip so I ended up using a cutting wheel.

VOLUME - I think I did as originally it was calculated to be 230 cubic inches even with all those parts. So to be safe, I modeled on 200 cubic inches just to be sure.

Here are the major parts:

Parts Express Formed Metal Grill Pair with 8mm Round Holes - 28" x 18" x 1"
Part # 262-884 .. $34.73


Bluetooth v4.0 Audio Receiver Board aptX +EDR 12 VDC
Part # 320-351 $24.93

Tang Band W5-1138SMF 5-1/4" Paper Cone Subwoofer Speaker Part # 264-917




2x15W at 4 Ohm TA2024 Class-D Audio Amplifier Board Only
Part # 320-330 $16.48

RGB LEDs WITH SOUND CONTROLLER AND SUBWOOFER AMPLIFIER FROM AMAZON

http://www.amazon.com/gp/product/B00PXUWAYG/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B00K0W30UU/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B00B5MUJ3U/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

RECHARGEABLE LITHIUM ION BATTERIES (YOU NEED 4 batteries TO GET 13VDC)
Note that I am using the LiFePO4 which is much safer than the laptop type lithium but the downside is capacity is half of the normal lithium ion. But better safe than sorry, especially for a teenager.

http://hobbyking.com/hobbyking/store/__48783__A123_3_3V_Lithium_Ion_2500mAh_Single_Cell_Battery.html?strSearch=A123%202

Although LiFePO4 is supposed to be safe I believe YOU WILL NEED THIS BATTERY MANAGEMENT BOARD (BMS) to prevent runaway thermal event by the lithium batteries

http://www.batterysupports.com/12v-146v-4s-30a-lifepo4-battery-bms-lfp-pcm-smt-system-p-243.html

But there are cheaper ones like this: http://www.ebay.com/itm/Battery-Prot...item27ed88eae9

there are little connectors (3.5 mm, spade connectors, etc).

My next project is to build a bluetooth using small 2.5 inches full range with the 3 inch Tang Band Sub. This will be for my own use when I travel and want to listen to music.

[poboy]

Re: portable bluetooth boom box for a teenager

I really like the W5-1138, given how small it is. In my car, at 560 cubic inch, it sounded like a 10 inch sub in the trunk. I thought about getting a Tang Band 6.5 or 8 inch sub but when I modeled them in WinISD, they couldn't reach 35 Hz, only 40 and up.