My plan on building a DIY portable bluetooth speaker

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#1
Thought of beefing up my old logitech ipod dock by moving the guts to a wooden enclosure and bigger battery but have decided instead to go all out and try to make use of a set of 6.5" car component speakers for a bigger setup. I'm trying to keep the costs down as much as possible because for around $150 I can just buy a new already built unit.

My plan is to pick up a cheap home subwoofer off criagslist to use as the enclosure. This way I won't have to assemble and finish the exterior if I go with a sub box kit and it's a lot cheaper as well. I'll keep the sub in there to use as a passive radiator but can pick up a real PR or plug up the hole entirely if they both don't work well.

I'll be using a 50w x 2 class D amp with builtin BT and the add-on board for USB ports, Aux in and power switch as well as a knob for volume control. The 6.5s will likely go on the sides and the controls on top. If there's enough space on top I may add a wireless charging pad too.

What I'm not certain of yet is battery power. I was initially thinking of going 2 12v sealed lead acid batteries in series for 24v to get as close to the amp's max output as possible. But this poses 2 problems - 1) additional weight from second battery and the enclosure is already heavy enough as it is. 2) more expensive charger to charge 24v and the correct balance charging of them. So I was thinking maybe go with just one battery and get a step up converter to boost the 12v to 24v. What do you guys think?

I'll also add some casters and a collapsible handle cause I sure don't want to carry this thing.
 
Oct 9, 1999
11,269
47
126
#2
Sounds like it will work, aim for as high efficiency on that step up converter as possible,try and wring every extra % you can out of it.

That said i got a 15w bluetooth speaker for $70 Canadian on amazon prime day thats waterproof, shockproof, dustproof as well as has the ability to charge USB devices off its battery. So doing this as a cost savings project may not result in much cost savings.
 

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#3
Yep, I realize there are tons of BT speakers out there but I'm going more for a "party" type box that can get loud but still sound good (hopefully). Something like the Ion block rocker or monoprice's party speaker. While these have nicely made enclosures their components are mediocre (paper woofers, cheap tweeters, weaker amps).
 
Oct 9, 1999
11,269
47
126
#4
Yep, I realize there are tons of BT speakers out there but I'm going more for a "party" type box that can get loud but still sound good (hopefully). Something like the Ion block rocker or monoprice's party speaker. While these have nicely made enclosures their components are mediocre (paper woofers, cheap tweeters, weaker amps).
In that case id probably go the two battery route and not dick around with the step up converter. Those 2 you mentioned are rather large, more than large enough to house the batteries.
 
Oct 6, 2008
387
1
101
#5
i would go for 2 batteries. mainly for runtime.. if this is a "party box" loud and runtime are important. a buck converter will lose you a few percent, not much but as someone mentioned if you get the best but the the better one will cost a little more.

i suppose you could use one battery with twice the capacity and use a buck but it may be easier to place two smaller batteries in the box than one bigger one.. more placement options in a tight space. might help balance it out a bit too as you can put a battery on each side. with one big battery, unless its central, if will be off. not that it really matters but might as well try to balance it out.
 

sdifox

No Lifer
Sep 30, 2005
74,338
301
126
#6
TPA3116D2 with bt? Dirt cheap on eBay. What is the target playtime and target charge time? Depending on target you may want to go to LiFePo battery.
Put the boombox on a dolly instead of installing wheels on the box itself, just so you don't break the box when you bump it on uneven surfaces.

Add a rpi if you want to go full media player :awe:

Example from google

http://m.ebay.com/itm/TPA3116D2-120...eceiver-Digital-Amplifier-Board-/172381209832


Example boombox

https://www.reddit.com/r/raspberry_pi/comments/5mqms2/a_boombox_using_an_raspberry_b/

http://pi-fidelity.blogspot.ca/2013/05/pifi-mini-ultimate-raspberry-pi-boombox.html?m=1

Example battery

https://hobbyking.com/en_us/turnigy-heavy-duty-5000mah-7s-60c-lipo-pack.html
 
Last edited:

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#7
i would go for 2 batteries. mainly for runtime.. if this is a "party box" loud and runtime are important. a buck converter will lose you a few percent, not much but as someone mentioned if you get the best but the the better one will cost a little more.

i suppose you could use one battery with twice the capacity and use a buck but it may be easier to place two smaller batteries in the box than one bigger one.. more placement options in a tight space. might help balance it out a bit too as you can put a battery on each side. with one big battery, unless its central, if will be off. not that it really matters but might as well try to balance it out.
I've ordered the amp and a meter with voltage and amp readings. I'll bench test this first to see what my amp draw is and that'll determine what battery route I'll go with. Cheapest will be SLA for the highest amp output I think.
 

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#8
TPA3116D2 with bt? Dirt cheap on eBay. What is the target playtime and target charge time? Depending on target you may want to go to LiFePo battery.
Put the boombox on a dolly instead of installing wheels on the box itself, just so you don't break the box when you bump it on uneven surfaces.

Add a rpi if you want to go full media player :awe:

Example from google

http://m.ebay.com/itm/TPA3116D2-120...eceiver-Digital-Amplifier-Board-/172381209832


Example boombox

https://www.reddit.com/r/raspberry_pi/comments/5mqms2/a_boombox_using_an_raspberry_b/

http://pi-fidelity.blogspot.ca/2013/05/pifi-mini-ultimate-raspberry-pi-boombox.html?m=1

Example battery

https://hobbyking.com/en_us/turnigy-heavy-duty-5000mah-7s-60c-lipo-pack.html

While all that is cool I don't think I'll need it. BT and aux input will be all I need. And lipo is just too expensive right now when I'm trying to build this thing at a budget. If this thing is still kicking when lipo prices come down more I'll convert it over.
 

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#9
*Update - I've decided to sacrifice a spare home sub to use as my enclosure. There's a 10" with a 100w plate amp in it but I'll be removing the amp and use the sub for one channel. One side of the 6.5 component set will be on the other channel. The small amp and volt/amp display meter came in so I got them bench tested with a 20v 3A laptop charger. I'm seeing 20.3v and amp draw of .11a at moderate levels and .3A when I crank it up on bass heavy songs. I'm pretty sure I got the connections right but that does seem a little too low of draw. But if that is correct then a 7Ah battery will last well past 20hrs cranked up. I think I may even go with a 10Ah for even longer runtime.

I haven't cut the hole for the 6.5 yet but the 10" sounds good right now for the amount of power it's getting. I think it will really rock if I can feed it atleast 100w, which I may later on with a second amp.
 

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#10
Here's a list of components I'm using if you're wondering.
Dayton Audio KAB-250 - 50w x 2 with BT 4.0
Dayton Audio KAB-INT - add-on module with 2x USB, AUX input, power switch and status LEDs
Dayton Audio KAB-FC - wiring kit with volume control, AUX input, power cables
Dayton Audio KAB-LED - 3 LED indicator lights for Power, BT, and Charging
Sure Electronics AA-AB31282 - 200w x 1 mono amp
Sealed lead acid battery at 12v 10Ah
12v to 24v step up converter
12v to 36v step up converter
Focal 6.5" Polyglass 165 component system
Peerless 1" tweeters
Athena Technologies AS-P400 with 10" subwoofer (used as the enclosure)
100hz low pass passive crossover
Voltage and Amp display meter.

I got the holes cut and the speakers mounted. Did a quick test before going to bed and it sounds great with the 10 sub screwed in place and the rear hole in the back for the plate amplifier covered up. I didn't have a chance to try it with the 10 sub powered up but can only imagine it dishing out even more lows for a more fuller sound.
 

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#11
Here are some pics of my progress. Now that I think about it, I should have mounted the side speakers a little higher up so the sound can disperse better than down by the ground.



 

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#13
6.5 sharing the same enclosure as the sub...
I realize it's not ideal and if the sound from the 6.5" are getting destroyed by the sub then I'll go back to my initial plan of replacing the sub with a passive radiator.
 

jtvang125

Diamond Member
Nov 10, 2004
5,396
3
91
#14
Ok I got almost everything wired up. Discovered the tweeter output on one of the crossovers was dead but I got that fixed. In my bench testing I didn't wire my volt/amp meter correctly so I got false amp readings. Thought I would get atleast 10hrs of runtime from my initial readings but with the correct readings I'm looking at only 5hrs and 2-3 if I have it cranked up. Because of this I wired in a switch to turn off the sub amp when I need the runtime.

It sounds fine with everything sharing the enclosure. I thought the sub will cause excess excursion in the 6.5s and introduce distortion but they both played nicely. I will need to plug any air leaks because those are causing a lot of wind noise. Just 2 or 3 more things and it's done.
 
Sep 11, 2017
1,098
88
66
#15
Yeah, this is necessary because no one makes a portable bluetooth speaker yet.
 

bazzaH

Junior Member
Dec 18, 2018
1
0
6
#16
Thought of beefing up my old logitech ipod dock by moving the guts to a wooden enclosure and bigger battery but have decided instead to go all out and try to make use of a set of 6.5" car component speakers for a bigger setup. I'm trying to keep the costs down as much as possible because for around $150 I can just buy a new already built unit.

My plan is to pick up a cheap home subwoofer off criagslist to use as the enclosure. This way I won't have to assemble and finish the exterior if I go with a sub box kit and it's a lot cheaper as well. I'll keep the sub in there to use as a passive radiator but can pick up a real PR or plug up the hole entirely if they both don't work well.

I'll be using a 50w x 2 class D amp with builtin BT and the add-on board for USB ports, Aux in and power switch as well as a knob for volume control. The 6.5s will likely go on the sides and the controls on top. If there's enough space on top I may add a wireless charging pad too.

What I'm not certain of yet is battery power. I was initially thinking of going 2 12v sealed lead acid batteries in series for 24v to get as close to the amp's max output as possible. But this poses 2 problems - 1) additional weight from second battery and the enclosure is already heavy enough as it is. 2) more expensive charger to charge 24v and the correct balance charging of them. So I was thinking maybe go with just one battery and get a step up converter to boost the 12v to 24v. What do you guys think?

I'll also add some casters and a collapsible handle cause I sure don't want to carry this thing.
Ok I got almost everything wired up. Discovered the tweeter output on one of the crossovers was dead but I got that fixed. In my bench testing I didn't wire my volt/amp meter correctly so I got false amp readings. Thought I would get atleast 10hrs of runtime from my initial readings but with the correct readings I'm looking at only 5hrs and 2-3 if I have it cranked up. Because of this I wired in a switch to turn off the sub amp when I need the runtime.

It sounds fine with everything sharing the enclosure. I thought the sub will cause excess excursion in the 6.5s and introduce distortion but they both played nicely. I will need to plug any air leaks because those are causing a lot of wind noise. Just 2 or 3 more things and it's done.
Hi jtvang please can you help me with a bluetooth speaker build .would be very appreciated barrykeithickman@gmail.com
 
Thread starter Similar threads Forum Replies Date
MaxDepth Audio Components 3

Similar threads



ASK THE COMMUNITY

TRENDING THREADS