I need some advice on building an inexpensive Bluetooth speaker.
My Makerspace is sponsoring a Maker Faire in June. My group is putting together a DIY speaker build to promote STEM. We're intend it for 10 - 14 year olds.
We've put together the kit from parts we found on Banggood. That will get us to the Maker Faire. But our BOM is about $20 and parts of the design, like the reset button, are kludgy. I'm sure we could optimize a lot of this.
Has anyone done a similar project? Would you share your BOM and suppliers?
Thanks.
My Makerspace is sponsoring a Maker Faire in June. My group is putting together a DIY speaker build to promote STEM. We're intend it for 10 - 14 year olds.
We've put together the kit from parts we found on Banggood. That will get us to the Maker Faire. But our BOM is about $20 and parts of the design, like the reset button, are kludgy. I'm sure we could optimize a lot of this.
Has anyone done a similar project? Would you share your BOM and suppliers?
Thanks.
It’s not clear to me what kind of information you’re looking for.
If you describe the type of speaker your building (single driver, two way, sealed, ported, etc) the electronics, the project goals, and the problems you’re encountering, it will be easier for people to know how they can help.
Im also a member of a maker space. I’m surprised I don’t see them mentioned more frequently in the diy audio community.
If you describe the type of speaker your building (single driver, two way, sealed, ported, etc) the electronics, the project goals, and the problems you’re encountering, it will be easier for people to know how they can help.
Im also a member of a maker space. I’m surprised I don’t see them mentioned more frequently in the diy audio community.
You gotta explore if your intended amp/BT kit will be any good and for how long? I would rather advise to invest in a better quality electronics than experience any consequences resulting from users being not satisfied with product longevity and everyday performance. If you attach a single wide band driver (dayton audio has plenty) to each of the stereo channel, put all this in a simple enclosure, you'd do well. The total cost should be in the 100 bucks range.
I run stem classes for kids and have a pretty good idea what 10-14 year olds can do. I think you should keep it relatively simple. I understand why you have chosen bluetooth but it does reduce your options.
The hiVi b3s is cheap but very good and widely used in the diy community. Everything you need to know about using it as a single driver in a cabinet is here. You can buy it at parts express and also look at this plate amp. Here. Ive never used the plate amp but its 20w, cheap and probably sounds very good.
As far as the cabinet goes, there are a couple of approaches. You could try and make a cabinet that is good by the standards of audio nuts, or something that is easy. Id go with easy. Do you have a laser cutter in your space? Use thin baltic ply and laser cut the openings for the driver and plate amp. Kids can hot glue the box together and if they are careful about the glue being hot enough it will be as strong as the wood its is gluing together.
If you need it to be something that they can build at home without access to a laser cutter, then some 1/2 ply, or even 1/4 hardboard could be used and they can cut the holes with a saber saw and a drill. The nice thing about the b3s driver is that it doesn't have to be counter sunk to avoid diffraction, although you are probably not aiming for a level of performance where diffraction will be an issue.
I hope this is helpful. You've got me thinking now and I might mess around with some ideas. PVC tube maybe? Speakers on both ends. Will have to experiment.
The hiVi b3s is cheap but very good and widely used in the diy community. Everything you need to know about using it as a single driver in a cabinet is here. You can buy it at parts express and also look at this plate amp. Here. Ive never used the plate amp but its 20w, cheap and probably sounds very good.
As far as the cabinet goes, there are a couple of approaches. You could try and make a cabinet that is good by the standards of audio nuts, or something that is easy. Id go with easy. Do you have a laser cutter in your space? Use thin baltic ply and laser cut the openings for the driver and plate amp. Kids can hot glue the box together and if they are careful about the glue being hot enough it will be as strong as the wood its is gluing together.
If you need it to be something that they can build at home without access to a laser cutter, then some 1/2 ply, or even 1/4 hardboard could be used and they can cut the holes with a saber saw and a drill. The nice thing about the b3s driver is that it doesn't have to be counter sunk to avoid diffraction, although you are probably not aiming for a level of performance where diffraction will be an issue.
I hope this is helpful. You've got me thinking now and I might mess around with some ideas. PVC tube maybe? Speakers on both ends. Will have to experiment.
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If you are willing to drop bluetooth, the Dayton DTA-1 is awesome and dirt cheap. Also battery powered which, now that i think about it, the plate amp above isn't.
i have two I've used for about 5 years and they are really terrific. I have occasionally had them stand in for real hifi gear that broke and been quite pleased with the sound.
i have two I've used for about 5 years and they are really terrific. I have occasionally had them stand in for real hifi gear that broke and been quite pleased with the sound.
Thanks guys,
Here are our goals and what we have so far.
Goals:
Simple enough for 10 year olds to assemble but with enough hands-on they learn something
Bluetooth, since they all have smart phones anyway
Sounds good enough they'll want to use it
Inexpensive, we need to so several dozen of them. Would like the BOM to be < $15 per unit. Right now we're at $20 without a charger
What we have:
SANWU HF69B Bluetooth/Amp combo. It's $5.99 per unit from Banggood. It has all the functionality we need and it's layout makes it easy to point to different chips, like the Bluetooth or the amps to explain what they do
Generic 1.5" drivers. Their big advantage is they are $3.99 per unit
3.7V LiPo battery packs
NC momentary contact reset switch
Laser cut birch plywood case
This is the first time we've done this. We plan to offer a longer, more hands-on class at the Makerspace in late June, after the Faire.
Knifeinthesink - Three of my favorite musicians are Canadian but none of them are Neil Young or Rush.
Here are our goals and what we have so far.
Goals:
Simple enough for 10 year olds to assemble but with enough hands-on they learn something
Bluetooth, since they all have smart phones anyway
Sounds good enough they'll want to use it
Inexpensive, we need to so several dozen of them. Would like the BOM to be < $15 per unit. Right now we're at $20 without a charger
What we have:
SANWU HF69B Bluetooth/Amp combo. It's $5.99 per unit from Banggood. It has all the functionality we need and it's layout makes it easy to point to different chips, like the Bluetooth or the amps to explain what they do
Generic 1.5" drivers. Their big advantage is they are $3.99 per unit
3.7V LiPo battery packs
NC momentary contact reset switch
Laser cut birch plywood case
This is the first time we've done this. We plan to offer a longer, more hands-on class at the Makerspace in late June, after the Faire.
Knifeinthesink - Three of my favorite musicians are Canadian but none of them are Neil Young or Rush.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Alternative bits:
1. search for the MH-M38 bluetooth stereo audio amp/receiver. The board itself sells for about 2.7 bucks, shipped. No wires, pcb connectors included.
2. a better driver solution is Dayton Audio CE32A-8, Parts Express charges 2.99 bucks for buying 10-99 pieces. This is a low Fs (274 Hz) wide range unit, probably one of the best offerings for this kind of quality.
1. search for the MH-M38 bluetooth stereo audio amp/receiver. The board itself sells for about 2.7 bucks, shipped. No wires, pcb connectors included.
2. a better driver solution is Dayton Audio CE32A-8, Parts Express charges 2.99 bucks for buying 10-99 pieces. This is a low Fs (274 Hz) wide range unit, probably one of the best offerings for this kind of quality.
I was considering a similar project, so I have ideas. Not tried yet though.
It can be mono! Saves a speaker, and the box won't have enough width for stereo sound anyway. Mono boards are a bit more rare though, and I don't think you can easily modify them to be mono yourself. Sanwu does make a very similar board to yours in mono (including battery charger), the SW hf77. It's yellow, and can be found on eBay and Ali under various names.
Another idea I was going to try: coin exciters, like Dayton makes. Cheapest ones are no more than few euros each.You stick them to a plate of XPS foam, and they are functional, surprisingly good speakers. Perhaps use foam core (paper-covered XPS), then the kids can paint them. Advantage is that the result is special, not just a cheaper-looking version of a store product.
Foam core and XPS might be good alternatives anyway for plywood, even when you make boxes. I do not how if you can laser cutters on them, but knives work, and might be faster than woodworking.
It can be mono! Saves a speaker, and the box won't have enough width for stereo sound anyway. Mono boards are a bit more rare though, and I don't think you can easily modify them to be mono yourself. Sanwu does make a very similar board to yours in mono (including battery charger), the SW hf77. It's yellow, and can be found on eBay and Ali under various names.
Another idea I was going to try: coin exciters, like Dayton makes. Cheapest ones are no more than few euros each.You stick them to a plate of XPS foam, and they are functional, surprisingly good speakers. Perhaps use foam core (paper-covered XPS), then the kids can paint them. Advantage is that the result is special, not just a cheaper-looking version of a store product.
Foam core and XPS might be good alternatives anyway for plywood, even when you make boxes. I do not how if you can laser cutters on them, but knives work, and might be faster than woodworking.
I just sourced parts for a similar project for my middle school makerspace. I too needed to keep the cost down, but wanted a decent sounding product the students would be proud of. Since we have so many old chromebook power cords, I chose the TPA3100 with bluetooth from Sanwu. The TPA3100 works well with 19v, has a reputation for decent sound quality, and was only $5. For drivers, I would have liked to use the B3S or Fountek FE85, but $20 for stereo drivers is too much. I just spotted the new HiVi C3N-III now as I look, but went with the Dayton Audio CE65W-8 for $5.20 each. The HiVi and Fountek both have suggested filters for optimal sound, but that would have also increased the cost. I bought a cheap set of male 5.5 mm barrel connectors for the power supplies and 5.5 mm female jacks for the speakers. The plan is to have the students design their speaker enclosure and cut it out of 1/4" birch plywood with the school laser cutter. Here is a great tool for designing finger joint boxes. The total cost of each speaker will come in under $20 if you have cheap cabinet material available.
Here is my hastily built test out of crappy fiber board.
Here is my hastily built test out of crappy fiber board.
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Thanks, LiitleZamfir.
I was stuck on two speakers when we started the project because I thought that was what everyone wanted. A teammate has convinced me that that was a mistake. We're not getting stereo with 1.5 inches separation, so don't pretend we are. We should just use one channel and invest in a better driver.
Too late for this iteration. Already ordered the parts.
But next class.
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