Hey everyone,
I'm starting to formulate a plan for a luggable, battery-powered boombox for summer fun and wanted to solicit input from the folks here. My goal is for it to be reasonably portable (<20lb), not be excessively large, have at least 2 hours of battery life, and be reasonably loud outside - not concert volume, but enough to dance to.
I'm thinking it'll be a 3-way system, with a sort of "mailbox" shape built around a 12" sonotube that will act as the box for the 10" subwoofer. I think I'll probably use a 6S LiPo battery to power it, with a nominal voltage of 22.2V and 88Wh capacity. I've attached a photo of a similar build that I did in 2016, with an 8" sub in 10" Sonotube, detachable speakers, and no battery. For this build I want to get a bit more LF extension and portability.
For the sub I'm thinking the Dayton Audio LS10-44, it's a 10" low-profile subwoofer that's pretty light (11lb) for how low it can go. It also can be wired to 2 ohms so I don't need a high system voltage. Not particularly efficient at 86.5dB sensitivity, though.
My plan is to give it a 30L enclosure tuned to 40Hz, for a peak of 109dB at 50Hz, 100W input.
For the mids I'll probably do these 4" GRS woofers and for tweeters these cheap Goldwoods
Then for the amps I plan to use this 100W Dayton mono amp for the sub and the 2-channel version of it for the mids/tweeters. I like the look of these amps cuz they're cheap, small, and have DSP so I can add dynamic bass boost to give it extra LF extension at low input amplitude.
What are everyone's thoughts? Is the LS10-44 good for this job, or should I pick a more efficient sub and use DSP to even out the response? The low system voltage cuts out a lot of higher impedance subs, but if it's really worth it I could do a larger battery pack.
I'm starting to formulate a plan for a luggable, battery-powered boombox for summer fun and wanted to solicit input from the folks here. My goal is for it to be reasonably portable (<20lb), not be excessively large, have at least 2 hours of battery life, and be reasonably loud outside - not concert volume, but enough to dance to.
I'm thinking it'll be a 3-way system, with a sort of "mailbox" shape built around a 12" sonotube that will act as the box for the 10" subwoofer. I think I'll probably use a 6S LiPo battery to power it, with a nominal voltage of 22.2V and 88Wh capacity. I've attached a photo of a similar build that I did in 2016, with an 8" sub in 10" Sonotube, detachable speakers, and no battery. For this build I want to get a bit more LF extension and portability.
For the sub I'm thinking the Dayton Audio LS10-44, it's a 10" low-profile subwoofer that's pretty light (11lb) for how low it can go. It also can be wired to 2 ohms so I don't need a high system voltage. Not particularly efficient at 86.5dB sensitivity, though.
My plan is to give it a 30L enclosure tuned to 40Hz, for a peak of 109dB at 50Hz, 100W input.
For the mids I'll probably do these 4" GRS woofers and for tweeters these cheap Goldwoods
Then for the amps I plan to use this 100W Dayton mono amp for the sub and the 2-channel version of it for the mids/tweeters. I like the look of these amps cuz they're cheap, small, and have DSP so I can add dynamic bass boost to give it extra LF extension at low input amplitude.
What are everyone's thoughts? Is the LS10-44 good for this job, or should I pick a more efficient sub and use DSP to even out the response? The low system voltage cuts out a lot of higher impedance subs, but if it's really worth it I could do a larger battery pack.
Attachments
Luckily I looked around a bit more and found a Kicker 8" sub that had almost the same response in my 35L enclosure as the Dayton 10", while being 4lb lighter and $50 cheaper:
Kicker 44CWCD84 CompC Series 8" subwoofer with dual 4-ohm voice coils at Crutchfield
I also ended up swapping the 4" GRS woofers for Dayton TCP115s. They are heavier than the GRS paper-cones but should have way better sound. Right now I'm using some cheap Drok 4" woofers for testing since the TCP115s are back-ordered.
I chose the 6S 20A version of this BMS to protect the battery:
6S 7S 8s 10S li ion smart Bluetooth BMS with 20A to 60A constant current for 24V 36V lithium ion battery pack|Integrated Circuits| - AliExpress
It's a little overkill but I really like the bluetooth functionality to keep my eye on the battery and make sure the BMS isn't gonna destroy anything.
This boost converter is used to charge the battery from a DC input:
https://www.amazon.com/gp/product/B07K2PBZ5Z/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
and this USB-C PD power board is on the input to get 20V from a USB C supply (seemed like the most future-proof charging solution)
https://www.amazon.com/gp/product/B07T6LPP9W/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
Here's some photos of the build:
I used 0.5" birch plywood for the sides and a 12" tube.
The electronics housing, with the battery (blue thing on the left), 3D printed battery/BMS holder, BMS (next to the battery), boost converter to charge the battery (foreground) and USB C input board to give power to the boost converter (background). No amplifiers installed yet
The whole thing mocked up with the woofers and tweeters and the 3D printed port.
The rats nest, with everything wired up. The amps are the stacked red PCBs on the left. I've only played it for a few moments at max volume but no overheating concerns yet, hopefully they run cool!
The whole thing, painted and put together, with 3D printed handles. The weird screw sticking out is a "temporary" solution to press the on/off button for the battery charging boost converter, because annoyingly it defaults to having the output be off when it powers up.
Here you can see the 3D printed feet that make it so it can sit on its side and point slightly upwards, as it is in the previous photo.
The weight is 17.4lb, so it's a hefty one but I'd say its worth it for the amount of bass that it puts out. The mids and highs are not too shabby either, even with the cheap placeholder woofers, but the tweeters could definitely use an inline resistor since they're so much more sensitive than the other drivers. At max volume over bluetooth, there's no noticeable distortion so I think there's still voltage headroom. But that volume is plenty to hurt your ears from 20ft away so I'm not too worried about maxing out the gain!
Also here's the onshape doc that I used to plan out the woodwork and design the 3D printed port, battery holder, handles, and feet:
Onshape
Kicker 44CWCD84 CompC Series 8" subwoofer with dual 4-ohm voice coils at Crutchfield
I also ended up swapping the 4" GRS woofers for Dayton TCP115s. They are heavier than the GRS paper-cones but should have way better sound. Right now I'm using some cheap Drok 4" woofers for testing since the TCP115s are back-ordered.
I chose the 6S 20A version of this BMS to protect the battery:
6S 7S 8s 10S li ion smart Bluetooth BMS with 20A to 60A constant current for 24V 36V lithium ion battery pack|Integrated Circuits| - AliExpress
It's a little overkill but I really like the bluetooth functionality to keep my eye on the battery and make sure the BMS isn't gonna destroy anything.
This boost converter is used to charge the battery from a DC input:
https://www.amazon.com/gp/product/B07K2PBZ5Z/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
and this USB-C PD power board is on the input to get 20V from a USB C supply (seemed like the most future-proof charging solution)
https://www.amazon.com/gp/product/B07T6LPP9W/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
Here's some photos of the build:
I used 0.5" birch plywood for the sides and a 12" tube.
The electronics housing, with the battery (blue thing on the left), 3D printed battery/BMS holder, BMS (next to the battery), boost converter to charge the battery (foreground) and USB C input board to give power to the boost converter (background). No amplifiers installed yet
The whole thing mocked up with the woofers and tweeters and the 3D printed port.
The rats nest, with everything wired up. The amps are the stacked red PCBs on the left. I've only played it for a few moments at max volume but no overheating concerns yet, hopefully they run cool!
The whole thing, painted and put together, with 3D printed handles. The weird screw sticking out is a "temporary" solution to press the on/off button for the battery charging boost converter, because annoyingly it defaults to having the output be off when it powers up.
Here you can see the 3D printed feet that make it so it can sit on its side and point slightly upwards, as it is in the previous photo.
The weight is 17.4lb, so it's a hefty one but I'd say its worth it for the amount of bass that it puts out. The mids and highs are not too shabby either, even with the cheap placeholder woofers, but the tweeters could definitely use an inline resistor since they're so much more sensitive than the other drivers. At max volume over bluetooth, there's no noticeable distortion so I think there's still voltage headroom. But that volume is plenty to hurt your ears from 20ft away so I'm not too worried about maxing out the gain!
Also here's the onshape doc that I used to plan out the woodwork and design the 3D printed port, battery holder, handles, and feet:
Onshape
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I realized the images are kinda distorted in the previous post. Here they are resized:
As an update, I used SigmaStudio to drop the response 6dB above 5kHz and that smoothed out the response a lot. I've been listening to it more and it's a bit muddy in the midrange, hopefully the TCP115 woofers will smooth that out. I also might brace the top panel a bit more since it's pretty large and thin.
As an update, I used SigmaStudio to drop the response 6dB above 5kHz and that smoothed out the response a lot. I've been listening to it more and it's a bit muddy in the midrange, hopefully the TCP115 woofers will smooth that out. I also might brace the top panel a bit more since it's pretty large and thin.