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Build process - sharp inspired 3d printed ghettoblaster (half size)
Hi all,
its been brought to my attention i have more than one project on the go and it is starting to get a bit confusing with what im asking in relation to which DIY job. SImilar to the boozetooth BT speakers, where i got up in the revisions due to design improvements. Originally this project started off as a full size Sharp GF 6565 to be printed and housing the W130 X - 2x4 woofers with the matched visaton full range driver, which got put on hold due to having issues with the printer than could indeed print 500mm high....
for a bit of fun and an excess of DMA45-8 drivers, it became a pair of them and 1x peerless 3.5inch passive as i had a couple in my garage i've never been able to use....this one became a failure due to trying a DIY hyrodip (spray cans, water and a bucket) and no matter what i tried the paint just would flake off and filled in the small details.
3rd iteration was the same print, but in white. The issue with this one was having 35mm internally which was fine to slide a driver in, but was impossible to glue in items and screw as it was one piece.
4th iteration was printing it like a traditional ghetto blaster would have been having front and rear panels that would ulimtately be glued together once assembled. This time the issue was the BT/AMP and the pot and additional SPST switch soldered to the board, it had too much interference and was continually browning out no matter what boost module i used. Also wondered if my original quarenteenie build sounded better with these smaller speakers as it had individual enclosures and not a shared one like the 2 above (listed as a failure). this one sampled a filter, which i dont know if it was causing the brown out, but it did appear to not fail as much when bypassed.
Now to the latest one currently rolling off the printer as i type (almost finished). The intention was to run 1x DMA45-4 with 1x ND90 PR per side, the rear and front panels were also designed to snap into place providing an air tight seal between the 2 sections. As i was reverting back to a previous amp choice (trusty QCC3003 module from the boozetooth's) i decided to do a little more design to look like the original unit with some uselss extra switches/knobs and a cosmetic spectrum analyiser. I also had about 100 of these 3mm magnets, where i designed them into the grill and front panel to assist the grill in holdiing in place. if they rattle off ill epoxy in.
Yes i know this isnt everyones cup of tea and a bit out there (weird even), but im civil engineering designer by trade, enjoy the 3d side of things and being able to print and make these models usable makes it all worthwhile in my opinion. I would be happy to provide the CAD if somebody wants to give this a go.
Now for the internals.
- Dayton Audio DMA45-4 x2
- Dayton Audio ND90-PR x2
- 1x 1KG Roll of PLA (approximate only could be less)
- QCC3003 2x5w BT AMP
- MT3608 buck converter
- 2200uF capacitor
- rocker switch
- Sony VTC6 3000mAH 18650 battery
- couple of LED bulbs and resistors
Something worth noting, you can program the BT modules, change EQ settings, change the name etc, which wasnt done for this as i misplaced the pogo pins clip. Natively supplying 5v's to these will give you 3w per channel at 4ohm, but they also mention that going 6.5v will give you 5w per channel, nothing to win a sound off at the local car meet, but not bad for a bit of portable fun. You can also solder a couple of momentary switches to control the volume, pre, next, play and pause, plus answer the phone (never tried the last one).
the below graph was based on the different scenario's
black - added 2g to the passive to lower the f3 to around 90hz. if the weight was removed it would model similar to the DMA45-8, but with a peak just shy of +2db and would be tuned to a F3 of 100hz. I wasnt sure if this would be a better option and be like the RS100 build in the actual 40 year boombox, where the higher F0 gave more the perception of bass. if 7grams of weight gets added it models very similar to the peerless passive scenaio with the dip from 200hz. I would be keen to know if this is similar as i can make this change relatively easy.
yellow - This option was using the Peerless 3.5inch passive, but requires 0.01cuft, which might not be achieveable unless using stuffing or some form of filler. This PR is quite large and might not actually fit even if was the better solution as 1 can fit, but would require the drivers sharing, but 2 definately wouldnt. This option was shelved as printing larger pieces on a 240 dia bed was preferred.
blue - similar to the first option, but using the DMA45-8 driver, with no weights. This was the original option, but with the change of BT/AMP, meant the output would go from 5w's to 2.5w per channel. I sampled this and just wasnt the loudness i wanted from, so shelved it.
Potentially i could have gone KAB board with the 12v battery board, but i just dont think i could get everything in the size i was going for. Potentially maybe a 3S configuration with the 16350's and some major redesign internally, but i think it would go past the point of return and sound average....
I also considered using the ND90-PR's with a ND65 driver, but just didnt want to sacrifice the additional 20-25mm of depth required to put a larger driver in a 3d print like this.
its been brought to my attention i have more than one project on the go and it is starting to get a bit confusing with what im asking in relation to which DIY job. SImilar to the boozetooth BT speakers, where i got up in the revisions due to design improvements. Originally this project started off as a full size Sharp GF 6565 to be printed and housing the W130 X - 2x4 woofers with the matched visaton full range driver, which got put on hold due to having issues with the printer than could indeed print 500mm high....
for a bit of fun and an excess of DMA45-8 drivers, it became a pair of them and 1x peerless 3.5inch passive as i had a couple in my garage i've never been able to use....this one became a failure due to trying a DIY hyrodip (spray cans, water and a bucket) and no matter what i tried the paint just would flake off and filled in the small details.
3rd iteration was the same print, but in white. The issue with this one was having 35mm internally which was fine to slide a driver in, but was impossible to glue in items and screw as it was one piece.
4th iteration was printing it like a traditional ghetto blaster would have been having front and rear panels that would ulimtately be glued together once assembled. This time the issue was the BT/AMP and the pot and additional SPST switch soldered to the board, it had too much interference and was continually browning out no matter what boost module i used. Also wondered if my original quarenteenie build sounded better with these smaller speakers as it had individual enclosures and not a shared one like the 2 above (listed as a failure). this one sampled a filter, which i dont know if it was causing the brown out, but it did appear to not fail as much when bypassed.
Now to the latest one currently rolling off the printer as i type (almost finished). The intention was to run 1x DMA45-4 with 1x ND90 PR per side, the rear and front panels were also designed to snap into place providing an air tight seal between the 2 sections. As i was reverting back to a previous amp choice (trusty QCC3003 module from the boozetooth's) i decided to do a little more design to look like the original unit with some uselss extra switches/knobs and a cosmetic spectrum analyiser. I also had about 100 of these 3mm magnets, where i designed them into the grill and front panel to assist the grill in holdiing in place. if they rattle off ill epoxy in.
Yes i know this isnt everyones cup of tea and a bit out there (weird even), but im civil engineering designer by trade, enjoy the 3d side of things and being able to print and make these models usable makes it all worthwhile in my opinion. I would be happy to provide the CAD if somebody wants to give this a go.
Now for the internals.
- Dayton Audio DMA45-4 x2
- Dayton Audio ND90-PR x2
- 1x 1KG Roll of PLA (approximate only could be less)
- QCC3003 2x5w BT AMP
- MT3608 buck converter
- 2200uF capacitor
- rocker switch
- Sony VTC6 3000mAH 18650 battery
- couple of LED bulbs and resistors
Something worth noting, you can program the BT modules, change EQ settings, change the name etc, which wasnt done for this as i misplaced the pogo pins clip. Natively supplying 5v's to these will give you 3w per channel at 4ohm, but they also mention that going 6.5v will give you 5w per channel, nothing to win a sound off at the local car meet, but not bad for a bit of portable fun. You can also solder a couple of momentary switches to control the volume, pre, next, play and pause, plus answer the phone (never tried the last one).
the below graph was based on the different scenario's
black - added 2g to the passive to lower the f3 to around 90hz. if the weight was removed it would model similar to the DMA45-8, but with a peak just shy of +2db and would be tuned to a F3 of 100hz. I wasnt sure if this would be a better option and be like the RS100 build in the actual 40 year boombox, where the higher F0 gave more the perception of bass. if 7grams of weight gets added it models very similar to the peerless passive scenaio with the dip from 200hz. I would be keen to know if this is similar as i can make this change relatively easy.
yellow - This option was using the Peerless 3.5inch passive, but requires 0.01cuft, which might not be achieveable unless using stuffing or some form of filler. This PR is quite large and might not actually fit even if was the better solution as 1 can fit, but would require the drivers sharing, but 2 definately wouldnt. This option was shelved as printing larger pieces on a 240 dia bed was preferred.
blue - similar to the first option, but using the DMA45-8 driver, with no weights. This was the original option, but with the change of BT/AMP, meant the output would go from 5w's to 2.5w per channel. I sampled this and just wasnt the loudness i wanted from, so shelved it.
Potentially i could have gone KAB board with the 12v battery board, but i just dont think i could get everything in the size i was going for. Potentially maybe a 3S configuration with the 16350's and some major redesign internally, but i think it would go past the point of return and sound average....
I also considered using the ND90-PR's with a ND65 driver, but just didnt want to sacrifice the additional 20-25mm of depth required to put a larger driver in a 3d print like this.
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