Boozetooth Speaker MKIII

[3rutu5]

Probably just annoying members more than being helpful, but I'm sure I'll be flammed If I hit a nerve... For the last 12-18 months I've been attempting to make something that's portable, small and a bit of fun. I've had a go at the quaranteenie and 7 iterations of the beer cans. Most of the beer cans honestly haven't been successful as to cram everything in you sacrifice the internal volume in some way or another. This has been the first almost completed version where a port was used in lieu of passive membranes.

I'm still trying to work out the EQ settings to help compensate the slightly smaller box. The Chinese by/amp board has a Qualcomm module which is fully customizable via a USB-spi programmer. I've also sourced a 18350 li ion battery with a 1200mah capacity and designed the top to be able to be unscrewed and have complete access to the battery, buttons/switches, buck converter and the amp.

The driver used is a 2 inch peerless one from a Google home device and as it is powered by a amp that runs of 6.5v will be lucky if it will put out 5 watts per channel. The port is 10mm diameter and about 120mm long.

[3rutu5]

Video of the difficult assembly process

https://youtu.be/BoLTSlS8DtA

[Steve Lee]

Left hand threads on the bottom and right hand threads on the top.

So antipodean . . .

[3rutu5]

Haha that was a mistake, I accidentally mirrored it in CAD and I reprinted one part only which was the top. The top is right thread

[3rutu5]

Sanded this through a few grits starting at 80 all the way to 800.. the print itself left a few imperfections, but hardly noticable.

I also designed up a stencil to spray on its name which actually didn't turn out as bad as I thought it would, just wish it was a bit darker at the top but I'm leaving it

[Steve Lee]

Nice!

[tomzarbo]

You're tenacious! It came out really good.
how does it sound?

TomZ

[3rutu5]

You're tenacious! It came out really good.
how does it sound?

TomZ

The try run sounded pretty good, but haven't finished the soldering of the internals. I really want to work at thst Eq

[3rutu5]

OK, maybe this one should have been called the EPIC FAILURE SERIES....i tried to get a bit creative with some stencils and stuffed up, then tried to fix it up and it was all downhill (as in snow balled out of control) from there. Tried that method of hydrodipping (spray painting into tub of water and dipping into it), which actually turned out pretty cool, just this idiot didnt wait long enough, screwed it together and it stuck together stopping me from getting it undone......SO, in the bin it went and just finished printing a new shell.

Been fiddling with the EQ and i think there is too many settings on that little chip. I tried the Standard EQ settings first and did something like attached. And it sounded a bit funky, maybe because i had an EQ on my phone and on the Chipset, so maybe with technology as it is today that isnt really needed. Which brings me to a couple of other options.

Bass Enhancement - i set the master to be -3 db and gave it a 2db boost from 150hz, which sounded ok, but when pushed too hard the chip resets itself as it is being saturated. And i'm not sure if it is my ears by it sounded like the mid and upper end was starting to breakup a little.

Parametric EQ - I have always been curious about this since seeing you could add one in WiniSD under the filters tab, not sure really what to expect, i tried setting it to 100hz, +5db and a Q = 2, then dropping the master to - 5db as from what im seeing, anything that really gets above the 0db line is considered "saturated" and resets the chip. Was interested to then go back to WiniSD and set the same info and see what it did to the model. Maybe this is the option and just go a 3db boost and Q of 1-1.4, would still let me have a F3 in the mid 80's if i'm doing this right.

The is also a crossover function where you could set low or high pass filters and a couple of other items, but just not sure what i should really do in that regards and what the quality of the Qualcomm BT chip is on this 20 AUD amp.

For something that is 0.014cut roughly, and no lining or stuffing and me with my hand on the top of it, i reckon this is the closest that i've gotten to replicating that bose feel/bass on the lower end, just need to figure out the rest to get this Lowfi/low powered speaker sounding great in all the volume ranges (within reason), which seemed to be ok on the first runs without fiddling with any of the settings, except......the bass needed a little extra help.

If anyone wants to journey down the rabbit hole with me, i was thinking in lieu of the 2inch apparent peerless full ranger, that the DA DMA45's with a bit of trimming to the square surrounds could fit in there as well, plus some other 2-ers, so if you have a 3d printer and know how to use CAD hit me up and i'll give you the DWG's to have a crack.

[3rutu5]

So after completely buggering it up and reprinting it, I'm.finally back where I was 2 weeks ago, except.ive given it a clear coat and just press fit my momentary switches in, spst switch and a usb c breakout. One good thing a reprint was I could redesign the top for a usb c plug, which I think is better.

Been stuffing around with the amp and trying to get it how I'd like it, but maybe being a little pedantic as I want it to sound good.

The top has been the hardest thing to spray as it just builds up and looks a little meh, but should look good once on as the switches have ref LEDs and will control.the volume.

[3rutu5]

What does it sound like with no input signal and the amp turned all the way up?

I think its a combination of the step up module, voltage and other things.

I had a play with the chip and settings, sounds a bit average. Then swapped over to a CSR64215 variant, which had APTX and it wasnt as loud, but sounds ok just less features. Then used a 2x50w bt amp (no namer) with 12v and it sounded great, but then hooked it up to the 5v supply, which it can do and it was slighty better than the QCC3003, but you could sense there was something funky happening. I had these little battery holders with a 5v output for raspberry pi's and arduinos to use as the test source. Just seems to handle and sound better with the 12v source.

issues i can see it the 5-24v amp is small, but has a pot on it, which will make mounting it an issue, but as i'm using 18350 cells, i could side mount them under the lid and get the 12v's, but would need to redesign the lid, providing i can put the amp in there, which i dont know if i can yet.

[3rutu5]

Ok, I've changed the booster chip to a MT3006 one and went back to the QCC3003 chip and it sounds good, so my issue was the step up module sending an average signal/supply. Downside is the loss of space as I need another two chips where I had one previously. I'm going to drop the volume buttons on this build as there are just too many wires kicking about at the moment...

Also as I an actually at MKVIII, I couldn't help myself and doing the 9 iteration of this series which has the 12v amp and battery setup. 80% through the print at the moment so will be interesting how this all goes.

[3rutu5]

getting closer, had to rebuy the pogo pin clip/bench which arrived today, so was able to test my theory regarding designing in a bass shelf within the internal qualcom chip. first impressions is it sounded pretty decent, but it will be different once i cram everything in. I did notice with the 12v variant, is that it very packed and sounding a little thin, but with the 3.7v 1S version i'm hoping to keep this as minimal as possible. I redesigned the lid to remove the buttons, but included 4x 2mm flattop LED''s, which 2 for the TP4056 chip and the other 2 hopefully i can solder to the amp to piggy back on the power on and BT signal. I still need to figure out if i need to provide resistors on the yellow bulbs as 3.7v appears to blow them, but teh blue ones appear to run on 3ish volts and ok. I'm not that smart, so will be doing some research into what i need to do and whether it is even a good idea.

the test today i've gone a boost of the low end from 150hz of 3 db, but then lowered the master to -3db, which gave that bass shelf graph. turning it up on some bass heavy music, it went loud enough, didnt distort nor cut out or clip. Could it go louder if i remove the EQ settings? yes, maybe but might restrict the lower end, could i mod the EQ settings on my phone and keep it stock, yes i could, but i would prefer not Been an interesting journey so far, i just want to sucessfully finish one of these cans.

[Steve Lee]

Try modeling MkIX in a Fosters Sized Can and increasing the diameter of the driver used?

[3rutu5]

Try modeling MkIX in a Fosters Sized Can and increasing the diameter of the driver used?

fosters lol, the drink the world thinks australians have\like haha. Unless you are talking about a darwin stubby

I ran it yesterday and it was sounding pretty decent, then when i glued, screwed and assebled i must of bumped a cable and something went in crooked and it was all painful from there. I'm just doing a few tweaks at the moment, but think it should sound ok for a 5w driver being powered by a 18350 3.7v battery. I'll be moving on from these ultra tiny builds after this one, you can only take so many hot glue and solder burns before you break lol

[Steve Lee]

Just thinking outside of the can, mate.

[3rutu5]

Wired up and i can honestly say i've had enough of this tiny project

https://youtu.be/7R068GGK1_w

it aint going to shake any fixtures off the walls, but considering its size and what it is powered by i can honestly say i'm happy with how it turned out.... I really need to take a page out of tomzarbo book and get some better recording equiptment thats for sure, my busted up pixel 2 really doesnt cut it and i can hear some parts in the video where it sounds like it is muffled, but its full 360 degrees sound baby!.

next will be a 12v version of something...........just nothing has popped into my head yet