I Made A 3D Printed Bluetooth Transmission Line Speaker

I've been inspired by an old KZbin video to try to build my own Bluetooth speaker. The design I came up with uses primarily 3D printed internal parts, with some laser-cut clear acrylic covers. I've also documented the build on my blog, so you can make your own Bluetooth transmission line speaker as well.
ADDITIONAL INFORMATION
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Visit my blog for the written build guide and more information - www.the-diy-life.com/3d-print...
Take a look at the LTT video that inspired the build - • Can we build a better ...
Download the 3D print files - etsy.me/3JyHASn
PURCHASE LINKS
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2 x Dayton Audio PC68-4 Drivers - amzn.to/3oK0pIM
ZK-502T Bluetooth Amplifier - amzn.to/3Xq5k14
12V Inline UPS - amzn.to/3cRL7yT
60 x M3 x 8mm Black Button Head Screws - amzn.to/3zLU5a3
4 x M3 x 12mm Button Head Screws - amzn.to/3zLU5a3
60 x M3 Brass Inserts - amzn.to/3BvdqNL
8 x Rubber Feet - amzn.to/3OOCliD
0.5m Speaker Wire - amzn.to/3cXq8uJ
Black PLA Filament - amzn.to/3JnmRRl
3mm Clear Acrylic - amzn.to/3Bs1WuA
Equipment Used
Creality Ender 3 S1 Pro 3D Printer - amzn.to/39lxlTX
K40 Laser Cutter/Engraver - amzn.to/3OcnT42
Electric Screwdriver - amzn.to/3zny0gl
TS100 Soldering Iron - amzn.to/3vw6MDo
Knipex Wire Strippers - amzn.to/3Q8xvh7
Some of the above parts are affiliate links. By purchasing products through the above links, you’ll be supporting this channel, at no additional cost to you.
CHAPTERS
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0:00 Intro
0:37 Selecting the Components
1:37 Desinging the Enclosure
3:32 Making up the Parts
4:33 Preparing the 3D Prints
5:12 Assembling the Speaker
8:13 Testing the Speaker
10:24 Final Thoughts
If you've got any ideas for Raspberry Pi, Arduino, or other Electronics projects or tutorials you'd like to see, let me know in the comments section.

[@mvrck-pb5pk]

Would love to hear them IRL. Thanks for sharing.

[@Sithhy]

I really like the design, looks like some premium hi-fi from the 80's

[@klave8511]

A lot of great ideas there, well done! Loved that you didn’t just print everything and that you used the laser where it was more appropriate for cutting and material selection. What I would have done differently (with 20-20 hindsight and not necessarily better). -Run a channel for the speaker wires internally so they don’t show (where possible) -More screws to hold the side panels onto the print and an O ring or foam strip between the panels and the baffle to prevent vibration of the side panel. -For a wideband speaker response I would have tuned the rear to a frequency lower than the resonance. This would depress the resonance and boost lower frequencies. -A mounting for the UPS (great idea BTW) to the back of the assembly. -To be honest, I would have used a PVC pipe for the setup and it wouldn’t have looked as nice but would have looked right at home in my shop. -To really kitch it up you can now add LED strips to light up those clear acrylic edges. You can laser some bold graphic into the sides that would come alive when the LEDs turn on. Add some electronics to drive the LEDs to the music. Well done and thanks for the video.

[@MichaelKlements]

Thanks for the feedback and ideas. I really should have tried to engrave something onto the side panels, that would like pretty cool with some RGB. I'll definitely look at including some sort of cable management or cable holders to neaten that up.

[@DocLois2010]

Awesome work!

[@KevinDC5]

I really like the clear sides to showcase the waveguide. I used mdf on my build and I recall what a shame it was that nobody would ever see the mechanism that made it sound so great. Great Work! I would add some ws2812 rgbleds under the handle to illuminate through the acrylic and make it glow!

[@Truth12345]

I'm currently creating a 3d printable subwoofer (6th order). Fs is not the only spec that matters for creating good speakers. I use winisd to calc the speaker enclosure. The port length is subtracted from the speaker internal volume. The diameter of the port/vent also determines the length of it. I had to made it smaller so length also is shorter. The only thing to watch is it doesn't produce to much wind. Anyways your speaker looks cool.

[@christopherbijsters7989]

This is really brilliant, Keep it up Mike Thanking you again for an awesome video

[@MichaelKlements]

Thanks Christopher!

[@keatonjones6115]

definitely use some weather stripping or double sides tape / something similar for sealing side panels i do alot of 3d printed stuff and too many times ive thought a design was crap but just turned out to be air leaks. It destroys bass even with the smallest of leaks especially in a transmission line! awesome build though man! i too am a fan of using printing to make hard designs easy to build!

[@MichaelKlements]

Thanks for the suggestions, I'll definitely look at using some weather stripping on my next build to seal the edges.

[@gregspeakman9337]

Another great build. Your skill at the CAD program makes this project look easy. I don't know if this is a suggested improvement, but as a lot my friends use their Bluetooth speaker with their cell phone, maybe a cell phone cradle on top of the amp would be a nice touch. Good vid.

[@MichaelKlements]

Thanks Greg. I actually thought about putting a cradle into the gap in the middle, my phone fits there perfectly. I thought this landed up being a bit too "retro" since a bluetooth speaker allowed you to just keep it in your pocket haha. It's something that would be super easy to add on though.

[@chrisgaddy10]

A wireless charger on the phone cradle would be nice

[@blackmennewstyle]

Your channel is absolutely amazing

[@MichaelKlements]

Thank you!

[@MarinusMakesStuff]

Nice design, I'm thinking of repurposing my speaker setup to turn it into a similar build. Just one word of caution: do not tin wires that you will put into a screw terminal. This will pose a problem in the future as the solder tin will deform and the wires may fall out. The best way of attaching them is by crimping the ends of the wires. This is especially important when dealing with power supply wiring, but still important for speakers since you want a solid connection.

[@MichaelKlements]

Yeah it's not something I usually do, I didn't have small enough terminals to fit into the blocks on the amp. Thanks for the tip though.

[@ikestoddard2458]

Please consider doing a video on tuning out bad freqs in the speakers.

[@minkorrh]

Really nice job. Doesn't sound too bad from my end, but of course it will lack depth in comparison to bigger drivers/more complex larger design.

[@squirralien1863]

Absolutely great, you do a great job with all your builds, it both frustrates me and inspires me because I have the 3d printer and the laser but both not setup yet, I just don't get much time, hopefully soon, then it is the learning curve to operate these machines. I looked at Fusion 360 yesterday and found I need to watch some tutorials first, I have been using Tinkercad and that's just too easy in comparison. Oh well, great job Michael, love watching your builds.

[@MichaelKlements]

Thanks for the support! Yeah it can be a bit overwhelming to start out, you just need to break it down into smaller and more manageable bits. Try playing around with Tinkercad and the 3D printer first, then look at adding laser cut pieces and then go on to improving your designs with Fusion360. Tinkercad is really basic, so you'll outgrow it quite quickly but at least it lets you focus on learning the printer and laser cutter.

[@squirralien1863]

@@MichaelKlements Thanks, I do like Tinkercad and can design anything I want on it now but I was feeling it might be time to step up to more function until I looked at Fusion 360, but I will watch many tutorials as time goes on and will eventually be comfortable with it. At the moment my dad is printing so I create things he wants. I really look forward to having my 3D printer and laser up and working well, both new just need to be setup. Thanks again for your guidance and video efforts,

[@richardbriansmith8562]

It's an Awesome design and an Awesome Bluetooth speaker AWESOME Video

[@MichaelKlements]

Thank you Richard!

[@simonburke6681]

That's really cool Mike, next you could add a I2S DAC and integrate it to HA with ESPHome

[@MichaelKlements]

Thanks for the suggestions! It would be great to add WiFi connectivity and some sort of AirPlay enabled device to it.

[@simonburke6681]

@@MichaelKlements CJMCU-1334 I2S DAC stereo Module UDA1334A, with ESP32 confirmed working with amplified computer speakers here if you have an input on that. Was simple using the ESPHome I2S Component Example

[@lotussymphony]

Great project! But this kind of projects are about researching and enjoying the process not about knowing if it’s cheaper to buy it.

[@DiscoCol08]

Looks really cool,

[@MichaelKlements]

Thanks Colin

[@gregglumus5303]

I would like to create a speaker enclosure for my rear 4"speakers in my Isuzu Rodeo. Right now they point straight down into the trunk area. I would love any advice you could give out even a video that focuses on what needs to be considered in a approaching a project like this.

[@ihatedietcola7920]

I'll buy that thing!!!!

[@GodisGood1776]

Epic

[@DrKlampit]

Michael - love your design process and the beauty of your videos. Well done! I did wince a little when you tinned the speaker wires and might suggest you look into using ferrules for screw terminals. Sharing this video with my Maker group now.

[@MichaelKlements]

Thank you! Yeah I don't usually do that, I didn't have terminals small enough for the blocks on the amp.

[@jackal6902]

Wish I could actually hear it.

[@cabasse_music]

this is the equivalent of skipping straight to expert mode. did you try playing with the response in hornresp? i've got some half finished designs that i have struggled to transpose into a 3d model. (i''m most comfortable in sketchup, but gave up after trying my hand at FreeCAD) i need to try fusion 360 out.

[@MichaelKlements]

I didn't stumble across hornresp, but I'll definitely try it out. It looks like a pretty neat tool. Fusion360 is not the most user friendly to get started with, but its powerful when you get the basics right. I use TinkerCAD for the more simple stuff, it's really easy to use but a little too basic for designs like this.

[@-someone-.]

Looks awesome, but if you’re serious about sound quality, consider using wood next time! Would love to see and hear it! 👍

[@MichaelKlements]

That would be ideal, I don't have the woodworking tools (or likely the skill haha) to be able to produce something like this from wood though.

[@-someone-.]

@@MichaelKlements I remember you did a wooden pi case, so I thought you might try it with the speaker😅👍

[@MichaelKlements]

Haha yeah I could probably laser cut the panels and do a "flat pack" design.

[@-someone-.]

@@MichaelKlements you’ll be amazed at the improvement in sound quality! 👍

[@A.X.N]

That looks like a back loaded horn, not a transmission line, the transmission line has a constant cross section area. Back loaded horns are very difficult to design properly. If small size is a priority a passive radiator box is a simpler and more effective way to it. Look cool though

[@MichaelKlements]

Thank you for the advice!

[@DDBAA24]

I would have made it wider , built a PC into it or a Raspberry your half way to the baddest-ass gaming cabinet or media server center. Power control would be easier there are just so many things you can do. Or even go small and just add a 3.5 - 5.0 inch touch screen for interfacing with the stored files. More like a jukebox, but keep the look, keep the dials analog 👍

[@MichaelKlements]

Haha this is actually a pretty cool idea. I quite like the thought of turning this into a mad looking little media centre or gaming setup.

[@davidvalens3337]

where did you get the portable screw driver from?

[@Joshpereira1012]

Hi i love your build but i am thinking of buying a 3D printer and i just wanted to know how much filament should i get and which type? also how long would it last. Thanks :)

[@MichaelKlements]

Hi JJP, that's great. Definitely go with PLA to start as it's one of the easiest materials to print with. The quantity depends on what you're printing (size and infill) - a 1kg roll goes quite a long way for small general prints.

[@Joshpereira1012]

Oh thanks so much for the help this helps me so much I'm subscribing :)

[@julianlott6466]

Nice Project, how big must my printer py? I don't finde any information.

[@MichaelKlements]

These print on an Ender 3, so a 220mm x 220mm print bed is fine

[@Shooter_FPV]

The ZK-502T Bluetooth Amplifier isn't available anymore... is there a suitable replacement?

[@MichaelKlements]

I've updated the link to one that is available

[@Shooter_FPV]

@@MichaelKlements Thanks!! Your work is incredible!

[@juststuff5216]

Folding the line too much, IMO, isn't a great idea when it comes to t-lines IMO. Better to keep the line as straight as possible. This is a larger example of what I'm trying to get at. But if I had two small drivers, I'd do something like this kzbin.info/www/bejne/oHKxfpyKi8xmgNk But killer build, dude! I'll leave you with this. I'm sure you'll enjoy it. it;'s an old video, and I suggest headphones! kzbin.info/www/bejne/Y4aWiYpsibtssKs

[@MichaelKlements]

Thanks for the advice, this was my first attempt at a transmission line speaker so I have a lot to learn! Is there no implication/tradeoff to sharing a t-line between two stereo speakers as in your design?

[@juststuff5216]

@@MichaelKlements Such a design, there are going to be slight acoustical issues, however, I aim for bass depth. As for this particular design, it wasn't an issue, as the hybrid nature of the design, meant essentially, each driver was operating independently.

[@juststuff5216]

​@@MichaelKlements However, the design is basically a console, which can be tricky acoustically. kzbin.info/www/bejne/mImVeJlvpZWEZ7ssi=yINsmQYBT0Mre_c4&t=40 With more drivers, maybe one could mitigate certain acoustical issues, or maybe create even more, but I enjoy getting big sound from small drivers.

[@kelvino5305]

I thinks this is kinda stupid to be honest to much time got invested just for some trashy speakers with bad highend and bad lowend, just my opinion. Think you could do better and cheaper

[@petert2922]

Picking 2.5" drivers instead of 2" for a bit more bass made me spit my tapeworm. Bass doesnt start before 8".