This project nearly broke me... Building a 1kW Subwoofer from Hempcrete!

Thanks to PVCase for sponsoring this video! pvcase.com/Tho...
Inspired by the design of the SpaceX Dragon capsule, I set out to mold its shape into a highly functional subwoofer, made with eco-friendly materials!
The amplifier I used (it's pretty good actually) go.toms3d.org/1...
Printed on the Prusa MK4 go.toms3d.org/MK4
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[@rodanvsandrew]

The mold development is what I find most interesting. I'd be fascinated to see your process for determining and creating the mold pieces.

[@thedabblingwarlock]

There's a technique that I remember hearing about for molding stuff like this. You first put on a relatively coat of just plaster on the mold surface, then you let that cure for a bit before adding in the reinforced stuff. it results in a better surface and allows you to make sure you got material everywhere you need it. Looks cool, though. Definitely one of a kind!

[@AndrewHelgeCox]

Yes that's used for glass fibre reinforced concrete projects like countertops and cool things. One I saw was a thin sheet that had a wide radius 90 degree bend in it so the same sheet started as one leg of a desk and became the top surface of it too.

[@bensimms7294]

The channel 'Modustrial Maker' does a lot of concrete moulded stuff and that's exactly his process.

[@mandrakejake]

Normal fibreglass (glass reinforced plastic) is made this way, a layer called gelcoat is applied to the mould surface before the rest of the bulk material is applied. This leaves a glossy outside face when it is removed from the mould

[@therick0996]

really loving the direction to "use 3d printing for projects" and not just 3d printing!

[@SianaGearz]

Every German's hobby: building speakers. I think Germany is the only country in the world with SEVERAL DIFFERENT periodical magazines available at every train station newspaper stand dedicated to DIY building loudspeakers, testing drivers and components etc. I can't imagine otherwise.

[@fnytnqsladcgqlefzcqxlzlcgj9220]

What are they called? Would love to read some

[@daskadse769]

@@fnytnqsladcgqlefzcqxlzlcgj9220 "Hobby Hifi" and Klang und Ton" are the usual two suspects.

[@SianaGearz]

@@fnytnqsladcgqlefzcqxlzlcgj9220 One is "Hobby HiFi" lead by acoustical engineer Bernd Timmermanns and another is "Klang+Ton" from a publishing group which does a lot of HiFi related things.

[@zebarzebra]

Isn't that something the Brits also do quite a lot?

[@bi0530]

@@fnytnqsladcgqlefzcqxlzlcgj9220 A lot of this has moved to online media now: google "lautsprecher selbstbau"

[@smellyfis]

Arm chairing engineering here but plaster you have to be really cautious on the clean up because already cured plaster acts as a catalyst to speed up plaster curing. so make sure all surfaces that touch the new plaster is super clean.

[@adambakercollege]

You can mix up some plaster as a slurry coat to fill in the any of the surface gaps and imperfections. Plaster is very sand-able and forgiving.

[@groggynod]

A concrete agitator would have prevented that, I would not have even thought about it had I not seen it on another channel recently.

[@jackmanatee3162]

I was thinking Bondo. Would that work?

[@NiHaoMike64]

@@groggynod Evan and Katelyn recently tested a vibrating pen for that use, worked surprisingly well.

[@H3xx1st]

How about one of those massage guns? That'd probably get enough vibration to settle/get bubbles out

[@TheRealCrzychicken]

Just want you to know you saved 3D printing for me. I have had an ender 3 for a few years and have never gotten great prints from it. Things have broken and been fixed and I've done a couple upgrades, so it seemed like I was working on the printer every time I used it. Add to that the fact that I don't like running my printer when I'm not home so I'm limited to small parts and the whole experience was pretty frustrating and I ended up rarely ever using my printer. Your video "0.4mm nozzles just became obsolete" convinced me to switch to a 0.6. Suddenly I can print small parts in half an hour or 2 hours. And the print quality looks good!? And I am able to print large parts overnight!? And my direct drive upgrade doesn't jam anymore when printing TPU!? So now I'm selling prints (with the correct licenses I promise) to save up for a bambu with an AMS. Thank you. Seriously THANK YOU for what you do.

[@VincentGroenewold]

Very cool! I personally would've made it easier to fix though, seems more engineering minded that way. :) But unique nonetheless and I like the variety this brings to the channel.

[@raonipr]

since you have 2 semi-identical subs with a minidsp on the loop i think it would be a great project to use them both to cancel room modes, and btw for normal listening levels plugging the port with dense foam (turning them into sealed subwoofers) and compensating for the low end loss on the minidsp just sounds way better IMO.

[@MadeWithLayers]

That's the plan (and the reason I haven't torn down the prototype yet ;-)

[@PeterScream]

To anyone interested in building their own speakers: 1. Do not glue your drivers; instead, use screws to mount them. This is essential for easy removal, which allows you to replace and service anything necessary. Moreover, it enables you to further tune the acoustics inside the enclosure. 2. If you decide on an active system (with amplification), use an amp that has twice the RMS power of the driver. This is a rule of thumb, but it definitely applies to subwoofers. You'll want to be able to handle the peak impulse power. 3. There are fantastic enclosures already calculated and optimized for small size and great response. Some may have complex internal structures. In general, it's fairly easy (if you don’t do something terribly wrong) to build a decent subwoofer. The difficulty lies in building something that performs great, has a small footprint, and is fairly cost-effective in terms of transducer and application. GL HF 😊

[@JBernhard72]

Shout out to @HexiBase ! Thomas you could have 3d printed the enclosure for a subwoofer!

[@mjc2ride336]

Cool project for sure, but for a better overall appearance, you could have just 3d printed an outer layer and filled using your plaster mix on the inside for the desired density needed.

[@JerameatC]

How much did the finished product weigh? I have been a long time fan of your works, please acknowledge me senpai.

[@AndrewHelgeCox]

For a one-off, another approach would be to print pieces of the shell mostly hollow and then fill them with plaster or concrete for mass. You could go with a polymer concrete mixing sand and aggregate with resin for the binder.

[@klave8511]

Looks like a good candidate for aircrete/ cellular concrete. Well done for completing this project, very interesting.

[@GnuMovies]

I would probably have a external amp for this subwoofer since you cannot open it as you said hopefully the amp keeps working for a long time

[@nhand42]

That's an epic build. I think the plaster with all its imperfections looks fantastic.

[@toolsaddiction]

Thats the kind of project i do and im super proud when done and then the GF says no way in hell its going in the living room

[@PierreVilleneuve88]

So much work. I think it deserves a much better driver. The mold is quite impressive.

[@raidzeromatt]

Am I the only one who was hoping for a flying subwoofer when they clicked on this video?

[@Les_Grossman]

😂👍

[@Zachary3DPrints]

Very very cool video, I love it to see the old recording set from the old days

[@ats1995]

I'd love a video more about CAD, your work is gorgeous!

[@ricardopereira3461]

I am very glad that you changed your chanel for something that you love like a maker ! Congrats

[@mickgibson370]

In 1975 I used a flame speaker. Propane was used. It wold go to 1 hertz. But 5 gallons propane a night, it really costly!

[@hillonwheels8838]

Nice job. If you want to in the future make it smoother I would recommend drywall compound because you can use a wet sponge or rag instead of sand paper to smooth it out and have a cleaner work area.

[@Zeldur]

I'd love to see a video with ways of splitting a model (with tolerance) more organically than a straight line. The split bodies feature looks like it might work

[@bsaddresss]

Just Awesome... That's the type of project that "Makers" love to do.

[@paulmiller7078]

This is a very cool project, I love this channel, and it came out very well for the first try... But all I can think about is that this video is like the love child of DIY PERKS and a concrete life hack KZbinr.

[@heyitshavoc]

This is one of the most creative things I've ever seen done with a 3d Printer. Consider me inspired. Well done!

[@Xailow]

Gorgeous design! Really opens up options for speaker designs

[@ericseidel4940]

If you want to use plaster to your project and want to harden it, an make it almost not prone to retract when drying: Add some TILE GLUE to your plaster mix, depending on thickness try 10 to 20% (not critical) . Very good and cheap way to get strong results and good finish when molding a big part, fill a big hole in your wall....

[@leighrobinson]

The mold process and the final form is pretty cool. I’m not sure I would have gone this route though, those speakers were begging for a redone crossover to take the brightness out and extend the sub bass. Might be worth it to make sure any caps haven’t dried out over the years. I have some O'heocha Saturn D2s in my living room that took quite a bit of wife convincing. I’m not sure I’d get approval for a concrete space capsule sub! :)

[@assuncaP]

Probably a good alternative would be using natural fibers composites. Or maybe a even crazier option denim like the sun glasses dude.

[@partsdave8943]

Cool Those Klipsch speakers were built 90 miles (145 KM) South from where I live in Arkansas. USA

[@davids.6671]

Good idea. But the materialselection is a little bit weird? Wouldnt kneading concrete and a paintjob with Joint color lead to a better result?

[@ShawnChristopher10101]

Did you change the title? The title changed from "This project almost broke me" to "Can I mold a 1kw "SpaceX" Subwoofer..." Without refreshing the page....new KZbin feature?

[@thomaskletzl6493]

changed again in Almost none of my prints for this project ended up in the final product!

[@starlingcz]

And even before this title was "Almost none of my prints for this project ended up in the final product!"

[@dotJata]

They change the titles to get more exposure on the YT algorithm.

[@HydraulicDesign]

3:25 straw reinforcement, lol reminded me of a customer I visited. He made giant masonry furnaces, had a cool house he built himself, he was giving me the tour and slightly sheepishly said "uh this part of the floor is reinforced with straw instead of rebar because at the time I was in to the dangers of electromagnetic fields."

[@stephenhobson8456]

Thank-you! Making custom shaped concrete moulded speakers has been on my "one day" project list for over 20 years - I hadn't thought about using 3D printing to achieve it though. As always your "walk through" video format is awesome, and I love the Dragon capsule design. If you do read this, could you please link to the sub amp you used?

[@MadeWithLayers]

Thanks! Directly 3D printing the shape would have taken way too much filament to make it work as an enclosure, so I think making molds is a great good middle ground. The amp I used is from Aliexpress, I specifically chose it because has its own 110/230V power supply built in in a way that won't introduce additional noise due to grounding issues etc. You can find it here: go.toms3d.org/1kwAMP

[@carstenschade8314]

Hi, I am making similar parts like you did with my 3d printer. I would like to know, why the acryl paste is not sandable? Is UV-resin better for smoothing parts? -Very nice work btw. Tip for Plaster builds:Next time start with a very light mix of plaster an apply it with a brush. Two layers of 1-2mm make a perfect finish an the big plaster filling won't leave holes and gaps. Also the fiber material will not be this much visible...

[@nerferx]

30kw of solar panels! WOW I wish we were aloud systems that big... most systems in Australia cant exceed 10kw... As an ex audio engineer, we used to cover standard speakers in a concrete render, and line the inside with DYNAMAT, and it would improve the sound quality immensely.

[@Esprit1711]

Erst wenn der Subwoofer die Katze inhaliert, fckt der Bass richtig übel! - Wolfgang Amadeus Mozart (1756 - 1791)

[@plastikbeau3695]

The muskrats are going to adore you.

[@JohnWinter-m5r]

This looks to be an interesting and unique project…. Just a suggestion - to make the it more serviceable and portable could you have perhaps placed a non/semi-adhesive gasket between the top and bottom sections? I imagine that the weight of the top section would be substantial enough to create an airtight seal? I do realise that the whole structure would not be as rigid but would this significantly impact the audio performance?

[@DerSolinski]

Yep, as a electrician I can confirm "Elektriker Gips" keeps the "Altbau" together...

[@bakaXY]

Great project and loved every minute of the video.

[@drfailbucket]

When you want to add some extra time with the plaster heres a pretty neat trick I've learned For 5kg of mix trhow in 2 Tablets of magnesium in I've to work with this stuff very often and we usually get 5kg buckets. We always had to split the bucket in order to be able to work with it and not having troubles with curing. When an old friend of an coworker was helping oit he throw 2 tablets in the bucket and could easily work with the entire bucket without any hassle. Maybe it comes handy for the next project

[@AndrewHelgeCox]

Did you consider moulding with a polymer concrete that's a mix of sand and aggregate with resin for the binder? You could pigment the resin or go for the natural look. You could try special sands and rocks like pure white or fancy colours. You could go with perlite aggregate for lightness and whiteness.

[@rklauco]

This video is worth watching even just for the dovetail cut! Thanks!

[@petergplus6667]

I never built a speaker but wonder why you wouldn't put the electronics on the outside or even separatly? The vibration may hurt the circuit on the long run and also no disassembly when there is a failure?

[@sergetheijspartner2005]

Moving heavy parts with those safety shoes, great thinking

[@Fejszi]

Hi Tom! Been watching your content for quite a while. I know that you don't want to locked into 3D printing. But your video on your homebuilt extruder was quite interesting, in it you say that one day you might try to rebuild it. I think it could make a great video, most of the currently available designs use custom made parts that are expensive, your extruder was built with off the shelf parts

[@jlg23us]

I'm actually going to try this for some outdoors decor.. maybe a combination of routed and 3d printed parts.. great idea.. totally inspiring

[@WreckDiver99]

I have a set of those speakers! Mine too are signed. The audio store I went to for purchase said that he was known to sign MANY of the speakers because he was VERY involved in the QA process.

Me and my father made a cement mixer with a bubbler system and created aircrete. Rally is amazing how lightweight the stuff is. Lots of trial and error to get the ratios right.

[@falxonPSN]

Would something being such a thick layer of plaster have a major issue on heat dissipation? It seems like it would build up a tremendous amount of heat inside the enclosure.

[@Art_Of_Sound]

Great work...again! Thanks Thomas. I do this for a living ie making speakers cast etc out of a proprietary material called woodstone acoustic. Just a tip. Dont glue speakers in...use butyl mastic...it is the ideal material as it stays pliable for years and can easily remove the speaker if needed

[@Art_Of_Sound]

oh an vibration would have solved your surface imperfections 🙂

[@TheButchersbLock]

Great video mate. Love the rocket sound at the end. Fill the port with paper confetti and play the launch audio for a short? That would look cool. 👍🇦🇺😊

[@sammyspade123]

Great process video. Nice to see this coming from your channel. Cool final piece. Going to check out the carbon fiber project. Thanks

[@leopoldogastel]

Looks great! Awsome project . . . but please sand down the globs on the side engine port, or at least make them not shiny

[@cris_k_b]

could you do a few layers of pure plaster and let it dry before adding the fiber mix to get a better surface finish? or would there be issues with bonding between the two layers, edit: great project !

[@extectic]

Maximum weight is better. For a subwoofer especially you want them inert. The issue might be that too hard materials will start ringing and making noise. But more mass more better.

[@sujithkr136]

Nice Project ...A little more post proessing would have been nice.Some fillers and little bit sanding to get rid of the parting lines between individual parts..Looking forward to you next project :)

[@CNC_ROBOT]

The concrete or any kind of mixture, used in construction building must be vibrated for to fill all the holes and achieve maximum strength.

[@RomanoPRODUCTION]

Thomas the CHAD of DIY :) Nice day!

[@Kaliumcyanidful]

Great video! It could be easier to 3d Print an outer Shell, assemble, make it look nice and then reinforce it from the inside 🤔

[@ywsx6489]

You should be able to find the original crossover for your version of Fortes and rebuild it with new components from say Mundorf. Or at least replace any electrolytic caps in the existing crossover.

[@rhalfik]

I don't understand what this breaking test had to do with the build. Even much better speakers are made from mdf, which would break too, but apart from it very interesting molding process. Regardless of the design the port must be kept as smooth as possible or else you're compromising performance.

[@TheAlastairBrown]

This is really awesome, but I don't understand going to so much trouble but not giving it a full smooth finish and gloss paint job like the real one, it could look amazing. Thumbnails get views too, and it's more content.

[@NoizieWorks]

That's so cool!

[@tombo7719]

Been wanting to design and print out enclosure for muh truck

[@roysigurdkarlsbakk3842]

You know, the electronics in there will eventually die. Usually the capacitors dry out first and then it all goes down. It'll take time, probably years, depending no the component quality, but it'll eventually happen regardless of your wishes. So - perhaps it'd be better to make it openable? For instanace, why not fasten that bass element so that you can remove it and use that hole as a service point?

[@MadeWithLayers]

The chassis is the entry point here. I intentionally mounted it so that it would be able to pop out the bottom of the enclosure, and made sure to angle the amplifier board up so that it would be accessible through that hole. So while not super convenient to access, I did give myself a bit of a chance to repair it should things go bad.

[@kissingfrogs]

Splendid. Thoroughly enjoyed the video. Great dive into suitable materials. I did cringe when you glued the speaker in and was curious as to why. Would have been a great access hatch for repairs.

[@thunderzone802]

What do you do with all the left over printed parts + waste?

[@freescape08]

I like the juxtaposition of the UFO subwoofer and your sponsored "solar system". I was looking away during that transition, and i thought you had a solar system diorama set up in your house. 😅

[@gryzman]

screed is something used for floors in the UK

[@capitalinventor4823]

I was a bit surprised that you didn't try different percentages of additives to the plaster in a second round of testing. Perhaps the plaster bricks failed in the first round because they had too much filler and a smaller amount would have given you a stronger result for just a little extra mass. While this project may not have needed it in the end it would have been interesting to see.

[@edgar9651]

Nice. I wonder why you didn't mount the speaker from the outside. In that case you could remove it for service i.e. if there is a problem with the amp. It would be sad if you have to destroy this thing to be able to change a fuse on the amp...

[@MadeWithLayers]

The driver is actually mounted from the outside - while the OSB is mounted non-removable from the inside, the driver itself slots in from below.

[@RomanoPRODUCTION]

Thomas : Made with Layers of CHAD

[@HayesHaugen]

I was surprised you didn't use Luban to automatically split the model into pieces for assembly. Any particular reason you didn't?

[@MadeWithLayers]

I placed the split lines on most of the parts quite intently as the lines would likely be visible in the final molded piece, which meant quite complex splits and non-planar splitting lines in many cases. That being said, I haven't tried Luban for splitting, but I'll give it a go. Thanks for the tip!

[@AndrewHelgeCox]

Did you start with a thin pure plaster layer against the mould before bulking up with the fibre mix?

[@MadeWithLayers]

I did not, because I did like the texture it gets when if the fibers poke through the surface

[@fouzaialaa7962]

maybe add a coat of resin on the outside and the inside and it defiantly needs paint plaster likes to flay and there WILL be particles all over your room ,from the plaster flaying on of itself ,but also from the subwoofer shaking the inside and pumping all of those particles into your room plaster is NOT a great material to keep indoors unless you paint over it to keep the particles in place.

[@DHyre]

What a great and unique project! Now you need to apply similar custom-molded cabinets to some smaller, more-modern mains, perhaps using a kit from CSS Audio :)

[@brydenquirk1176]

I donno i cant help but think just printing the parts out with nearly no infill and filling them with plaster may have given a better result

[@youtubeviewer7077]

Cool. How long to print all the molds combined?

[@notG1O]

Fantastoc project and attention to detail. DIY audio gear is always cool! Curious on why you chose OSB over something like MDF? My understanding is that mdfs consistent density is really good for speakers. Wiwh i coild do something like this but my wood framed apartment would get the neighbors upset pretty quickly lol

[@RobinRastle]

mdf, nasty stuff to machine, need high power exhaust fans then you blow all that carcinogen powder all over your neighbours

[@capitalinventor4823]

The advice about the MDF and speakers is concerned about building the case. Changing the little bit of OSB to MDF in this build would do very little, if anything, to the sound quality, especially as it not involved in producing the sound.

[@notG1O]

@@capitalinventor4823 that makes sense, also holy hell the typos in my original message.

[@radry100]

1 week is not enough to cure cement/concrete though. It needs at least 2-3 weeks and even then it will get stronger over time afterwards.

[@MarinusMakesStuff]

Absolutely fantastic project Thomas. Well documented. I would really like to see how you worked out how to make the mold. I've been planning to make smaller molds with my X1C but I keep running into the issue of having my PLA curl up around the edges. Still haven't found a solution for that sadly. The PLA stays attached to the bed, but it just pulls up the flexplate from the magnet. Really annoying, so I hope to find a fix soon and then I'll be looking at making the mold in Fusion360.

[@homiethefish]

I love seeing these "other interests" videos from time to time. I've been interested in 3D printed molds since first seeing Ramy RC use them for carbon fiber to create beautiful scale commercial airliners. In America, because your business is making videos, this entire would have been tax deductible.

[@frogmandave1]

What an awesome project. Great job. Great content.

[@BlackOmegaVirus]

Du lebst im Traum, extrem großartig! ❤

[@gregoryp203]

Why not print the parts hollow and fill them with the plaster

[@flymypg]

I was secretly hoping for a plaster extruder on a large delta printer...

[@StumblingBumblingIdiot]

That was cool. Now how loud can you take it before it cracks the case 😁 METALLICA!

[@Audio_Simon]

Wow super nice project Tom and you sure put the work in! A shame you can only cook very small pizza in there 🍕

[@RobinRastle]

why didnt you use a vibro hammer its what builders use to get ait bubbles out

[@deedsvp6990]

What adhesive did you use to glue the panels together? It looked like you were using a UV light after each panel was installed. Thanks for sharing.

[@MadeWithLayers]

There are actually a couple of "adhesive" steps in this project: - Gluing the individual printed mold pieces together: Construction adhesive, as it sticks well to PLA and is gap-filling - Topcoat to smooth out the layer lines (1): "Acrylic modelling paste" (this didn't work well) - Topcoat to smooth out the layer lines (2): Brushed on UV printer resin, cured with a UV LED (this worked well) - Gluing the molded plaster pieces: Construction adhesive, again mostly for its gap-filling properties Hope this answered your question!

[@kazolar]

I am too paranoid about surface finish, unless I have battle damage in the design -- I would go over the final part with extra plaster and sand it smooth.

[@avejst]

Impressive build, wow, I'm blown away..;-)

[@falki]

Great Video, I realy enjoyed it. Learned a Lot and have some new Inspirations for my next projects. BTW: Did you use Vibration to compact the plaster in Mold?

[@jspikeball123]

Did you model this box? The inner volume seems huge for the size of the driver

[@MadeWithLayers]

I did run some simulations, and often end up with somewhat unconventional designs that would be quite lame without heavy DSP assistance. Optimizing for maximum SPL / minimum distortion and good low frequency capabilities, while also sticking with affordable components usually means relatively small drivers (10" GRS 10SW-4 in this case) in relatively large enclosures (60l) with low port tunes (IIRC this one boosts at around 22Hz). However, designing them like this means the speakers end up with relatively poor impulse response, especially once you add the high-gain FIR filters in the DSP to pull the frequency response flat. Always wanted to try IIR filters for that, but now the subwoofer works well as a classic "low frequency effects" / LFE channel.