Building EXCEPTIONAL speakers using MODERN TECHNIQUES

building homemade speakers that can compare favorably to Manufactured units that have all manner of built-in Digital Signal processors precisely tuned ports and computer calculated internal air volumes is hard simple boxes just aren't going to cut it anymore however 3D printers might be able to help here their ability to make complex shapes with millimeter Precision is perfect for making computer aided designs but there's a bit of a problem in the thin extruded plastic is acoustically not that great as it's low in Mass it vibrates and resonates easily which is awful for sound quality if this basic enclosure for example is measured with a calibrated microphone we can see this resonance appearing in the 100 to 500 Hertz range and it presents as distortion making the chamber walls thicker would of course help here but it would require a lot of filament and take days to actually print however what if we print only a hollow shell and then use it as a form mold instead doing it this way results in Speedy Print times as the filament only has to be deposited for the Shell with a large internal Gap left for a filler material a cheap and readily available option for this filler material is of course plaster of Paris which can be added to water to make a paste that sets hard it does have a problem for sound applications though in that it's a very brittle material giving it a ringing quality a bit like a teacup it has the potential to sound worse than the plastic alone but there is a way to fix it by adding PVA glue during the mixing process which changes this quality entirely and the difference between the two is night and day edition of PVA creates a microscopic level of flexibility reducing its brittle nature and making it behave like a much duller sounding material perfect for using in our 3D printed mold which once dried is way more solid than our previous version these new thick chamber walls reduce the 100 to 500 Hertz Distortion significantly which is great but as the enclosure is so much stiffer now there's a new problem to contend with internal Reflections you see when a speaker driver moves back and forth it sends sound waves not only forwards towards the listener but also backwards into the enclosure an ideal enclosure is supposed to prevent these sound waves from escaping which are a solid enclosure now does a decent job of but as these sound waves have nowhere else to go they bounce around and eventually hit the back of the speaker driver again coloring its output due to the time delay this is less than ideal but adding soft materials to the inside of the enclosure is a good way to dampen these Reflections here I'm going with some soft Automotive acoustic pants followed by a folded layer of cotton towel and then some sheep's wool which will all act together to stop the sound waves from being reflected back and overall compared to our original fin enclosure we've gone from this to this further improvements can be had by utilizing higher quality drivers which we'll be diving into later but essentially this forming technique has made 3D printing a viable option for Hi-Fi sound quality which is really exciting because we can now use their ability to make complex shapes to our advantage and one area in particular that's going to benefit a lot from this is the subwoofer frequencies you see if we replace the enclosure with a long tube it will keep the rear sound waves contained only until they exit at the other end due to the time that this takes it essentially delays the audibility of these rear sound waves just enough for them to become additive rather than subtractive to the driver's forward sound waves which makes far more use of the speaker's energy one notable subwoofer that's become somewhat of a legend in this configuration mostly thanks to fellow YouTuber hexibase is this three inch unit from Tang band despite its diminutive eyes it should go down to the low 40 Hertz range which is insane for such a small driver calculating the required dimensions for this to be done properly can be done with a piece of software called horn resp which can map out the predicted response allowing us to get two key measurements the tube length and the area of its cross-section the 1.4 meter length required for this is rather long so it can be made into a folded configuration to make it more compact so that we can actually print it off with the 3D printer again in an effort to reduce print times I'm making this design entirely Hollow with the goal being to fill it with our special PVA and plaster of Paris mix as it approaches 60 centimeters in height it's necessary to split it up into three individual sections so that it can be printed with the widest variety of printers and as you can see I've included a sealed enclosure above it all for a dedicated mid-tone driver as the subwoofer isn't really very good at reproducing these tones filling this whole thing with plaster of Paris can be done through a hole at the top though it does need to be knocked repeatedly to make sure that there are no air pockets makes thick walls around the subwoofer port and the mid-tone Chamber and it makes the unit extremely heavy for its size but it does feel high quality for it and very solid during testing though I found that subwoofer notes while extremely deep weren't as loud as I'd like now being me I'm not satisfied with this yet I want to take this design as far as we can possibly go to make it the ultimate 3D printed speaker and to do this my conclusion is to add yet another subwoofer driver this doubles the surface area that's going to be providing base and should hopefully solve the issue but it does come with its own challenges namely that we not only need to find space for the driver itself but also the port has to literally double in dimensional volume and if I want this thing to remain the same size that's going to be a massive challenge but to be honest the solution is it's annoyingly obvious you see in an effort to have enough room for the plaster of Paris to form good solid boundary walls throughout the speaker including those surrounding the subwoofers Port I forgot to ask myself whether they were all necessary you see the whole point of this subwoofer tube is to redirect energy not contain it as the end is open its walls really don't have to be as thick as I've made them because they don't have to hold in any energy they merely direct it through with this in mind for the second attempt I've decided to remove the need for plaster of Paris for the subwoofers Port entirely and instead have gone with four millimeter 3D printed boundaries which saves just enough space for the now much wider and longer Port the downside is that it consumes twice as much filament and takes twice as long to print compared to the original so let's hope it's all worth it so a few days of print time later and we've got everything printed off ready to be mounted together now this is a relatively simple process due to the way it's being designed and divided up but we do need some glue now this isn't actually for anything structural it's just to form an airtight seal between the different layers so let's get to it that is after an ad from nordvpn with nordvpn you normally get the fastest VPN in the world but also their included threat protection which protects you from malware trackers and ads that are potentially malicious this works at the connection level rather than just within a browser making it effective and secure they also offer a data breach scanner which will inform you if your credit card details passwords or email addresses have appeared in a data breach which is essential for keeping your online account safe of course all of this is on top of their core VPN service which can provide you with an encrypted pathway through which you can route all of your data adding another layer of protection against unscrupulous actors one of the coolest things about nordvpn is that they 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printed build platforms 1 and 2 can be glued together first utilizing a couple of h-clips to make sure that they're nice and tight as you can see the glue has a tendency to squeeze all over the place but it's easy enough to wipe away any excess now you'll have probably noticed that these pieces have many small discs on them these are actually centering guides which line up with the subsequent pieces making them easy to position accurately here I'm adding the bottom part of the subwoofers chamber and if we flip it over we can see that there are four holes beneath it these offer two millimeter diameter self-tapping screws which allow us to clamp the pieces together from here the internal air guides can now be added starting with piece a this just needs a thin bead of glue along the bottom as well as any vertical seams it touches the guides help a lot in positioning it correctly after which the screws take over it's important to ensure adequate glue here for a tight seam keeping in mind that any spillover can be easily wiped away this process needs to be continued with all of the internal air guides which completes the subwoofers tuning Port allowing us to move on to the mid-tone chamber as you can see this is the only section that has carried over the hollow forming technique as it's proven so effective for mid-tone use for a nice strong length this final platform can get extra support from the subwoofers exit Port which as you can see has a wiring guide in its top half there are a total of four pairs of wires that need to be rooted through this a pair for the top chamber a pair for the Middle Chamber and two pairs for the lowest subwoofer chamber the holes for these of course all need to be sealed up so that no air can pass through with that done the hollow cavity below the mid-tone chamber can now be covered ready for the PVA and plaster of Paris mix in just a moment but before we do that we might as well add the chamber's dampening materials at this stage while we have easy access to it again this is just a layer of 15 millimeter thick Automotive acoustic foam followed by a folded layer of cotton towel and then some sheep's wool if you can't find any sheep's wool by the way it's worth noting that loose and rock wool can also be used here which is something that you can find in most hardware stores all this being done means that we can finally cap the unit off with its top Lids as well as the brackets for the speakers themselves it's worth noting that these being separate is intentional as it means that the design can be easily adapted to different speaker drivers so to finish things off it's time to make what will hopefully be our last batch of PVA and plaster of Paris while plaster of Paris is generally safe it does need to be respected as it can set quickly and generate some heat while doing so make sure you read the safety notes in the video's description before attempting to use it the quantity required for our pore is 750 milliliters of water that's already been mixed with PVA at a ratio of about 10 to 20 percent this can be followed with one kilogram of plaster of Paris powder which needs to be mixed in gradually once a smooth consistency has been achieved it can be poured into the chamber at the back which completely surrounds the mid-tone chamber with a solid 16 millimeter thick wall it doesn't take too long for this to set after which the rear can be closed up with a little cap now technically the enclosure is ready for the various drivers to be mounted but aesthetically I think there's room for improvement especially as not everyone is fond of the 3D printed look particularly when there are joins that are still visible but thankfully there are loads of different techniques that we can utilize to make this thing look really special to make the joins less of an issue they can simply be filled and then thoroughly sanded down while this can be done by hemp it's worthwhile borrowing a Disc Sander as it saves so much time and it gives a really smooth finish ready in fact for some paint some plastic primer can be used here first as it gives a good key for the top coat there are loads of cool finishes available these days and I'm going with the textured paint that looks a little bit like metal a far cry from the original printed plastic that's for sure now if you look closely at the sides of mine you'll see that I've masked them off what's underneath some beautiful wood veneer I added this before the painting process by spreading around a load of glue and sticking the veneer on top veneer for those who don't know is a very slim slice of real hardwood mind being Rosewood it gives the enclosure a really high-end appearance particularly when it's oiled as it brings out the richness of the wood lovely the rapid transformation of how this looks is really quite remarkable and it's only going to get better from here to prepare for the mounting of the speaker drivers the holes for them need some little M3 threaded inserts which are for screwing them in place when wiring them up it's worth noting that the polarity of each speaker needs to be correct with the red wires going to the positive terminals one often overlooked but very vital addition is to add a rim of blue tack around the edge before the driver gets screwed in place as this makes an airtight seal for it as you can see they are slightly proud rather than flush so to make them aesthetically more pleasing they can be tied together visually with a little bracket very nice so with the two subwoofer drivers now installed it's time to tackle the mid-tone driver choosing a suitable one is somewhat daunting as there are literally hundreds of different models available each with wildly varying performance characteristics in an effort to select the best possible driver for this project I spent literally days testing various drivers ultimately settling on this one which is again a Tang band unit it's got a nice smooth character to its sound output with plenty of mid-range detail and it looks really smart to boot an amazing feature of this driver is that it can actually cover high frequencies as well so it can pull double duty as a tweeter which is great for those on a tighter budget for those who want the absolute best high frequency detail however the design does cater for dedicated tweeters though they'll only likely be appreciated by the most demanding of listeners so it's your call whether to include one or not as the speaker can be printed without the hole either way with all of the drivers added it looks really elegant and it's easy to forget that it is in fact 3D printed now some people might prefer the drivers to be covered which is why I've included these holes they're for a grill which can be made by gluing some threaded steel rods to some mesh which can in turn be held in front of the speaker with some 3D printed pegs you could even Paint It Black for a different look an optional extra I've included for Hi-Fi Buffs by the way are some side baffles I embedded magnets for these before the painting process which allows them to be easily added or removed and the idea is to provide a smooth surface for the sound waves to spread out on to describe the effect is like the sound gets projected forward slightly with them but it's only a tiny difference still the options there for those of you who want it now to get the very best possible sound from this thing we're going to need some help from our secret ingredient a digital signal processor shockingly these are really cheap to buy now and can provide four fully programmable sound outputs allowing it to function as an advanced crossover to make use of it we can simply mount it into a little 3D printed box along with a voltage regulator for power it's going to get its audio signal from a phono socket that can be inserted here alongside a DC Barrel plug this essentially takes the audio signal from the phono socket and internally splits it up into four separate signals with specific processing for each as the board can't do any amplification though it needs to send these signals to a 4 channel amplifier the one I have here is a class A B type which uses slightly more power than class D amplifiers but it has a very low level of output hiss which can be at annoying levels on so many other amps there is of course a ready-made chamber for it on the back of the speaker and each driver wire pair needs to be hooked up to it being careful of polarity trading cooling a little shroud can be fitted on top that features a slow-moving fan the amp can run passively but when listening to loud content for an extended period of time it's likely to get quite hot and the tiny amount of air movement that the fan provides is all that's required to keep it nice and cool so it's well worth it the signal processor can be added just below this and wired up to the amplifier's input wires their order doesn't really matter as we can configure them digitally later the last thing to do is add a cab to cover everything up which completes the build now for stereo I've made an identical pair and they look way better than I thought that they ever would particularly for 3D printed speakers but do they have the audio quality to match their looks let's find out after giving them power the first thing we need to do is program the signal processor this can be done with a free piece of software called Sigma Studio which has loads of different filters and algorithms I've spent many hours making a profile that gets the most from this design and you can find it with the Project's 3D printable files Link in the description to upload it to the DSP we can simply use a cheap USB programmer this has three pins gendi scl and SDA that corresponds to ones labeled on the DSP so merely need to be connected together this allows the profile to be compiled and tested live though to save it to the DSP itself the wp pin needs to be bridged to ground after which the profile can be written to its entire General memory now if you're wondering what the frequency response looks like I've tuned it to be extremely flat right down to 50 hertz where it then tapers slightly to 40 Hertz this measurement is without any boundary reinforcement as it's been done in the open air but in a typical indoor location with a wall behind them they measure flat right down to 35 Hertz this is incredibly deep for such small speakers and this level of performance is usually only found in floor standing units or external subwoofers as these would make excellent gaming speakers it's a perfect opportunity to show you how Vivid their Sound Stage can be [Music] foreign few as they're tall and elegant having them sit either side of TV is a great alternative to a sound bar particularly as they'll sound significantly better as well here's an example against a much more expensive Bose unit foreign [Music] they can even trade blows with high-end bookshelf speakers as well [Music] foreign [Music] if you'd like to build a pair for yourself you can find the printable components for them in the video's description though do note that they take about five days to print now I can't offer any warranty or support for them but as you've seen from the video they're easy enough to put together and they're well worth building it's taken many weeks of prototyping to evolve the design to where it's ultimately ended up and I'd say it's a massive success we've made them very competitive to Manufactured units and they look good to boot now for my next video I'm actually going to be doing the first PC build I've done in ages and it's going to be going underwater so make sure you're subscribed so you don't miss it and I'll see you there

Channel: DIY Perks

Views: 1,041,190

Keywords:

Id: XEspOD1NHr0

Length: 22min 19sec (1339 seconds)

Published: Fri Jun 09 2023

Reddit Comments

[u/tupisac]

I'm a bit scared to watch. Last time took 3 months of my life researching and completing a DIY microphone.

[u/Snoo93079]

His videos are always a must watch for me and my wife when they appear in my subscription list!

[u/DanP999]

That's really impressive. I'd love to actually hear those.

[u/Turk3ySandw1ch]

He's done speakers before but nothing that would be traditional full ranger speaker, though I'm hesitant to call this traditional. I didn't watch the video yet but I'm interested to see how he did with the crossover design and how it measures.

[u/ianganderton]

Impressive 🤩

[u/ozzyissabbath]

Cool video, but what a let down for someone without a 3d printer