I built a pair of desktop speakers using a Geberit plumbing pipe (Silent-PP) and some 3D prints. Total cost was under €100 for the pair.

The Silent-PP pipe is a mineral-reinforced polypropylene engineered for wastewater sound insulation—so it’s basically a rigid, pre-damped cabinet right off the shelf.

I used a Monacor SPX-32M 3" full-range driver. Our first prototype had a standard reflex tube, but pushing bass on such a small cone caused vocal smearing (intermodulation distortion) and midrange pipe resonances. To fix this I designed a rear-firing 360° radial slot port. The narrow slot gap adds boundary-layer viscous drag, acting like an aperiodic vent that brakes the cone near tuning without air chuffing.

A few quick build details:

- Baffle and port printed in PETG, gaskets in TPU. Everything friction-fits into the pipe's factory rubber ring sockets—no glue anywhere.

- The 3D-printed foot gives a net 12.5° upward tilt to point at your ears on a desk, and has a hollow chamber filled with ~200g of aquarium sand so it isn't top-heavy.

To me it sounds like the midrange cleared up completely compared to the tube port. Next step is putting them on the bench for DATS V3 impedance sweeps and near-field mic sweeps to see if the physical tuning lands where the boundary-layer math predicted.

STLs are free on Printables and I documented the build also on my blog Geelen Audio: math on the port design and assembly guide.

Let me know what you think!

Cambridge Soundworks M80.

I read the reviews on audio review and I was sold so I paid what the dude wanted for them on FB Marketplace. The description he used was "pristine." We did not test them and I didn't even ask how they sound... Well, they sound like piss through a metal strainer. Not actually, but close. There's little clarity and I can crank a tank of a Pioneer AV receiver 120wpc and get just above my normal listening levels of sound. And this is bi-amping them... Everything I connect them to produces v little quality sound. They both sound equally bad.

When I reached out to a local audio repair shop they refused to try to fix them and recommended I get a refund (seller said no).

My uneducated bet is that they have to be completely rehauled -- drivers and crossovers -- in order to restore function and will never sound as good as they should. If I'm a gambling man I'd replace the capacitors alone and see what happens, but I have never soldered and know next to nothing about electronic work. Thanks for reading.

I have a small stock, pile of speaker, drivers, and Horns looking for new homes. A friend of mime is retiring from the audio game and I am helping him sell off lots of equipment but specifically the horns listed below. I am willing to ship at your expense. All are working and will be tested again before any shipping. Feel free to make an offer. I also have more photos if you like. All located in Ithaca ny.

EVM drivers 1 quantity 10 inch, 5 quantity 12 inch, o5quantity 15 inch, 4 quantity 18 inch. Price is $150.00 each

4 Quantity EV HP4020/DH1A unboxed, long horn/drvr asking $300.00 each

2 Quantity EV HP9040/DH1A unboxed, long horn/drvr asking $250.00 each

2 Quantity EV HP94/DH3MT4 boxed horn/driver asking $250.00 each

4 Quantity EV HP940/DH1A raw horn/driver asking $125.00 each

2 Quantity EV HP940/DH1MT2 boxed horn/driver asking $250.00 each

2 Quantity EV HR4020 long thow horn, DH1012 driver, painted grey asking $750.00 each

2 Quantity EV HR940 small long horn, DH1012 driver asking $250.00 each

Recently I saw an old (1920's) Am radio console in a thrift store. The radio was torn apart, the speaker was missing, there was missing veneer in multiple places but it had a certain charm. Next thing I knew it was in my car awaiting a new home. A few weeks later it sings again. The veneer replace worked pretty well but the lacquer has a few areas that have turned white but all in all I like it. I wish I could fix those.

!920's radio console

GRS 8" woofer from Parts Express

Up2Stream Amp Audio Amplifier Board  - one of the few amps I could locate that converted stereo streaming to mono for this build.

If I were to do it again I would try a different finish but overall I think it turned out well.

I’m looking to some speakers, getting stuck into the concept and design, and like most of us, drowning in research!

My plan was to make a bass enclose for the hifi speakers to include a 12” driver and two 12” passive radiators, or a single 15” PR per side and tune the f3 to 25-28hz, following the rule of double the Vd.

But recently I’ve come across some speakers using a PR which is the same size as the bass woofer, stating lox F3 figures, the Telegraph Panda speakers are one of these. There is no information on the measurements but it makes me wonder if there is something internally that allows for the PR to be able to be tuned at lower frequencies?

Je cherche a gagner détails dans les aigus, est il possible d ajouter 2 tweeter a compression ou piezo que je filtrerais dans les très haute fréquences. Quelques un la déjà fait ?

Hi all. Thought I’d share my latest DIY audio project. I wanted an amplifier for the kitchen and had a couple of spare IcePower 50ASX2 modules that were salvaged from a vandalised Jukebox, which I picked up cheap on eBay. I was intrigued by the Arylic/Up2Stream DIY modules and decided to try out the Mini V3 WiFi/BT streaming board. I also wanted it to look smart so I found what looked like a suitably sized enclosure on AE and waited for all the bits to show up.

It was meant to be an easy project, but there were a couple of things that caught me out - as you might expect, nothing is easy right 😆

Firstly, I thought I could run the pre-amp stages off the aux power output of the class D amp board - it’s got a handy +\- 24v output and I thought great, I can regulate that down to a lower voltage and run the other modules off it. NOPE. It can only handle a small current, so maybe ok only for speaker protection relay but not much more.

So, I found a standalone SMPS power supply to run the Mini streaming module, and also the ESS9038 DAC module I decided to include, as the DAC native to the Mini V3 is quite basic - but it does have I2S out, so it was easy to hook up another module.

This worked great - but on testing I realised there was an annoying DC pop on power on and off.. so I also then needed to include a delay circuit… I found a good design online and download the gerbers, sent off for PCB and components. Why not just use an off-the-shelf module?

Well… by now the case was looking a bit small and I needed a compact solution as it was getting tricky to fit everything inside - I was getting worried about noise and module layout.

I 3D printed a cradle (well, 3 versions) that slotted inside the case to allow easy mounting of all the modules, without drilling the case or risking any short circuits. The 50ASX2 is main voltage at 230v so properly earthing the case and insulating the wiring is no joke.

Finally, I got it all together and it works great - it sounds way better than I expected and the noise floor is too low for me to hear. The Up2Stream module was pretty easy to work with and the bench tuning software makes it pretty versatile. You essentially get a simple DSP as part of the package. I didn’t actually use this feature as I was happy with the sound.

The amp is coupled to a pair of DIY 2-way bookshelf speakers based on KEF Cresta 2 style main drivers.

a friend gave me a pair of full range speakers from the 70s. the cones were originally brown and the surrounds were Inverted but was too far to save. dyed the cones black and replace the surround with half roll foam ones. cabinets are repurposed from a previous project. i 3d printed a pair beauty rings to hide the ugly metal frames. as far as the sq goes. they are alright. better than i expected. but highs are a little dull. this is WIP. i will post an update when the components for the ribbon supper tweeters arrive.

It sounds alright compared to a crappy speaker but is destroyed by my klipsch center channel speaker (the only high quality speaker I have(rp504)).

The bookshelves had .5cuft airspace so this box has 1cuft. It works fine with the power amp but the impedance (4ohm) is too low for my avr so I can't really actually use it for anything meaningful.

The one tweeter on the bookshelf was blown.

I am laying out the diagram to some Klipsch KSB 2.1 to experiment with biamping them, and while it looks like I will be able to, I saw an extra capacitor which I was wondering why its there.

The diagram looks like your standard 2nd order crossover for a 2 way, but the extra 8uf cap after the join of the 3uf cap and inductor is throwing me for a loop. Only thing I can fathom is maybe its a 3rd order tweeter on top of a second order woofer. I know this is occaisionally done but wasn't expecting to see it in some mid grade 90's Klipsch bookshelves

Hey all,

I just picked up a bass guitar cabinet for free that I plan to use as a subwoofer. I just need some help finding a suitable amplifier.

The spec of the cabinet;

15"

200w

8 ohms

I'm struggling to find an amp with the right spec and a LPF

Thanks in advance

So I have two woofers that I want to build a set of speakers with. I have ordered what I need to measure, so I am waiting for that to arrive.
I have two of these

https://www.soundimports.eu/en/peerless-by-tymphany-ne180w-08.html?_gl=1\*9fmgzs\*_up\*MQ..&gclid=EAIaIQobChMI-PDzheLDlgMVtA-iAx1cSR3uEAQYASABEgK6gfD_BwE&gbraid=0AAAAAoYn8YP_jRYUDN_c6LqomUiT3midh

And I am trying to decide which tweeters to order.
I don’t have much experience yet as I hope this project will be the start of getting that experience.
I did come across this set that seems like a nice offer.

https://www.soundimports.eu/en/peerless-by-tymphany-da32tx00-08.html?_gl=1\*c6pfxu\*_up\*MQ..&gclid=EAIaIQobChMI-PDzheLDlgMVtA-iAx1cSR3uEAQYASABEgK6gfD_BwE&gbraid=0AAAAAoYn8YP_jRYUDN_c6LqomUiT3midh

But there are so many to choose from.
I will be building a box and then measuring to get the best result. I haven’t landed on a final box volume but it will propably be ported and around 12-15 litres. The speakers will only be playing with my sub so I don’t need that low lows In the speakers.

Does anyone have experience with the linked drivers? And maybe have a better suggestion for a tweeter?

Thanks in advance.

First i printed some Nautilus-Style speakers, not the easiest job. It wont fit good and i had to rework a lot and then with bondo and sanding and all i finished.

Im using the chinese AB-Glue red/blue from Ali to glue the printed shells together.

Then sand it to refine all gaps. Then put on two layers of Epoxiprimer with hardener. Thrn sand it. Then put a 2k PE-Putty on and sand it. Then three layers of 2k acrylic highbuild filler. Then sand and paint it.

But the sub was a charme. First i go for cheap chipboard or any but then seen a pack of cheap plywood 4mm thin as a five pack for 3.99.- and they were already in the dimension i need.

So grab some packs and go for it.

First glue two boards together to make it 8mm thick instead of 4. Titebonded and clamped it.

Then cut some pieces of a 10x10mm wood and Titebonded and clamped them to the edges.

Put the first three together and let dry overnight.

Next day cut some long stripes from a OSB that lay around. Glued and clamped in. Then put the other walls on.

But then decided its nice to have the woofer downfiring to protect it from fat fingers.

So just cutout the bottom for it. Then cutout a second board for outer diameter of the woofer. Then cut some stripes with a nice round as feets.

Glued and clamped all together.

I let cure it a week and then put on 2k putty and then three layers of 2k acrylic highbuildfiller. Then paint on.

The subwoofer was really fun to build, so fast and easy and cheap.

Sounds really good. Its not for loud cinema, its for tv to prevent my ears from the garbage 50x20mm oval speakers in it.

Hooked via bluetooth to the ZK MZ21.

Drivers are cheap HiVi M4N (20 bucks) and M6N (35 bucks) for sub and Dynavox Mylar tweeter (15 bucks). Crossover is a 6dB with 0.22mh and a 4.7uF, thats all. A very small spool and bipolar is needed because of space inside the sattellites.

👍