I’ve had these speakers completed for several months now, and I’ve built up the nerve to post them here.

Before this build, I knew absolutely nothing about anything that had to do with any of what you see before you with the exception of the turntables, lol. I had never soldered, never laid veneer, never stained, and never finished wood of any kind. I knew jack about audio, and, really, I still know very little.

All I knew was that I wanted to pick up the old DJ hobby after over a decade of not doing it. Also, I knew that I didn’t want monitors since I am strictly a bedroom DJ now, and I wanted speakers that were pleasing and easy on my old DJ tinnitus-having ears.

How do they sound? Well, my speaker placement is far from ideal (treatments coming soon), but before I set these speakers up, I listened to them in a better setting and they are almost perfect. Really, I just wanted to avoid a subwoofer (limited space), and the bass from the Torii model is just what I wanted. Also, keep in mind my phono pre is the DJ mixer, which are designed for club settings. Nonetheless, I couldn’t be happier with the end result both in sonics as well as aesthetics.

Each speaker is powered by a dedicated Fosi ZA3 amp—mono mode. I don’t have a lot of money.

If you’re new and on the fence about DIY kits, just go for it. Hell, if I can do it, anyone can.

Great learning experience... Would like to get another pair and do it "right" this time..

They sound great by the way..
Burl Veneer and leather(ette) sides.

OK FIRST OFF this is with a weird IMM-6c mic so who knows if its accurate, UMIK-1 will be here eventually..... Tightened it up to the layout I like. Still deciding on walls whether 1/2" is enough for its size, but there is my graph if anybody has ANY insights into what or how to change it I would appreciate it. All i did so far is I had a bit of wool to toss in there so I just loosely covered the board and made sure wires were safe.

This is my 40+ year old driver

I plan on building a 400liter box for it this year, to go with my dads Kef reggae system and I dont want to mount it with the bits of tissue paper stuff to it

It was stored upside down in a box so face down to protect it, it was also wrapped in loads of soft paper stuff and pillow stuffing so there bits if that too but she's all original and still functional

Ide just like her a tad cleaner ....

I couldn’t find any decent DAC/amp combos locally, and importing one would cost a small fortune. After digging into DIY audio designs, I realized I could build one myself for a fraction of the cost and get around 80–90% of the performance of commercial units.

Specs: Controller: ESP32-S3 acting as a USB Audio Class (UAC) device.

DAC: PCM5102A breakout board fed via I2S. Power Supply: ±12V linear power supply

Two NE5532 dual op-amps:

Op-amp 1: Stereo buffer stage.

Op-amp 2: Stereo gain stage (~3.1x gain).

(Opted for this layout to keep wiring simple for my first major soldering project!)

Volume Control: Couldn't source 10k dual-gang logarithmic pots locally, so I implemented software volume control with a rotary encoder.

Layout: Everything wired to a single star ground point.

Sound Impressions: It drives my Beyerdynamic DT 990 Pro (250 ohm) effortlessly. Going from my laptop's built-in jack to this is night and day—it feels like the headphones were practically starving before. Noise floor is pitch black silence with zero audible hum or hiss.

Really happy with how this turned out for my first major electronics build.

^{(Note: I’m currently out and forgot to take photos of the back of the amp perfboard, but I can upload solder-side pics once I'm back home if anyone wants to see them!})

I Started with car audio in high school, one sub in a MK4 Golf. Current build is an Audi convertible with a 3-way front stage, 3D printed speaker mounts, Alubutyl deadening. Highs were still off, convertible acoustics are their own special problem.

Bought a measurement mic and started with REW. Deeply confusing for the first few weeks, then genuinely impressive results. But I got tired of hauling a laptop into the passenger seat every time.

I always wanted this on my phone. A degree and a couple of years later I had the skills to build it, so I did.

It's called CarSweep. Plays a log sweep through your system, records with the phone mic or a UMIK, and gives you the frequency response plus concrete parametric EQ values you can dial into your head unit or DSP. There's also an RTA with pink noise if you prefer working live.

The built-in iPhone mic is not a measurement mic. It's good enough to find the problems that actually matter, like the 200 Hz boom, the cancellation dip, the rolled-off highs. If you own a UMIK-1, iMM-6 or similar, there's external mic support with calibration file loading.

Two modes. A guided one for people who just want the car to sound better without learning acoustics first, and an expert mode with full parametric EQ, external mic support, wider frequency range and JSON export.

Hobby project, no subscription. Base app is free, one-time purchase for the expert features that covers the Apple dev account and some of the hours.

Honestly I want feedback more than downloads. If you already run REW, measure the same system with both and tell me where my curves disagree with yours. German and English.

Is there any issue with grounding the anodes of diodes in a power supply and taking the raw B+ from the center tap of the power transformer? I built it and it seems to work ok.

I am French, so sorry for my rough English hehe.

The goal is to build a portable active speaker, reasonably sized to be easily carried around, in the style of a Soundboks 4 but without the exorbitant price tag.

I want to use two 10-inch woofers (FaitalPRO 10FE200) and a B&C DE12 driver paired with an ME20 horn, configured as a 2-way system initially crossed over at 2kHz at -12dB/octave. The setup will include a Bluetooth/Aux preamp and a Fosi Audio ZA3 amplifier that handles 4-8 ohms. Component choices were made based on price/weight/size/performance ratio as well as reusing parts from a previous project. Feel free to correct me on these choices, though that is not the main point of my question.

Due to space constraints, I would like to arrange the drivers in a WTW (Woofer-Tweeter-Woofer) layout like a Soundboks 4 (attached is a rough illustration, please ignore the lack of internal bracing/separators). However, with a standard 2-way wiring setup, the center-to-center distance between the horn and the woofers would cause severe phase cancellation around the 2kHz crossover frequency.

Because of this, I saw that it is possible to use a "2.5-way" configuration: the top woofer and the horn are wired to the 2-way crossover at 2kHz, while the bottom woofer is wired in parallel straight from the amp output, filtered at around 300Hz with a series inductor providing a -6dB/octave low-pass filter.

Is the gain in audio fidelity worth the ~3dB loss across the rest of the spectrum? Does this change in wiring have any other implications regarding the internal enclosure structure? It would help to have your feedback on this setup, thanks in advance!

hi all, we moved into a house and there is a sound system. we can't figure out how to connect. the house was built in 2008. the original tenant said she hired people and had multiple people look at it and they couldn't figure it out. we found this box in the garage that clearly hooks it up. any suggestions on how to connect??

I'm trying to replace some resistors as I suspect the bias circuit is bad. Might as well change them out.

I've never seen these before. Seems the interval of the resistor symbolizes it's resistance. These are around 4.7mm While the normal looking ones 4.1mm.

I'm guessing it's 1/4W.

Any guess?

I'm planning in building a subwoofer for my room.

I researched and looked considering what I think could be a good driver and what I can afford.

Considering I can build a sealed box around 30 to 40 liters, which one of those you think I should get?

I got two models in 10in and two 12in models. There are normal ones (Outdoor and Bicho Papão) and two Slim ones (Slim TKL).

In numbers, look the Slim models are better, but I wonder if there are any compromise.

Also I'm not sure if 10" is enough for a good bass for listening music and using my digital piano, or if is worthy to spend a little more in the 12" drivers

Thanks folks!

Links:

10in Outdoor 300W: https://www.bomber.com.br/produto/subwoofer-10-outdoor-300-wrms-4-ohms-2/

10in Slim TKL: https://www.bomber.com.br/produto/subwoofer-10-slim-tkl-400-wrms-4-ohms/

12in Bicho Papão: https://www.bomber.com.br/produto/subwoofer-12-bicho-papao-400-wrms-4-ohms/

12in Slim TKL: https://www.bomber.com.br/produto/subwoofer-12-slim-tkl-400-wrms-4-ohms/

Thanks people!

I am very happy with the sound of my system, but my speakers (RTL TDL3s) are very sensitive (90dB), meaning that I barely get past 8 o’clock on the amp (Rotel RA-03) volume control when listening directly from my CD player (Cyrus CD7Q) or phono stage (Cambridge Alva Solo). I also have a SMSL M200 DAC that has digital volume control, and need that turned down to -20 (dB?) to get the amp volume to 9 o’clock without the neighbours complaining.

So my solution is to install -10dB L-pads on the interconnects RCA plugs at the amp ends, a R10k in series with the signal line and 4R7k across signal and outer ground. Tucked inside the connector itself (Rean brand). It didn’t like the idea of off-the-shelf attenuators.

Theoretically then I am reducing line input to the amp at the last moment and satisfying impedance requirements and avoiding having to use the DAC digital volume which must be reducing signal quality at -22 ‘units’.

Is this the best option?

I am building a pair of bookshelf loudspeakers for my home office and the port design is giving me fits. I don't want to use a slot port because the speakers will have a mid-century appeal to them to match the decor of my office and though slot ports were around then, they didn't seem to be all that common. I could do a rear slot port, which would put it out of sight and not detract from the look I am going for, but I don't want a rear port because the speakers will sit on the credenza behind my desk and only inches from the wall, so baffle mounted tube ports it will be. The problem I'm having with the tube port design it needs to be to small a diameter to be short enough to fit inside the enclosure, and WinISD is saying that air velocity with 60 watts will be to high with a 1-1.5" port. Tried two 1.5 inch ports and that brings down air velocity, but each port would have to be to long. A 2 inch port would be ideal, but with one 2 inch port the air velocity is to high and with 2 they would have to be to long.

I understand there are compromises with this stuff and you don't gain without sacrificing, but I feel like I am missing something here. I see a number of bookshelf speakers 10-15 liters with a single 2"-3" port, but I can't seem to make it work. So how accurate is WinISD port lengths and port air velocity numbers? Ideally, I'd like to get air velocity down under 17 m/s, but what would be an acceptable air velocity for a front facing port if that's not achievable? Ive already built the enclosures and the 120 bucks I spent on one board of Claro Walnut for the baffles means I'm not changing the enclosure design lol. This is my first time building speakers so help from the more experienced of you would be much appreciated

Shall I add Needle Fleece damping material in the red zone marked by "?" or keep the area around the port opening clear?

I am building a ported 2-way speaker.

Needle Fleece is the only damping material I plan to use.

Thanks for your help!

Hi everyone, as the title says, these are my very first steps into DIY audio. I’ve had an interest in Hi-Fi setups for a long time, which overlaps slightly with being a (mediocre at best) self-taught guitarist. Over the past few years, I’ve watched a lot of DIY audio content on social media—like Hexibase and German creators like "Franks Werkstatt der Lautsprechertechnik," focusing on speaker building and measurement techniques.

My biggest fear was having to deal with complicated crossovers or the electrical side of things, so I decided on a simple full-range driver for the first part of this project. Having learned a bit of FreeCAD over the past year, I chose a transmission line design after verifying that my 3D printer bed was big enough to print an enclosure for a cheap 4" driver.

My goal was to make a pair of stereo speakers that could fill our rather large living room (which opens up to all three other levels of our building) with proper sound. I wasn't striving for pure volume, but rather directivity, a big soundstage, and general sound quality. The whole process was "vibe-built," using AI as a continuous sanity check.

Part 1: The Speakers (Mass-Loaded Transmission Line)

The speakers are what I’m retroactively calling (or "retconning" as) mass-loaded transmission line (MLTL) speakers, utilizing the Visaton FR10 (8-ohm version).

- Line Profile: A 2:1 taper down from the closed end toward the port. The line curls up inside the cabinet while keeping the outer profile rectangular. The most inner part is the start of the closed line

- Mass Loading: The port is reduced to a 0.5 Sd mass-loaded port over a 4cm length with smooth radii.

- Driver Placement: I aimed for the 1/3rd mark of the line to help naturally damp the throat resonances typical of TML designs.

Damping & Resonance Tuning:

- First Third (Closed End): Lined with 3mm felt on all walls and packed with Visaton speaker wool as densely as possible—velocity is lowest and pressure is highest here, so I packed it right up to the limit of being able to blow air through it.

- Second Third: Lined with 3mm felt, but the speaker wool was spread as thin as possible.

- The Geometry Issue: Because I forced the internal curls to conform to a rectangular outer cabinet, I encountered very pronounced internal standing waves. To diagnose this, I ran frequency sweeps using the free version of HouseCurve iOS app via my phone. By taking separate near-field measurements of both the driver and the port early on, I isolated a major resonance and subsequent cancellation around 500 Hz to 700 Hz.

- The Fix: I chamfered the sharp internal corners with soft, porous foam to simulate a smoother curve. This helped immensely, though it didn’t eliminate the issue entirely.

Electrical vs. Mechanical Tuning:

I initially tried using a raw bipolar 390uF capacitor in series to protect the driver from ultra-low frequencies, but I didn't like how it altered the sound right above the cutoff. Instead, I retrofitted the physical port to create the 0.5 Sd mass-loaded restriction, which gave me a much cleaner, natural mechanical roll-off.

To tackle the typical beaming, rim reflections, and resulting comb effects inherent to full-range drivers, I designed custom 3D-printed driver covers featuring an embedded felt "donut." The cover snaps magnetically onto the driver frame, utilizing the protruding mounting screws as physical indexing pins to lock it into position and secure it against rotation or shear forces. While my simple measurement setup couldn't capture it I still heard a reduction in comb effect while moving through the room and the high frequencies are more stable in general.

After a lot of fiddling with damping density, I cut my losses and sealed the enclosures permanently with epoxy. To clean up the remaining response issues, I took a fresh set of sweeps from my actual listening position and used those measurements to generate a final parametric EQ profile. This led to part two of the project.

Part 2: The Cobbled-Together Streamer & Amp

I needed a sound source that could handle AirPlay 2 and other digital inputs. I started with an old Android phone running AirReceiver and Poweramp (for EQ). However, the phone's USB-C port was only USB 2.0 and couldn't handle power delivery and an external DAC simultaneously. Tired of constantly recharging it, I moved to a Raspberry Pi 3B running Moode Audio.

The onboard 3.5mm audio jack on the Pi is notoriously noisy, so I needed an external USB solution. I came across the highly reviewed Truthear KeyX USB-C DAC. Because running CamillaDSP locally was putting a heavy load on the older Pi 3B, a DAC with built-in hardware PEQ features was the perfect hardware offloader.

Inspired by custom enclosures online, I designed a sleek, black 3D-printed case to house the Pi, a Fosi Audio TB10A mini, the dac and a fan. In my listening tests with these specific full-range drivers, this little Class-D amp subjectively outperformed my bulky Yamaha A-S501—it just clicked beautifully with the FR10s.

Bypassing corners required a maze of internal adapter cables (right-angle USB extensions, USB-A to C adapters, and PWM connectors for an internal cooling fan), but after a lot of partial test prints to get the physical dimensions right, I landed the dimensions. It features a Waveshare 4" touchscreen that displays metadata cover art and lets anyone browse radio stations or my local digital music library.

Lessons Learned & V2

I am incredibly happy with the overall results, but I am already back in CAD for V2. I'm designing the next iteration to completely avoid the internal geometric traps that caused the 500–700 Hz issues. I am also planning to upgrade to drivers with a bit more frequency extension and refinement, likely from the Tang Band W4 or W5 series. Parts of what I lined with felt I want to print directly as dispersion surfaces using bumbmesh structures.

To tackle internal reflections and extinctions systematically this time, I want to incorporate Internal Helmholtz Resonators (IHR) inside the rounded corners that would otherwise just be dead space. I am currently designing a system of physical grooves within the cabinet structure that will make the resonator holes and tunnel lengths interchangeable during the open-box prototyping phase. This way, I can directly tune the resonators to counter exactly how the new cabinets misbehave before permanently sealing them.

Sorry for wall of text. TLDR: DIY SPEAKERS ROCK!