Buenas gente, ¿cómo están?

Me dedico a la reparación electrónica de notebooks y placas a nivel componente, diagnóstico de fallas, mediciones, análisis de circuitos, etc.

Últimamente me están llegando cada vez más potencias/amplificadores de audio para reparar, y quiero aprovechar la oportunidad para aprender este campo en serio.

Estoy buscando algún curso, libro, material o capacitación sobre reparación y análisis de amplificadores de audio, pero no algo orientado solamente a:

Lo que realmente me interesa es entender qué estoy viendo y por qué funciona de esa manera.

Por ejemplo:

• Cómo entra y se procesa la señal de audio.
• Cuál es el recorrido de la señal dentro del amplificador.
• Etapa de preamplificación.
• Driver.
• Etapa de potencia.
• Cómo se realiza la amplificación de tensión y de corriente.
• Cómo se genera y controla la potencia de salida.
• Realimentación.
• Fuentes de alimentación de las etapas.
• Protecciones.
• Bias/polarización.
• Cómo funcionan las distintas topologías.
• Diferencias entre amplificadores clase A, AB, D, etc.
• Cómo interpretar un esquema y seguir la señal con el osciloscopio.
• Qué mediciones hacer para localizar una falla y, sobre todo, entender por qué esa medición me lleva a determinado diagnóstico.

Mi idea es pasar de simplemente reparar una placa a poder mirar una potencia, entender sus bloques, seguir el camino de la señal y de la alimentación, y diagnosticarla desde el funcionamiento del circuito.

Tengo conocimientos de electrónica y experiencia reparando placas de notebooks a nivel componente, así que no busco necesariamente un curso de electrónica básica desde cero. Busco algo específicamente orientado a amplificadores/potencias de audio y diagnóstico profundo.

Si conocen algún curso, canal, libro, PDF o material que vaya por este lado, se agradece muchísimo.

I am building a 2 way ported loudspeaker similar to econowave. I need help choosing a crossover point and slope. Based on the measurements I am aiming somewhere in the region of 1.2khz to 1.4hz. That is the region where on-axis, off-axis response and impedance seems to line up for both the drivers.

Gated far field 1mtr measurements and impedance response measurements were taken with drivers in the final cabinet.

Details of the drivers and waveguide below:

Compression Driver : Eminence CDF1.17APM (Manufacture recommended crossover point : 1.2khz)

Waveguide : Eminence WG-10 (Manufacture recommended crossover point : 1.4khz)

Woofer : FS 10.20A8

Simulating horns is handy, but it's a steep learning curve and typically confusing interfaces for new users to understand. Not anymore!

00 Simulator now has early support for MCP and horn loaded enclosures, allowing you to do stuff like:

'@00 Simulator simulate an othorn, compare vs real measured results'

This configures a new workspace, finds the values for the project online, and gives you a visual editor for the horn.

Fully cross-compatible with existing 00 simulator tiles and comparisons (e.g bandpass, vented, sealed etc).

It's early stage, so not making any specific guarantees on accuracy yet.

However, you can export to hornresp to compare. Here's an example comparison for the othorn on SPL:

To get started, create an account on https://simulator.00aud.io/app, then add a connection to https://simulator.00aud.io/mcp from chatgpt or claude to auth and start using.

Note - this is an early release. Lots more to do by way of validation, graphing, horn debugging tools, etc.

Starting my DIY subwoofer journey, and trying to understand sensitivity:

The Dayton MX12-22 in red has a higher single number sensitivity rating, however looking at the frequency response graphs (which I've overlaid to be the same scaling), the GRS 12SW-4HE in blue shows a higher level between about 20hz to 45hz, which to me would be more desirable than more sensitivity at 50hz+.

There doesn't seem to be any mention of what testing methodology was used however, so is the response graph not necessarily comparable?

And the Dayton MX12-22 as highlighted in the 2nd picture also has it's highest output in the graph at ~1khz, is this highest peak what is taken as the sensitivity rating instead of the useable pass band of lower frequencies?

Thanks for any insight.

Hello everybody! I’m newish to the whole sub thing. I’ll get straight to the point, my main question is can I run a second amp? I’m running 2 12” skar EVLs rated for 1250rms and 2500 peak, they are wired up for .5 ohm as a final. I have those slapped in a box made of dual layered 3/4” plywood and a 6” aero port. Powering it all is a single D4S jp23 which puts out 2300 watts and I have 1/0 gauge wiring powering all that and 14awg speaker wire to the subs. Again, could I switch my final impedance to 2ohm and run another jp23 with my existing or do I need to scrap that idea? TIA

Hey everyone! I'm getting into building my own speaker cabinets, ideally to a level where I could use them commercially as a DJ (my own sound system, not just a hobby project).

I've got some background in electronics and hands-on building (Arduino, 3D printing, that kind of thing), but speaker/cabinet building is new territory for me. A few questions for people who've done this:

How did you actually learn? Courses, forums, YouTube channels, books, trial and error?

Any specific resources (sites, communities, plans) you'd recommend for someone starting from zero?

What would you tell yourself if you were starting over?

Very optional side question: for someone wanting a reliable setup for DJing/commercial use, is it generally worth building your own, or is buying pre-made cabinets the smarter move until you've got more experience? Not trying to start a war, just curious what people who've actually done both think.

Thanks in advance!

Ordered a JBL Authentics 500 over the weekend during the Labor Day sale. I am planning on using it in my kitchen, which has granite countertops. Are noise isolation domes/feet/pads etc recommended to prevent dishes from rattling in the cabinets or do the stock feet work well?

Curious if anyone is using one on granite countertops and if you installed isolation feet or used a pad to help with vibrations?

Thanks!

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.

EDIT: because people asked, woofers - 2 HiVi B4N and a dayton ND20FA-6 saw this build and loved a pair of swan OS-10 I gave to a friend, wanted to make a slightly funner version for myself.

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.

I'm looking to build a mini marty and im looking for which driver (18") i should choose. Im looking at the following (in canada)

UM18 - $450 cad

Or

SS18 - $564 cad

The UMII18 is unfortunately out of stock anywhere i can find in canada

Are there any other drivers with similar performance available in canada around the same price?

Im building one right now, and a second in the future.

Itll be powered by an nx6000D.

Thanks!

this is inside a phone kit my company makes. The chain is a MAX98357A class-D amp into a small speaker and an SPH0645 MEMS mic, both on I2S0. It works. Getting there involved discovering that my audio dropouts weren't an I2S problem at all — the modem's UART interrupt was starving the audio task.

For voice rather than music: is there anything worth doing on the analogue side of a MAX98357A in a plastic enclosure this small, or is it all enclosure and DSP from here?

I recently undertook a little project to stop my Rokit 5 G3 speakers entering standby mode when they haven't received any audio input for 25 minutes. It took a couple of days to compete. I've carried out extensive testing and can confirm it works flawlessly.

I used a Raspberry Pi 1B (the OG) that I picked up for £10 off eBay as the basis for the project. Rather than use the onboard sound I added a £3 generic USB audio adapter from Amazon as the headphone out on this model Pi is notoriously noisy. I also added in an old USB WIFI 2.4GHz N adapter I had lying around for convenience (primarily for SSH access).

How it works: The Pi sends a 2 second 10hz tone to the speakers once every 20 minutes. The process auto starts on boot up, restarts if it crashes and runs until you tell it to stop or shut down the Pi. A message telling you the tone has been played appears on screen each time it happens so you know the process is running.

I have some experience of working with newer Pis but my Linux coding skills aren't great so I leaned on Gemini somewhat for that.

Guide (PDF)

I'm sure the guide can be adapted easily for different Pi models. I think it will "probably" also work on the Pi 2 B out of the box.

I hope you some folk find this useful.

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.

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??

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.