I built a couple of DIY speakers (Quark and Speedster), and I really enjoy how much value you can get for not much money.
One day I'd like to build a bigger/better multi-way speaker using something like Hypex Fa123, but I have too much to learn before I start spending real money.
I was thinking of starting with something much cheaper to get into active crossover and active speaker designs, using a ADAU1701 board and cheap chip amplifiers.
I looked at some of the Sure offerings, e.g. WONDOM | STORE or even WONDOM | STORE which will allow to build a 2-way design with just a power supply. Or WONDOM | STORE for both speakers.
But I've read mixed feedback on the Sure modules, so I'm wondering if there are better boards I should consider. Any advice in how to get started is welcome
One day I'd like to build a bigger/better multi-way speaker using something like Hypex Fa123, but I have too much to learn before I start spending real money.
I was thinking of starting with something much cheaper to get into active crossover and active speaker designs, using a ADAU1701 board and cheap chip amplifiers.
I looked at some of the Sure offerings, e.g. WONDOM | STORE or even WONDOM | STORE which will allow to build a 2-way design with just a power supply. Or WONDOM | STORE for both speakers.
But I've read mixed feedback on the Sure modules, so I'm wondering if there are better boards I should consider. Any advice in how to get started is welcome
If this is for learning, and you don't mind stringing together a few modules then have a look on aliexpress for ADAU1452 boards. It has significantly more power than the 1701. For about 90 dollars you can get a board that has a 4 in 8 out codec and the device to program it.
For development a Dayton DSP-408 + a used home theater receiver (e.g. Yamaha RX-V667) with separate inputs allows you to make on-the-fly adjustments. After you've worked out a design you can move to individual components.
I learned how to use DSP with a basic miniDSP 2x4 ($80) and a pair of TPA3116 amps ($10 ea). Plus a microphone ($100). Add REW software and for about $200 you can do 2 way speakers any way you like.
The Dayton DSP-408 is nicely made and software is simple and easy to use. Nothing extra to buy as miniDSP charges for the different modules. It won’t do fancy filters though.
ADAU-1452 and SigmaDSP is super powerful but more complicated. The official EVM from AD is $225. Worth it in my opinion vs an AliExpress unit with zero documentation and questionable parts (ADC and DAC).
The Dayton DSP-408 is nicely made and software is simple and easy to use. Nothing extra to buy as miniDSP charges for the different modules. It won’t do fancy filters though.
ADAU-1452 and SigmaDSP is super powerful but more complicated. The official EVM from AD is $225. Worth it in my opinion vs an AliExpress unit with zero documentation and questionable parts (ADC and DAC).
Thanks for the input so far.
Let me add some more info to my requests. I'm relatively proficient in microprocessor and digital electronics, having built and programmed a variety of boards (mostly ESP32, STM32 and nRF52). I do have a decent oscilloscope (Rigol DS2302A), signal generator, logic analyzer (DSLogic) and multimeters. I also have an UMIK-1 and used REW to check out my kit speakers. I know nothing about DSP but have some understanding of digital protocols (e.g. I2S, SPDIF) used in a modern audio device
At the moment, I'm more interested in learning and figuring things out than listening to high quality sounds. And I'd like to learn more about handling sounds purely in the digital domain (then converting to analog at the proper time). I'm not worried about adding extra modules and having to solve problems
And at the moment I really want to spend the least possible, given that I still "don't know what i don't know", so spending a couple of hundred dollars without knowing what for is less than ideal. A Dayton Audio DSPB K and DSPB KE or similar Sure Electronic is ~$35 shipped, which is much more interesting. Plus the programmer, and I was thinking about using a CY7C68013A board (and all the necessary black magic to make it work)
A generic ADAU1701 (or 1452 as suggested here) should allow me to use a purely digital input (I2S or SDIP-to_I2S converter) and either output an analog signal over 4 channels, or 4 I2S channels (assuming I understand how the ADAU1701 works). Then I can further decide how to handle the output (for example, using the ADAU1701 board as an equalizer and sending SPDIF to a stereo amplifier)
Going with a DSP-408 or similar "ready" devices, assumes purely analog input and output. The same would be with a Dayton Audio DSPB-250
Am I right in thinking that with a DSP board (Dayton Audio, Sure Electronics or similar) and plenty of time, I could build both the equivalent of a speaker crossover or modify I2S signals?
Let me add some more info to my requests. I'm relatively proficient in microprocessor and digital electronics, having built and programmed a variety of boards (mostly ESP32, STM32 and nRF52). I do have a decent oscilloscope (Rigol DS2302A), signal generator, logic analyzer (DSLogic) and multimeters. I also have an UMIK-1 and used REW to check out my kit speakers. I know nothing about DSP but have some understanding of digital protocols (e.g. I2S, SPDIF) used in a modern audio device
At the moment, I'm more interested in learning and figuring things out than listening to high quality sounds. And I'd like to learn more about handling sounds purely in the digital domain (then converting to analog at the proper time). I'm not worried about adding extra modules and having to solve problems
And at the moment I really want to spend the least possible, given that I still "don't know what i don't know", so spending a couple of hundred dollars without knowing what for is less than ideal. A Dayton Audio DSPB K and DSPB KE or similar Sure Electronic is ~$35 shipped, which is much more interesting. Plus the programmer, and I was thinking about using a CY7C68013A board (and all the necessary black magic to make it work)
A generic ADAU1701 (or 1452 as suggested here) should allow me to use a purely digital input (I2S or SDIP-to_I2S converter) and either output an analog signal over 4 channels, or 4 I2S channels (assuming I understand how the ADAU1701 works). Then I can further decide how to handle the output (for example, using the ADAU1701 board as an equalizer and sending SPDIF to a stereo amplifier)
Going with a DSP-408 or similar "ready" devices, assumes purely analog input and output. The same would be with a Dayton Audio DSPB-250
Am I right in thinking that with a DSP board (Dayton Audio, Sure Electronics or similar) and plenty of time, I could build both the equivalent of a speaker crossover or modify I2S signals?
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I didn't think of miniDSP. I need to ask them if they have the gradient low-mid frequency cancellation utilized in this paper.
https://aaltodoc.aalto.fi/bitstream...Kantamaa_Olli_2020.pdf?sequence=2&isAllowed=y
Free DSP
freeDSP main thread
freeDSP | An Open-Source Low-Budget Audio DSP
freeDSP | An Open-Source Low-Budget Audio DSP
freeDSP main thread
freeDSP | An Open-Source Low-Budget Audio DSP
freeDSP | An Open-Source Low-Budget Audio DSP
I'm a bit at a loss here. I did look at the freeDSP site and various boards, but especially for someone living in the USA, the prices are simply not competitive at all. I can get one of those eBay/Aliexpress "green ADAU1701" boards for $18 shipped.
None of the freeDSP boards I found for sale (and that might be poor search skills on my part) are close to the direct-from-China prices and there doesn't seem to be any additional value offered in the freeDSP boards outside of being open hardware, which is nice but not enough for my purposes.
What am I missing?
Hi Robca,
You actually have lots of good experience then. The ADAU1452 from AliExpress might even work if you are handy either SPI/I2S/I2C and programming MCUs.
The ADAU1452 EVM is also a good choice. It has headers to access the SPI/I2S stream in out out. Has SPDIF too.
You actually have lots of good experience then. The ADAU1452 from AliExpress might even work if you are handy either SPI/I2S/I2C and programming MCUs.
The ADAU1452 EVM is also a good choice. It has headers to access the SPI/I2S stream in out out. Has SPDIF too.
I'd recommend downloading and playing with sigma studio before settling on a specific dsp chip. you can throw a few filters together quite quickly, and see whether or not your program will fit on a 1701. Furthermore, the more ubiquitous 1452 options on Aliexpress have the dsp chip on a seperate board to the codec, that way if you wanted to roll your own adc/dac board it could give you a jumpstart.
You can have one of these boards for free by simply buying the owner a coffee. They are an early design that is no longer supported, but they work and are a good way to learn about the ADAU1701 and how to control it. You can have the code, but it is very difficult to follow--see the main blog (Feb 16, 2021) for details.
I didn't realize that the 1452 boards had the option to use a separate codec board with AD1938, which definitely adds a lot of flexibility. Thanks for pointing that out.
Yes, I downloaded Sigmastudio and promptly got lost 🙂 🙂 Lots and lots of functionality, even for the "lowly" 1701. I will probably get the cheapest 1701 board and use a signal generator+oscilloscope to see what happens to the signal with the various options. Right now, given my lack of DSP experience, most of those options are obscure.
Thanks Neil, really appreciated. Will follow up with you in a PM for this.
Incidentally, and I'm sure you hear it a lot, I'm a big fan of your site, which I discovered early in my exploration. Still slowly digesting the content, and I'm blown away by how much work you did on the site. Kudos and thanks for sharing your knowledge with us
I found a suitable box for the learning board, and I'll send out tomorrow. You will need a microUSB cable to power it up. I'll send out the code tomorrow as well.
I wrote up some new information about the software at this link: Finally: Some Shareable Code – Audiodevelopers Reborn
That write-up might give you a better idea of how the code is organized, plus what sort of collaborative effort I would be interested in. Again, my time is limited right now, but I'm not going to walk away from many years of work on this project, either.
My primary interest right now is either line arrays or multi-way speakers with more than 3 bands of DSP (5-way, for example). So, I'm not really interested in "perfecting" the 3-way software...just trying to re-architect it so it is modular library code that I can adapt to these other designs.
I wrote up some new information about the software at this link: Finally: Some Shareable Code – Audiodevelopers Reborn
That write-up might give you a better idea of how the code is organized, plus what sort of collaborative effort I would be interested in. Again, my time is limited right now, but I'm not going to walk away from many years of work on this project, either.
My primary interest right now is either line arrays or multi-way speakers with more than 3 bands of DSP (5-way, for example). So, I'm not really interested in "perfecting" the 3-way software...just trying to re-architect it so it is modular library code that I can adapt to these other designs.
@robca; "And I'd like to learn more about handling sounds purely in the digital domain (then converting to analog at the proper time)"
You could try your hand at TI TAS amplifiers, using the Zoudio board (~$100) found in the https://www.diyaudio.com/forums/vendor-s-bazaar/. It's good for running a pair of two way speakers; other configurations are possible.
TAS amplifiers do DSP "purely in the digital domain" and convert to analog at the power output stage. Unsure if that's "the proper time" for you or not. I think the sound is nice.
Setup of the amplifier and its DSP is all through register programming using an I2C interface. (You get one and a custom setup program when you buy the Zoudio amp).
TI however doesnt just give their control software panel away as an easy download, unless you're developing a product using their hardware. Unsure how tough a nut it would be to crack; making sense out of the register programming, which of course anyone with a I2C interface can do.
Have a look at the Zoudio amp and the TAS product line to see what you think,
You could try your hand at TI TAS amplifiers, using the Zoudio board (~$100) found in the https://www.diyaudio.com/forums/vendor-s-bazaar/. It's good for running a pair of two way speakers; other configurations are possible.
TAS amplifiers do DSP "purely in the digital domain" and convert to analog at the power output stage. Unsure if that's "the proper time" for you or not. I think the sound is nice.
Setup of the amplifier and its DSP is all through register programming using an I2C interface. (You get one and a custom setup program when you buy the Zoudio amp).
TI however doesnt just give their control software panel away as an easy download, unless you're developing a product using their hardware. Unsure how tough a nut it would be to crack; making sense out of the register programming, which of course anyone with a I2C interface can do.
Have a look at the Zoudio amp and the TAS product line to see what you think,
Thanks again Neil. I did send you a few coffees as a small token of appreciation.
In parallel, I started building a framework to program an ADAU1701 using "modern" ESP32 libraries. I'm using quite a few standard libraries (including the MCUdude one), a WiFi manager with captive portal to set the device upon first power on, then a website offering the device UI (using the modern Bootstrap reactive framework, with the ability to duplicate basically the same functionality of the Android app), including the ability to upload newer versions of the web UI over the air. Also the overall firmware can be updated over the air. Basically once the ESP32 is programmed the first time, everything that needs updating is done over the air using the web server in the ESP32 itself, requiring nothing more than a browser. And all settings are retained even between updates.
At the moment is nothing more than a rough skeleton, with none of the actual functionality. It's gong to be quite a lot of work to get it to full functionality, but the basic concepts are in place and working. I will contact you separately to see how open you are to allow me to reshare the code using your same logic (i.e. ADAU1701 generic implementation plus an Arduino device to change parameters in real time) and/or to port your code to the new framework. I will not share anything coming from you without your preliminary approval, to be clear.
Since I plan to sooner or later diverge from your functionality in my experiments, developing a more modern ESP32 implementation will help me anyway for any device I will end up building. And the basic functionality I'm implementing now will work for any future ESP32 project of mine where I need a web server implementation, so worth doing on its own.
If you are interested, I can send you a skeleton proof of concept in a few days, just to give you a sense of how it will look like.
If any of the above gives you concern even after my assurances, I would suggest holding off on sharing your code until I can address your concerns. The last thing I want to do is play fast and loose with someone else IP and hard work
In parallel, I started building a framework to program an ADAU1701 using "modern" ESP32 libraries. I'm using quite a few standard libraries (including the MCUdude one), a WiFi manager with captive portal to set the device upon first power on, then a website offering the device UI (using the modern Bootstrap reactive framework, with the ability to duplicate basically the same functionality of the Android app), including the ability to upload newer versions of the web UI over the air. Also the overall firmware can be updated over the air. Basically once the ESP32 is programmed the first time, everything that needs updating is done over the air using the web server in the ESP32 itself, requiring nothing more than a browser. And all settings are retained even between updates.
At the moment is nothing more than a rough skeleton, with none of the actual functionality. It's gong to be quite a lot of work to get it to full functionality, but the basic concepts are in place and working. I will contact you separately to see how open you are to allow me to reshare the code using your same logic (i.e. ADAU1701 generic implementation plus an Arduino device to change parameters in real time) and/or to port your code to the new framework. I will not share anything coming from you without your preliminary approval, to be clear.
Since I plan to sooner or later diverge from your functionality in my experiments, developing a more modern ESP32 implementation will help me anyway for any device I will end up building. And the basic functionality I'm implementing now will work for any future ESP32 project of mine where I need a web server implementation, so worth doing on its own.
If you are interested, I can send you a skeleton proof of concept in a few days, just to give you a sense of how it will look like.
If any of the above gives you concern even after my assurances, I would suggest holding off on sharing your code until I can address your concerns. The last thing I want to do is play fast and loose with someone else IP and hard work
Thanks @jjasniew, I'll look into that.
But from a cursory look and based on what I learned in the last few days, the ADAU1701 seems a better option, not only because the tools are freely available, but also because most of the more powerful ADI DSPs are pretty much compatible with each other and very affordable. For example, the ADAU1462 which can also use external codecs is available for ~$40 on Aliexpress (codec boards are extra)
I also would like to limit moving from analog to digital domains too many times. My main sources are all digital (streamers or PCs), and can provide SPDIF outputs. The ADAU1701 can accept I2S signals, and with a cheap SPDIF to I2S converter I can avoid going PC->DAC->A/D to ADAU1701->DAC to the D class amplifier. Even better, with an ADAU1462, I can get PC->SPDIF directly to ADAU1462-> SSM3582 which is a D-class amplifier that can use digital inputs directly. Everything happens in the digital domain, with no analog components apart from the speakers and my ears 🙂
So even if I'm not ready to go ADAU1462 & SSM3582 yet, learning on the ADAU1701 will be more usable later on
But from a cursory look and based on what I learned in the last few days, the ADAU1701 seems a better option, not only because the tools are freely available, but also because most of the more powerful ADI DSPs are pretty much compatible with each other and very affordable. For example, the ADAU1462 which can also use external codecs is available for ~$40 on Aliexpress (codec boards are extra)
I also would like to limit moving from analog to digital domains too many times. My main sources are all digital (streamers or PCs), and can provide SPDIF outputs. The ADAU1701 can accept I2S signals, and with a cheap SPDIF to I2S converter I can avoid going PC->DAC->A/D to ADAU1701->DAC to the D class amplifier. Even better, with an ADAU1462, I can get PC->SPDIF directly to ADAU1462-> SSM3582 which is a D-class amplifier that can use digital inputs directly. Everything happens in the digital domain, with no analog components apart from the speakers and my ears 🙂
So even if I'm not ready to go ADAU1462 & SSM3582 yet, learning on the ADAU1701 will be more usable later on
