DSP Info

[BKr0n]

Actually one thing I have noticed is most boards use codecs as opposed to separate ADCs and DACs. Is this mostly a cost saving measure or a more meaningful design choice?

 

[BKr0n]

So yeah this is another reason I think I'm just better off with digital...

 

[voodooless]

Actually one thing I have noticed is most boards use codecs as opposed to separate ADCs and DACs. Is this mostly a cost saving measure or a more meaningful design choice?

It’s mostly for cost. Those AliExpress boards often use AD1938. It’s a cheap and simple codec, but its performance isn’t that much better than the one the ADAU1701 has built in. You can easily add your own DAC and ADC boards via I2S. I haven’t seen any DSP boards with high SINAD chips from China so far.

 

[BKr0n]

https://orchardaudio.com/shop/pecanpi-dac-plus/ found this one while looking stuff up. I do have a little bit of experience with sbcs, but not RPi specifically. I have noticed there are definitely a TON of aliexpress boards with all sorts of combinations of chips. One of the issues I've been running into is actually that the chip makers don't post reference designs for the parts that are considered high end. Makes it a little tougher to make an informed decision.

 

[Snarfie]

I'm one of those people that does make a new measurment when something is changed in my room that could alter my roommodes. Even it is minute difference So realtime would work for me probably

 

[voodooless]

https://orchardaudio.com/shop/pecanpi-dac-plus/ found this one while looking stuff up. I do have a little bit of experience with sbcs, but not RPi specifically

Pi HATs are stereo only, except for a few with DSP chip onboard (and even those only offer stereo from the pi). If you want multichannel get a USB interface.

 

[BKr0n]

I'm one of those people that does make a new measurment when something is changed in my room that could alter my roommodes. Even it is minute difference So realtime would work for me probably

Pffft. This is just for a set of speakers. I can't even imagine how anal retentive I would get if I was doing this for a room lol

 

[BKr0n]

Pi HATs are stereo only, except for a few with DSP chip onboard (and even those only offer stereo from the pi). If you want multichannel get a USB interface.

https://alitools.io/en/showcase/ads...put-4-in-6-8-out-processor-b4-007-32978121788 there's a few listings that have this board. Would love to know if there are other modules floating out there for it. If so, it's damn near perfect.

 

[voodooless]

https://alitools.io/en/showcase/ads...put-4-in-6-8-out-processor-b4-007-32978121788 there's a few listings that have this board. Would love to know if there are other modules floating out there for it. If so, it's damn near perfect.

Yes, from what I heard it’s not very good performance wise though. Haven’t seen any measurements and it’s too expensive to just gamble on.

 

[BKr0n]

There are definitely lots of modules. With all that's available, is it possible to do adc as well? Or is just doing the DAC conversion the safer bet?

 

[Snarfie]

Pffft. This is just for a set of speakers. I can't even imagine how anal retentive I would get if I was doing this for a room lol

It's toxic for me

 

[BKr0n]

It's toxic for me

If it's any consolation, this is now month 6 of development. So far, the only thing I have done is I got two of the drivers I need... I still need to get the other 4 and the corresponding PRs. Maybe ASR should start a support group

 

[Snarfie]

Pffft. This is just for a set of speakers. I can't even imagine how anal retentive I would get if I was doing this for a room lol

It's toxic for me

If it's any consolation, this is now month 6 of development. So far, the only thing I have done is I got two of the drivers I need... I still need to get the other 4 and the corresponding PRs. Maybe ASR should start a support group

ASR should test DSP systems in general to get a overview regarding functionality quality. It is one of the most used application on ASR.

 

[BKr0n]

ASR should test DSP systems in general to get a overview regarding functionality quality. It is one of the most used application on ASR.

They do as far as I know. They even have a whole SINAD chart from best to worst. @kemmler3D gave me the idea to start this thread to get some good info out about application more than just simple products. Example: if I do go the modular approach, I need two things in particular to make everything work as intended:
1) Some sort of reclocker. Something that will help reduce lag time between boards and keep timings tight.
2) The microcontroller to conduct this whole symphony. RPi is definitely an option here. It has plenty of I/O and documentation for days on how to use it.
I also need to figure out where I'm going to put everything. More than likely the inside of the enclosure will be insulated. Electronics do not like heat.

 

[voodooless]

if I do go the modular approach, I need two things in particular to make everything work as intended:
1) Some sort of reclocker. Something that will help reduce lag time between boards.

If you hook the board up via I2S, they are usually slaved from the DSP clock for DACs, and ADCs or digital inputs are usually master for the DSP. The DSP can then perform ASRC to convert clock domains.

2) The microcontroller to conduct this whole symphony. RPi is definitely an option here. It has plenty of I/O and documentation for days on how to use it.

Generally a DSP board will not need additional control. You have quite a bit of control via SigmaStudio and can even use buttons to change functionality if needed. DAC and ADC boards can be found with hardware interfaces, so no CPU needed either. It will make the whole thing much simpler.

 

[BKr0n]

Generally a DSP board will not need additional control. You have quite a bit of control via SigmaStudio and can even use buttons to change functionality if needed. DAC and ADC boards can be found with hardware interfaces, so no CPU needed either. It will make the whole thing much simpler.

By any chance do you have any favorites in particular?

 

[voodooless]

By any chance do you have any favorites in particular?

Nope, I’ve been eyeing them for a while. A DSP board is fairly easy, there are plenty. Any with ADAUxxx are probably fine for most use cases. The bigger problem is the unknown performance of the DAC boards.. no measurements to be found, and badly implementing ESS (most of them are..) chips can easily lead to crappy performance.

So I’ll be going the SBC route and I’ll be using a PCIE soundcard to get 8 channel of 100+ SINAD for little money.

 

[Snarfie]

They do as far as I know. They even have a whole SINAD chart from best to worst. @kemmler3D gave me the idea to start this thread to get some good info out about application more than just simple products. Example: if I do go the modular approach, I need two things in particular to make everything work as intended:
1) Some sort of reclocker. Something that will help reduce lag time between boards and keep timings tight.
2) The microcontroller to conduct this whole symphony. RPi is definitely an option here. It has plenty of I/O and documentation for days on how to use it.
I also need to figure out where I'm going to put everything. More than likely the inside of the enclosure will be insulated. Electronics do not like heat.

You are far far ahead on me. I use RPi in combination with my backup 3TB hdd to play house wide my music over my bluetooth Sony headphone. Don't have to start up my Windows laptop anymore. Headphone correction done by Wavelet.

 

[BKr0n]

So I’ll be going the SBC route and I’ll be using a PCIE soundcard to get 8 channel of 100+ SINAD for little money.

Uh... that's a really neat idea. Mind if I borrow it?

You are far far ahead on me. I use RPi in combination with my backup 3TB hdd to play house wide my music over my bluetooth Sony headphone. Don't have to start up my Windows laptop anymore. Headphone correction done by Wavelet.

Everyone has to start somewhere. I started this journey not knowing much about Acoustics and mixed signal design. Now I'm designing an entire system. In the words of Dr. Seuss "oh, the places you'll go"

 

[BKr0n]

Nope, I’ve been eyeing them for a while. A DSP board is fairly easy, there are plenty. Any with ADAUxxx are probably fine for most use cases. The bigger problem is the unknown performance of the DAC boards.. no measurements to be found, and badly implementing ESS (most of them are..) chips can easily lead to crappy performance.

Actually I did get sent this a while ago. Not sure if I'm going to use it, but overall it seems really cool http://www.jlsounds.com/FAQ.html