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Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

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Re: Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

#21

Post by MrBuddyCasino »

vladvasiliu wrote: post #18
MrBuddyCasino wrote: post #9

Earlier quoted context omitted.

Did you ever use Dirac Live and can compare the results? Hardware that supports Dirac is unfortunately very expensive.

FWIW, I've tried Dirac Live and compared it to the correction suggested by REW [0]. In both cases, the measurements were taken with a UMIK-1, and the correction was done on a computer. Contrary to GP, I didn't have to fix borked components, just a random, untreated living room. Dirac seemed to have a fairly heavy-handed correction. In my case, I only had fairly narrow frequency ranges that needed correcting, but Dira…

I also have a UMIK-1, and tried the REW route once, but it made everything worse. I suspect a lot of the know-how in Dirac is how to automatically get good results.

Re: Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

#22

Post by vladvasiliu »

MrBuddyCasino wrote: post #21
vladvasiliu wrote: post #18

Earlier quoted context omitted.

FWIW, I've tried Dirac Live and compared it to the correction suggested by REW [0]. In both cases, the measurements were taken with a UMIK-1, and the correction was done on a computer. Contrary to GP, I didn't have to fix borked components, just a random, untreated living room. Dirac seemed to have a fairly heavy-handed correction. In my case, I only had fairly narrow frequency ranges that needed correcting, but Dira…

I also have a UMIK-1, and tried the REW route once, but it made everything worse. I suspect a lot of the know-how in Dirac is how to automatically get good results.

In my case, the setup is pretty simple. I have full-range floorstanders that only take a single input, and I mostly wanted to control some booming in my listening position. So there's no crossover to handle or anything fancy.

Maybe for more involved situations Dirac does a better job, but, in my case, it didn't really solve anything. Also, I see they now have this newer "bass control" thing, and it's not clear if my version had it when I last tested it (around November 2025).

Re: Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

#23

Post by jamesfmilne »

aa-jv wrote: post #19
alhirzel wrote: post #6

Earlier quoted context omitted.

85ms https://github.com/WeebLabs/DSPi/commit/ba8e481570e6a5ce3d35...

Ouch, thats pretty average, what a pity ..

That's the maximum delay when adding a delay for synchronising with other sources.

The end-to-end delay is about 10ms, according to this comment:

https://www.audiosciencereview.com/forum/index.php?threads/i...

Re: Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

#25

Post by Neywiny »

joenot443 wrote: post #17

This is awesome. What are the odds a Raspberry Pi could keep up with BTrack? https://github.com/adamstark/BTrack

Pi or pi pico? At first glance it looks like that software is designed for double precision floats. That would certainly be some compute. The M0+ doesn't have hardware floating point let alone double precision. The M33 on the newer chip I think has hardware single precision float so a simple find-replace should let it go.

If it's not doing anything else and the sample rates aren't outrageous it might be doable but I'd have to dig into the code more to see how much work they're doing per sample.

Re: Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

#26

Post by Kirby64 »

lysace wrote: post #16
hexmiles wrote: post #12

I wonder if you could do the same thing in reverse and have a cheap way to get multiple inputs. I would love a cheap way to add 8–16 inputs to my PC; all the audio interfaces I found cost quite a bit.

The ADCs on RP2040/2350 only have 12 bit resolution.

Even worse, the ENOB is closer to 9 bits in testing. It’s got horrible DNL/INL. Totally worthless for any audio unless you’re trying to do chiptunes or something.

Re: Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

#27

Post by beepbooptheory »

aa-jv wrote: post #19
alhirzel wrote: post #6

Earlier quoted context omitted.

85ms https://github.com/WeebLabs/DSPi/commit/ba8e481570e6a5ce3d35...

Ouch, thats pretty average, what a pity ..

Why? This is a device more for home audio/audiophile uses it seems? Why does latency matter there?

Re: Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

#29

Post by nereye »

Kirby64 wrote: post #26
lysace wrote: post #16

Earlier quoted context omitted.

The ADCs on RP2040/2350 only have 12 bit resolution.

Even worse, the ENOB is closer to 9 bits in testing. It’s got horrible DNL/INL. Totally worthless for any audio unless you’re trying to do chiptunes or something.

FWIW, this project is entirely digital (audio in: USB, audio out: S/PDIF or I2S).

There are other projects for the Pico which implement S/PDIF in.

In either case, since it is digital, the quality (or lack of) of the internal ADCs should not matter.

Re: Fully Featured Audio DSP Firmware for the Raspberry Pi Pico

#30

Post by gsliepen »

lysace wrote: post #16
hexmiles wrote: post #12

I wonder if you could do the same thing in reverse and have a cheap way to get multiple inputs. I would love a cheap way to add 8–16 inputs to my PC; all the audio interfaces I found cost quite a bit.

The ADCs on RP2040/2350 only have 12 bit resolution.

Yes, but this project doesn't do anything analog to begin with. It could just have several S/PDIF and I2S inputs, and convert that to USB. You probably don't want any processing then, and just pass the digital inputs straight to USB. The limit of how many channels you could simultaneously process would then be the USB bandwidth.
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