Lots of clipping from Voice PE

[lyric pawn]

I posted about this here: https://community.home-assistant.io/t/voice-pe-distorted-audio/966203/6?u=sawtaytoes

This is the most important thing (the waveform image).

The Voice PE is clipping like mad and has basically no output volume.

The top part is the Voice PE at max output and the bottom is the Google Chromecast Audio.

With the same settings, this is what the 3.5mm jack output. I use the same line-in input on my PC.

The Voice PE:

1. No volume compared to the Chromecast Audio which supports 2VRMS and up to 2.8V peak.
2. Clipping audibly to the point where even my wife heard it and said something to me unpromoted. It's that bad.
3. Doesn't have the same quality (only 16-bit and 44.1kHz).

I found out about this because I bought a whole bunch of speakers (15) to use with my Voice PEs, and realized something was very wrong.

This is the latest firmware as of today with Sendspin capability. That's how I did the test.

[abstract veldt]

I also noticed that the output of the PE seems to be higher than a typical line out. So when volume is set to 100% it seems to clip.

I didn’t do the test if it is still less loud than other devices when the volume is reduced to avoid clipping like the thread starter.

Is there any official documentation how it should behave and which output level it should generate?

[lyric pawn]

I'm noticing the opposite. The output of the PE is much softer. You can see it in the waveform image. Max volume is a lot softer. Both of those waveforms are max volume on both the PE and the Chromecast.

So it's clipping even by being softer.

[lyric pawn]

I mean, how it should behave is it outputs close to 2V RMS minimum.

But how it's designed? I'm not sure. There are a lot of variables, but I think the DAC wasn't wired directly to the 3.5mm jack, so it's 100% dependent on the quality of the amp inside which was only there to drive the built-in speaker.

[summer flame]

the dac is wired to the 3.5mm jack and the amp for the speaker.
the 3.5mm jack is a line out.

@lyric pawn have you tried adding a ground isolation transformer on the 3.5mm connection?
it could be a ground loop or other ground noise between the devices causing the issue.

[lyric pawn]

Looks like the DAC was correctly wired. My assumptions are wrong which makes this weirder.

The ground loop does cause noise. How can I isolate that? These are USB devices, and the AC plug has only 2 pins. It should be shared when they're plugged into the same USB PSU.

Also, while there is a ground loop with USB power, the Marshall Stockwell II has a battery, so I tried it like that, and it still has the same clipping issue.

Someone suggested to me the issue is the voltage is too hot coming off Voice PE from an impedance mismatch and that might be the issue which I can fix with resistors. I'll have to do more research on impedance to really understand though.

[summer flame]

pop one of these inline - https://www.amazon.co.uk/Isolator-Eliminate-Buzzing-Completely-Playing/dp/B019FC6ZQQ (amazon uk link but I am sure other countries have similar products as required. they are cheap and readily available because they solve ground loop issues in cars.)
it may not help because as you say its less likely to be an issue if something is running battery. but its possible there could still be some noise which this could filter.
however its also a pretty cheap and easy thing to try. (and if you want to run from usb supply down the line you may end up needing it anyway)

[lyric pawn]

I bought one to test with.

[lyric pawn]

It didn't fix it. I can measure tonight, but I doesn't sound any different.

Same clipping problem because it's clipping at the 3.5mm jack. It's not my recording device. I'll have to check at what volume it doesn't clip.

But if I have to lower the Voice PE and raise it up somewhere else, I won't get the same noise floor. Nor will it fix the issue of the output directly from the 3.5mm output being too quiet. I'll need to add something to amplify the gain a ton for each speaker.

[lyric pawn]

I've heard two ways of fixing this:

1. Lower the input gain from Music Assistant and Home Assistant. The DAC input might be too sensitive.
2. Lower the output gain from the Voice PE.

Neither of these is a good solution because ultimately my output volume will be too low.

I'm already maxing out this powered speaker, and lowering the volume doesn't fix the fact that I want the output louder to match what I'm used to from the Google Chromecast Audio.

I also have Google Home Minis, and while they don't sound great, they don't clip and sound distorted at max volume. That's my expectation.

[lyric pawn]

I got my Pimaroni Audio DAC SHIM today, and it's working better than I could've imagined. I don't wanna have a bunch of Raspberry Pis around the house, but the Zero models are very small and don't need much power.

I'm thinking this is a good enough solution for now, but it's not ideal in any respect :/.

I'll still have to figure out how to 3D print a case for these guys that supports this DAC hat.

Is there a way to replace the Voice PE with a Raspberry Pi or only ESPHome devices?

[summer flame]

Look at Linux Voice Assistant.
It is currently "experimental" and having a lot of work done on it but a bunch of people have used it successfully.
It uses the ESPHome protocol to run a satellite on linux so it should be fairly easy to keep feature parity with ESPhome hardware.

[lyric pawn]

Being able to use ESPHome (similar) on Linux is INCREDIBLE! That's exactly what I want :). I'd be even nicer if the whole OS could be like that.

Does this also get programmed via YAML, or it just provides API access, so you can upgrade the Voice Assistant "firmware"?