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Re: Tweaking the audio performance Rpi3

PostPosted: 24 Jan 2017, 00:24
by pietpara
BTW I just noticed during boot that I get 3 failed messages:

Failed to open vchi service
Failed to initialize shared memory services
Failed to start Load Kernel Modules

I guess that should not happen, right?

But, apart from playback with gaps between tracks and a pop, all works well.

Hmmm.
Is that something very obvious for the experts here? :roll:

Pietpara

Re: Tweaking the audio performance Rpi3

PostPosted: 24 Jan 2017, 00:34
by Frost_dk
pietpara wrote:Hi RuneFrost,

Yes, all changes, step by step. The last was the soxr thing.
I always listen to full albums and most, or lots, are continuous, so it's really nasty to hear the gap each time with a loud pop.

The GPIO thing I may try. Is that (part of) the fboe mod?
Thing is, I'm not a soldering expert.

Cheers!


btw.
You can try to add
Code: Select all
always_on     "yes"

to /etc/mpd.conf

you should add it to the active device (the one that you already has added the soxr part to)

Perhaps this will help you with the pop sounds..

Re: Tweaking the audio performance Rpi3

PostPosted: 24 Jan 2017, 12:27
by pietpara
Thank you for the tip, but it did not help.
I thought it might be the format 192000:24:2 that I set, so I changed it to 192000:16:2, but also no help.

That raises a question about the format too. Does setting 16 or 24 (assuming those are bit depth of the sound signal) depend on or affected somehow by what the source stream is?

Cheers
Pietpara

Re: Tweaking the audio performance Rpi3

PostPosted: 24 Jan 2017, 22:04
by pietpara
Hello,
I hope I may ask Frank if he has any ideas related to the error messages I receive during boot. These are the very first 3 messages upon booting:
Code: Select all
Failed to open vchi service
Failed to initialize shared memory services
Failed to start Load Kernel Modules


I have double checked the files I had modified, my cmdline.txt and config.txt, but see no errors.

Also, maybe this post belongs elsewhere, but since it started occurring at some point playing with all these settings...

Thanks in advance
Pietpara

Re: Tweaking the audio performance Rpi3

PostPosted: 24 Jan 2017, 22:07
by Discovery
pietpara,

Did you start with a nightly build...?

Re: Tweaking the audio performance Rpi3

PostPosted: 24 Jan 2017, 22:08
by pietpara
Discovery wrote:pietpara,

Did you start with a nightly build...?


Nope, I have a RaspTouch, and Frank advised therefore not to do that. I think because it is a version that is adapted for the RaspTouch.

Cheers

Re: Tweaking the audio performance Rpi3

PostPosted: 24 Jan 2017, 23:44
by hondagx35
Hi,

I hope I may ask Frank if he has any ideas related to the error messages I receive during boot.

Yes, that is expected. Most vchiq services on GPU are disabled when using cut down firmware (which you get with gpu_mem<32), but it is harmless.

Frank

Re: Tweaking the audio performance Rpi3

PostPosted: 25 Jan 2017, 08:40
by pietpara
[Yes, that is expected. Most vchiq services on GPU are disabled when using cut down firmware (which you get with gpu_mem<32), but it is harmless.


That is great news.
I have gpu_mem at 16.

About the gaps between tracks with nasty popping sound when using the SOXR sampling or manually changing tracks in rune audio with any setting, I have tried many settings, but so far nothing helps.

I was thinking ...Could it have anything to do with over or underclocking?

Re: Tweaking the audio performance Rpi3

PostPosted: 25 Jan 2017, 18:13
by hondagx35
Hi all,

I have no answer to all your questions belonging to SOXR and other sample rate converters.

But I have my own point of view:
It's really silly (bad idea) to modify the audio source instead of passing it untouched to your device unless you have some shitty sound card that doesn't handle the correct sample rate. It is arguable that padding the signal to 32bit is good, or at least harmless.

If you like to play highres audio I would recommend buying a DAC that can handle this natively.

Maybe someone can explain me (electronic engineer) why I should do sample rate conversion.

Frank

Re: Tweaking the audio performance Rpi3

PostPosted: 25 Jan 2017, 19:09
by pietpara
Hello Frank,

I totally agree with you. But I was under the impression that the ES9018K2M DAC in the RaspTouch also uses it's internal upsampling and by using the SOXR one, which is considered a very good one, you can kind of by-pass that one, because the ESS need not upsample anymore.

Here's a bit of backround: http://bitperfectsound.blogspot.com.es/2013/11/upsample.html

So, it seems that due to the way modern DACs work, with Delta-Sigma converters, upsampling is a must and almost standard in any DAC chip.



Anyhow, my questions are more towards the popping sound when switching tracks in RuneAudio. This is independent of the settings of RuneAudio. No matter what audio profile or config.txt or cdmline.txt, I always have a 'pop' when I manually change tracks. And I do not hear a pop when just playing the queue (playlist).
Now, when I turn on the SOXR upsampler, then I even get a gap and a pop between tracks when playing a playlist.

I would really like to solve this, since the pop is so nasty that I feel my tweeters don't like it either.

Doesn't anyone else have this issue?

Best,
Pietpara