[LAU] Full-featured mixers

[Tim]

On 3/31/19 5:02 PM, Len Ovens wrote:
> On Sun, 31 Mar 2019, Tim wrote:
> 
>> I found a tip for KMix to show ALSA *not* Pulse controls:
>>   "export KMIX_PULSEAUDIO_DISABLE=1 && kmix"
>> But unfortunately it's either Pulse or ALSA, not both at the
>>  same time in KMix. To me that's a bad thing.
> 
> Pulse and alsa are effectively two different audio "devices".

I don't know a lot about Pulse, but I thought I read the other day
  that Pulse talks to ALSA via an ALSA driver. Is that correct?
Or Pulse bypasses ALSA somewhat or totally (as I first thought)?

> Pulse does weird things with the alsa controls for most alsa mixers, 
> Thankfully, the ice1712 is one of the ones it does not touch :)

I remember trying Pulse while helping with mudita24 mixer.
Maybe I was mistaken but I remarked that at one point Pulse seemed
  to take control of the hardware - even my ice1712 - I was puzzled
  how the hardware registers were being changed. I thought it was kind
  of 'smart', low level. But maybe it was just an ALSA driver working.

> However, if you watch the alsa controls for input levels on an HDA card 
> (I know, the input on these is not worth using for anything beyond phone 
> work) The boost and level controls bounce all over the place such that a 
> lower level may have more boost (and more noise) than a higher level. It 
> also means that after setting the alsa level exactly how you want it, 
> pulse comes along and messes it up.

Hm yeah weird. Maybe just Pulse talking to ALSA talking
  to the registers. I'd have thought it would be the other way around,
  that Pulse might first read what's in ALSA and start from there.
But who knows, maybe ALSA defaults or user settings aren't
  necessarily correct for how Pulse needs to work. After all,
  I guess Pulse sits on top of ALSA somewhat, so ALSA is just
  obeying its master. Again not a Pulse expert here.

>> So I want to give a big shout out for QasMixer
>>  https://sourceforge.net/projects/qastools/
>>  and ask what general mixers you might use and what
>>  you think of QasMixer and QasHctl. They're pretty cool.
>> They show all my ice1712 controls.
> 
> I like qasmixer except it does not allow one to edit the layout. On my 
> ice1712 it does show all the controls including duplicate ADC and DAC 
> controls. I would like to be able to not show duplicates (or is this 
> just a Delta 44/66 problem).

Hm, didn't notice any duplicates here. Yeah sure looks like a lot of
  controls in qasmixer and qashctl but amazingly I don't think I
  caught anything duplicated. I'll keep an eye out.

> In the end, I tell pulse not to look at any alsa devices and to use jack 
> as it's only device. In this case it only does sw levels (-inf to +11db).

I see. Yes I know that I can select a Jack device from pav.

>> I think a desktop mixer icon should eventually bring you
>>  to something like that instead of only Pulse.
>> What do you think?
> 
> <rant>
> One word "convergence"... All computers must be the same to operate as a 
> phone. After all nobody does real work on a computer, they just browse 
> and use one or two other apps at most. Most phone users just want one 
> level control... The reality is that PCs are not made for audio 
> creation, they are entertainment boxes. "Low latency" is 30ms by design, 
> if you got less it is because they made a mistake and "should" have used 
> cheaper parts. If they make an audio computer with super low latency 
> (10-15ms) it will be at musician prices (think brand new Gibson Les Paul).

I've had my eye on the Fender Custom Shop for while now.
The Gary Moore red Stratocaster (from his strat days) would be so nice.

Aren't there still places that build Linux audio computers?

> </rant>

> Anyway, yes I agree. On the other hand, when I use a browser to watch YT 
> stuff, the Pulse single level control is just perfect and because of the 
> way I use my Delta66, my alsa level controls are pretty much set and 
> forget anyway.

Yes I have to admit I mostly set and forget my delta1010 - but that's
  'cause I already know about envy24 and mudita24.
I guess I was concerned about people not getting the full picture
  from their mixers and being disappointed.

> They are line level and so I have a cr1604 in front of it 
> for mic/line preamps and speaker level controls. I do not use the 
> internal monitor mixer because I have the external one that has faders 
> and eq and sends and all that so I don't need to. Mixers are cheap, even 
> digital ones with 32 ADC/DAC built in that can also act as DAW 
> controlers.

I have an analog mixer but it sits in a box. Just a desktop
  composer here, so the card does everything I need.
Except yeah, I really should put an analog compressor/limiter in
  front of it, the one thing a digital card can't watch out for.
But I'm so used to playing/recording without a compressor/limiter.
I just watch my peaks, that's all.

Speaking of which...
I mentioned on Jack ml that QasMixer didn't seem to have any meters.
I seemed to recall that envy24/mudita24 meters were ALSA components
  and wondered whether this could be added to Qas.
But another user remarked something about his Focusrite Scarlett where
  ALSA don't do the meters in a good way (splitting them into channels?).

Another user pointed out that ALSA may not be the answer for all
  cards and may even get some things incorrect whereas a dedicated
  mixer might not. And said "usually class compliant USB devices don't
  have alsamixer volume controls".

> (stay away from new A&H SQ series which 96K only and is not 
> stable when used with Linux and maybe other OS as a digital interface)

OK! I... guess?
Cheers.
Tim.

> 
> -- 
> Len Ovens
> www.ovenwerks.net