[LAU] asoundrc questions

[John Murphy]

On Mon, 31 Dec 2012 16:42:01 -0800, Len Ovens wrote:

> 
> On Mon, December 31, 2012 8:33 am, John Murphy wrote:
> > On Mon, 31 Dec 2012 11:10:31 -0500, Paul Davis wrote:
> >
> >> On Mon, Dec 31, 2012 at 11:07 AM, John Murphy
> >> <rosegardener at freeode.co.uk>wrote:
> >>
> >> > I'm trying to follow the example .asoundrc provided at
> >> > http://alsa.opensrc.org/RME_Hammerfall_.asoundrc
> >> >
> >>
> >> what are you trying to accomplish?
> >
> > Hello Paul. Thanks for asking.
> >
> > I'm hoping this is the way to use jack on both cards at the same time.
> > I'd also like to configure most inputs as stereo pairs. I'm hoping
> > mixers will then provide a single fader and pan control.
> 
> The .asoundrc will make it possible for jack to see the two cards, though
> if you read the thread on the two deltas, you will understand it is not
> perfect :) It works better for some people than others.

Thanks; yes I had a look at that thread, but it seemed to be concerned
with synchronisation, where that wasn't a feature of the cards. I have
the two RMEs connected internally. They have on board headers for the
purpose, and I'm fairly convinced that's working at least.

> As for mixers... which mixers? Any of the applications that provide mixers
> like ardour or non-mixer (anything that deals with jack ports) allow you
> to choose which inputs belong to a channel. So you can create a stereo
> channel with input 1+2 or 1+7 if that is what you want and use a pan
> control (or something more advanced). As for the alsa mixer, changes to
> the .asoundrc look like they may effect that. For most uses the alsa mixer
> is pretty much set and forget though, so I am not sure how valuable that
> is. In any case, jack does not show stereo pairs anyway. In any case any
> stereo pair should be confined to one card. It should not be left from
> hw:0 and right from hw:1 as the stereo imaging will suffer. It is ok to
> mix sound from a stereo pair on one card with the sound from a stereo pair
> on another card though... so long as the sounds are not acoustically
> related (recorded from mics sets that are recording the same sounds).

It was the assignment of stereo channels in the example .asoundrc
which led me to believe it would be worth setting them up there, but
I'll not bother with those then. Your comments on which inputs are
best used together are much appreciated, thanks.

> I don't know how the rme cards work if they use phase lock loop to sync as
> the cheaper deltas do. In any case it is best to use the channels from the
> master card (the one supplying clock) for the most important audio. Cable
> length should be kept as short as practical for sync.

I'm afraid the link is a couple of old motherboard led/switch etc.
leads soldered together (which just happen to fit the headers). :)
Card 2 is showing sync lock on spdif in HDSPconf, so it should be fine.
I read some good things about the RME Multiface sync capabilities, but
I'm not sure how much better they are over the 9652s.

> Best of all, try it and see.

Indeed, and I've had my first core dump of the year already. Trying
to make too many changes at once caused it. But I can only get it
to work with the 'card N' designations. If I change instances of
those in my .asoundrc to the names they are given by the udev rule
(eg. s/card 0/RME_1/g) I get complaints like:

ALSA lib conf.c:1686:(snd_config_load1) _toplevel_:14:1:Unexpected char
ALSA lib conf.c:3406:(config_file_open) /home/john/.asoundrc may be old or corrupted: consider to remove or fix it

Without the ability to always have an alias (even if it's 'card 0')
pointing to the same card; a two card user can never know which one is
which after a reboot, which must be very confusing. I must be missing
some nugget of information somewhere. Or maybe it's just the extra unwanted
'card' in my system which is causing the variation of designation. The only
way I can test currently, is to discover which card is where with aplay -l,
adjust instances of 'card N' in the .asoundrc to reflect that, and then
log off/on and start the jack daemon.

The "unwanted card" is hdmi sound on my graphics card and I don't
know if I can disable it. That may be a workaround if I can...

-- 
John. 2013! This *must* be the future.