1 May
2021
1 May
'21
9:45 p.m.
Hi all,
I have recently acquired a Focusrite SaffireLE (analog: 4ins & 6 outs,
firewire) and I am trying to figure out how can I consolidate its analog
ins/outs with the rest of my setup:
The same audio server hosts other soundcards that are happily driven by
alsa. so JACK can see all the rest of the sound cards (through zita-a2j,
etc).
Now comes the firewire card. If I start a separate jackd session with the
firewire backend
jackd -R -n firejack -dfirewire
then I get to see 6 ins and 8 outs (digital in/out included). I have 2
problems with this setup:
- how do I connect the 2 jack sessions (with 0ms latency if possible). I
tried with zita-n2j but with anything less than 100ms buffer the sound is
unbearably choppy.
- I tried to route some audio stream to each one of the outputs but from
some outputs I could not get any sound, then routing to out1,2 would play
from physical outs 3,4 - so not ideal.
I tried to use the ffado-mixer to fiddle around with routing , but did not
manage anything.
Then I thought, to use the alsa driver , since alsa "sees" the card
normally.
$ cat /proc/asound/cards
6 [SaffireLE ]: BeBoB - SaffireLE
Focusrite SaffireLE (id:2, rev:1), GUID
00130e010004184f at fw1.0, S400
but aplay only registeres a single PCM device:
$ aplay -l
card 6: SaffireLE [SaffireLE], device 0: BeBoB [SaffireLE PCM]
Subdevices: 1/1
Subdevice #0: subdevice #0
so this is not ideal. IS there a way to get the alsa driver to identify all
the ins and outs ?
Alternatively, is there a better way to use a single jack session and load
the 2nd backend as well ? (maybe through audioadapter or otherwise)
Finally, is there a chance to coordinate 2 jack sessions (each with one of
alsa, firewire backends) with 0 latency between them ? In this setup does
anyone have experience with SaffireLE and how to control the mixer?
Thank you!
1 May
1 May
10:08 p.m.
Athanasios Silis <athanasios.silis(a)gmail.com> writes:
Finally, is there a chance to coordinate 2 jack
sessions (each with
one of alsa, firewire backends) with 0 latency between them ? In this
setup does anyone have experience with SaffireLE and how to control
the mixer?
How is 0-latency supposed to work with unsynchronised clocks?
If you want to consolidate multiple soundcards without adding
significant latency for resampling filtering, they must be running on
the same clock (which means that it's mainly comparatively expensive
soundcards that can be consolidated). Even then you'll not be able to
split a stereo channel across two non-identical cards without
introducing problems from the differing phase response of their
oversampling and filtering circuitry.
Synchronisation can happen in some cases via Firewire (for example, if
you daisychain multiple Alesis i|O 26 devices) but more usually with a
separate word clock sync cable.
For juggling numerous sources, there can be a point in getting a mixer
with digital multi-channel in- and output.
That means you don't need to consolidate multiple soundcards but rather
get to work with some flexible multichannel device. That tends to be
quite more robust.
--
David Kastrup
2 May
2 May
10:39 a.m.
Hi there,
Thank you for the information. Yes synchronisation is always an issue and
perhaps I framed the question inadequately, but what I am after is not
complete synchronisation but rather to utilise the analog ins and outs of
this additional soundcard too.
So I am not after 0ms latency per se, but rather something in the order
<12msec. This has been possible across soundcards using the alsa driver, so
I assume it is not out of place to aim for it now too. Perhaps this is not
possible across different jack backend which is why I ask for the various
setup possibilities.
The easiest for me would be to use the saffireLE through the alsa driver,
but that only exposes 1 single stereo playback stream. I want all 3. So
what do I have?
Thanks,
Nass
On Sat, 1 May 2021, 23:07 David Kastrup, <dak(a)gnu.org> wrote:
Athanasios Silis <athanasios.silis(a)gmail.com>
writes:
Finally, is there a chance to coordinate 2 jack
sessions (each with
one of alsa, firewire backends) with 0 latency between them ? In this
setup does anyone have experience with SaffireLE and how to control
the mixer?
How is 0-latency supposed to work with unsynchronised clocks?
If you want to consolidate multiple soundcards without adding
significant latency for resampling filtering, they must be running on
the same clock (which means that it's mainly comparatively expensive
soundcards that can be consolidated). Even then you'll not be able to
split a stereo channel across two non-identical cards without
introducing problems from the differing phase response of their
oversampling and filtering circuitry.
Synchronisation can happen in some cases via Firewire (for example, if
you daisychain multiple Alesis i|O 26 devices) but more usually with a
separate word clock sync cable.
For juggling numerous sources, there can be a point in getting a mixer
with digital multi-channel in- and output.
That means you don't need to consolidate multiple soundcards but rather
get to work with some flexible multichannel device. That tends to be
quite more robust.
--
David Kastrup
6:42 p.m.
Have you tried having one jack server active with the firewire-backend
and then adding the other, ALSA-compatible cards via zita-a2j or a
similar option?
That would only work if you don't need your current "primary" audio card
as the actual primary card.
And it might be some hassle if your FW-card is not always available or
you tend to change your setup frequently.
Jannis
Am 02.05.21 um 10:38 schrieb Athanasios Silis:
Hi there,
Thank you for the information. Yes synchronisation is always an issue
and perhaps I framed the question inadequately, but what I am after is
not complete synchronisation but rather to utilise the analog ins and
outs of this additional soundcard too.
So I am not after 0ms latency per se, but rather something in the order
<12msec. This has been possible across soundcards using the alsa driver,
so I assume it is not out of place to aim for it now too. Perhaps this
is not possible across different jack backend which is why I ask for the
various setup possibilities.
The easiest for me would be to use the saffireLE through the alsa
driver, but that only exposes 1 single stereo playback stream. I want
all 3. So what do I have?
Thanks,
Nass
On Sat, 1 May 2021, 23:07 David Kastrup, <dak(a)gnu.org
<mailto:dak@gnu.org>> wrote:
Athanasios Silis <athanasios.silis(a)gmail.com
<mailto:athanasios.silis@gmail.com>> writes:
Finally, is there a chance to coordinate 2 jack
sessions (each with
one of alsa, firewire backends) with 0 latency between them ? In this
setup does anyone have experience with SaffireLE and how to control
the mixer?
How is 0-latency supposed to work with unsynchronised clocks?
If you want to consolidate multiple soundcards without adding
significant latency for resampling filtering, they must be running on
the same clock (which means that it's mainly comparatively expensive
soundcards that can be consolidated). Even then you'll not be able to
split a stereo channel across two non-identical cards without
introducing problems from the differing phase response of their
oversampling and filtering circuitry.
Synchronisation can happen in some cases via Firewire (for example, if
you daisychain multiple Alesis i|O 26 devices) but more usually with a
separate word clock sync cable.
For juggling numerous sources, there can be a point in getting a mixer
with digital multi-channel in- and output.
That means you don't need to consolidate multiple soundcards but rather
get to work with some flexible multichannel device. That tends to be
quite more robust.
--
David Kastrup
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3 comments
3 participants
participants (3)
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Athanasios Silis -
David Kastrup -
Jannis Achstetter