8 Jan
2017
8 Jan
'17
11:06 p.m.
On Sun, 8 Jan 2017 21:25:35 +0100, Johannes Kroll wrote:
...which would mean that you if you listen to an input,
you mix it with
a copy of itself delayed by the buffer size. That would definately
sound weird, and could explain Ralf's experience.
No, since on Linux I used Ardour and directly connected the stereo
track's outputs by jackd to playback_n. I didn't test any of the
18i20's inputs.
[rocketmouse@archlinux ~]$ pacman -Q ardour5 jack2
ardour5 5.5-1
jack2 1.9.10.r202.gf2ece24-1
On the iPad I used Cubasis 2 with a single stereo audio track and
directly connected Cubasis 2 to the Focusrite outputs.
The original WAV is ripped from Crowded House's CD "Woodface", track
5, "weather with you", a 44.1 KHz, 16 bit file and then imported by
Ardour at 44.1 KHz, 32 bit float and by Cubasis at 48 KHz, 24 bit.
Not just that,
my focusrite sounds crappy when the outputs are "too
loud" in alsamixer. means over 80% its not usable. so maybe that is
an issue, Ralf?
That's definately an issue with my 18i8 first-gen as well. When I set
an output control to more than 0db, the output doesn't clip -- it
integer-wraps, which causes really evil distortion. I confirmed that
with an oscilloscope. I'm not sure whether this is a Linux driver
issue, or bad design. It shouldn't be possible to turn volume up beyond
the 0db setting if that causes such distortion. 0 dB related to what? The audio files were played with
an output
< 0 dBFS and perhaps at max. 0 dBFS here. Does the Focusrite mixer
control the analog domain? Does it increase a digital signal that comes
from the DAW by the digital domain?
On Sun, 8 Jan 2017 21:46:40 +0100, Johannes Kroll wrote:
First, look here:
https://github.com/smilingthax/alsa-driver_scarlett/commit/7a77707b66ee476d…
(This patch is now inside the mainline kernel; I did not write it)
It's neither part of the latest kernel supported by the rt project, nor
by the current mainline rc, https://www.kernel.org/ :
[rocketmouse@archlinux tmp]$ wget -q
https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.9.tar.gz
[rocketmouse@archlinux tmp]$ tar -xf linux-4.9.tar.gz
[rocketmouse@archlinux tmp]$ grep USB_ID -n linux-4.9/sound/usb/mixer.c
850: case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
851: case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
878: case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */
879: case USB_ID(0x0763, 0x2080): /* M-Audio Fast Track Ultra */
898: case USB_ID(0x0471, 0x0101):
899: case USB_ID(0x0471, 0x0104):
900: case USB_ID(0x0471, 0x0105):
901: case USB_ID(0x0672, 0x1041):
915: case USB_ID(0x046d, 0x09a4):
925: case USB_ID(0x046d, 0x0807): /* Logitech Webcam C500 */
926: case USB_ID(0x046d, 0x0808):
927: case USB_ID(0x046d, 0x0809):
928: case USB_ID(0x046d, 0x0819): /* Logitech Webcam C210 */
929: case USB_ID(0x046d, 0x081b): /* HD Webcam c310 */
930: case USB_ID(0x046d, 0x081d): /* HD Webcam c510 */
931: case USB_ID(0x046d, 0x0825): /* HD Webcam c270 */
932: case USB_ID(0x046d, 0x0826): /* HD Webcam c525 */
933: case USB_ID(0x046d, 0x08ca): /* Logitech Quickcam Fusion */
934: case USB_ID(0x046d, 0x0991):
1503: case USB_ID(0x08bb, 0x2702):
1509: case USB_ID(0x1130, 0xf211):
[rocketmouse@archlinux tmp]$ ls -lh linux-4.9/sound/usb/sc*
ls: cannot access 'linux-4.9/sound/usb/sc*': No such file or directory
[rocketmouse@archlinux tmp]$ ls -lh linux-4.9/sound/usb/s*
-rw-r--r-- 1 rocketmouse rocketmouse 21K Dec 11 20:17 linux-4.9/sound/usb/stream.c
-rw-r--r-- 1 rocketmouse rocketmouse 286 Dec 11 20:17 linux-4.9/sound/usb/stream.h
[rocketmouse@archlinux tmp]$ wget -q
https://cdn.kernel.org/pub/linux/kernel/v4.x/testing/linux-4.10-rc2.tar.xz
[rocketmouse@archlinux tmp]$ tar -xf linux-4.10-rc2.tar.xz
[rocketmouse@archlinux tmp]$ grep USB_ID -n linux-4.10-rc2/sound/usb/mixer.c
850: case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
851: case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
878: case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */
879: case USB_ID(0x0763, 0x2080): /* M-Audio Fast Track Ultra */
898: case USB_ID(0x0471, 0x0101):
899: case USB_ID(0x0471, 0x0104):
900: case USB_ID(0x0471, 0x0105):
901: case USB_ID(0x0672, 0x1041):
915: case USB_ID(0x046d, 0x09a4):
925: case USB_ID(0x046d, 0x0807): /* Logitech Webcam C500 */
926: case USB_ID(0x046d, 0x0808):
927: case USB_ID(0x046d, 0x0809):
928: case USB_ID(0x046d, 0x0819): /* Logitech Webcam C210 */
929: case USB_ID(0x046d, 0x081b): /* HD Webcam c310 */
930: case USB_ID(0x046d, 0x081d): /* HD Webcam c510 */
931: case USB_ID(0x046d, 0x0825): /* HD Webcam c270 */
932: case USB_ID(0x046d, 0x0826): /* HD Webcam c525 */
933: case USB_ID(0x046d, 0x08ca): /* Logitech Quickcam Fusion */
934: case USB_ID(0x046d, 0x0991):
935: case USB_ID(0x046d, 0x09a2): /* QuickCam Communicate Deluxe/S7500 */
1504: case USB_ID(0x08bb, 0x2702):
1510: case USB_ID(0x1130, 0xf211):
[rocketmouse@archlinux tmp]$ ls -lh linux-4.10-rc2/sound/usb/sc*
ls: cannot access 'linux-4.10-rc2/sound/usb/sc*': No such file or directory
[rocketmouse@archlinux tmp]$ ls -lh linux-4.10-rc2/sound/usb/s*
-rw-r--r-- 1 rocketmouse rocketmouse 21K Jan 1 23:31 linux-4.10-rc2/sound/usb/stream.c
-rw-r--r-- 1 rocketmouse rocketmouse 286 Jan 1 23:31 linux-4.10-rc2/sound/usb/stream.h
[rocketmouse@archlinux tmp]$
Regards,
Ralf