On 2020-12-27 11:32:02 William Morder via tde-users wrote:
On Friday 11 December 2020 13:10:15 William Morder wrote:
On Thursday 10 December 2020 13:06:05 Dr. Nikolaus Klepp wrote:
hi Bill!
Anno domini 2020 Thu, 10 Dec 12:47:09 -0800
William Morder via tde-users scripsit:
Just wondering if anybody else here has encountered this problem, and what to do about it.
When I play an instrument through kmix, I must enable loopback mixing, but this creates a hiss in the speakers, which in turn tends to create feedback -- in particular, when I plug in a hollow-body electric guitar.
This has only been a problem since I upgraded from Devuan Jessie. I used to play through my computer speakers all the time, using them like a guitar amplifier. (There is another device, a headphone amplifier, which I use as a kind of pre-amp.) But otherwise, nothing in my setup has changed, except that I have upgraded to Devuan Beowulf.
I would like to get rid of that hiss, and I don't remember having to enable loopback mixing before. I have only recorded a little since upgrading (using audacity), but it doesn't seem to affect recording quality too much, because I plug headphones into my computer speakers, which eliminates both hiss & feedback problems.
Sorry for the detailed presentation; feel free to snip. The main problem is kmix-trinity, and whether anything has changed between Devuan Jessie and Beowulf, namely, loopback mixing. Or have I somehow misconfigured it?
Bill
If I recall correctly the loopbackdevice is connected internally to PCM, but not to the line-in-plugs. That hising is just noise. Please start alsamixer and play around with the controls, on some hardware you need to bring the sound devices into a "good" state before kmix can take over.
Nik
Hail, Nik! Greetings from my hell of cacophony. I hate noise, unless I make it myself, in which case I call it jazz.
Thanks for the tip on alsamixer. I don't know when last I looked at it. I've played round with it a little, and it did help me to enable both channels on surround (when the right channel was diminished for unknown reasons). I still haven't figured out the source of the hiss, but I haven't gone through every possible option yet.
If it worked before without the hiss, then it seems reasonable to expect that I can restore those settings again. I'll report more, if I find anything worth telling.
Bill
Okay, so maybe an update on this issue is worth posting.
After playing round with all my settings, I discovered that rear mic was enabled for input source. I didn't remember having changed this, but it's easy to correct. Once more I set my input source as line-in; also, I turned down the sound levels for these items. No more hiss, no more feedback, so the issue would seem to be resolved ... almost.
I restarted kmix and alsamixer, and my settings were preserved; but after a reboot, the same problems arise again. Input source resets for rear mic instead of line-in, and the sound level is changed to 100% instead of 0%.
The underlying issue -- why *something* keeps resetting to rear mic, and changing the sound level -- is the problem. I *believe* that, after restarting kmix and alsamixer, I ought to be able to preserve my chosen settings as defaults, rather than having settings revert to something else. (As I noted earlier, this was never an issue until I upgraded to Beowulf; in Jessie, I got my settings right, then left it alone, and everything was always fine.)
I have already tracked down the config file:
/home/<USER>/.trinity/share/config/kmixrc
-- but it doesn't seem to help. The config files in opt (/opt/trinity/share/config.kcfg/) don't seem to do anything for me.
So how to preserve my mixer or sound system settings through reboots?
Bill
There is also .trinity/share/config/kmictrlrc, which on my machine has entries for rear-mic and rear-mic-boost; see if that has pertinence, and perhaps make it read-only once the settings are right?
Leslie --