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Author Topic: Sound Devices and Volume  (Read 3445 times)

blgentry

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Sound Devices and Volume
« on: June 17, 2017, 03:16:59 pm »

I've been fighting with MC and my DAC for a few days now.  It sounds fine, but the volume level is REALLY low. I've verified that alsamixer is all the way up.  The graphical volume control in the VNC desktop is all the way up.  I was using Internal Volume mode with that volume all the way up.

For fun I switched to System Volume mode and noticed that it was at about 70%.  I moved that up to 100% and BOOM!  The volume went up by at least 15 if not 20 dB, which is where I wanted it.  I switched back to Internal and it "stuck".  That is, it kept the same high volume.

But I was paranoid, so I switched back to System Volume.  Guess what?  Now the volume control is disabled in MC's interface.  Totally scratching my head over this.  I stopped and started MC.  Choose another device from the HUGE list of devices.  Same thing.

At least the volume level is nice and high still.

On a related note, I'm confused as to which devices do what.  I have at least 5 if not 6 different prefixes for sound devices like HW, plugHW, Surround, default, etc.  I'm currently using HW:Card , with the name of my device and lots of other info.  It also says "direct hardware device without any conversions".

Which device is the best one to use with MC?

Brian.
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Zhillsguy

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Re: Sound Devices and Volume
« Reply #1 on: June 17, 2017, 07:03:56 pm »

I am interested in these questions as well. Don't want to derail this one, and will start a new thread if needed for previous content posted.

EDIT: One thing I find interesting.... using pavucontrol the active devices have a "detent" at 100% / 0 db... but can be turned up to 153% / 11 db. I would assume that 100% would be safe, anything more could lead to saturation/distortion? Not sure, may be different for analog vs. digital outputs.
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Ryzen 5 W11 x64 MC 29 HTPC/Server and HP G2 Mini Elitedesk W11 MC 29 (music only zone), various Android Phones and Tablets for control of both, powering two lanai surround systems, 5.1 and 4.1 respectively.

bob

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Re: Sound Devices and Volume
« Reply #2 on: June 19, 2017, 08:39:41 am »

In general you should use the hw: or front: devices (for 2 channel) UNLESS you need to allow other system sounds to mix with MC in which case you need to use the default: or pulse: devices. If you use the default: or pulse: devices you will have to use DSP studio to resample to the default sample rate which is usually 48k. This is because the ALSA mixer can't handle more than one sample rate at a time.

Now as far as the volume controls go, this is really deep. There are multiple volume controls in linux and it's made more complex when pulse or jack are added into the mix because the pulse basically sits on top of ALSA as well as along the side of it.

I haven't had any issues with alsamixer. If you cycle through the devices and check all of the volume controls. There can be one for PCM, one for the device itself, a MASTER, etc.

MC tries to find the master for it's system volume but the ALSA drivers for specific devices make this not always consistent.
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blgentry

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Re: Sound Devices and Volume
« Reply #3 on: June 19, 2017, 08:46:04 am »

Thanks for the reply Bob.  When using HW, does MC still go through some sort of ALSA volume control?  I would think not, but...

Like you said, this gets pretty deep because there is (potentially) a hardware volume control that can be accessed via software, the system mixer, and of course MC's internal volume.

In this particular case, I'm hoping to max out the hardware volume (which I think I've done) and bypass any kind of Linux volume control (which I think I've done).  The purpose of this thread is to understand what's going on better.  I think my issue is "solved", but I'm trying to understand more of how it all works under Linux.

Thanks again,

Brian.
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bob

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Re: Sound Devices and Volume
« Reply #4 on: June 19, 2017, 08:59:39 am »

Thanks for the reply Bob.  When using HW, does MC still go through some sort of ALSA volume control?  I would think not, but...

Like you said, this gets pretty deep because there is (potentially) a hardware volume control that can be accessed via software, the system mixer, and of course MC's internal volume.

In this particular case, I'm hoping to max out the hardware volume (which I think I've done) and bypass any kind of Linux volume control (which I think I've done).  The purpose of this thread is to understand what's going on better.  I think my issue is "solved", but I'm trying to understand more of how it all works under Linux.

Thanks again,

Brian.
Hi Brian,
It SHOULD bypass the ALSA volume controls other than the device control when using the hw: device. I have seen however where the PCM volume control still affects the level in some cases.
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