[solved] Eden Audio Quality

Just a thought that slipped my mind while reading:

(2012-03-22 12:53)Ned Scott Wrote:  XBMC audio runs a lot quieter than other applications on Mac OS X, which in turn requires the volume to be higher.

Is it possible that the default settings for the limiterhold (0.025) and limiterrelease (0.1) are based upon windows audio levels?
So in order to work correctly on MAC, they should be adjusted?
I have no clue if they should be up or down. I read the whole section with the explanation (http://forum.xbmc.org/showthread.php?tid...#pid898388 ), but sorry, I don't understand it

try this version please. http://dl.dropbox.com/u/14341410/XBMC-audio-test2.zip

(2012-03-22 12:53)Ned Scott Wrote:  XBMC audio runs a lot quieter than other applications on Mac OS X, which in turn requires the volume to be higher. Try listening to the audio and unplugging your power supply. I noticed the other day hearing the same thing on my MBP, and unplugging my power supply fixed it. That can be caused by the power supply itself being "dirty" or even another device somewhere in your house that is "dirty" but on the same circuit.

Now obviously you don't want to run just on battery power, so you would want to find what is making the dirty power or get a UPS to plug the laptop into (which will clean the power, in addition to providing a battery backup), etc.

If that still doesn't fix it, or isn't the issue... then I would be worried.

I think you will find that the thing that is actually dirty is the MBP power supply. The reason is that laptop power supplies don't generally have to be very good since the majority of their work is to charge a battery, which doesn't require clean power to begin with. Because of this the small laptop power supplies are manufacture really cheap because they don't need to be high end to do what they do. Unfortunately the side effect is noise in you are using headphones.

(2012-04-24 15:52)WordMasterRice Wrote:  

(2012-03-22 12:53)Ned Scott Wrote:  XBMC audio runs a lot quieter than other applications on Mac OS X, which in turn requires the volume to be higher. Try listening to the audio and unplugging your power supply. I noticed the other day hearing the same thing on my MBP, and unplugging my power supply fixed it. That can be caused by the power supply itself being "dirty" or even another device somewhere in your house that is "dirty" but on the same circuit.

Now obviously you don't want to run just on battery power, so you would want to find what is making the dirty power or get a UPS to plug the laptop into (which will clean the power, in addition to providing a battery backup), etc.

If that still doesn't fix it, or isn't the issue... then I would be worried.

I think you will find that the thing that is actually dirty is the MBP power supply. The reason is that laptop power supplies don't generally have to be very good since the majority of their work is to charge a battery, which doesn't require clean power to begin with. Because of this the small laptop power supplies are manufacture really cheap because they don't need to be high end to do what they do. Unfortunately the side effect is noise in you are using headphones.

Sorry, but not the problem!
If you read the next comment: http://forum.xbmc.org/showthread.php?tid...pid1052523
And along with all others who share this problem: the audio in itunes/finder/any other program is fine. can't possibly be that a power supply only affects XBMC? We call that racisme

(2012-04-24 14:48)davilla Wrote:  try this version please. http://dl.dropbox.com/u/14341410/XBMC-audio-test2.zip

Tried, no change.

Zokkel's samples are very good, that's exactly what is going on. I can hear right from the start in sample2 that it's not what it's supposed to be.

humm, very odd, There should be some difference seen. MasterGain initial value was dropped from 6 to 0.

@toiva, describe exactly how you captured the signal in audacity. Details matter so be exact.

(2012-04-24 16:42)davilla Wrote:  @toiva, describe exactly how you captured the signal in audacity. Details matter so be exact.

I really only pressed record So the audio was playing from Macbook speakers and recorded by the built-in mic. Then simply turned on the waveform view. The worst possible to record it, i know. I tried to keep the system volume level same in Finder and XBMC.

(2012-04-24 12:48)Zokkel Wrote:  If I understand it correctly: sharing your guissettings.xml (can be found in the userdata folder: http://wiki.xbmc.org/index.php?title=Userdata )

Here goes; advancedsettings.xml
And guissettings.xml

Hope this helps...

[Edit] Also tested the version posted by davilla, but as toiva i don't hear any difference

I guess the way Zokkel was doing it is even better since Soundflower just routes the the signal from the internal output to the input, i.e. some sort of loop back device. The mic can always produce strange things since its frequency response is, uhm, not hifi.

Later this evening I will again record my test sample and put it on soundcloud. I will use the new version davilla posted.

@Zokkel:
Let's talk about the noise again. I guess we're thinking of different issues. I always keep the volume of the MacBook at 100% since in that way I'm fully using the dynamic range of the DAC. And assuming that I don't use any EQ and master levels this should not cause clipping at all, since no processing is involved. When I was using itunes I had the iTunes volume at 100%, the MAcBook hardware volume at 100% and the volume I was controlling on the amplifier - the last point of the signal chain. As soon as you fiddle on the digital volume, you can either get clipping, or noise. In both cases you reduce the dynamic range of the signal.

Just my 2ct