Clicking/popping noises during playback?

[ozphactor]

I'm using VLC on Mac OS 10.4.7, and I get clicking and popping noises whenever I play back MP3 files. I have verified that this is not an issue with the files themselves, as they play without artifacts in Quicktime and iTunes, as well as on other computers. It's just VLC. I've Googled around, to no avail. If anyone has some insight as to why this might be occurring, I'd greatly appreciate your input. Thanks in advance.

[Guest]

You are using too much output gain and your sound card can't handle it.

[ozphactor]

Could you elaborate on what you mean by "output gain"? I have the volume set at 100% (out of a possible 400%). It works fine at 100% volume in iTunes and Quicktime. Is there some sort of setting I have to adjust in VLC?

[puntloos]

If guest's theory is true, turn down the output volume of VLC.. if that helps (just increase volume on your amplifier to compensate) then it is an output clipping problem. Are you using any equaliser settings (like 'bass boost') somewhere?

[ozphactor]

The clicking/popping noises seem to subside at around 25% volume, but they're audible even at 50%. My equalizer is disabled. Also, I run MP3Gain on all my MP3 files, which should prevent clipping. Again, I have no problems playing these files with Quicktime at 100% volume. And I have no problems cranking the volume on other files, like videos.

One of my primary reasons for using VLC is that it allows me to crank the volume past 100% (which is unbearably quiet on my MacBook speakers). Is there anything I can do to have both clean audio, and high volume?

[ozphactor]

Bump?

[DJ]

VLC has the unique ability to boost gain. The default is set at half volume and is no boost or 100% in most other players. Anything over this is a boost. At full gain the player can produce 4 times the max volume (+12db) of other players. For some sound cards this can be a problem as it can saturate the front end of the sound card.

[ozphactor]

Ah, thanks for the explanation. So you're saying 50% volume in VLC is equivalent to 100% in other players? And above that, there's nothing I can do to prevent artifacts if it's too much for my sound card?

[DJ]

Ah, thanks for the explanation. So you're saying 50% volume in VLC is equivalent to 100% in other players? And above that, there's nothing I can do to prevent artifacts if it's too much for my sound card?

Well! That's one theory! Some sound cards are sensitive to the amount of input gain. But it also depends on the source and how it was recorded. MP3's for example are generally highly compressed and don't have a large dynamic range. In this case distortions and overs occur across the frequency spectrum and appear more as pops or clicks. Where as DTS with a large dynamic range and little to no compression will show distortion in a high volume passage in a certain frequency spectrum (generally in the lower frequencies associated with bass). Try looking at messages within VLC. If it's a gain problem there probably won't be any kind of error message where the problem is occurring.

Another issue is that overs can and do create noises. Overs are digital saturation that converters can't handle. I don't care what kind of program you use or what the source is. If the record gain is to high these will occur. These will show up in messages and adjusting your volume will not help.