Hydrogenaudio Forums

Hosted Forums => foobar2000 => Support - (fb2k) => Topic started by: macdekker on 02 February, 2013, 06:29:57 AM

Title: Undulating playback
Post by: macdekker on 02 February, 2013, 06:29:57 AM
Hi,
I play all my lossy and lossless music with Foobar2000 1.2.2. But the sound seems to be undulating, as if someone is constantly playing with the volumecontrol. Really irritating.
It seems to have started when I downloaded and integrated the equalizer. Any views on this?
Thanks in advance.
Title: Undulating playback
Post by: db1989 on 02 February, 2013, 08:00:45 AM
Yes. You probably have bands equalised upwards in gain, which is causing the final signal to exceed full scale (0 dB), causing some element of the subsequent signal chain to limit the signal to avoid this, causing ‘pumping’ compression.

Click on the “Auto level” button to fix this. It decreases the gains of all bands proportionally so that none are positive. Never equalise any bands over 0 dB unless you are highly confident that (A) the entire signal was quiet enough that the EQd result will not clip or (B) the increase in overall gain from the increased frequencies will be offset by decreases at other frequencies.

This applies generally, not just to foobar2000. I accept the need for it to be possible to EQ bands upwards in some cases, but applications would do well to provide more caveats about the potential results, as questions like this pop up every few months.
Title: Undulating playback
Post by: dhromed on 02 February, 2013, 08:08:42 AM
Alternative: Do you have a Xonar sound card on XP?
Title: Undulating playback
Post by: macdekker on 03 February, 2013, 11:00:21 AM
Hi,
I play all my lossy and lossless music with Foobar2000 1.2.2. But the sound seems to be undulating, as if someone is constantly playing with the volumecontrol. Really irritating.
It seems to have started when I downloaded and integrated the equalizer. Any views on this?
Thanks in advance.


Wow, never considered this solution.

Tried it and it works. Thanks a lot.

   
Title: Undulating playback
Post by: db1989 on 03 February, 2013, 12:56:44 PM
Wow, never considered this solution.

Tried it and it works. Thanks a lot.

 

Do you mean the auto levelling? If so, glad to help!

I don’t mean to indicate that positive gain will always cause the signal to exceed 0 dB (and thus introduce clipping or other adverse effects), as it does of course depend upon the signal in question, but it’s most definitely something to watch out for whenever EQing. One could perhaps offset the overall decrease of an auto-levelled EQ curve using careful manual adjustment or a separate gain control, but it depends on how much you need the extra volume in software and how confident you are in your ability to tweak to a final volume. Definitely the safest option is never to gain anything positively/past 0 dB.
Title: Undulating playback
Post by: macdekker on 04 February, 2013, 03:17:06 AM
Wow, never considered this solution.

Tried it and it works. Thanks a lot.

 

Do you mean the auto levelling? If so, glad to help!

I don’t mean to indicate that positive gain will always cause the signal to exceed 0 dB (and thus introduce clipping or other adverse effects), as it does of course depend upon the signal in question, but it’s most definitely something to watch out for whenever EQing. One could perhaps offset the overall decrease of an auto-levelled EQ curve using careful manual adjustment or a separate gain control, but it depends on how much you need the extra volume in software and how confident you are in your ability to tweak to a final volume. Definitely the safest option is never to gain anything positively/past 0 dB.


I indeed used the autolevel button and this had the desired effect.
I installed the equalizer in Foobar because I bought a Creative T3 set of speakers and the bass-unit produced way too much bass. With the equalizer I brought it down only to experience the undulating sound. It's fixed now and the combination of Foobar and the T3 set works perfectly now.

Thanks again for your help.

Regards,
Rob