OT: Pops on the Head...

[Stashu]

I've noticed a problem for some time, and can't find a solution.
When I play a sound file, there is a soft tiny 'pop' or click when I press Play.
This happens in SAW, and also in every Player I have. This is also on all types of files. (.wav, .mp3, etc.) It's always when I hit Play.
It even happens when I hit Play on a blank section of track, seconds before the sound file.
Can this be a ground problem somehow? It also happens in my radio automation system, when the system kicks in the next event. It's not very loud, but with headsets on, you can hear it when the next sound event is triggered.

Any help appreciated.

[Bob L]

What soundcard... many SoundBlaster drivers were guilty of this problem.

Most likely the driver is not clearing the buffers from the last play when they start up again... a terrible driver error in my opinion.

You can see if this is the case by playing into a silent section of a song (the end for instance)... then stop... then start a new play and the pop will possibly be gone... since the last buffers were silent when you last stopped.

If that is so... then your driver is guilty of being poorly written.

Bob L

[Dave Labrecque]

Stash --

Could there be any DC offset being created somewhere in the output chain from your sound card?

Or maybe all your stuff's being recorded with DC offset. A test of this possibility would be to play something that you didn't record and see if you still get a pop. Which you may already have done.

[Les Woollam]

I think Bob's hit the nail on the head.
When I upgraded my sound card to an M-Audio 410 I had exactly the same problem. I eventually cured it by discarding the driver disc which came with the card, and downloading the latest driver.
Best of luck!

[Bob L]

A simple external firewire or usb soundcard with good drivers can keep you using your current machine without the problem and with much better sound quality than your internal card now.

Try an M-Audio Firewire 410 for only $299 US... its a simple way to go.

Of course many other higher end choices are out there if you have the budget.

Bob L

[Bob L]

Glad you are enjoying it.

Bob L

[Dave McKenna]

Bob,

I have been having this identical problem for a couple of years now... clicks on playback after playing a loud section of music. I am using an RME HDSP 9652 sound card on WinXP SP2 - does this card's driver have the buffer problem you mention? Could other elements of a system cause buffers to be withheld? It would be great to get rid of the click... I have applied all of your suggested tweaks and otherwise everything seems to work fine.

Dave McKenna

[Bob L]

Dave, I have never had the problem mentioned with any RME driver...

So... the idea that something in your audio chain (hardware) may be causing a DC offset in the line... this would cause the click problem as the DC level jumps when playback starts or stops.

Also... realize that if you start any playback in the middle of a waveform, you will cause a starting click because the signal will instantly jump from zero to some value.

But when starting in a silent section... there should be no pop... this all applies to stopping in the middle of a waveform also.

Bob L

[MMP]

Yesterday, I had reason to use ASIO on my RME Multiface for the first time in a while. I am on the latest version. On larger buffer sizes, the last buffer would loop endlessly. So, there may be something up with the ASIO driver, or my system.

Regards,

MM

[Bob L]

I am using an older RME driver on my systems... something like 2.62 or 2.64... ASIO and MME work fine...

Bob L

[Dave McKenna]

Bob,

The clicks I speak of are most noticable when starting playback in a silent section after stopping in the middle of a loud section of music. I used to think this was an intermittent problem until I read this thread and tested it. If I play a silent section, stop, then restart there is no click. If I stop in the middle of a loud section of music, then restart in a silent spot there is a loud click. Click loudness is proportional to the volume of music where previously stopped. This seems to show that there is indeed buffers withheld. If there was a DC offset, wouldn't there be a click every time, regardless of volume of music when stopped?

I am using the most recent version of the RME drivers (MME )... I'll see if I can find a previous version and try that.

Dave McKenna

[MMP]

Dave.

Make sure to match the SAW buffer size in the RME drive applet.

Regards,

MM

[Bob L]

Well... sounds like it would be a buffer problem... I am not sure if it has to do with the latest drivers or not... I use older ones because I know they work perfectly for me.

Bob L

[Dave McKenna]

Bob,

OK - I just spent some time trying to nail this thing down and I think I have it. I tried an older version driver, and made sure the buffer settings in the driver matched SAW, but no change.

I had the Sonoris meter up on the stereo output channel and I noticed that when I got a click, it showed on the meter. Inspecting further, I also saw the click on one of the sub channels I use. What did they have the others didn't? Effects.

Removing all effects eliminated the clicks. I added them back one at a time and found that SAW and DX effects did not cause a click, but the VST ones did (in this case Digitalfishphones' Endorphin and Dominion). Anywhere I put them, the click could be clearly seen (and heard) on the channel meter.

At this point I don't know if it is specifically those plugs, or VST in general, but at least now I know what to look for. Have you run into this at all?

Dave McKenna

[Bob L]

Dave,

Good find... but it is not a VST general problem... I have never run into it.

It could very well be plugin specific though... the real problem there would be the way the plugin holds onto data when the engine is stopped.

VST itself is a concern there because they don't expect the engine to ever stop... so when I shutdown, I force x number of blank buffers thru all VST plugs before shutting down... but SS looks for the return data levels to be below a certain low level and stops feeding buffers to that plug in order to attempt to save shutdown time.

Some plugs may hold data sustains a lot longer than my max number of blanks... which has a limit... again to save shutdown time and keep a plug with noise in the output stream from locking the system in an endless loop.

Bob L

[Dave McKenna]

Bob,

Thanks for the explanation. I have tested all of the VST plugs I have - some click and some don't. All the Digitalfishphones plugs click as well as a tape echo emulator called 'Karlette'. Sir, all Kjaerhus plugs, GSnap do not click. I guess it just depends on the design - thanks for walking through this with me.

Dave McKenna

[Bob L]

No head scratch... no surprise for many SoundBlaster models and drivers.

Didn't you say you had a SoundBlaster card?

Bob L

[Bob L]

The Realtek internal is just like a SoundBlaster... drivers are weak.

You may want to try the Asio4All driver and see what happens in ASIO mode... it may be different.

Bob L