Audio pops and clicks
 

I'm getting some unpleasant audio clicks and pops when I play back material on the timeline. It seems (stress 'seems') to be more obvious at points where video clips overlap but it also occurs anywhere else on the timeline. This only occurs within Vegas (not in After Effects or any other app using audio). It isn't a levels issue, ie the combined audio is way below 0dB.

I am using just the default fx on the three audio tracks (ie compressor, eq and noise gate) having already prepped the audio in Sound Forge. I have a volume envelope on two of the tracks (music bed and v/o).

I am using an Edirol UA25 external sound device with the latest drivers.

Any ideas?

Aha. I think I just answered my own question - at least as to the cause, if not a solution.

I thought I should check to see if I had put any fx on the master audio track and indeed I had. I had used an instance of iZotope Ozone 3.

By bypassing Ozone, the clicking stopped, so I am deducing that the overheads Ozone introduces are pushing Vegas/my audio device beyond its limits. I have tried an instance of BBE Maximiser and that is significantly better but still introduces the occasional pop.

I should stress that these clicks etc don't appear on the final rendered track but they are very off-putting when monitoring audio while editing.

Anyone got any ideas for being able to use Ozone or other process intensive fx safely? Am I right in understanding that part or all of the Ozone engine is used in Ultimate S from VASST? Anyone else had problems?

Ian, this likely can be fixed with adjusting the buffer size upwards, which will also result in greater latency.

Check out the support section on izotope.com, search for something like "buffer size". I think this is also covered in the ozone documentation.

As I recall, buffer size can be adjusted in up to three places: in the driver software of many sound cards (this will affect all apps), in the options | preferences | audio device | advanced prefs in Vegas, or in Ozone prefs. If you're only experiencing problems in Ozone, that's probably where you want to adjust buffer size upwards to rectify.

A good practice for ozone is to turn off the modules you're not using to help reduce required buffer size. The filter comes up with all six (?) modules activated, and they're chewing up resources even if you've not touched them. For example, I frequently use the loudness maximizer on the master bus, so, turn off eq, multiband compress, etc. in that instance of the filter. This is especially important when using multiple instances on tracks.

Ozone is one really awesome audio tool, I use it all the time.

Great advice Seth, thanks. I'll have a play tomorrow (just opened bottle of vino number two so unlikely to achieve anything useful tonight!).

I agree - Ozone is a fantastic tool. I've used v3 since it was released so I'm not entirely sure why I should have only recently noticed these problems. Weird . . .

Thanks again.

Ian . . .

I'm not saying the same thing, but I had something similar. I had mismatched my sampling rate of the Media and the Project Prefs. Once set the same, problem gone.

When Izotope loads it engages all of the effects which uses quite a bit of processing power. Try unclicking the effects you don't need and see if that helps. Reverb in particular, is a resource hog and not something you would typically use on the main bus anyway.

Thanks guys. I'm in mid-render at the moment so I can't experiment!