Audio Limiter not working correctly...

Hey!
Not sure if this is a Mavericks issue or if it depends on something else, but can't remember this being an issue before upgrading to Mavericks...

Putting the limiter to audio and the output level to -0.1dB for example and still the audio goes way into the red... it's like the limiter is just raising the volume without actually limiting the signal...

Anyone else ssen this or have any suggestions what could be the issue here?

thanks
DZ

Have you raised the level of the audio on the timeline?

- Ronny

Is it a mono or a stereo track? Stereo is added together after the limiter so can still go above the limit.

Do you have anything else running along side?

Both the points above would be my guess. Make sure you're using a single channel mono file, and make sure the volume is set to zero in the timeline.

It's stereo but try with mono.
But surely there must be a way to make it work correctly with stereo sounds?

The Limiter has a Gain setting, which boosts the output signal of the Limiter, after it has done it's limiting job. Pull that down.

Well, no matter what the gain setting is the final signal should never exceed the output level. And that is the weird thing, the meter never shows any gain reduction...

What are you settings?
What is the average level of the audio before the limiter?
A limiter can only make a signal stronger if it's gain setting is above 0.

I know how a limiter works.
The more gain the more it should limit the signal, and the output level should govern the max output. So if output level is set to -0.1 dB that should be the maximum out put. But that doesn't happen, the limiter never kicks in and the signal goes way beyond 0dB...

It's why FCPX needs a better audio mixing environment. At least in Premiere Pro you can limit each track, then send it to a bus and limit that if you want, oh and then limit the final stereo output too!

Not quite so easy in FCPX. I hope they work on this somewhat over the coming days/weeks/months/years. Leaving the track based methodology behind definitely made audio mixing harder.

And, before people jump in and tell me to send it to a proper audio mixing app like ProTools or Logic, they are way over the top for simple adjustments like this and often there is no budget for it either.

Hi Dmitr,

When you set the volume slider of your audio clip to zero without any audio filters applied, how high is the average volume of your audio on the audio meters?

- Ronny

Well, the volume is fairly low, not sure what that should have to do with anything though?

The limiter still shouldn't let anything through than what is set by the output level... It doesn't matter if I raise the volume in the clip or with the gain in the limiter, there's still no gain reduction and the signal goes over 0dB and into the red...

Dave_EP, I agree a little more possibilities in that regard would be great!
This issue is new though, the limiter plug used to work as it's supposed to before...

Well, the volume is fairly low, not sure what that should have to do with anything though?

It has everything to do with it. The Limiter only kicks in as soon as its input channel receives audio levels that go above a certain peak (I think for the Logic limiter it is set to -6dB). So if your original audio is too low you have to raise the Input level of the Limiter to make the Limiter work. Raising the volume of the clip on the timeline has no effect on the input level of the Limiter, as the clip volume is only added after the Limiter. Try this:

- Leave the volume slider of the clip at zero (very important!), then apply the Limiter (I guess you are using the Logic Limiter?)

- Open the Limiter hud in the Inspector and while you play the clip pull the Input Gain slider of the Limiter up until you see the Limiter kicking in. When you see the limiting occur in the Audio meters (none of your audio channels ever go beyond a certain level) you can then adjust the Output level on your Limiter or the volume on your clip until your overall volume is where you want it to be.

- If the level of your original audio is so low that you cannot make the Limiter kick in even if you pull its Input Gain slider way up, you can add a Gain filter onto your clip. The Gain filter will allow you to further increase the volume of the audio that is sent to the Input channel of your Limiter to make the limiter kick in. Just remember that to do this your Gain filter must be stacked ABOVE the Limiter filter in your Inspector > Audio tab.

- Ronny

Well, that is what I'm doing. I can pull up the gain in the limiter and make the signal go way beyont 0dB but the LIMITER NEVER KICKS IN. That is the issue. It doesn't limit the signal.
I've had a music studio for 15 years, I know about gain staging and how limiters and compressors work.

I use Compound Clips for routing buses, does the same thing. Just FYI. But yes, pro level color wheels and a pro level mixer would be nice.

I'm testing the limiter now, and it is working as expected. Very odd behavior. Are there any other audio filters on this clip? I've never seen the limiter increase an audio signal level if the output is 0 or less, and the gain peak is a negative value. Very strange indeed...

Can you show us a screen shot of how you have it set and also the wave form in the timeline at a point that it peaks over 0db on the final meters?

Yes, it's very odd. Either there's some bug that crept into my system or I'm missing something. But it's not working as expected! I have used the limiter in FCPX before and have no memory of this behaviour...