Should the Adaptive Limiter be set to -01?

Should the Adaptive Limiter be set to -0.1 or -1?

Please someone confirm! I have heard conflicting reports.

Many thanks

Put it to -0.3 to avoid intersample peaks that might get through.

That makes sense! thank you, and should the true peak detection be ON?

You can generate inter-sample peaks at levels much lower than -0.3 dB.

In the Adaptive Limiter, set the Output Ceiling to 0 dB and turn on the True Peak detection option, that will take care of making sure you don't have inter-sample peaks (that are indicated by a red "0" reading on the peak detector on the Stereo Out).

You can generate inter-sample peaks at levels much lower than -0.3 dB.

 

In the Adaptive Limiter, set the Output Ceiling to 0 dB and turn on the True Peak detection option, that will take care of making sure you don't have inter-sample peaks (that are indicated by a red "0" reading on the peak detector on the Stereo Out).

Thank you, that sounds straight forward enough!

Unfortunately, even with True Peak On, IS peaks will go through with Output ceiling at 0, hence my suggestion for -0.3.

Just put the Roundtrip plugin from Apple after the AL and you can try.

Unfortunately, even with True Peak On, IS peaks will go through with Output ceiling at 0, hence my suggestion for -0.3.

Just put the Roundtrip plugin from Apple after the AL and you can try.

That plugin is for AAC compression isn’t it? (I’ve never used it)

That plugin is for AAC compression isn’t it? (I’ve never used it)

Correct. And since iTunes uses AAC, it's a good reference I think.

That plugin is for AAC compression isn’t it? (I’ve never used it)

 

Correct. And since iTunes uses AAC, it's a good reference I think.

So (again, not familiar with that plug-in), is that plug-in a better judge of ISP than Logic's Adaptive Limiter?

is that plug-in a better judge of ISP than Logic's Adaptive Limiter?

I think so because it catches IS peaks that come thru in the AAC compression process.

They might not be visible on PCM but Roundtrip sees them before and after AAC formatting.

Every time I put the AL on 0 dB in Output Ceiling, Roundtrip saw peaks come thru, especially on very maximized music.

Other 3rd party Limiters might be better at brickwalling, but I like how the AL sounds.

Conversion to lossy formats can increase the peaks of audio files. See

https://www.izotope.com/en/learn/mastering-for-compressed-audio-formats.html

"What do MP3 and AAC do to your audio?

Lossy compression refers to a class of data encoding methods that uses inexact approximations (or partial data discarding) for representing the content that has been encoded. (Read the Wiki article for more.) In simple terms, lossy compression formats utilize psychoacoustic models in an attempt to remove the audio information our ears won’t detect as missing.

This often means removing audio information from both the high end and the wider elements of the stereo image. Any lossy encoder introduces an approximation error, a noise which can increase peak levels and cause clipping in an audio signal, even if the uncompressed source audio file appears to peak under 0 dB. It can be hard for the average ear to isolate and detect the artifacts, so consider the following audio examples."

is that plug-in a better judge of ISP than Logic's Adaptive Limiter?

 

I think so because it catches IS peaks that come thru in the AAC compression process.

They might not be visible on PCM but Roundtrip sees them before and after AAC formatting.

I don't believe that's how it works. True Peak limiters like the Adaptive Limiter use oversampling to reconstitute a signal that is pretty much identical to the analog signal so that it can catch any ISP. I believe you're seeing ISPs in the roundtrip plug-in because after conversion to AAC the signal peaks higher. If you're not converting to AAC, then there's no need for the additional 0.3 dB headroom you're suggesting.