Stereo Tool

Hans, could you explain the intended difference between these? I think some time ago it was said that AEHP was "better than" de-essing, but I'm not sure about whether I'm remembering that right, and I'm thinking that the discussion was involving FM broadcasting, which I don't do.

Anyway, I'm thoroughly confused about how I don't see any presets using AEHP to clip highs at, say, -8 dB or lower. This includes my own, because I don't understand the purpose behind AEHP, so I just use the de-esser.

Thanks...

It depends on what you need it for.

In FM broadcasts, the highs are a lot louder due to pre-emphasis. Due to that, very loud highs cause other sounds to be "pushed down", causing ugly drops in other frequencies (it sounds really bad, much worse than for example drops caused by loud lows).

Here the de-esser is a "dumb" filter that just keeps the highs below a certain configurable level.

The AEHP takes a different approach: It measures how much the highs must be reduced to keep the drop of other frequencies at a tolerable level (set with "Do not allow other sounds to be dropped below").

So if there are no problems with the highs (they don't cause drops), the highs are kept at the "Always clip highs below" level. If they DO cause drops, they cannot be dropped below the "Do not reduce highs below" level.


If your intention is to get rid of loud highs because you don't like them, use the de-esser. If you want to reduce the highs as little as possible, only when they cause issues with other sounds, use AEHP. And you can also combine them

You can also try to combine AEHP with pre-emphasis.
For example, pre-emphasis to 20us and AEHP to 60% or less.

As Ricky says, you got some splainin to do...



OK. So, are the values for AEHP stated in absolute decibels or relative?

To illustrate my confusion, you can set always clip down to -12, but do not reduce to only -6. This would seem to imply that if you set always clip lower than -6, it would serve no purpose, as the other setting would prevent the highs from being dropped that low. Contrast that with a de-esser setting going all the way down to almost -100

So, if I de-ess at -10, does having AEHP enabled do anything at all really?

If it's not doing anything at all, then I'd prefer to turn it off to decrease processing load, but I think I'm remembering some claim that you can uncheck it, but it still is enabled if Advanced Bass Distortion Protection is enabled.

So, see my reply to Hans and you try splainin

First, don't look numbers.. If i am getting right, you say that if it is unchecked it's still working ? I just checked and it can be turned off and also it is really off.
Try settings pre-emphasis 25us and -9dB at AEHP, with some loud_s_track. I know it's not logical (numbers) but maybe you'll like it.
When FM is enabled. those numbers gets more real, because FM pre-emphasis (50/75us) is added.

Silly me...!
I was remembering some vague discussion some time ago from you about checking and unchecking and what not, so if you're saying it does get disabled, that's good to know...
I don't do FM, and I only added the MP3 Lossy Compression into the V6 preset because it's trendy (you and others are doing it, and I guess it makes sense if someone was to use the preset for an output to a stream).

So, to this point, I'm not sure what the advantage is for keeping it enabled, other than preset-sharing compatibility. Unless I'm missing something and you or Hans haven't splained it good enough for me yet...