Demystifying Event Horizon

I have done a lot of surfing/searching for information on Limiters and Clippers, I’m still not totally satisfied that I understand what’s going on here. Was hoping to get some guidance:

-Limiter Mode
In limiter mode, if I’m understanding this correctly, the threshold is the level at which compression begins; since it’s a limiter not a ‘compressor’, I can expect that the compression level is > 20:1. The ceiling control is the final level that is allowed to pass. There is gain compensation (I’m guessing automatic since there’s no control for this) somewhere around the order of the compression threshold. I should expect attack to be reasonably fast, not sure about release on a limiter. How is your attack/release setup?
Is that about right?

-Clipper Mode
Threshold is the level after which the top of the wave is truncated. The amount of threshold decreased is somewhere around the order of the amount of gain added back in. The ceiling is still the final level that is allowed to pass. Is that about right?

-Thresh = 0, Ceiling = -2
Is this type of setting a brickwall limiter? Where no compression affects the sound since the threshold is unable to get up past -2 (the ceiling), but nothing above -2 is able to pass either? What happens in this exact same scenario in Clip mode?

-Soft Clip
This setting is mysterious to me. I did some comparisons (of a) 1KHz sine wave and b) pink-ish noise) between these two samples with -12 threshold/-2 ceiling between limit, clip and clip with 6.0 dB of soft clip (I realize this is way past the specs that EH is expected to run, but I wanted to really see the difference). Between the FFT analyzer, spectrograms and 1/3 octave charts, I’m not sure I’m seeing what that 6 dB of soft clip is doing.

-What exactly is the difference between Event Horizon and Event Horizon +? The site says:
“Limiter mode adds a new spin to a traditional lookahead limiter that can allow more gain reduction than a clipper, yet still remain VERY transparent.” Without asking you for info which is too detailed or might give away a trade secret, can you elaborate on this any?

I don’t use a limiter for much (to occasionally squeeze an extra dB or two out of a program that’s too close to clipping to just turn it up), but I’m wanting to know more so I can use it more effectively. As it is, I compared about 5 or 6 limiters when I purchased EH (in the manner I’m used to) and it sounded a heck of a lot better than the comparison products.

In all cases, it is a brickwall limiter. Signal will NOT go above the selected ceiling value. Setting the threshold is saying “take whatever signal is at THIS level and push it up until it’s at the CEILING level.” In other words, you’re going to get (CEILING - THRESHOLD) dB of gain out of the plugin. If ceiling is at -0.2 and threshold is at -6.0, then 5.8 dB of gain will be applied to the signal and it will be clipped or limited as need be after that.

Clipper does exactly what it says it does, and I’m sure you understand that part correctly.

Limiter does not have a fixed ratio, but it does have instantaneous effective attack time due to lookahead. Due to the way it works, attack and release times aren’t really pertinent…but think of it as a VERY fast attack and a release that is frequency dependent.

Soft clip will start rounding off the tops of waveforms ‘x’ dB below the ceiling value, where ‘x’ is the setting of the soft clip control. It’s controlled distortion…just use it wherever it seems to sound good and don’t worry too much about HOW it’s doing it.

As far as the difference between EH and EH+, just think of EH+ as being version 2 of the older plug. Going forward EH+ will be the standard plug…I kept EH around for compatibility purposes…it didn’t get ported to the Mac and won’t be.


Exactly what I needed to know, thanks Scott.

hi scott.

i played around with Event Horizon + today and one question came to my mind:

Do I have to feed the Plugin with a normalized audio file that is already at -0,1 ?

What will the Plugin do, when i feed it with audio that is at -2,5dB

Will it then do nothing but raise the volume until the treshhold is set to more than 2,5 and then start clipping/limiting it?

No, you don’t need to feed it a normalized signal. You DO probably want a signal that is below zero dB, or you’ll have very little control over how it gets limited.

As I explained above regarding how it works…

“In all cases, it is a brickwall limiter. Signal will NOT go above the selected ceiling value. Setting the threshold is saying “take whatever signal is at THIS level and push it up until it’s at the CEILING level.” In other words, you’re going to get (CEILING - THRESHOLD) dB of gain out of the plugin. If ceiling is at -0.2 and threshold is at -6.0, then 5.8 dB of gain will be applied to the signal and it will be clipped or limited as need be after that.”

So, if your signal is at around -2.5 and you want it pushing up against -0.2 dB, then you’d set the ceiling at -0.2 (the default), and set the threshold to somewhere between -2.3 and -3.0 (or even farther, if you want to squash it harder…please don’t destroy your music by squashing it too much).

Hope that helps.



so have i understood that correct:

if i have audio at -2,5 dB and set the treshhold to -2,2 the ceiling to -0,2 then there will be no clipping/limiting at all, just a volume raise?
And the limiting/clipping would start at -2,3 and more treshhold?

And another small question`:

can i push the ceiling to 0,0 without fear, when it is the last step in mastering?

and no worry i dont want to use it too hard and ruin my music with it :slight_smile: I hate that, too.


You understand the gain structuring correctly, yes, as long as you are referring to peak levels and not RMS. If your audio is at -2.5 dB RMS, it’s already squashed so loud that it’s going to sound horrible.

You would generally NOT want to push the ceiling all the way to zero dB. When you actually play back the audio through a DAC (Digital-to-analog converter), there is always the possibility of what are called “inter-sample peaks”…where even though no sample goes over zero, the analog output TRIES to, due to the way the oversampling and filtering of the converters work. Better to keep it a few tenths of a dB below zero to hopefully avoid the problem…that’s why the default ceiling of Event Horizon is -0.2 dB. The actual digital signal can go precisely up to zero with no problems…it’s when you actually convert it back to analog that it potentially becomes a problem.


ok thanks!
then i will leave the ceiling at -0,2,
thanks for explaining this, i didnt know that there can occur these intersample peaks.

And i am not talking about -2,5 dB RMS, that would be sick :astonished:

Thank you for clearing all the things up, now i can use it properly!



Event Horizon defaults to the bypass position when I open a DP 7.22 sequence… yet the seq was saved with EV as active. What do I need to do to have it recalled exactly as I left it?
Thanks, G

Unfortunately, you have to wait for me to find that bug and kill it. :frowning:


Ok, just so that I have understood this correctly.

I had a project a few days ago where the levels went up to about +0,2 to +0,5dB on the master channel.
Usually, I just lower the master channel volume or the tracks volume within the project, but this time I inserted the Event Horizon instead and left it at it’s default setting to kill those spikes.

Should I lower the master channel volume so the peakes go to about -2 or -3 dB and then let Event do it’s thing, or can I just leave the master channel volume as it is now, at 0dB?

And thank you for this plug, Scott, I’m a happy owner of it and right now I’m demoing the Rocket Compressor and it sure looks like I’m bying that one too. :slight_smile:

If all you’re doing is killing the overs, then inserting it at the default values in that case is perfectly valid usage. What I had tried to point out with my earlier statement is that if your level is constantly running at +5 dBFS RMS, you aren’t going to be able to do anything gentle with Event Horizon, since it assumes you are going to keep your levels under 0 dBFS. As soon as you insert it in that case it’s going to start whacking 5-10 dB off the top off everything…which may sound loud, but probably won’t sound “good” except in limited use cases.

Beware that you don’t let the 0.2 - 0.5 dB overs creep into a habit of letting your gain staging get out of whack (something I’m guilty of on occasion).


Thank you very much, Scott.

I normally don’t use Event Horizon to only kill overs, I am pushing up the volume a bit but I don’t engage in overkill.

Most of the time I’m tracking with a bit of headroom so my peak meters on the master channel goes to something like -5 dB.