As an audio electronics engineer I can assure you that the square wave is a very valid test signal. It is quite a difficult test signal for audio electronics and will show up many things. A sine wave is a useless test signal also in some circumstances as it won't reveal a host of issues either.[/quote]

I agree - as far as audio goes (EE here as well). But, doesn't his output waveform look like classic filter ringing to you?

Not disagreeing that the artefacts are there, but I don't think that we should assume that they are aliasing. With upsampling/downsampling there could be other errors at play.

When you isolate it, yes, the noise is very audible!

The attached song file proves this.

Process:

1. turn your monitors/headphones volume down to zero;
2. Download the attached .song file;
3. When the attached file loaded and running, gradually turn up your monitors/headphones' volume until you hear the 'whooshing' sound.
4. Now, in the EQ window, grab the little point/handle at the top of the notch with your mouse.
5. Hold your mouse button down and drag the handle anywhere you want -- the whooshing will change according to the frequency and the cutoff/boost which you are commanding.
6. Now, in order to enjoy the added white noise, engage the 'High-Quality' button and do exactly the same -- as per steps 4 & 5 above.

Summary: It is digital noise' which makes no musical contribution whatsoever. It absolutely should not be there if you have selected "high quality".

Best, Martin.

Oh, one other thing that I did notice. The displayed filter curve is different for HQ vs. standard.



The effect is more obvious the higher the filter frequency.

Just seeing a difference from the Pro Eq itself isn't going to tell booh, really without the correct tools for analysis. Typically all frequency should be checked with a test tone generator, and spectrum analyzer, but that aside, assuming it's only at 1k hertz, (ant to what bandwidth?), if this is all about a 1k thing (and someone just pointed to a difference at 10k), then you need to graph before and after the EQ with some other frequency analyzer). If the Pro EQ is in question and you're viewing only it, where's the validation? What, that it's wonky?

Sorry don't mean to be an armchair quarterback. I'm not home (family member in hospital).

Just pointing to some better analytics might help. This morning, I checked my master that's in "Projects". I was typically using Pro EQ, after I'd evaluate recordings with Ozone 8. So Ozone handled most of getting things flat response everywhere (to my settings) with limiter, and I use Pro EQ after to tweak little things like cymbal levels, and subtle stuff for overall feel. I was real, good with the results. Hardly scientific, I admit. I'll look again when I get home for high res vs low res, and I'll check before and after analyzer graphs with Blue Cat Pro analyzer, Voxengo, or something just to compare to.

What I did see is when Pro EQ is set to high CPU setting, it typically resolves better at 10k, and above and produces better resolution with it on.. Evidently, it uses the extra horsepower (more complex algorithms) to produce better results. Therefore it should just stay on. I guess this will hold somewhat true with resonances, or similar keys, like you guys are seeing at 1k.

As to the origin of this whole thing, I'm not aware of its place, insight, or anything.

Just got home. Yeah, I do see serious aliasing along the leading edge as you spoke about Jemusic.

nothing to be done there but leave it to Development to weed out.

I'm simply going to take a few peeks (Peaks?) and change out the Pro EQ where I need to replace it for the Master only places in Project.

Cheers, not much can be done. Sort of like watching that foreign auto mechanic. Better be nice to him.

I don't see any issue.
Here is a square wave 60 Hz with harmonics out to 20k @ 48k
I applied a 6db raise at 120 Hz (changing freq or dB has no effect. )
See switch of HQ on and off with no detectable shift in harmonics to 20k

Jpetit,
The screen you have chosen to capture in your GIF image does not show what the differences are between HQ button 'on' and HQ button 'off'.
And if there is no difference then why not remove the button completely?

The button clearly has a purpose:
~ to allow the user to make a draft mix with less processing overhead with ** oversampling off ** ; and ...
~ for a mixdown of the final product to engage oversampling with HQ on.

My test -- if you were to download and run it -- would show you exactly what effect the button does impart to the audio.

Martin.

Good point.
I was thinking the same thing but it was late last night.
I will dig up your test and give it a try later today.

Martin's test is pretty convincing. It certainly shows that there is something not so good present when the HQ mode is ON compared to being OFF!

What he is doing here is by using the null approach he is removing a large component of the sound and only leaving the boost at that particular frequency behind and the noise that is being introduced is also being emphasised a lot. At least one can hear the noise with this test. And noise it is too.

martin14 wrote1) (Presonus Support are fully aware, and I am told that the software developers in Germany are "tracking" it.)

2) Another user is demonstrates it even better here on You Tube:
https://www.youtube.com/watch?v=Q2p_hlH6eVI

3) Summary: Until this bug is fixed you should **not** use the HQ setting for Pro-EQ.

Sorry for being late to the conversation. Very busy with the public beta.
2) I watched the video. The conclusion the YT person came to was the HQ button was inverted. I think that was your conclusion as well?
1) I assume the inverse behavior is what the developers will fix.

3) So you do not have to avoid it but just use it (inversely) until it gets addressed.

Keep in mine any real EQ levels on a square wave is going to grossly contort it anyway.
Thanks Martin

j0001s wroteOh, one other thing that I did notice. The displayed filter curve is different for HQ vs. standard.

Not HQ.jpg

HQ.jpg

The effect is more obvious the higher the filter frequency.

Did you take these images yourself?

The images you posted show the right behavior for the curves with HQ enabling oversampling, which lets you have more analog-like symmetrical curves near the Nyquist frequency. Without oversampling (or some other technique that some companies use), you'll get a cramped curve like in your first image. If you took the images yourself, then the HQ button's on/off state functionality is correct and not inverted, and the problem must be in the algorithm. I think it's most likely that the problem is with the coding and not just an on/off bug, cause a clean digital eq (without saturation) is not supposed to be aliasing like that, oversampled or not.

Disclaimer: I never use the stock eq plug-in.

With some further tests I noticed that it shows the same behavior in other EQ plugins aswell. Of course not in every other! So maybe there is a certain code in some plugins and in some others not. Here is the compare with a Softube EQ. Or the Manley Massive Passive EQ. Looks similar on both sides.

Don't understand me wrong! I will investigate what it is exactly to tell you the result. But to make a panic thread with orders not to use the Pro EQ because you saw something strange is simply wrong!

I have a few other EQ's and have tried them all in the position of the Pro EQ in Martin's test and I must say none of them contribute the extra noise that the Pro EQ does with HQ mode ON. They also all pass the square wave test as well.

Even the Presonus Channel strip EQ's don't do it. I also invested in the Waves H-EQ as well. ($49 instead of $279. Good value) It certainly does not do it either.

Although none of the other EQ's offer a quality mode, none of them add the extra noise in meaning they must be permanently running in a high quality mode. In my case anyway the Pro EQ is the only one that does this for me.

I agree with Ari though there is still no reason to not use Pro EQ either. I would like to see it behaving the way all my other EQ's do though.

I also did tests with other EQs as well but unless they have an HQ mode with the different oversampling option in each it's not a valid test. In the video, the guys compared two EQs capable of that mode.

So let's try to be clear here. The HQ button appears to be inverted.

Ari, I changed the title to be more accurate.

I stopped using the Pro-EQ because I bought a third party EQ. Mainly because the Pro-EQ lacked features I wanted but I never did feel like it sounded as good as other EQ's. Not 'bad', but other EQ's I used, including free ones, had a much smoother high end. I also found the way the Pro-EQ is laid out to be distracting.

That said, even if the HQ button is reversed, that's not a valid reason for the noise that is being introduced. It's not unusual to stack EQ's and the more you stack, the more noise, and it snowballs. This is something I noticed a long time ago and part of the reason I stopped using it a long time ago.

Thanks,

What features do you need with an EQ?
What is missing from your daily work?

And what EQ do u use to compare "sounds good" sounds "not good". So what is your favorite in sound? (not in features!!!)

Ari

I never knew EQ's could be such a bother.
To me, any EQ should be transparent when flat-lined. Much like a 'True Bypass' is supposed to behave in guitar foot pedal gear.

If it's not, then it is introducing a 'color' much like a 'Neve' has vs an 'API' board.

But of course the degree of adjustment comes into play when comparing the Q, number of bands, etc..

Myself, I really like and only use the 'Pro-EQ' cuz it's detailed enough for me.

I don't need to focus to the 'nth' degree with the type (or my skill level ) of music I create.

Skaperverket wrote

j0001s wroteOh, one other thing that I did notice. The displayed filter curve is different for HQ vs. standard.

Not HQ.jpg

HQ.jpg

The effect is more obvious the higher the filter frequency.

Did you take these images yourself?

The images you posted show the right behavior for the curves with HQ enabling oversampling, which lets you have more analog-like symmetrical curves near the Nyquist frequency. Without oversampling (or some other technique that some companies use), you'll get a cramped curve like in your first image. If you took the images yourself, then the HQ button's on/off state functionality is correct and not inverted, and the problem must be in the algorithm. I think it's most likely that the problem is with the coding and not just an on/off bug, cause a clean digital eq (without saturation) is not supposed to be aliasing like that, oversampled or not.

Disclaimer: I never use the stock eq plug-in.

Yes, I took the images, FWIW.