Eiosis AirEQ v1.3

[TrevorMag]

btw - the demo "restrictions" are nice but seem a bit strange since everyone tells me you shouldn't have presets for eq anyway so its almost making it a freebie if you don't care about automation - strange when the full version uses a dongle especially (not that I'm complaining)

How does a VST not support automation? I thought automation was only an optional extra (from the internal programming interfaces) for DirectX. That's why I tell my Sonar users to use the Sonar-wrapped VST versions of my plugins if they need automation (as my DirectX versions don't have it).

[Eiosis]

fabrice, how do you avoid aliasing at 44k without oversampling?

In fact a filter can't produce any aliasing by itself if its behaviour is purely linear (i.e. it produces no new harmonics in the sound).

I think that you talked about the warping of standard digital filters near 44k that is not present in AirEQ.

The challenge in AirEQ was to avoid this warping with a zero-delay technique,
while keeping a curve matched on the analog reference curve.

But I'm afraid that I can't reveal this technique !

The problem with oversampling for digital filtering is that you must find the right balance between performance and quality :
the better oversampling and anti aliasing filters are, the more you need CPU power and processing delay.

Since there is no oversampling in AirEQ, there is no quality vs performance problems,
and we can have a zero-delay processing.

Hope this helps.

Fabrice,
Eliosound

[Zaphod (giancarlo)]

I've already done some measurements with the demo. Here are the first results:

....

The interpretation is up to you, just some ear candy for people who don't only want to trust their ears...

Christian

christian, are you going to measure everything now?

If you speak with a developer, he has got plenty of tools for understand it by himself.
If you speak with an user, he measures it with its music/tastes, and doesn't care to match exactly 12dB gain. A lot of eq destroy audio even with little corrections.

[Christian Budde]

fabrice, how do you avoid aliasing at 44k without oversampling?

I think that you talked about the warping of standard digital filters near 44k that is not present in AirEQ.

The challenge in AirEQ was to avoid this warping with a zero-delay technique,
while keeping a curve matched on the analog reference curve.

But I'm afraid that I can't reveal this technique !

It is described in this paper of orfanidis: http://www.aes.org/e-lib/browse.cfm?elib=7418 I'm not sure if you can download it elsewhere for free. Anyway the paper is not clear in every point. Some interpretation is still up to the developer.

To understand it, imagine the use of a very resonant high shelf filter instead of a peak filter near nyquist. The classical high shelf gain is the gain at nyquist frequency and the overshot has to be designed in the way, that it maches the according peak filter.

christian, are you going to measure everything now?

If you speak with a developer, he has got plenty of tools for understand it by himself.
If you speak with an user, he measures it with its music/tastes, and doesn't care to match exactly 12dB gain. A lot of eq destroy audio even with little corrections.

I won't measure too much, just a little bit, to show people, what is in there at all. It's towards a better understanding and comparison. Especially in this case, because the plugin uses its non-linear parameter mapping (well at least the gain is linear between 0..2.5, 2.5..5 and 5..15, but different gradients).

Sorry about this more technical explanations, I should write an article about EQ in the Wiki instead of spamming forums. I'll shut up now.

Christian



[***EDIT*** moved from first page]

Here are the measurement results:
[1k Peak Filter, Q=1, -15dB, -10dB, -5dB, -2dB, 0dB, 2dB, 5dB, 10dB, 15dB]

[1k Peak Filter, Gain=10dB, Q=0.1 (blue), 0.5 (green), 1 (orange), 2 (red), 7(violett)]

[Red 6dB/okt, Blue 12dB/okt]

The interpretation is up to you, just some ear candy for people who don't only want to trust their ears...

[Zaphod (giancarlo)]

No, I'm not forcing you to shut-up, and I don't consider
this a spamming. You are a good fellow, and you say a lot of interesting and truly things. As said before, you are a good developer.
I just wrote these words following this personal thought: eliosound is trying to sell something to users, so probably he needs user comments here/ comments on gui/ on bugs/ on the sound in general from the user point of view; technical explanations could be posted instead in techical topics. For example, before being a developer I didn't care all these diagrams printed in manuals.
The dangerous is to make people thing: "ehi, it sounds good for me, but people who write code say this thing is a bit strange, or is a bit different, or for comparing I should pay attention" 'BEFORE' they even try the demo version a while.

[Christian Budde]

That's why I want to shut up here. I also removed the measurements from the first page.

Anyway some constructive critic: If you try to tweak settings, the mouse cursor is sometimes over the value read-out. Maybe you could disable the cursor while tweaking. At least for people who want to know the vaule they are adjusting.

[MickGael]

Lord knows I have enough EQ, but I noticed a dongleless demo so I thought I would give it a try.

I have to say I like what it did for drums. Here is a before and after of a drum pattern (using the AirEQ and the Nomand Factory LM-662:

http://www.danieljslewis.com/aireq/AirE ... LM-662.mp3

Still, I'm more interested in picking up an AEA R92 (and building up my outboard gear) these days.

[Eiosis]

It is described in this paper of orfanidis: http://www.aes.org/e-lib/browse.cfm?elib=7418 I'm not sure if you can download it elsewhere for free. Anyway the paper is not clear in every point. Some interpretation is still up to the developer.

Christian, sorry but AirEQ is not based on Orfanidis filters implementation.
Honestly, we would not have renamed Orfanidis filters into AMLT filters just for marketing reasons, we are not here to fool people with a new and exotic name.

Orfanidis filters are well known for many years and are used in many excellent products, from Spectral Design Q-Metric, to Sony Oxford EQ and UAD Cambridge EQ.

But if you look at the Orfanidis filters more closely, you will find that they are rather good for some settings, but for other settings the curve can have several dBs of difference compared to the analog reference curve. And these differences occur for the "strategic" frequencies of the audio spectrum, that is especially true for digital audio. These frequencies are generally between 7 kHz and 12 kHz, where it is very difficult to make digital audio sounds right, and where the human ear is very sensitive to high frequency problems and digital imperfections.

The main advantage of the Orfanidis filters is that they are zero delay and very CPU-friendly, but AirEQ process is also zero delay and very light on CPU.

Compared to Orfanidis EQs, AirEQ curves are far closest to the analog curve reference ; and even if the differences between the Orfanidis and the analog curves may not seem very significant, an experienced sound engineer will hear that "something goes wrong" with an Orfanidis EQ compared to an analog EQ.

I will post here some screenshots to compare the different curves, sorry, another set of technical arguments...

Sorry about this more technical explanations, I should write an article about EQ in the Wiki instead of spamming forums. I'll shut up now.

Please, Christian, do not censure yourself !
I believe that everybody's point of view is welcome here, especially yours.

I agree that purely technical points of view may be boring for some people, but some other may find it interesting.
But, Zaphod, yes, sometimes we would just better forget technology and just try to judge with a more user point of wiew. Most users, I think, are more interested by practical issues rather than technical ones.

Anyway some constructive critic: If you try to tweak settings, the mouse cursor is sometimes over the value read-out. Maybe you could disable the cursor while tweaking. At least for people who want to know the vaule they are adjusting.

Thanks Christian. Here is a very good remark !

Fabrice,
Eliosound

[Highvoltage]

sooooo about the sound. this eq sounds f**king amazing!!!! really really mmmmmhhh.... the air knob is better than an exciter. love it. so nice and smooth yet keeps the transients hitting like shit.

[MickGael]

sooooo about the sound. this eq sounds f**king amazing!!!! really really mmmmmhhh.... the air knob is better than an exciter. love it. so nice and smooth yet keeps the transients hitting like shit.

I did use that in the sound sample I posted, but at less than 3 o'clock on the dial. Like most sweetening, I find that if you apply too much the top becomes gritty and abrasive. Still, when used in small amounts I liked it, as well.

[defjamm]

I will post here some screenshots to compare the different curves, sorry, another set of technical arguments...

would be interesting!

[Eiosis]

the air knob is better than an exciter.

Even in the analog domain, an exciter may sound good if it is used in the mid frequency range with reasonable settings, but I personaly found that it sounds not so good for high frequencies. I own an analog EQ with a built-in frequency exciter, and I love to use it for vocal mediums/high mediums, but not for the high frequencies. We designed the Air Band of AirEQ with this goal in mind : refresh high frequencies without problems that an exciter may introduce.

I did use that in the sound sample I posted, but at less that 3 o'clock on the dial. Like most sweetening, I foind that if you apply too much the top becomes gritty and abrasive. Still, when used in small amounts I liked it, as well.

You are right, the Air Band must be used very carefully. In fact we had to choose between :
1) giving to the user a small range of gain for the Air Band, so that even at the maximum gain value, it will never sound harsh
2) giving to the user a important range of gain for the Air Band, while knowing that extreme settings may sound harsh with some audio material, may produce digital clipping, etc..

We choose the second solution because extreme settings may be useful in the case of old or damaged recordings. I tried the Air Band maximum gain on an old acapella Beatles' recording, and it sounds so amazing, the "refresh" effect was so natural and transparent that I decided to keep the high gain settings for the Air Band.

Fabrice,
Eliosound

[Eiosis]

I will post here some screenshots to compare the different curves, sorry, another set of technical arguments...

would be interesting!

And I'll do !
I did not forget it.

I'm also always on the lookout for sound and ergonomics feelings and comments about AirEQ !

Fabrice,
Eliosound

[Frippertronix]

I can't get the dongle-less demo to work on my machine. It gives me the same Synchrosoft error (no license on the dongle) as the dongle demo. I have a Synchrosoft dongle plugged into the machine---maybe taking it out would stop the error?

I'm not trying the dongle version because I don't have my music machine hooked up to the internet.

[fgimian]

My opinion on this EQ is as follows. Firstly, I have tried many many EQs, I own Voxengo & Kjaerhus Gold EQs that I use daily.

Sound: Beautiful, I truly love what this EQ sounds like, it is so smooth and at the same time it's so musical, wonderful job.

GUI: I'm sorry but I dislike it. The reasons are ... I dislike the button approach used (I'd match prefer a switch since it's easier to see what you're doing). There should be a way to type values in with the keyboard for all parameters. I truly do prefer to have a graph view and control points. Once you get used to seeing what you're doing to the sound, it's hard to go back. I relate the sound back to the EQ curve, personally this is a huge drawback for me.

Price: In my opinion, price is not "too" bad, but I do think it's a little more expensive that I would normally pay for an EQ plugin especially considering the sub-standard GUI. I guess you can compare these plugins with the URS stuff which have similar GUIs, so this is just a matter of personal taste.

Copy Protection: I use Cubase so I have a Syncrosoft dongle and think that it's a great choice for dongle protection (instead of iLok). However, at this stage I would never buy a single plugin by a relateively new developer to run on a dongle. No offense to you at all, but if we were talking about Korg Legacy Edition (huge company), no probs, I'd buy that in a second and run it off the dongle, but a new company which I have not seen history of would not be something I would consider to buy if it is dongle protected. Maybe further down the line though.

I'll be keeping an eye on your products to see how they progress. Great work on this EQ.

Fots