You are probably already using Zero Delay Feedback filters, so let your customers know!

[ObsoleteAcc99]

[DELETED]

[toothnclaw]

I mean i am tending to trust what he is saying

This is not religion. Because the other prophet says:

Well, I for one feel crucified by people who have neither seen our code nor our method.

Hmmm, he may have a point there. Because:

When comparing those two implementations, the one without a unit delay in the feedback path will most certainly show superior behaviour.

Thus, by a quite simple logic, the term "zero delay feedback filter" can have an essential meaning, no matter what anyone else believes

And the prophets at Native Instruments made Monark using Vadim's work, so... I hope this is not going to turn into a relgious war or something.

[ObsoleteAcc99]

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[Urs]

I hope not either, and i love U-He products AND NI, but i was trying to say that since i never heard a filter better than Andy's, i took what he said at face value. This is not in any way meant to insult any one else. Plus, disclaimer, i am only going by my ear, i have ZERO dsp knowledge, so my opinion is somewhat not even meaningful in any way. I was just surprised to see a couple people for example challenge Andy as if he was some sort of noob with no knowledge.(i don't mean UHE or VLAD )

Only because Andy doesn't like the marketing this doesn't mean that his filters have a unit delay in the feedback path. I'm pretty sure they don't, and that's why he takes years to develop one.

I think we can also agree easily that not all zero delay feedback filters automatically sound great. 0df alone doesn't make an otherwise average filter model any better.

[Flandersh]

Please show me a particular place where I pretended to have invented the prior art. ...

As for your claim that you never argued about the TPT method, I think you're trying to be too smart here. The only thing I ever claimed to invent is the TPT method, which currently is being referred to by others as the ZDF.

Vadim, your TPT method is what I'm talking about, you claim it is new. It is just different notation applied to standard circuit modelling methods, it offers nothing new, apart from introducing new acronyms and alternative notation:

https://cytomic.com/files/dsp/OnePoleLinearLowPass.pdf

"The revolutionary changes that have occured since 1890 in the world of science - especially in physics but also in chemistry, biology, and the sciences of man - have been due not so much to new facts as to new ways of thinking about facts. [...] I say new ways of thinking about facts, but a more nearly accurate statement would say new ways of talking about facts. It is this use of language upon data that is central to scientific progress" (Whorf, 1982, p. 220).

My experience as a social scientist is that there exist many terms with a wide array of different discourses that correlates. Not many of these different terms has the same historical background, they are not a causation of each others, and they are all seen as new from a scientifical perspective since they have different historical pathways.

I'm by no way a DSP or math expert, and I have to rely on the meanings of different persons I do not know. Vadim has, as I have understood, stated that he did not know about the progress behind this old method you claim to be the same as TPT and as such I have to understand Vadim's work as new because of his historical pathways to it which emerge as different to yours.

Source:
Whorf, B. L. (1982). Linguistics as an exact science. In John B. Carroll (Ed.), Language, Thought and Reality: Selected Writings of Benjamin Lee Whorf. (p. 220-233). Massachusetts: The MIT Press.

[2DaT]

12 dbo sem-like filter.
TPT ,DF , or even analog?
https://dl.dropboxusercontent.com/s/tcm ... terseq.wav


Term "zero delay feedback" is applied to digital filter models,not analogue ones. Usually , every analog filter have its "zero delay" loop , and from this point of view, every single digital filter can be called "zero delay feedback" filter.

[Urs]

Usually , every analog filter have its "zero delay" loop , and from this point of view, every single digital filter can be called "zero delay feedback" filter.

That would be a stretch IMHO (just like the OP)

[toothnclaw]

Usually , every analog filter have its "zero delay" loop , and from this point of view, every single digital filter can be called "zero delay feedback" filter.

That would be a stretch IMHO (just like the OP)

Urs, could you please tell us in brief how much more complex filter design is (or can be), apart from the zero delay thing? I understand that this 'term' doesn't even begin to describe what's going on in a filter, real world analog or a good emulation. It would be nice to put things in perspective for the uninitiated and shift the focus off a little.

Some great examples would be Imposcar2, ABL Pro and VAZ filters. How did they do it? How much more do YOU have to do to achieve a satisfying result?

[xoxos]

this thread is even more dramatic than when Jessie Spano got hooked on diet pills

i was just thinking, i hope there's a lot of people on kvr today telling me who the bad person is, because i can never figure that shit out for myself

[Kriminal]

this thread is even more dramatic than when Jessie Spano got hooked on diet pills

i was just thinking, i hope there's a lot of people on kvr today telling me who the bad person is, because i can never figure that shit out for myself

Its me

[andy-cytomic]

ps: the point of this thread is to highlight the problems with the terminology "zero delay feedback" when applied to describe the quality of an algorithm.

What terminology for the actual properties and perceived 'quality' of algorithms would you propose? Keeping in mind that: 1. people of differing skill levels do need to talk on these topics by using precise and descriptive terms that have been commonly accepted, and 2. any number of implementations and modifications at various levels of sophistication are doable or have been done?

I am not proposing an alternative marketing term that fits all your above points, I am pointing out that the current one anyone almost anyone can legitimately use to describe their products, especially if customers perceive the term as being desirable.

I have read similar debates on the terminology that should be used when talking about the quality and 'sound' of reverb algorithms, and have come to the conclusion that it's not possible to use precise terms or enforce any kind of terminological standardization.

Hence the need for 'wooly' 'terms' that have the benefit of: 1. being fuzzy* enough to include a variety of close but differing meanings, and 2. being easily recognizable and memorizable to your average person.

* http://en.wikipedia.org/wiki/Fuzzy_concept

This term is fuzzy enough to include almost all digital filters. Any filters that don't fit it are able to be called "topology preserving" so that pretty much covers everyone all around. I am not trying to stop people using the terminology as that is clearly not going to happen, instead I'm encouraging everyone to use it all the time, and hence nullify any possibly distinctions that can be made between products that use such terminology in their descriptions.

[Urs]

This term is fuzzy enough to include almost all digital filters. Any filters that don't fit it are able to be called "topology preserving" so that pretty much covers everyone all around. I am not trying to stop people using the terminology as that is clearly not going to happen, instead I'm encouraging everyone to use it all the time, and hence nullify any possibly distinctions that can be made between products that use such terminology in their descriptions.

That's ridiculous.

As analogue filters don't have unit delays in the feedback path, the term is clearly used to describe a property of a digital filter algorithm. Any claim of software to feature zero delay feedback filters when in fact placing unit delays in feedback paths is a fraud. That naturally includes standard biquad filters, as opposed to your semantic stunt in the first post.

[Urs]

A quick Google search showed that an estimated total of 5 companies use or have used the term on their websites (after some pages no further company name comes up). It's quite amazing that this thread comes about for such a non-issue.

[miedex]

A quick Google search showed that an estimated total of 5 companies use or have used the term on their websites (after some pages no further company name comes up). It's quite amazing that this thread comes about for such a non-issue.

yes the KVR circlejerk has matured to the point that you don't even know its there until you actually google the topic

[DaveGamble]

IBTL. This thread is pretty toxic. I just like to be close to the danger.

Here's my unsolicited personal opinion.

Andy, to my eyes, this thread doesn't read like a critique of a marketing phrase, it reads like a personal attack against Vadim (and partly towards Urs). I'm sure that's not intentional, but I've just read the entire thread start to finish, and that's what I took away from it.

Of course, you can write this off as my poor grasp of language, but other comments in the thread concur.

In Vadim's posts, he's on the defensive from Andy.

I was briefly active in the musicdsp thread on this topic, and just found this thread this morning.

I was on IM to Andy about 8 months ago and explained that a BLT discretisation of an analogue Biquad was technically "delay free" in the precise original sense that gives the strategy utility. (No delay is added since there's no nonlinearity which complicates the solution).

[Aside: The reason I was wanting to explain this to Andy was because, at the time, he was driving a hard marketing campaign to support the inclusion of his code in the Live9 EQ. The phrase "zero delay" was being bandied around liberally. I was about to release EQuilibrium, for which I spared absolutely no mathematical expense, and was eager to avoid being steamrollered over by Andy's marketing drive. In case you're not aware, Andy has significant marketing reach.]

Now I'm concerned that this idea has gestated with him. At the time, he strongly rejected the explanation I gave him. I'm concerned I've somehow contributed to this situation, and if I have, I'm genuinely sorry and upset.

The fact that Urs states that without Vadim's explanation, the DIVA filters would not have happened within the timeframe that they have is adequate defence of utility, whatever your position.

Honestly, if I were Andy, I'd request this thread be deleted. It has gone badly.

Dave.

Edit for the people who follow me around trying to work out how my EQ maths works: EQuilibrium is it's own special world of algebraic pain and death by numerical analysis. The above discussion is not intended to imply the usage of BLT in the EQuilibrium code.