Are filters what make the sound of a synth stand out from the crowd?

[enCiphered]

There is a lot of discussion about filters lately and I wonder if high quality filters are the most important component that make the sound of a software or hardware synth so special and popular.

And if so, how complex is the process of creating high quality filters or even precise emulations of analogue ones?

[Urs]

There is a lot of discussion about filters lately and I wonder if high quality filters are the most important component that make the sound of a software or hardware synth so special and popular.

Great filters can not make up for mediocre oscillators.

And if so, how complex is the process of creating high quality filters or even precise emulations of analogue ones?

It's complex enough that certain academics in the field of DSP can not comprehend their existence. Which is why apparently only a few people have figured it out, pretty much all of which being KVR members

[enCiphered]

There is a lot of discussion about filters lately and I wonder if high quality filters are the most important component that make the sound of a software or hardware synth so special and popular.

Great filters can not make up for mediocre oscillators.

And if so, how complex is the process of creating high quality filters or even precise emulations of analogue ones?

It's complex enough that certain academics in the field of DSP can not comprehend their existence. Which is why apparently only a few people have figured it out, pretty much all of which being KVR members

Thanks for your reply
I want to understand how intense a good filter is polishing the sound, really.
I don´t have a clue about programming but it has always interested me how complex it is for developers to create them.
Reading through many kvr threads and posts there often are big discussions about filters and less about oscillators, this is why I´m asking.

[fluffy_little_something]

I suppose filters are particularly important with subtractive synthesis as the filters are the subtracting components.

[recursive one]

Some of my favourite synths have not really great filters... Virus TI, Parawave Rapid. Can't really call their filter implementation being remotely on the same level as Repro or Diva. But they do great things on the oscillator level so the filters can be used, well .. for filtering - I mean just basic envelope controlled tone shaping with no extra coloration ( I'm not talking about Virus TI filter FX here because it's essentially just FX put before the filters).

On the other hand, Diva and Repro have totally amazing filters, when i think "this sound needs some heavy filter tweaking" these two are usualy my first choices.

I'm still waiting for someone to combine the power of digital oscillators similar to what can be found in Virus TI with state-of-art analogue modelled filters.

[zvenx]

I actually loved the Virus filters.
May not have been accurate to anything real, but I loved them.
rsp

[Urs]

Reading through many kvr threads and posts there often are big discussions about filters and less about oscillators, this is why I´m asking.

Oscillators are great when they are precise. That is, when their spectral/structural content is correct and when there's no aliasing or other artifacts. Once that's done, typical problem cases (sync, FM) can be sonically improved simply by oversampling. It's a pretty objective task to make a good sounding oscillator. What academia has written about them is pretty usable to make a good sounding VCO emulation, with a bit of pitch drift sprinkled on top.

Filters on the other hand get their particular sound *because* of artifacts. Distortion, voltage bleed, stuff like that. Those artifacts are next to non-existent in DSP literature, particularly in abstract filter theory. They are a pain in the ass to observe, explain and model. And then, there's a subjective decision as to which artifacts are good and which are not. And you want to compare them to not just one specimen but as many as possible. Try gathering three Minimoogs or so to compare their filters your model, and throw everything you thought you knew away when the next one arrives.

[Stefken]

There is a lot of discussion about filters lately and I wonder if high quality filters are the most important component that make the sound of a software or hardware synth so special and popular.

For me it is (for subtractive synthesis), especially when the filter has a lot of character.

And if so, how complex is the process of creating high quality filters or even precise emulations of analogue ones?

It's very complex.
This video gives some insight in the process and demonstrates some filters that I find pretty great.

https://www.youtube.com/watch?v=R2kUzw-C9Ao

[Stokely]

As someone who owned a few analog synths way back, I think effects are, if not the most important, one of the most important aspects of a synth sound.

Granted, if you start with a great sound and THEN add great effects, well that's the winning combo right there

The Virus is a good example, I played live with the Virus b for a while. Awesome keyboard--fantastic key action, aftertouch, build quality, basic sound quality and fx were amazing.

[perfumer]

Filters on the other hand get their particular sound *because* of artifacts. Distortion, voltage bleed, stuff like that. Those artifacts are next to non-existent in DSP literature, particularly in abstract filter theory. They are a pain in the ass to observe, explain and model. And then, there's a subjective decision as to which artifacts are good and which are not. And you want to compare them to not just one specimen but as many as possible. Try gathering three Minimoogs or so to compare their filters your model, and throw everything you thought you knew away when the next one arrives.

What about digital filters better than analogues? Without the 'stuff like that'? Impossible? Nobody has tried yet? Forever stuck in the 70's is the way of the future?

[enCiphered]

Some of my favourite synths have not really great filters... Virus TI, Parawave Rapid. Can't really call their filter implementation being remotely on the same level as Repro or Diva. But they do great things on the oscillator level so the filters can be used, well .. for filtering - I mean just basic envelope controlled tone shaping with no extra coloration ( I'm not talking about Virus TI filter FX here because it's essentially just FX put before the filters).

On the other hand, Diva and Repro have totally amazing filters, when i think "this sound needs some heavy filter tweaking" these two are usualy my first choices.

I'm still waiting for someone to combine the power of digital oscillators similar to what can be found in Virus TI with state-of-art analogue modelled filters.

Interesting, thanks.
But can you tell what is it that makes the Diva and Repro filters so special? From a non-developer point of view I mean

[recursive one]

Interesting, thanks.
But can you tell what is it that makes the Diva and Repro filters so special? From a non-developer point of view I mean

There is someone else in this thread who could answer this much better than me (from a developer point of view).

From a non-developer point of view I can only say that these filters react in a very nice way to automation and modulation. Smooth, muscial, liquid, you name it. The resonance integrates very nicely into the sound, even when heavily cranked up.

[fluffy_little_something]

Filters on the other hand get their particular sound *because* of artifacts. Distortion, voltage bleed, stuff like that. Those artifacts are next to non-existent in DSP literature, particularly in abstract filter theory. They are a pain in the ass to observe, explain and model. And then, there's a subjective decision as to which artifacts are good and which are not. And you want to compare them to not just one specimen but as many as possible. Try gathering three Minimoogs or so to compare their filters your model, and throw everything you thought you knew away when the next one arrives.

What about digital filters better than analogues? Without the 'stuff like that'? Impossible? Nobody has tried yet? Forever stuck in the 70's is the way of the future?

Indeed, or make a filter that sounds better than analog ones. I mean, what does "better" mean? Fuller? Livelier? Once identified, one could simply ignore analog filters and go way beyond that, basically building the filter around the human hearing system.

[mjudge55]

It really depends on the synth and the design goals behind it, I think. A developer aiming to create an authentic minimoog emulation would want to get their filter sounding as close as possible to the real thing. Others may disagree, but I'm thinking that would be #1 priority, sonically, for that design goal. Then maybe you'd look at oscillators.

So in that sense, the answer to your first question is yes. I'll leave it to smarter folks to answer the complexity question.

Now, on synths with different design goals, the filter may not be top priority. Say you're looking to make the highest fidelity wavetable synth you can. Then you probably want to focus in heavily on those wavetable oscillators -- the character is in those. Of course you won't want a bad filter (whatever that means) in your wavetable synth, but filter may not be the #1 consideration. Or another example, say it's a modular synth your designing. Number one priority there, I imagine, is variety of modules and high fidelity in audio rate modulation on all of them. Again, you don't want a crappy filter in that, but the designer might not be preoccupied with the sound of the filter and still release a great product.

Finally, "high quality" is very subjective. My Nord Modular G1's filters were designed 20+ years ago without the benefit of all we've learned since, and all the increased processing power. They definitely don't sound like Repro-5 filters. That said, you can make great, filter intensive music on it without heavy tweaking - as long as the songs are good and the context works. Old/primitive doesn't mean bad, even in filter land. Albums made with the G1 still sound good today.

[mellotronaut]

But can you tell what is it that makes the Diva and Repro filters so special? From a non-developer point of view I mean

http://www.ziggipapers.com/index.php?la ... bpageid=10