Filter Audition Poll  (resonant lowpass audio filters)
[ this web page is private and don't follow any commercial or promotional aspects ]

 

This page is a result of a discussion topic we started on a public forum (kvr-vst.com) to examine the tastes of experienced VST users regarding virtual analog modeled audio filters (especially resonant lowpass filters with several slopes and models). The only thing that counts here is the sound. So you will not find any direct links to the software used (for the poll) to achieve those results. Although, some examples may sound obviously due the strong sound characteristics...

We prepared some real analog filter examples for direct comparison, which are out of the "battle", because we finally want to find good sounding digital implementations with this project. Therefore the used analog gear is named and linked here.

Analog filters (reference material, for comparison only):

Legacy stuff, supplied by different people:

The following examples are all recorded from (actual available) commercial analog filter modules and synthesizers provided by Pierre Zeeman. Many thanks to him for this great resource! The rules applied to those sound snippets are the same as for the digital filters you'll see later here. You should listen to this stuff *before* you go to the digital simulations for some obvious reasons.

Extras / Durchgeknallt:

We have to admit, that the following examples are merely for your enjoyment, because this is some recorded crazy analog stuff, so that you know, what filters finally are for:

  • Frostwave, The Resonator (a real analog re-creation of the Korg MS-20 synthesizer filter unit)
    playing only itself (virtuous self oscillation). Listen to it !!!
  • Sherman Filterbank 2 (durchgeknallt, total crazy philthering) You'll never buy a digital filter unit once again !!!
  • MF-101 (Moogerfooger) Patchworking an external synthesizer sequence. Not so crazy, but legendary. (Da Grandmotherfucker.)

Digital simulations:

The different filter sounds are all created with the same rules. We used mostly (virtual analog modeled) VST Instruments (synthesizers) but also VST Effect plugins. Synthesizers use their integrated sawtooth wave generator (oscillator), effects use a pre-recorded sawtooth sample. There are 3 wide filter sweeps applied to each example with the resonance adjusted to 0%, 50% and 100%. We preferred filters with the capability of resonance up to self oscillation. There are no saturation or drive nor any other effects used, unless they aren't directly built into the filter models. So the filter sound is as clean as even possible.

The tested filters are all LPFs with different slopes and techniques recorded/bounced with 44100 Hz sampling frequency, encoded to mono (mp3, higher quality). There were in some cases a smart mastering (peak) limiter used to prevent digital distortion thru the hosts master bus. If you hear the signal clipping, so this is the result of the internal applied signal limiters by the filter models. We tried to reduce such effects as much as possible. (We cannot guarant this with the user supplied examples.) Whatever, some of the tested filters have generally a very unbalanced loudness, especially with high resonance, therefore the (look ahead) mastering limiter was necessary. This phenomenon is very typical for digital systems and don't happen with real analog gear in general. Whatever is is a quality criterion, because developers of digital implementations have to ensure, that the loudnes of their filters is well balanced to finally satisfy the users.

Some special words to the automation:

Wherever possible, we used the same technique for standard high resolution VST automation. In fact linear internal interpolated VST parameter changes (for the filter sweep) with Cubase SX. There are some examples "showing" audible digital rastering especially with highest resonance. Those plugins process each automation in this way regardless how good the internal resolution of the host may be. The reason lies simply in their (questionable?) implementation, because they obviuosly process parameter changes only ones per audio block (but the host defines the size of audio blocks dynamically, developers cannot assume that the lengths are always the same or short enougth for a smooth automation!).

This is finally also a quality criterion for digital filters, we tried to demonstrate here. Even some examples, which were processed with much lower "rastered" MIDI controller automation show often much better results finally (i.e. hear the Filter 1 for excellent parameter interpolation via MIDI). We find, that parameter interpolation on filters (especially cutoff parameter) is nearly as important as for instance the interpolation of the pitch bend wheel and other relaltime controls on quality synthesizers...

The snippets:

Tip: You should really use some higher quality headphones or solid audio monitors and not those of your walkmen... And decrease the volume on sweeps with full resonance!

Usage: Please play each sound by clicking on the links (this may still need some time!). After you listened to all the sounds you should choose your favourite one and use the link to the poll. You can also write a detailed comment and do your your personal ranking inside the comment (placeed on 1, 2, 3 ...) then. We and many users are especially interested in the comments. Some further technical descriptions to the examples follow here...

Here is the link to the poll system (clickme).

Here are the initial snippets (provided by Jackle&Hyde development team):
- Filter 1: digital virtual analog (VA) hardware synthesizer, 12db, external MIDI automation
- Filter 2: VST Effect (filterbank), 12, 24 and 48db, signal internal clipped, VST automation
- Filter 3: VA VST synthesizer, circuit modelled filters, 12, 24db Type 1, VST automation
- Filter 4: VA VST synthesizer, circuit modelled filters, 12, 24db Type 2, VST automation
- Filter 5: VA VST synthesizer, circuit modelled filters, 12, 24db Type 3, VST automation
- Filter 6: VA VST synthesizer, 12/24db?, VST automation
- Filter 7: VA VST synthesizer, modeled after analog hardware, 24db, VST automation
- Filter 8: VA VST synthesizer, modeled after analog hardware, 12/24db?, VST automation
- Filter 9: VA VST synthesizer, modeled after analog hardware, 24db, VST automation
- Filter 10: VST Effect, 24db?, internal saturation (could't be switched off completely ), VST automation
- Filter 11: VST Effect (filterbank), 12, 24 and 48db, VST automation
- Filter 12: VST Synthesizer, 12, 24, 36db, signal internal clipped, VST automation
- Filter 13: VST Synthesizer, modeled after digital VA hardware, 12, 24db, VST automation
- Filter 14: VST Effect , 12, 24 db, signal internal clipped, VST automation
- Filter 15: semi-modular VA VST synthesizer 24db Type 1, MIDI automation
- Filter 16: semi-modular VA VST synthesizer 24db Type 2, MIDI automation
- Filter 17: semi-modular VA VST synthesizer 24db Type 3, MIDI automation
- Filter 18: semi-modular VA VST synthesizer 24db Type 4, MIDI automation

User supplied (many tanks to Doug Smith, Product Development Engineer):
- Filter 19: (workstation host bundled) software synthesizer, 12db, internal host automation
- Filter 20: (workstation host bundled) sampler, 12db, internal host automation

(many thanks to rawcan / kvr-vst forum)
- Filter 21_1: semi modular hybrid VST synthesizer, 12db, VST automation
- Filter 21_2: same as above, 18db
- Filter 21_3: same as above, 24db
- Filter 22: semi modular hybrid VST synthesizer, 24db Type2, VST automation
- Filter 23: VST synthesizer, diverse models, VST automation
- Filter 24: VST synthesizer, diverse models, MIDI automation
- Filter 25: VST synthesizer, diverse models, VST automation
- Filter 26: VST sampler, diverse models, VST automation
- Filter 27: multi module VST synthesizer, diverse models, MIDI automation
- Filter 28: VST multimode sampler, diverse models, MIDI automation
- Filter 29: VST synthesizer, diverse models, VST automation
- Filter 30: VST synthesizer, diverse models, VST automation

(just more interesting examples, user supplied, consecutive added)
Those examples where posted after the poll was opened.

- Filter 31: Hybrid VST synthesizer, 24db Type1, VST automation (rules not 100 % matching)
- Filter 32: Hybrid VST synthesizer, 24db Type2, VST automation (rules not 100 % matching)
- Filter 33: unknown product, 24db LPF, automation unknown, (rules not 100 % matching)

Here is again the link to the poll system (clickme).

Please avoid a guessing game inside the comments regarding the used software, this don't count here.
And also don't comment such things like: "Why do you spend your time with such picky behaviour?", cause we'll delete such nonsense immediately...

You can vote your favourite sound and write comments to tell, why you voted this way. We and most visitors are very interested in the comments because our experiences show, that the subjective feeling of human audition (even by experienced musicians) is often very different to the pure practical, theoretical and technical facts and the musical tastes are finally very different.

Also the digital "hype" of the last years destroyed somehow the definition of "analog sound" or better expressed: the understanding of analog sounding in general. The new "digital community", biased by the VA marketing hypes of the last years, even seems not to know anymore how analog equipment really sounds, which (unfortunately) don't avoid them to heavily discuss the theme without any substance. Not to forget to say, that obviously some of the people don't even hear (anymore) any differences between all that ... ?

Maybe we find out the tastes, what the today's users associate with "analog sounding" or at least "excellent digital simulation" and which kind of filter sound most of the users definitively prefer. It could also be a good advice for future developments and the common improvement (!) of all "virtual analog" soft- and hardware products.

Perhaps, one day, if the clear preferences are shown, we will resolve the riddle and unveil (merely) the clear winners, if there are any...

Jackle&Hyde
development team
info@dizainer.net