how I listen to audio today

Developing audio effect plugins involves quite a lot of testing. While this appears to be an easy task as long as its all about measurable criteria, it gets way more tricky beyond that. Then there is no way around (extensive) listening tests which must be structured and follow some systematic approach to avoid ending up in fluffy “wine tasting” categories.

I’ve spend quite some time with such listening tests over the years and some of the insights and principles are distilled in this brief article. They are not only useful for checking mix qualities or judging device capabilities in general but also give some  essential hints about developing our hearing.

No matter what specific audio assessment task one is up to, its always about judging the dynamic response of the audio (dynamics) vs its distribution across the frequency spectrum in particular (tonality). Both dimensions can be tested best by utilizing transient rich program material like mixes containing several acoustic instruments – e.g. guitars, percussion and so on – but which has sustaining elements and room information as well.

Drums are also a good starting point but they do not offer enough variety to cover both aspects we are talking about and to spot modulation artifacts (IMD) easily, just as an example. A rough but decent mix should do the job. On my very own, I do prefer raw mixes which are not yet processed that much to minimize the influence of flaws already burned into the audio content but more on that later.

Having such content in place allows to focus the hearing and to hear along a) the instrument transients – instrument by instrument – and b) the changes and impact within particular frequency ranges. Lets have a look into both aspects in more detail.

a) The transient information is crucial for our hearing because it is used not only to identify intruments but also to perform stereo localization. They basically impact how we can separate between different sources and how they are positioned in the stereo field. So lets say if something “lacks definition” it might be just caused by not having enough transient information available and not necessarily about flaws in equalizing. Transients tend to mask other audio events for a very short period of time and when a transient decays and the signal sustains, it unveils its pitch information to our hearing.

b) For the sustaining signal phases it is more relevant to focus on frequency ranges since our hearing is organized in bands of the entire spectrum and is not able to distinguish different affairs within the very same band. For most comparision tasks its already sufficient to consciously distinguish between the low, low-mid, high-mid and high frequency ranges and only drilling down further if necessary, e.g. to identify specific resonances. Assigning specific attributes to according ranges is the key to improve our conscious hearing abilities. As an example, one might spot something “boxy sounding” just reflecting in the mid frequency range at first sight. But focusing on the very low frequency range might also expose effects contributing to the overall impression of “boxyness”. This reveals further and previously unseen strategies to properly manage such kinds of effects.

Overall, I can not recommend highly enough to educate the hearing in both dimensions to enable a more detailed listening experience and to get more confident in assessing certain audio qualities. Most kinds of compression/distortion/saturation effects are presenting a good learning challenge since they can impact both audio dimensions very deeply. On the other hand, using already mixed material to assess the qualities of e.g. a new audio device turns out to be a very delicate matter.

Lets say an additional HF boost applied now sounds unpleasant and harsh: Is this the flaw of the added effect or was it already there but now just pulled out of that mix? During all the listening tests I’ve did so far, a lot of tainted mixes unveiled such flaws not visible at first sight. In case of the given example you might find root causes like too much mid frequency distortion (coming from compression IMD or saturation artifacts) mirroring in the HF or just inferior de-essing attempts. The most recent trend to grind each and every frequency resonance is also prone to unwanted side-effects but that’s another story.

Further psychoacoustic related hearing effects needs to be taken into account when we perform A/B testing. While comparing content at equal loudness is a well known subject (nonetheless ignored by lots of reviewers out there) it is also crucial to switch forth and back sources instantaneously and not with a break. This is due to the fact that our hearing system is not able to memorize a full audio profile much longer than a second. Then there is the “confirmation bias” effect which basically is all about that we always tend to be biased concerning the test result: Just having that button pressed or knowing the brand name has already to be seen as an influence in this regard. The only solution for this is utilizing blind testing.

Most of the time I listen through nearfield speakers and rarely by cans. I’m sticking to my speakers since more than 15 years now and it was very important for me to get used to them over time. Before that I’ve “upgraded” speakers several times unnecessarily. Having said that, using a coaxial speaker design is key for nearfield listening environments. After ditching digital room correction here in my studio the signal path is now fully analog right after the converter. The converter itself is high-end but today I think proper room acoustics right from the start would have been a better investment.

BootEQ mkIII released

BootEQ mkIII – a musical sounding Preamp/EQ

BootEQ mkIII is a musical sounding mixing EQ and pre-amplifier simulation. With its
four parametric and independent EQ bands it offers special selected and musical
sounding asymmetric and proportional EQ curves capable of reproducing several
‘classic’ EQ curves and tones accordingly.

It provides further audio coloration capabilities utilizing pre-amplifier harmonic distortion as well as tube and transformer-style signal saturation. Within its mkIII incarnation, the Preamp itself contains an opto-style compression circuit providing a very distinct and consistent harmonic distortion profile over a wide range of input levels, all based now on a true stateful saturation model.

Also the EQ curve slopes has been revised, plugin calibration takes place for better gain-staging and metering and the plugin offers zero latency processing now.

Available for Windows VST in 32 and 64bit as freeware. Download your copy here.

TesslaSE mkII released

TesslaSE mkII – All the analog goodness in subtle doses

TesslaSE never meant to be a distortion box but rather focused on bringing all those subtle saturation and widening (side-) effects from the analog right into the digital domain. It sligthly colors the sound, polishes transients and creates depth and dimension in the stereo field. All the analog goodness in subtle doses. It’s a mixing effect intended to be used here and there where the mix demands it. It offers a low CPU profile and (almost) zero latency.

With it’s 2021 remake, TesslaSE mkII sticks to exactly that by just polishing whats already there. The internal gainstaging has been reworked so that everything appears gain compensated to the outside and is dead-easy to operate within a slick, modernized user interface. Also the transformer/tube cicuit modeling got some updates to appear more detailed and vibrant, while all non-linear algorithms got oversampled for additional aliasing supression.

Available for Windows VST in 32 and 64bit as freeware. Download your copy here.

modeling the distortion in Thrillseeker VBL

It’s so important to get the non-linear modeling right if we would like to have a sort of analog feel in the digital domain. I can’t stress this ever enough since it still seems to be a common practise in todays audio plug-in design to just throw in a static waveshaper, oversample it and hope this will make everything alright. Not! Even worse, in a recently released plug-in I saw the static waveshapers curve not being continuous again and I’m not going to talk about the sound.

But what should one expect to hear if the analog modeling is just done right? Only by driving the gain of the unit but way before we notice the obvious distortions there appear different by-products caused by circuit side-effects. Depending on the actual device, circuit and components, it might be that the signal starts just getting thicker and more mid-focused, as an example. Or, the signal might appear much deeper and bigger in other cases.

Whatever it might be in particular, I do call this the “Mojo” of the device – it’s not the primary intention of the device but turns out to be a sort of an added sugar. Such effects are highly frequency, transient and gain structure dependent and this is what makes the processed signal to be much more vibrant and alive. Furthermore, the obvious harmonic distortions are not introduced abruptly but they emerge gradually.

tasty meal preparations with Density mkIII

Since precise routing and stuff like that is not taken down into the cookbook as of now, here are some exciting tips and tricks to experiment with and maybe to obtain a different approach to cook audio with Density mkIII.

Starter

As a starter just use the default preset and dial in huge amounts of compression right with the DRIVE knob. Now mix this back to the dry signal by using the DRY:WET option to obtain a thick sounding result (New York style compression). Since the COLOR option ignores any DRY:WET settings one can dial it in afterwards to thicken the soup even further. Hmm, tasty!

Second course

Set DRY:WET back to a 100% wet signal but also pull RANGE back to the left so that there will be no gain reduction anymore. There is no compression anymore now but one can still use the MAKEUP knob to drive the gain of the non-linear circuits. Use this and experience a hot (driven) meal.

Main course

By finishing the second course, you not only have a sophisticated non-linear amplifier now where you can dial in the coloration with the COLOR knob to taste. You also can use this in M/S mode to adjust the stereo imaging in a quite unique fashion just by adjusting the amounts of saturation per channel right with the MAKEUP knobs. Omph, I’m feelin so wide now!

Dessert

Just dial in again some amounts of compression by turning RANGE clockwise, maybe full to the right but RELAX the attack times so that some transients can pass. Those will be eaten now by the non-linear amplifier as an added sugar.

Espresso, anyone?

announcing mkII versions for NastyDLA and TesslaPRO

Variety Of Sound announces mkII versions for NastyDLA and TesslaPRO to be released during Q2/2012. By this, all the sonic bliss of stateful saturation algorithms will be made available for both, the highly regarded classic chorus echo device with tape-delay simulation and the critically acclaimed “transient aware” signal saturator.

Stateful Saturation takes advantage of some sought after analog qualities and preserves them accurately during their transfer into the digital domain:

  • high frequency shimmer and sheen without digital harshness
  • depth and ’3d’ imaging side effects before distortion itself becomes apparent
  • audio transient dynamics that remains vibrant and alive
  • natural and impressive bass response

NastyDLA mkII remains feature wise the very same but introduces the input stage modelled by this new and exciting technology and also redesigns the tape compression algorithm for an improved IM distortion performance. TesslaPRO mkII will go way further by introducing a variety of different signal coloration options, ranging from console style distortion models up to typical mic/preamp colors.

More details will be unveiled during this month. Stay tuned!

ThrillseekerLA – released today

[Read more…]

introducing ThrillseekerLA

ThrillseekerLA – digital stereo leveling amplifier with truly analog qualities.

At a glance

  • Sophisticated and deep gain riding full of musical character and attitude but with virtually no inter-modulation (IM) distortion artifacts
  • Feedback compression design w/o any samplerate based delay in the loop
  • Classic input level driven two knob design with additional manual attack and release time interventions
  • Highly program dependent envelope timing adoption offering attack times ranging from “instantaneously” up to around 100ms and release times from 30ms up to several seconds
  • Mix level switch to adopt the plug-ins internal gain staging to mixing levels at around -18dBFS
  • Custom SC filter option to attenuate the SC bass response while slightly boosting the HF spectrum
  • Additional one pole (6dB per octave) SC low-cut filter adjustable from 20 to 500Hz
  • External sidechain support
  • Switchable Input/GR/Output metering display
  • Variable compression range control from 0 to 100% [Read more…]

announcing the “Thrillseeker” audio plug-in series

I’m bringing sexy back

The brand new and upcoming Variety of Sound Thrillseeker audio plug-ins series is going to be a plug-in collection premiering Stateful Saturation which is a sophisticated DSP core system for musical harmonic distortion generation based on authentic and truly stateful non-linear models.

Stateful Saturation takes advantage of some sought after analog qualities and preserves them accurately during their transfer right into the digital domain:

  • high frequency shimmer and sheen without digital harshness
  • depth and ‘3d’ imaging side effects before distortion itself becomes apparent
  • audio transient dynamics that remains vibrant and alive
  • natural and impressive bass response

Stateful Saturation opens the door for quite a number of amazing applications ranging from smooth harmonic exciters up to convincing amplifier effects and the DSP core can easily be set in context whether it’s a compressor output stage or a preamplifier circuit, just to name the two. [Read more…]

preFIX – getting those alignments done

getting those alignments done - finally is easy and fun

The upcoming preFIX audio plug-in was originally designed to meet the recording engineers needs and is all about audio alignment tasks: fix all that stuff that can’t be fixed outside the box (anymore) and do that fast and with highest quality right before the mixing starts itself.

preFIX is a pre-mixing and audio alignment tool which typically takes place upfront the mixing process. It provides a clever tool set to clean-up, fix and align audio tracks (typically taken from recordings) concerning overall frequency correction, phase alignment, spatial stereo field corrections and routing. It contains a complete gate/expander solution with a dedicated and comprehensive sidechain filtering path as well.

Though, preFIX is not only tailored to the recording engineers environment but delivers a truly great performance when shaping and lifting poor sample sources, sculpt electronic softsynth instruments or just by dialing in that super tight drum bus sensation as well. [Read more…]