2) What about John Kenny designs, philosophy, business model, and customer relationships make it unique in the marketplace?
Early on, I decided to specialize in computer audio and USB input in my devices as I felt that it was capable of truly excellent sound and it was becoming a serious platform for audiophiles. I reasoned that designing a single input excellently (USB) was much better than designing a number of inputs adequately such as SPDIF, Toslink, I2S, HDMI. USB was often an afterthought input on many audio devices, at the time.
I found that with low noise, highly stable battery power to crucial areas of digital audio devices, (like USB receiver chips, low jitter clocks, D/A converter chips), great improvements in sound could be achieved. The reasons for these improvements only became clear when I found answers in the workings of auditory perception and ASA.
Auditory Scene Analysis (ASA). research, instigated by Al Bregman, arose from trying to understand the well-known “cocktail party effect” which is our ability to focus on a particular conversation in a noisy room full of other conversations. This is achieved by the brain’s processing of the auditory signals from the ear, not by the ear, itself.
The significance of this research to me is this — audio playback is attempting to achieve an audio illusion — an illusion that the listener can believe is ‘natural’ sounding. The more natural sounding, the more believable and engaging is the playback. But ‘natural sounding’ isn’t just ‘preference’, it’s explainable by ASA’s research findings. From infancy, we absorb how sound behaves in the world & this teaches our fledgling auditory perception as to what is natural. ASA is the study of exactly how auditory perception creates an auditory scene from the nerve signals on the auditory nerve — much the same as visual perception creates a visual scene from the signals arriving from the optic nerve.
My clarity about how power supply stability affects auditory perception is explained by ASA. Low levels of power fluctuation are ground noise fluctuations which ultimately affect sensitive circuitry in DACs, for instance. (We even see new ways of hacking what is being typed on computers by sensing ground leakage fluctuations on power outlets powering the computer). Now these noise fluctuations on the DAC are not random, like the hiss we hear from analogue tape–they are correlated with signal processing. Random noise is categorized by ASA as background & easily ignored – it doesn’t intrude into our perception of the foreground sound. Fluctuating noise is analyzed differently – it has pattern characteristics (temporal, amplitude, spectral) which ASA tries to make sense of – group into any of the auditory objects it has already identified. If it can’t make sense of this signal, it is confusing to our perception & leads to a perception of a less clear auditory scene, less believable, less natural.
When this source of fluctuating noise is removed by using stable power from batteries, the whole auditory scene becomes clear, more realistic, more natural – the scene falls into place & makes sense. It’s a system-wide effect, not a change in certain frequencies or amplitude — all of which makes it difficult for some to understand.
Just to be clear – the concept of fluctuation of the PS during processing is well established in engineering and it is now one of the well established techniques for hacking called side channel analysis where unintended side channels give an indication of the signal processing activity and can be used to hack it . In Simple Power Analysis (SPA) key bits are seen directly in the power consumption of a chip using it in a multiplication operation.
There’s one important point to understand about the whole area of auditory perception and it is exemplified in this phrase, borrowed from linguistics, “poverty of the stimulus”. The meaning here is that there isn’t enough data in the signals coming from the eardrum to create an auditory scene we are sure of. Our perception has to use all sorts of other information to try to resolve this dilemma — the dilemma of achieving, in real time, a stable auditory scene which is trustworthy and useful for our interaction with the physical world.
To resolve this we have to draw on other data, data from sight being a primary one but also our prior knowledge and experience of how sound objects behave in the world — for instance a lot of natural sounds have a fast attack and slow decay — the reverse, (slow attack and fast decay) is unnatural sounding. We know that a sound which has a slow decay & then abruptly stops that it is being damped. Through experience we have built a library of such ‘sound pattern information’ which we draw on to make inferences and predictions about the sounds we are perceiving.
How does ASA inform my designs? I realised that what I was focused on in my designs was having an audible effect on the whole presentation, not just better bass or better treble. Other aspects that listeners commented on were a perception of increases in depth of soundstage, solidity of the individual auditory objects in the scene, naturalness — in essence a more realistic auditory scene. My current working premise is that, below a certain low noise floor, what is crucial is the stability of this noise. If this noise is fluctuating, it affects how we perceive sound but isn’t heard as an entity in itself. An exaggerated example of this is pre-echo in some low quality MP3s which blur transients but the pre-echoes themselves are not heard, just their effects (here’s a Youtube video of this effect).
ASA research, even though started in 1990, is still at a relatively early stage of investigation — 27 years is a short time in perceptual research. This makes for a difficult task in uncovering the exact ASA mechanisms in operation during auditory perception of complex signals such as music. ASA is still at the stage of using relatively simple audio signals for testing and is only now beginning to consider more complex signals. Until there are advances in this aspect, all we can rely on is intuition, experiments and knowledge of ASA to guide us.
My philosophy …
Doesn’t just apply in the scientific arena but in all of life. Remaining open-minded and inquisitive is a struggle but one worth trying to pursue.
Having established a relationship with those people who engaged me to modify their Hiface products, I have stayed loyal to this type of customer relationship — a personal interest in ensuring that they are getting the most from any product of mine. That includes giving advice about the surrounding equipment being used with my audio devices. In the past this has uncovered ground loop issues & sub-optimal playback settings in customer’s systems.
My direct sales business model allows me to stay in touch with my customer base and also ensure the best value for money that my products have been renowned for.