Is there any such thing as a bad sounding DAC these days?


I think the problem of DAC for quality audio has been pretty much universally solved.  Not to say all DACs are equal, they aren’t, but do any that really matter these days not sound “good”?

128x128mapman

You might be surprised by hearing some very nice sounding DACs / players from long ago. They will absolutely measure like dog crap compared to modern. But our ear-brains do not process information via Fast Fourier Transform!

Perhaps surprisingly, our ears and brain DO process sound almost exactly like a Fast Fourier Transform.

Our cochlea and our auditory cortex are tonotopic.  When a complex wave gets to our inner ear, different frequencies within the complex wave have peak resonant points at different physical locations along the basilar membranes of our cochlea which have different stereocilia bundles connected to them. Our inner ear actually breaks down the complex wave into component frequencies based on where each component frequency maximally excites the basilar membrane, and we have separate nerve firings for each of those component frequencies based on the hair cell bundles connected to the basilar membrane at those locations. The tonotopic geography continues into the auditory cortex in the brain, which Dr. Nina Kraus of Northwestern likens to a piano, where you see different physical regions in the auditory cortex responding to different frequency components of the complex waveform.

So, yeah, actually, our ears and our brains are breaking down incoming complex waveforms into their component frequencies very much like an FFT, and, further, actually converting them into binary-like neural spikes -- when a stereocilia bundle is deflected it creates a nerve spike or no spike, functionally like a 1 or a 0 -- and those go up to higher centers of our brains where the physical separation continues until other processes take place to create a perception of an integrated sound (or multiple separate sounds).

It's a sidebar to matter of what people prefer in terms of the particular sound of a particular piece of equipment. But our ears and are brains, when we hear, are very much doing something very like an FFT.

@chervokas 

Thanks, very interesting, I did not know that.

our ears and our brains are breaking down incoming complex waveforms into their component frequencies very much like an FFT, and, further, actually converting them into binary-like neural spikes -- when a stereocilia bundle is deflected it creates a nerve spike or no spike, functionally like a 1 or a 0

So, if I'm reading you correctly you are saying that our brains re-convert (analog) sound waves into digital?

FFT is a mathematical transformation from time to frequency domain. Our ears respond to frequencies over time. The details of how they do that is a whole different story.  chervokas  seems to have a good handle on it.

So, if I’m reading you correctly you are saying that our brains re-convert (analog) sound waves into digital?

It’s not really digital, though Susan Rogers, who was Prince’s recording engineer then went on to get a PhD in music cognition and psychoacoustics and now is the director of the Berklee Music Perception and Cognition Laboratory, quaintly does describe our stereocilia as the inner ear’s little A to D converters. There are aspects of our hearing and our auditory processing that are like analog audio signal processing, and aspects that are like digital audio signal processing. Better to say that our ears convert mechanical motion into nerve impulses and those nerve impulse are generated when little channels open and let ions flood in, and those channels are either open or closed, and that train of either/or electrochemical impulses are the stuff the higher order areas of our brain uses to form a perception of the sound -- Psychoacoustics: Hair Cells in Ears are Analog-to-Digital Converters | Susan Rogers | Berklee Online