Is it possible to “improve” the basic audio fidelity of a recording after the fact? I know audiophiles strive to get every last bit of tone color, spatial distribution, warmth, clarity, and detail out of their sources. We’re constantly on the look out for new and improved components, better cables, accessories, and acoustic treatments, but is there really an “Absolute Sound” as many believe? Or do we exist in a world full of fidelity variations that provide sonic bliss to some and irritation to others. The continual rants about the merits of expensive cables, consumer formats, speaker types, DACs, and audio accessories ignore the most fundamental fact of music recording and reproduction — the innate sound of the master as delivered by the replication facility. The fidelity of the master is the peak of the sonic pyramid; there is no besting the sound as distributed by the label. Period.
And we all know there are recordings that sound fabulous and recordings that sound like crap. Sadly, the percentage of bad recordings to good ones is way too high IMHO. I find it very difficult to listen to most contemporary commercial releases due to over compressed sound, the reliance on virtual rather than real instruments, and the focus on repetitive rhythmic loops in lieu of song craft. Maybe my aesthetics are rooted in musicianship, production creativity, and expressive lyrics to the extreme but I’m less impressed by the new music I hear than I expect to be.
The new generation of artists and producers isn’t really interested in high fidelity — they want hits. I can understand that. So we’re stuck with trying getting our personal “best” fidelity out of the existing masters. And just what constitutes a master. Is it the first incarnation of the album? Or is it perhaps the “remastered” version done by the record company on the 30th anniversary of a successful project? Maybe the Mobile Fidelity version tops them all? I know the mastering guys are busy making new transfers of the analog originals (who know which versions) to high-resolution digital files for HDtracks and the other digital download sites. These same files will ultimately be available as “high-resolution” streams if MQA gets their way and TIDAL buys into their technology.
There are a number of companies — big ones like SONY and small mom and pop ones — claiming to be able to upconvert standard fidelity music to “high-resolution”. I’ve already written about DSEE from Sony (click here for the article). Today, I’d like to take a serious look — and listen — to a process Eilex claims to be able to convert standard-resolution CD fidelity sound to Hi-Res is real-time! They claim it works on any digital source — radios, televisions, CDs, and DVDs.
This is not simple sample rate conversion or sample interpolation. Their process “generates multiple even-order harmonics from the audio source” and adds them to the original audio. It’s an interesting idea. We all know that PCM digital files have a maximum high frequency limit due to the sampling rate and the Shannon-Nyquist frequency. Looking at the spectra of a compact disc shows a plateau at just below 22 kHz. The uppermost harmonics are truncated — if they were there to begin with (which is not an unreasonable qualification).
Figure 1 – This is the spectra of a 44.1 CD specification file in a 96 kHz graph. Notice the hard flat line at 22 kHz. This is a high-resolution PCM files from AIX Records called “Mosaic” by Laurence Juber.
Is it possible to cleverly add the missing partials back into a standard-resolution file? I would imagine it is possible to create some new ultrasonic components. But will having them make a track sound better?
To be continued…