Welcome to Jeff Chan's Audio Pages

My main audio page was getting kind of long, so I've reorganized the subjects into separate pages. Please choose a topic from the menu at the left or from this main window. (If you're not seeing the menu bar on the left, please go to my home page and click "Audio" at the top.) Some general topics appear below.

The Parts Connexion

Note that my favorite maker of affordable audiophile digital audio gear, Assemblage, formerly part of Sonic Frontiers' division called The Parts Connection, has been re-formed as a new company: The Parts Connexion. I am leaving the links to the old SFI site since the Assemblage info is still there for now, but future product info and sales should be directed to the new company soon.

"There's Life Above 20 Kilohertz!"

If you think sound ends at 20 kHz, then please see James Boyk's paper "There's Life Above 20 Kilohertz!" Boyk measures real world musical instrument spectras out to 102 kHz and very clearly shows harmonics of real sounds way above 20 kHz. Whether we perceive this information is an open question, but the sounds themselves probably need 192 kHz sampling for accurate recording.

Favorite Audio Discussion Boards

The best discussion board for general audio including some tweakery and modifications seems to be AudioAsylum.com. Another site that focuses more on home-built audio equipment is DIYaudio.com. Nelson Pass occasionally lends his comments on DIYaudio, where he and his designs are held in high regard. A site with links to many professional equipment reviews is eCoustics.com. Another interesting site is Audio Review which facilitates user reviews and discussion of equipment. The level of discussion and quality of reviews is not as high as in the other groups, but it can be useful. HighFidelityReview.com is one site with reviews of high resolution digital audio SACD and DVD-Audio discs. Others include Amazon's customer reviews, etc.

Keeping An Open Mind

The frontiers of high fidelity music and sound reproduction are often explored with subjective judgements since instrumentation and measurement capabilities can lag far behind what we can discern by ear. (Consider that our hearing has evolved over many millions of years, whereas science has only been with us for a few hundred. Science certainly cannot yet present a complete understanding of hearing or perception in general. I say this as someone who has done human auditory perception experiments at university.) The scientific goal should always be to model and repeatably measure what we can hear, but that rigorous process frequently can not keep pace with the experiments engineers and scientists come up with, sometimes in the form of commercial products. Until it can be repeatably measured, it's not science, but there's a lot of apparently good sound that science can't measure yet.

That's not because science can't measure everthing we can hear, but because science hasn't yet come up with workable theories for all that we can hear. Science will never be able to explain everything, but it's the only reliable tool we have available to attempt to find those answers. Just because science can't yet explain something doesn't necessarily mean that something doesn't exist or that a scientific explanation of it is impossible. It may simply mean that there is no scientific explanation yet.
Within this atmosphere of novel experimentation there can be controversy, since the question often comes down to what a listener or listening panel judges to "sound good". This is especially the case with new developments such as high resolution digital audio, upsampling, new digital filter algorithms, etc. With these truly new areas, the old references of vinyl sound, analog tape sound, and even conventional Compact Disc sound can be less than useful or even potentially misleading to an open-minded and keen-eared listener.

For example, I find that upsampling seems to let the music on CDs through better. I definitely hear more detail, spaces and general clarity, while at the same time it's smoother and more liquid. The general consensus seems to be that raising the sampling frequency moves filter artifacts further away from the desired signal and this may be some of what we're hearing. In other words upsampling lets the analog filters do less damage to the music.

At first I was uncertain about the sound of the upsampled music. But a few things changed that for me. First, native 96 x 24 DVDs like the Cheskys or Classic Records ones have a smoothness to the sound that is unlike anything else I have heard, whether it's vinyl, CD, or analog tape. Upsampling regular CDs seems to get closer to that sound so the filter argument above may have some merit. Second, downsampling 96 x 24s to 48 x 24 moves the sound in the direction of non-upsampled 44.1 CD: less depth, harder, grainier, etc. Third, I came to realize that I had associated the harder CD sound with "quality" because I had been listening to CDs that way for so long and had assumed it was "right". Well I'm pretty positive it's not "right" now and that higher sampling rates and to a lesser extent upsampling bring us closer to the original event and are therefore higher fidelity.

I think the final point is very important. It's very easy for perceptions to be influenced by prior experience and present expectations. It's important to have an open-minded approach and to give new things some time for the brain to "relearn" and adjust. Hearing live music often also helps. How do we know when we're hearing truly better sound? What's our reference? Live music probably makes a much better and safer reference than CD, LP, or even 15 IPS analog master tape....

But Most Of All, Enjoy

Among all this talk about science, measurements, hardware, and formats, don't forget to kick back and enjoy the music. That's the point of all this. The magic of high fidelity is to bring us closer to the original event and the artists' intentions and emotions. Better equipment will make that happen better and contribute to our enjoyment of the music, but it's not necessarily an end unto itself. The real goal is to bring us closer to the music and the music makers. Happy listening!