SUMMER MUSINGS: Who/What is an "Audiophool"? (And old quad album mixes.)

Hey guys and gals. This week, I thought it'd be fun to just talk about something that was brought up over at the Audiophile Style forums in this thread "Who or What Is An Audiophool?". Seeing that there were a number of comments already, I figured why not jump in over the past week and engage?

Doing this brought back memories of the early 2010's when I would spend more time on the forums to chat with fellow audiophiles. As you can imagine, over time with work, family life, having fewer questions to ask as I progressed through the hobby, and turning to writing articles here, my time on the forums have significantly been reduced. I'll still pop in once awhile but not like in the early 2010's to read and participate.

So this past week, as you can see from Page 6 of the thread onwards, it was fun to get back into the weeds a bit and liberally engage. Over many pages, we got into quite a few topics including ideas around blind testing, importance (or not depending on whose opinion) of objective measurements, anecdotes, human behaviors, the role reviewers play in the Industry, examples of bizarre pseudo-science, why we enjoy audio as a hobby, JG Holt's interview from 2007, personal values, anti-vaxxers, agreeing to disagree, ASR, website traffic numbers, quotes from Richard Feynman, what is knowledge, etc.

A look at the music library: How much DAC intersample overhead is enough? True Peak analysis of genres in an eclectic digital collection.

In a recent article about Linn DS streamers, I touched again on intersample peaks ("True Peaks") as I measured the DAC hardware. In the comments section, there was further talk about this topic so this got me thinking over the last few weeks to spend some more time on this but from a different angle.

For those who are not aware of what "intersample peaks" are, recall that DACs implement filters to ensure accurate reconstruction of the waveforms (unlike the jagged-looking NOS DACs which some audiophiles still subjectively appear to prefer). Typically this is done through oversampling whereby 44.1kHz (ie. CD samplerate) might be increased by something like 8x (352.8kHz) while applying a low-pass filter that cuts off content beyond the 22.05kHz Nyquist frequency. The DAC will interpolate to create those extra upsampled datapoints. In this DSP process, some of the reconstructed "intersample" points might have >0dBFS values. If these "True Peak" values are too high beyond the limits of the digital filter or output level of our DACs, the samples will "clip", resulting in extra distortion in the playback.

For this post, instead of considering from a hardware measurement viewpoint what kind of overhead a DAC can handle, let's consider from the music content side by using a relatively large music library - my library of thousands of albums - and consider just how much overhead peak we might find and "need" based on the commonly-owned music genres in an audiophile's collection.

Another Digital Volume Control Article 🙂 (Guest post by Bennet Ng)

Back in 2019 I wrote the article "Why We Should Use Software Volume Control / Management" which not only addressed about intersample overs, but also floating point induced clipping which cannot be solved by having intersample headroom in the DAC. (For a quick listening test, try the files in this thread on ASR). However it seems that some people are still not happy with the proposed solutions (e.g. ReplayGain) and resort to some other methods. For example in some of the recent blog comments someone mentioned about BitShiftGain.

Here is a snippet from the BitShiftGain website:

Digital audio is like some crystalline structure: it’s fragile, brittle, and suffers tiny fractures at the tiniest alterations. There’s almost nothing you can do in digital audio that’s not going to cause some damage. But as long as you stick to 6 dB steps and rigidly control the implementation (BitShiftGain doesn’t even store the audio in a temporary variable!), you can chip away at that least significant bit, and the whole minutes-or-hours-long crystalline structure of digital bits can remain perfectly intact above it.