Recent Comments

1. 5 days ago on Dick Tracy

   If the implication is that Pa Totten worked under Himmler in the SS, it’s a stretch. Even if he were in his early 20s at the time, that would make him over 100 now.

2. 19 days ago on Phoebe and Her Unicorn

   LP mastering did not usually involve high-frequency filtering; it was just a struggle to get very high frequencies onto and off of a vinyl record. Anyhow, there are many other issues with LPs. It’s nearly impossible to get frequency response flat enough for the errors not to be audible. Dynamic range is pretty limited, especially at low frequencies. Impulse noise. Audible time-base errors (wow and flutter) are almost inevitable. Phono cartridges (some worse than others) tend to generate excess vertical stylus motion at high frequencies, resulting in excess L-R information in the output. This can masquerade as greater depth or width in the stereo image, but it’s essentially fake.

3. 19 days ago on Phoebe and Her Unicorn

   Square waves are not what come out of a digital-to-analog converter, though. What comes out is identical to the waveform that entered the analog-to-digital converter used when the recording was made (or the equivalent after whatever manipulation is applied during production). The only way to get a square wave out is to start out with a square wave, and even then it can’t have a fundamental at too high a frequency or the squareness will get lost, because square wave is generated by taking a tone and adding odd-order harmonics to it at precise levels. Put a square wave with a 10-kHz fundamental into an A/D converter and the only thing that will survive is the fundamental, because all the other components of the square wave will have been filtered out. I think the idea that square waves are involved emerged from the diagrams commonly used to illustrate sampling, which unfortunately give the impression that a smooth waveform is being permanently transformed into a jagged one. I wrote one of the first articles explaining digital audio to consumers and to this day regret not creating a sidebar to explain sampling in greater detail, because of this misconception. Although the process does generate spurious signal components at frequencies above half the sampling rate, these are filtered out on playback. In the end, what comes out is, very pristinely, what went in. Raising the sampling rate just increases the highest frequency that can be recorded without distortion. Although there’s no harm in going to a sampling rate greater than 44.1 or 48 kHz, there’s no real benefit, either. A 96-kHz sampling rate just means that you could cleanly record frequencies up to almost 48 kHz, yet only young people with exceptional hearing will notice the insertion of a filter that removes everything above about 16 kHz, especially on music. Bats we ain’t.

4. 23 days ago on Phoebe and Her Unicorn

   Not simulated. Standard PCM digitization occurs in two stages. First is sampling. As long as the sampling rate is at least twice the frequency of the highest frequency in the signal to be sampled, this process is completely lossless. Filter the sampled signal to remove components above half the sampling frequency, and you get back the original signal exactly. Sampling is required to facilitate the second stage of digitization, quantization, which is not lossless. If enough bits are used to quantize each sample, however, the losses will be very, very small. Each bit affords about 6 dB of dynamic range, so once you get to 12 bits the loss across the entire frequency band is smaller than for even the best vinyl records at just midband, and at 16 bits (CD quality), LPs are totally smoked. Put any sort of signal onto a CD and onto an LP, then compare the output from each of those media to the original on a scope. The signal from the CD will be identical to the original, while the signal from the LP will be a bit of a mess, relatively speaking, especially at high frequencies. LP playback is a bit like attaching a rock to the end of a telephone pole and dragging it through a canyon—it’s amazing it works as well as it does.

5. 23 days ago on Phoebe and Her Unicorn

   Analog is not inherently warmer than digital. That’s a myth, though that becomes most clearly apparent when comparing a very good analog tape master to a digital copy of it. The copy will sound identical. Vinyl LPs, though a terrific medium for their day, are compromised in important ways. Back in the day, almost all LP masters were filtered below 40 Hz to prevent overcutting and to extend playing times, for example. Frequency response on playback was almost never flat, and frequency response is what we’re most sensitive to once noise and distortion are adequately low. Typically there would be a dip around 3 kHz inherent to the phono-cartridge response (often exacerbated by improper loading) and a mild low-frequency rise caused by tonearm/cartridge resonance—a little false warmth. A few years ago, some folks did a carefully controlled blind comparison of a CD, an LP, and a 192-kbps MP3 file all mastered from the same original. The LP always came in last for all listeners. Unblinding the experiment, so listeners knew which source they were hearing when ranking them, resulted in some preferring the vinyl. CD is actually the highest-quality mass-market music distribution medium we’ve ever had.

6. about 2 months ago on Gasoline Alley

   Turning into a Magic School Bus adventure.

7. about 2 months ago on Last Kiss

   It can be worked out by testing how they respond to different colors and by examination of the cone cells in their retinas. Dogs also tend to be near-sighted relative to humans. A dog’s visual world is rather drab and somewhat blurry compared to ours. On the other hand, they have a wider field of view, see significantly better at night, and have superior motion detection. It’s hypothesized that our sharper, clearer vision emerged in tandem with bipedality, because when your eyes are several feet above the ground, seeing distant objects becomes both practical and valuable. (Same with birds.) Animals whose heads are close to the ground, on the other hand, usually have a much better sense of smell than we do. Our sense of smell stinks.

8. about 2 months ago on Last Kiss

   Dogs aren’t actually color blind, but they have only two types of color receptors instead of the three we have, so the range of colors they can see is much more restricted. They can see shades of blue and yellow but not red, green, or orange, for example.

9. about 2 months ago on Gasoline Alley

   Strictly speaking, far side of the moon, which does not have a consistently dark side any more than Earth does.

10. 3 months ago on Luann

    Like “fun with Gun.”