Bill Sommerwerck

dbx 700 digital audio processor

Bill Sommerwerck Jun 10, 2021

As ALF would say, "There's more than one way to cook a cat." We've been so overwhelmed with linear pulse-code modulation (PCM) recording, we forget there are other ways to pass from the analog domain to the digital.

One of these is delta modulation. The Greek delta (which in its upper-case, block-letter form, looks like an equilateral triangle) is the mathematical symbol for the difference between two quantities; accordingly, in delta modulation, we record not the absolute value of a signal sample, but the difference between successive samples.

Headphone Reviews J. Gordon Holt

Koss PRO-4, PRO-4A and Pro/4 AAA Plus headphones

J. Gordon Holt, Bill Sommerwerck Jun 09, 2020

Almost a dead-ringer for the early-model Sharpe HA-10, Koss's PRO-4 ($45) is readily distinguishable by a large knurled protuberance sticking out of the lower part of the right-hand phone. This, in case you've wondered, is a mounting for a "boom-type" lip microphone, for use in speech labs and for communication purposes. (Sharpe and Permoflux also provide facilities for attaching a lip-mike.)

Features J. Gordon Holt

Controversy: The Single Speaker Dem Myth

Bill Sommerwerck, Others Aug 08, 2017

The issue is this business of "single-speaker" listening and demonstration, which has become fashionable in the UK.

The premise: bringing a second pair of loudspeakers into your auditioning room upsets the sound of the pair you're listening so badly that the first speaker's ability to correctly reproduce the timbre of musical instruments is destroyed. This observation is almost surely correct.

CD Player/Transport Reviews

Sony D-7S portable CD player

Bill Sommerwerck, Sam Tellig Jul 05, 2016

There's a race on between Sony and Matsushita, to determine who can build the smallest battery-operated CD player with the most features. Sony currently holds the lead with its second-generation D-7 ($300), about 30% smaller than the first "pocket" CD, the D-5. Most of the reduction is in height; both players have a horizontal cross-section only slightly larger than the CD itself. The illusion of smallness is further enhanced by an angled front panel with beveled edges.