Dahlquist DQ-1W (late 1970s)

Little is documented about the Dahlquist DQ-1W, and the name can mislead. This was not a full-range loudspeaker. The period record identifies the DQ-1W as a low-bass module - a subwoofer designed to be added to an existing speaker system, and a companion in Dahlquist's move toward biamplification.

The clearest surviving documentation is the advertising Dahlquist ran in early 1977 when it introduced four new products. Audio (Feb 1977, p.35) described the DQ-1W as a superior subwoofer design that adds an octave or more of very tight, well-defined low-frequency response to most speakers. The same campaign also ran in High Fidelity (June 1977, p.105). It pitched the module as part of a biamplified system and listed continuously variable crossover settings from 40 to 400 Hz at 18 dB/octave, bass level adjustments with up to 15 dB of gain, and 0 to +5 dB equalization.

A follow-up essay-style ad laid out the reasoning. Audio (Sept 1977, p.41) argued that a speaker designer faces a tradeoff. A woofer that reaches deep into the bass often gives up upper-bass definition. A lighter, faster cone blends smoothly with the midrange but rolls off earlier. Dahlquist's answer was to let the main speaker do what it does best and add the missing bottom octave with the DQ-1W.

Beyond these ads, the record is thin. No independent lab measurements, production figures, or original price have surfaced, and surviving units appear to be uncommon.

Type: low-bass module (subwoofer) for use with existing speakers
Claimed function: adds an octave or more of tight low-frequency response
Marketed as part of a biamplified system
System features: variable crossover 40–400 Hz, 18 dB/octave; bass level up to +15 dB gain; 0 to +5 dB equalization