I sure remember them. I worked at Stereo Mart on Anaheim Blvd 1975-6. The store was a satellite of Audio Associates of Pasadena, started in the ’40s and claimed to be the oldest high fidelity store in Southern California. We had most of the big players of the time (e.g., Marantz, Revox, JBL, Ohm, Tandberg, Sequerra, Infinity, Altec-Lansing, ESS, B&O, Accuphase, Kenwood, Dual, Technics DD TTs, Philips, Nakamichi, etc.) and that included Dahlquist. We were always on the mfrs’ demo stopping points, and that included Saul Marantz stopping by for a half-day event demonstrating his (and Jon Dahlquist’s) new Dahlquist 10 speakers.
I had been an audio enthusiast for five years by then but the combination of the Marantz 1600 preamp (from their USA-made Pro line) and Dahlquist’s phased array speakers introduced me to the sound of 3D imaging, where you could hear not just a left-to-right sweep, but also front-to-back. We loved the Dahlquists; they sounded so much more real and threw that 3D soundstage that pulled you right into the music.
Rather than keeping the DQ-10s on the floor with their little feet, we were placing them on the Bose pedestals to increase the clarity and imaging. Around that same time Dahlquist came out with much better and cosmetically matching stands, which we switched to.
I was able to talk at some length with Mr. Marantz, who was a great guy to hang with. He mentioned that they were working on another base or stand for the DQ-10s which would house subwoofers, turning them into 6-way speakers. Dahlquist did come out with the DQ-1, a sub for the DQ-10s, but it was box-shaped and not an integrated base for the DQ-10. I never heard the DQ-10s with it because I moved onto another store before they came out.
I asked Mr. Marantz if he had any musical background that inspired him to do high end audio. He said he played classical guitar and mentioned that several of the other high-fi pioneers were musicians as well, mentioning that Avery Fisher was a violinist and Joe Grado an opera tenor.
We usually used a Beogram linear tracking turntable in our "high end" room, but when we got ahold of a Fidelity Research LOMC, we mounted it on a new Marantz 6300 DD turntable with Supex steup-up transformer. This was our source for playing the music for the demo and Saul was quite impressed with the sound of the rig. We used either Accuphase separates or the Marantz Pro 1600 preamp and one of their power amps to drive the DQ-10s.
Later the store picked up B&G electronics and the evening crew found that when you put a pair of their amps in mono mode making 500 wpc, "the Dahlquists really opened up!"
I have a guitar-playing buddy whose home system sources from a turntable playing a pair of DQ-20s powered by a Phase Linear 700. It's a good-sounding rig and doesn't sound particularly dated. My impression is that the DQ-20 is smoother and more refined than the DQ-10, as would be expected.