When I was visiting Audio Note (UK) last fall, Daniel Qvortrup showed me drivers and cabinets of some prototype field-coil loudspeakers they were in the process of developing, as we did a walk-about of the facility.
Audio Note UK prototype low-frequency field-coil driver.
Audio Note UK prototype field-coil high-frequency driver.
Cabinet for the prototype Audio Note UK field-coil loudspeaker project.
Daniel just sent me some photos of the completed prototype Audio Note (UK) field-coil loudspeakers that were installed into Peter's listening room at home for evaluation (photo below).
This is exciting news that the field-coils are up and running!
Note the field-coil power supplies located on the floor in front of the prototype loudspeakers.
Let me repeat part of my discussion of field-coil drivers from my "Sneak Peek: The Audio Note (UK) Oto Phono SE Signature Integrated Amplifier Feature Review for Positive Feedback! Part 1." post HERE." (I'll be updating that post with Daniel's photos as well.)
Oto feature review coming soon to Positive Feedback!
"Now back to those prototype field-coil loudspeakers that Peter and his research & development teams at Audio Note (UK) are developing."
"In case you are not familiar with field-coil drivers, they utilize electromagnets as a motor to drive the cone of the speaker instead of a permanent magnet."
"In a recent discussion I had with longtime Altec employee and expert, Todd W. White, we discussed the history and evolution of the Altec 801/802 series of compression drivers, one of history’s more important and successful driver designs in cinema sound research & development."
"The Dr. John F. Blackburn designed Altec 801B field-coil compression driver of 1937 was the Granddaddy from which the later Altec 802 series of permanent magnet compression drivers would evolve (like those in my vintage “Stokowski” Altec’s used as reference loudspeakers in this article, or in my vintage Altec 832A Corona loudspeakers, for example)."
801B field-coil design that the 802 series evolved from.
"Field-coil electromagnet drivers have a number of advantages over permanent magnet drivers due to their powerful magnet strength. The field-coil electromagnet driver follows the soundtrack or music signal much more accurately, meaning you get greatly reduced distortion from the driver, resulting in much higher fidelity to the music or soundtrack signal."
"This much lower level of distortion in the reproduction of the signal from the field-coil electromagnet driver gives a smoother, more tonally natural, and more “real” presentation of the music. The field-coil electromagnet driver provides more resolution of recorded musical and sonic nuance, gradations in dynamics are tracked more accurately, and the listener experiences more “presence” of the musicians."
"As a result, with the field-coil electromagnet driver the listener hears more of the artistry of the musicians or film effects, and the listener experiences a greater sense of emotional engagement because of it."
"During the Second World War AlNiCo 5 magnets were perfected for military applications, and Altec’s John Hilliard adapted AlNiCo 5 magnets to loudspeaker drivers."
"Shortly after the war, the Dr. John F. Blackburn designed Altec 801 field-coil compression driver was modified by John Hilliard with a permanent AlNiCo 5 magnet replacing the field-coil electromagnet, which became the Altec 802 driver."
"From the perspective of a cinema sound company like Altec, even though field-coil electromagnet compression drivers sounded better, the permanent AlNiCo 5 magnets still sounded very good (as I can attest to), were much cheaper to manufacture, and much easier to maintain in the field for theater installations."
"From that point on, permanent magnets dominated drivers in cinema sound research & development."
Prototype Audio Note (UK) field-coil loudspeakers in Peter's listening room.
"However, true high-fidelity audio companies - like Audio Note (UK) - are again investigating that historic peak of research & development into field-coil electromagnet drivers because of their much greater performance potential."
"So, by observing the lessons taught by the peaks of audio research & development in history, and applying them to contemporary designs with the best of today’s materials science and design discoveries, the audio arts advance."
"Peter and I have been exchanging emails about the exciting 78rpm transfers of Peter’s late friend, Anatoly Markovich Likhnitsky, and after writing this section of the article (which was unknown to Peter), he described their progress on their field-coil electromagnet drivers that I just mentioned above, “… the first prototype of a field-coil version of the AN-E is ready. It is a fairly rough approximation of what it will eventually become, but it already beats pretty much all the permanent magnet versions of the AN-E we make, so there is no question that the field-coil is a massive game changer, well at least within our world as it stands.”
"That’s exciting news indeed!"
As you might imagine, I find what Peter is doing with the prototype Audio Note (UK) field-coil loudspeakers to be quite intriguing, so as I find out more about them I'll be providing updates.
Many thanks to Daniel Qvortrup for taking time to stop by Peter's home and shoot some photos of the speakers for us!
It's a good time to stay home and listen to music during the COVID-19 pandemic if you can - stay safe my friends!
As always, thanks for stopping by, and may the tone be with you!
