Field-coil drivers, pros and cons. Relics of the past, or still relevant?

[mhardy6647]

HaHa, they shine beautifully blue.

I remember power supply setups by Thomas Mayer (aka VinylSavor) with such rectifiers, which would be better described as 'lighthouse'. I don't like them that way, as they make a lot of RF noise.

That they do. But they're good for high power requirements at high B+ and controlled voltage drop.
Lots of "hash" though -- but in this age of digital signal processing and SMPS, it's a drop in the bucket!

 

[fpitas]

That driver uses a simple field coil like the rest of them. Its not a bad driver but it certainly doesn't do 20Hz!

I'm sure the cone wiggles enthusiastically.

 

[atmasphere]

I'm sure the cone wiggles enthusiastically.

It does that at other frequencies too.

 

[ocinn]

Some PA midwoofers from18sound have a secondary stator coil which could be used in a likewise fashion.

Wow, these are some pretty major advantages. H3 practically disappears in the upper (800-2k) frequencies in a lot of the tests. IMD is way down. White Paper
I haven't heard it talked about much, seems ideal for small 2-way PA Monitor style speakers that need to do a lot of vocal frequencies.

 

[Newman]

Yes I have had those 18Sound midwoofers in my system since 2006, very cool tech.

 

[pLudio]

Measurements in the November issue of audioXpress.

Following a presentation by Wolf von Langa, a renowned designer and manufacturer of premium loudspeakers who pioneered the use of field coil drivers, Rens Tellers and Jan Didden offered to do some technical measurements on one of his drivers, to which Wolf graciously agreed. In this article they share their test bench findings.

Discover New Dimensions of Sound in audioXpress November 2024

This November 2024 issue of audioXpress explores perspectives on signal processing, and sound reproduction. Read a review of the PSI Audio AVAA C214 digital active bass absorber, learn about the exciting possibilities of Audioscenic's Amphi Technology and how to explore the Boundaries of Active...

audioxpress.com

 

[egellings]

Some old radios with electrodynamic (what field coil speakers were called then) used the coil as a filter choke in the power supply, and an additional small amount of winding (few dozen turns or so) was placed at the voice coil end of the pole piece. This winding was connected in series-opposing with the voice coil, and the winding cancelled out the 120Hz hum from the supply's ripple voltage.

 

[mhardy6647]

Measurements in the November issue of audioXpress.

Discover New Dimensions of Sound in audioXpress November 2024

This November 2024 issue of audioXpress explores perspectives on signal processing, and sound reproduction. Read a review of the PSI Audio AVAA C214 digital active bass absorber, learn about the exciting possibilities of Audioscenic's Amphi Technology and how to explore the Boundaries of Active...

audioxpress.com

Following a presentation by Wolf von Langa, a renowned designer and manufacturer of premium loudspeakers who pioneered the use of field coil drivers...

Umm... the use of field coil drivers was pioneered by folks like Peter Jensen (who originated the electrodynamic loudspeaker -- the "Magnificent Magnavox", ca. 1919), and of course, people like Jim Lansing, Harry F. Olson, Paul Voigt, and many others at places like RCA, Western Electric (ERPI), JBL, Altec (and other concerns such as Klangfilm, Vitavox, Lowther, etc.).