Where did you see that Supravox is doing field coil drivers ?
The 215 is a very famous driver, i have a pair inherited from my grand father, and the reissue is based on these. I never saw any fieldcoil from this era, I am confused ?
If it can help, these drivers the 215's really shine around 100 liters from my own experiments in full range mode.
The 215 is a very famous driver, i have a pair inherited from my grand father, and the reissue is based on these. I never saw any fieldcoil from this era, I am confused ?
If it can help, these drivers the 215's really shine around 100 liters from my own experiments in full range mode.
"One advantage of field coils is their ability to adjust the magnetic field tension within the dynamics of the T coil, allowing for fine-tuning of speaker tone balance and bass playback quality"
Then, the magnetic field of the coil can be more intense and more focused than the one of a passive permanent magnet resulting in a better control of the cone movement. If the power supply is well designed and low noise the general audio quality of a field coil driver is great.
........i.e. effectively changing the driver's Qts (Qts') in T/S parlance by adding series resistance (Rg) to best match the cab's tuning or whatever system Q (sysQ) is desired.
(Qts'): (Qts) + any added series resistance (Rs):
https://web.archive.org/web/20220707003028/http://www.mh-audio.nl/Calculators/newqts.html
Power supplies, needing space / funds to run those, potential for interference (which shouldn't happen, but we all know about what should[n't] happen & what's actually the case... 😉 ).
There aren't really very many arguments against field-coils beyond the cost angle & to a point size / space reduction -it was largely because of those & the convenience factor we got permanent magnets. Although that came with its own issues, not least that many of those last (and the enclosure alignments of the era) assumed they'd be used on the end of variable output impedance amplifiers. Which promptly got forgotten the second power started to get cheap (okay, I'm exaggerating. 😉 But not by much).
There aren't really very many arguments against field-coils beyond the cost angle & to a point size / space reduction -it was largely because of those & the convenience factor we got permanent magnets. Although that came with its own issues, not least that many of those last (and the enclosure alignments of the era) assumed they'd be used on the end of variable output impedance amplifiers. Which promptly got forgotten the second power started to get cheap (okay, I'm exaggerating. 😉 But not by much).
I already fall into single ended full range category niche. If I try one of these field coil I am afraid i would end up in even darker category...
But those sounds very interesting information. Thanks for sharing.
But those sounds very interesting information. Thanks for sharing.
Wonderful to learn of your plans & progress! I'd call it 1.5-way too -- N-way having 2(N-1) pass filters.
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A little more info from my time developing pro slot car motors; it wasn't until AlNiCo batteries could be made powerful enough and be reduced in size enough to replace existing FC drivers for which we Americans can thank Union Carbide, ditto Neodymium.
Only in mass production, 'we' could still custom order FC 'replacements' into the '70s and hindsight being 20-20, one more thing I 'kick' myself for not taking advantage of.
Yeah -wonderful thing, hindsight. I guess we're all searching for those crystal balls. 😉
Great extra information (as always) -many thanks! 🙂
Great extra information (as always) -many thanks! 🙂