[scansp7]

Hi Just found myself back here after over a decade.  Looking to build a pair of new speakers and wanted to find out more info on field coils, specifically Rullit 12" or 8" drivers.  I heard these at a hifi event back in Germany and was pleasnatly surprised.  Any info would be greatly appreciated?

[scansp7]

[FullRangeMan]

I will move this topíc to the Single Driver Circle where it become.

[FullRangeMan]

Hi, in my personal opinion FCs FR drivers dont sound better than Ferrite or Alnicos, they sound different, they are more one option available, unfortunately they are expensives and need a quality supply to drive the Coil, so they dont offer value or a purist solution.

So I would not lose my time with FCs IMO, mainly Rullit and EMS that are the more expensives available, I would look over Lii Audio F15 or F18 in a ( ) barrel OB baffle as Decware use, the F18 dont need a sub in a small room IMO.
http://www.glowinthedarkaudio.com/lii-audio-f18.html
Its hard to refuse the F18 at $520/pair (not each):
https://www.lii-audio.com/product/one-pair-18-inch-full-range-speakers-superb-scale-soundstage-with-new-imaging-f-18/

[planet10]

Hi, in my personal opinion FCs FR drivers dont sound better than Ferrite or Alnicos, they sound different, they are more one option available, unfortunately they are expensives and need a quality supply to drive the Coil, so they dont offer value or a purist solution.

Hard to disagree with.

Rare and pricey. I have heard only 1, it sucked.

Rulitt, the few i have seen, have been prasied. Sonido probably offers teh best value.

One advantage of an FC is that the driver parameters, and hence the box loading, by changing the power supply voiltage.

If you have no issues with budget, go ahead and try some, but some of the modern, more convential FRs, do a pretty good job, likely better than at least some of the FCs, for a lot less cash.

dave

[scansp7]

Thanks for the suggestions.  I have been a big fan of open baffle and dipole speakers.  Would really like to try something that gives me the sound and large sweet spot.  Does not have to be a Field Coil, but like the idea of horn loading the driver.

[Delta77]

https://songeraudio.com/

I've heard a few F/C setups at the Home Audio shows.
Only one room has garnered my attention.
Songer Audio...
I spent most of the lasts show (Emeryville, Ca.) in one room.
The Songer Audio room.
Custom made by a very small company.

Definitely a step up from your average speakers.

[FullRangeMan]

Thanks for the suggestions.  I have been a big fan of open baffle and dipole speakers.  Would really like to try something that gives me the sound and large sweet spot.  Does not have to be a Field Coil, but like the idea of horn loading the driver.

horn loading the driver.
Please note that a speaker suited to horn needs low Qts,
a speaker suited to OB needs a hi Qts.
The only horn that call my attention are the Frugal Horn that Dave can supply you the PDF plans, also there is a bigger Frugal-Horn for 8'' FR drivers, that I cant remember the exact name.

the sound and large sweet spot.
Overall custumers opinions as the Glow in The Dark Link I posted to you agree that the F-18 delivery the largest soundstage available due the big cone, what also help the bass freq.

[planet10]

Please note that a speaker suited to horn needs low Qts

Tnag is a myth.

a speaker suited to OB needs a hi Qts.

Or EQ.

Frugal Horn

Frugel-Horn



There are 4 horns, tne original FH Mk3 (which happened in a week after struggling with it for some time).

People “demanded” what followed. Frugel-Horn XL (for 5-6” drivers nominally), and Frugel-Horn Lite for 3” drivers. We resisted for a long time, but demand for an even larger one lead to Joan (not in the above picture, 6.5" [Markaudio] and some 8” drivers, really a cousin, not a sibling, it has a slightly different alignment to keep the size from being giant.

These were designed to be very verstaile and suit higher Qts drivers over the typical drivers used in horns (like the Fostex FExxx which really aren’t happy unless in a horn and driven by a highish outpot impedance amplifier.

FH Mk3, and Lite plans are free (https://frugal-horn.com/fh3-plans.html), the larger ones require a minimum $10 donation to diyAudio.com (as payback for all the member support). These designs are our (Scott, Chrois, and myself) contribuition to diyers everywhere, and a solid design for local cottage industries making flat-paks you can buy without paying huge shipping costs or intermediate distributors. A small effort to bring back speaker making from the Chinese.

We are happy that thousands of pairs have been built. https://frugal-horn.com/FH-family.html

dave

[shooter]

The Rullit field coil in solid wood horns can be heard at the upcoming Southwest Audio Fest in Dallas in March. Judge for yourself!

[Rusty Jefferson]

The Rullit field coil in solid wood horns can be heard at the upcoming Southwest Audio Fest in Dallas in March. Judge for yourself!

I haven't heard those particular field coil drivers yet but will look for them in the future. I'm just getting exposed to some lately but haven't had an ah-ha moment yet. Several people told me the Songer room at CAF was great but I didn't see it in a short day there. They are pricey though.

I haven't been a fan of full range drivers though I appreciate why some folks like them. I did hear some at CAF that caught my attention. The VK Music room was using AER full range drivers, horn loaded. Combined with their new 45 amplifier, there was some magic in the room. Great top end extension and of course great midrange. Requires subwoofer use in the arrangement they showed.

https://aer-loudspeakers.com/aer-breitbandchassis-bd/

[FullRangeMan]

+ 1 on AER  (Audio Electric Research).
I cant afford these drivers due the 100% of Customs Duties in my country,
but AER are the best German full-range drivers by far since 1985, and now
with these 16Ω and hi sensitivity models they are specially suited to small
tube amps, and Phillip Keller is a very kind and friendly seller 
Recommended.