AlnIco - Ferrite - Neo - Field coil: which one rules?!

Let's mention the two camps:
electromagnets VS permanent magnets.
Permanent magnets: field strength tops off at 2 Teslas, REGARDLESS magnet material (Fe, Neo, AlNiCo - ANY of these will get you a 2T driver).
Want more? You need an electromagnet!
How strong can that be? Mighty hard to make one significantly greater than 2T on a comprehensible budget, yet today technology tops off at 10T(!!!) althought there's only one magnet like that, and it's used in the large hardon collider at CERN (building a driver with such magnet would get you in the budget of about 100 million dollars, making today's million dollar ultra-boutique speakers little more than a weak laugh).
However 1 thing Zupa clear: future is NOT NEODYMIUM drivers.
FUTURE IS FIELD COIL We just need to make it smaller and more affordable. (Yeah, and find a room temperature superconductor first! Cheers ;)
Opening credits:
Current densities of 100.000 A/mm2 to 600.000 A/mm2 are feasible in the temperature range of 4 K to 20 K (-269 degrees Celsius to -253 degrees Celsius) compared to 35 A/mm2 in state-of-the-art copper motor coils at room-temperature.
phys.org/news/...

[@bobstenerson3276]

This was a great description of the differences of the magnets. Spoke to Peter Q. from AN and thinking about enhancing my system with Ongaku and AN SEC Signature. We talked about a preamp or digital upgrade but he also mentioned his new field coil speaker. I was wondering if it was really going to be a significant upgrade and it sounds like it certainly should be a consideration in enhancing my system. Being an engineer I do enjoy understanding the why things are better so thank you for your videos.

[@realworldaudio]

Thank you Bob! Yes, I'd warmly recommend to hear the field coil AN-E, should be quite special. I'm glad you picked the brains of Peter Q! ;).

[@user-od9iz9cv1w]

Fascinating. I use alnico coax drivers for 150 up. Together with OTL triode monoblocs they work very well at soft volumes bringing out micro details that provide that sense of space around sound sources. I listen to DIY digital which is very good. It also has triode output amp and then autoformer line source which allows the low-level info to come through. My bass is handled by very large ferrite drivers, and it does collapse at low volumes. As I improved the source with very low phase noise clocks, I found I would be happy with lower and lower volumes.

[@realworldaudio]

Sweet setup! Interesting observation on the clock noise, thank you! That is something I have not played around with yet.

[@iampuzzleman282]

These issues are never really discussed when choosing between speakers or understanding them. It's always a mystery. So this is very interesting. It's all about the presentation of pressure amplitudes by the speakers as supported by the amplifiers as supported by everything else in the food chain. Ultimately it's the Rocky Mountains versus the Appalachians. Rocky Mountains have the pressure amplitudes in synch, versus muddiness and poorly timed frequencies which are the Appalachian mountains. Noise floor is pristine with the Rocky Mountains. Interesting video, its something to think about.

[@realworldaudio]

Beautiful analogy, thank you! ;

[@polkiju7]

I have experimented with FC drivers and using very modest sources and amplification, found them really engaging. My main system (in storage at the moment) is all alnico. The video linked here uses a laptop as a source and a $10 chip amp. Power supply is a well designed DIY DC power supply. Recording is via an IPhone: kzbin.info/www/bejne/kHbcnJiQj7d7d7M

[@dannixon247]

->lemme tell a story about a fine Australian Pedal Steel player who is a friend of mine... When he was first making a name for himself, you HAD to have killer tone so he played a fender vibrosonic reverb. -It was the best- Once established and gigging all over the country as a fly-in session musician he 'upgraded' to a very hi-end class D power amp with a valve pre and a 'best in class' 15inch Neo driver & cab.... why? Because -it was the best- Since covid struck and live gigs got canned he setup a very nice home studio and now works for commission on recordings for country bands all over the world. He sold his 'touring rig' and puchased another Vibrosonic for the studio. I asked him why and he said: "Everything is usually a huge compromise, but when it came to drivers, James Lansing tried really REALLY hard not to on the D130. It's the only game in town for clean efficient head room. But like the laws of physics you can't win, you can't break even and in the long run you always lose. Every amp worth having with a D130 was IMPOSSIBLE to gig with because it was just simply to big and heavy." -but it is the best- -within a certain context- The finest things on this earth are not simply stuff for sale, but more an opportunity for one to participate in a journey of discovery heartbreak and joy -with others- If you should so choose. I am really enjoying your sharing and wisdom Janos, thankyou. Dan.

[@realworldaudio]

Hi Dan, thank you for the wonderful share, it says all about audio gear! It;s not a simple "quest for the best", it's about finding the solution (sweet compromise) for what works on a daily basis. A wonderful aspect about the Neo drivers and class D is light weight and compact cabinets... my musician friend Taltosh is also changing from his Mesa Boogie to a class D amp and a light Neo speaker cab, as he had enough lugging the heavy beast around esp with gigs having parking lots far away.

[@asadabbasmirza9519]

My view is still that the price for higher or powerful.magnets doesn't justify the cost . Again individual magnets cost calculations is not difficult..

[@dannixon247]

Awesome Thumb nail dude!😃

[@realworldaudio]

Yup, field coil magnet with half a MILLION Amperes of current driving it! Creates the mother of all magnetic fields ;) Would make incredible speakers... although it needs an industrial establishment to house and operate... yet. Yet! Quite likely in any home in 70 years.... ; :)

[@dannixon247]

@@realworldaudio WOAH.... And I thought my pair of 6080w tubes were current hungry!😏. Cheers man

[@rickg8015]

Permendur would rule them all.. LOL😉.. Tonally though, Electromagnets with well designed/implemented Tungar supplies are the beesknees..

[@realworldaudio]

Indeed, permendur is the super-magnet! Can achieve 2.4T!!!! (And Supermendur, which has even lower hysteresis losses.) Too bad nobody's making driver motors with them. (Not that I know of...) Would be likely ridiculously expensive, it's extremely hard to machine. Luckily, it's being used for cartridges ; ).

[@rickg8015]

@@realworldaudio Hi Janos.. GOTO and ALE of Japan makes drivers with Permendur magnets for decades now.. The granddaddy of those companies is YL Acoustic (now owned by Kondo - Audio Note Japan).. They make Mid-Bass compression drivers that could go lower than a WE 555.. They use both Beryllium (HF) and Duralumin (LF) frams for their drivers..

[@realworldaudio]

@@rickg8015 Thank you Rick! Did not know that GOTO uses permendur for their magnets... that explains their crazy motor strengths! 2.4T for the CD, and 2T for the 15in woofer! Absolutely next level. Too bad they don't export, only for Japanese market. Anyway, they are way out of my current budget. One day, when my mortgage is paid off, I'll go on a trip to Japan and return with a set of these beauties.

[@rickg8015]

@@realworldaudio There was a USA/Canada distributor, but I dunno if they are still in business..

[@realworldaudio]

@@rickg8015 Thank you Rick! ;

[@LuxAudi]

Why power supply quality in field is so important?

[@sandeepjawalkar3619]

InventionAudio will be coming up with new Field coils relatively affordable ones.

[@be2the4out]

isnt it true that alnico 'compresses' the signal? thats why it is able in lower level volume to hear more detail.. also with the volume al the way up, alnico is fast saturated and thus not sutable for very loud levels.. ?

[@realworldaudio]

Saturation with alnico is only an issue when nearing peak levels, at low to normal and even high levels it does not occur, only when someone forces the driver to work well outside normal expected conditions. Sadly, with volume all the way up (provided amp delivers more than driver handles) beyond the designed operating range of the driver, all drivers go to hell in a handbasket regardless the technology used. Alnico will go to hell in a cultured manner, becoming softer and gentler, and ferrite will go to hell screaming and tearing your ears out and leaving you hearing impaired.

[@nicktube3904]

I’m so curious about your opinion about the top range of CA drivers since they use Neo magnets. Can the CA Magus use Alnico drivers form wise ?