Sunday, Sunday
Neodymium > Alnico
Edition
/ag/&/am/: audio general & audiophile memes
Noah Carter
Other urls found in this thread:
diyaudio.com
soundandrecording.de
soundandrecording.de
community.genelec.com
whathifi.com
audio-database.com
monoprice.com
gikacoustics.com
twitter.com
Aiden White
Neodymium master race
Jason Ortiz
Neodymium is a metal which is ferromagnetic (more specifically it shows antiferromagnetic properties), meaning that like iron it can be magnetized to become a magnet, but its Curie temperature (the temperature above which its ferromagnetism disappears) is 19 K (−254 °C), so in pure form its magnetism only appears at extremely low temperatures. However, compounds of neodymium with transition metals such as iron can have Curie temperatures well above room temperature, and these are used to make neodymium magnets.
The strength of neodymium magnets is due to several factors. The most important is that the tetragonal Nd2Fe14B crystal structure has exceptionally high uniaxial magnetocrystalline anisotropy. This means a crystal of the material preferentially magnetizes along a specific crystal axis, but is very difficult to magnetize in other directions. Like other magnets, the neodymium magnet alloy is composed of microcrystalline grains which are aligned in a powerful magnetic field during manufacture so their magnetic axes all point in the same direction. The resistance of the crystal lattice to turning its direction of magnetization gives the compound a very high coercivity, or resistance to being demagnetized.
Jordan Myers
The neodymium atom also can have a large magnetic dipole moment because it has 4 unpaired electrons in its electron structure as opposed to 3 in iron.
In a magnet it is the unpaired electrons, aligned so they spin in the same direction, which generate the magnetic field. This gives the Nd2Fe14B compound a high saturation magnetization. Therefore, as the maximum energy density is proportional to Js2, this magnetic phase has the potential for storing large amounts of magnetic energy. This magnetic energy value is about 18 times greater than "ordinary" magnets by volume. This property is higher in NdFeB alloys than in samarium cobalt (SmCo) magnets, which were the first type of rare-earth magnet to be commercialized. In practice, the magnetic properties of neodymium magnets depend on the alloy composition, microstructure, and manufacturing technique employed.
The Nd2Fe14B crystal structure can be described as alternating layers of iron atoms and a neodymium-boron compound. The diamagnetic boron atoms do not contribute directly to the magnetism, but improve cohesion by strong covalent bonding. The relatively low rare earth content (12% by volume) and the relative abundance of neodymium and iron compared with samarium and cobalt makes neodymium magnets lower in price than samarium-cobalt magnets.
Jaxon King
General Motors (GM) and Sumitomo Special Metals independently discovered the Nd2Fe14B compound almost simultaneously in 1984. The research was initially driven by the high raw materials cost of SmCo permanent magnets, which had been developed earlier. GM focused on the development of melt-spun nanocrystalline Nd2Fe14B magnets, while Sumitomo developed full-density sintered Nd2Fe14B magnets.
GM commercialized its inventions of isotropic Neo powder, bonded Neo magnets, and the related production processes by founding Magnequench in 1986 (Magnequench has since become part of Neo Materials Technology, Inc., which later merged into Molycorp). The company supplied melt-spun Nd2Fe14B powder to bonded magnet manufacturers.
The Sumitomo facility became part of the Hitachi Corporation, and currently manufactures and licenses other companies to produce sintered Nd2Fe14B magnets. Hitachi holds more than 600 patents covering neodymium magnets.
Michael Bennett
As of 2012, 50,000 tons of neodymium magnets are produced officially each year in China, and 80,000 tons in a "company-by-company" build-up done in 2013. China produces more than 95% of rare earth elements, and produces about 76% of the world's total rare-earth magnets.
Neodymium magnets have replaced alnico and ferrite magnets in many of the myriad applications in modern technology where strong permanent magnets are required, because their greater strength allows the use of smaller, lighter magnets for a given application. Some examples are:
Head actuators for computer hard disks
Erase heads for cheap cassette recorders
Mechanical e-cigarette firing switches
Locks for doors
Loudspeakers and headphones
Mobile phone speakers, taptic feedback and auto focus actuators
Magnetic bearings and couplings
Benchtop NMR spectrometers
Electric motors
Daniel Miller
Alnico and neodymium are not directly comparable, because they function differently, and give the designer the freedom to use different types of magnetic circuits. I should also add a caveat that the total performance will depend very much on the design of the magnetic circuit, and this may very well be a bigger variable than the magnet material used.
Alnico needs separate pole-pieces to function correctly, while the rare-earth magnets like neodymium can function with or without.
Using a similar grade of iron, an alnico will usually measure as having lower distortion than a ferrite, and particularly the midrange will sound cleaner.
On to rare-earth magnets. If such are used with polepieces, the distortion figures and listening results usually will both be better than a ferrite. OTOH, samarium-cobalt, presidymium and neodymium all sound different from alnico, and they also sound different from each other. Depending on personal preferences, some listeners may like the alnicos, while others may choose one or another of the rare-earths.
What I particular like about the rare-earths is their ability to be used in a magnetic circuit without any polepieces whatsoever. For a given design, improving the grade of the polepiece material nearly always provides better measured and subjective results, but in my experience, designs that eliminate them completely provide the lowest overall distortion.
But there are other prices to be paid. First, the efficiency goes way down. Next, neodymium is far more sensitive to temperature than alnico. Above 70 degrees C, for all practical purposes it is non-functional as a magnet material.
James Stewart
i have a fairly small apartment and my living room (sofa, tv) setup is at an angle, i want a decent speaker setup (for music) that doesn't take up the whole room. what do you recommend?
Carson Gray
qx guy here again
been really satisfied with the jbl lsr 305 so far. really nice nearfield experience, i can deal with the slight hiss when not in use
i got some discounted Focal Alpha 50 in the mail arriving tuesday, pretty excited hehe
Jason Perez
if you want something minimalistic, look up iloud micro monitors
go reasonably loud and sound exceptionally for their dimensions, you can get them in white now too
Adrian Thompson
How bad is 10% distortion?
>diyaudio.com
Genelec is a company I hold in high regard, but I wonder how much of their coaxial innovation is novelty and how much of it is practice?
Comparing the specs of 8350 to the 8351, the only regular measurements that the 8351 best the 8350 is directivity, which is a critical metric, but to what extent?
>soundandrecording.de
>soundandrecording.de
Look at that phase, power response and decay times of the 8350 to 8351. Genelec's own response on their forums disappointed me with their flowery prose, reminds of an audiophile review.
>community.genelec.com
Still, everyone thats heard them (the ones) says they're fucking incredible, beyond traditional metrics for measuring performance. But this answer doesn't satisfy me.
Aiden Johnson
Day 17 of waiting for my Harbeths. JBL Swede postman, if you're here, I wanted to ask what you thought of Coincident Pure Reference Extreme?
John Sanchez
i also don't trust genelec preachers but at some point i might try some of the smaller 300ish monitor speakers if i happen to see a good deal.
i hardly make uneducated purchases in my life so its really hard to say if something doesnt sound as it should for the price
Robert Scott
qacoustics and a small receiver
Lucas Evans
how u like them, any comparison before them?
Connor Myers
whathifi.com
can be mixed with small receivers like from denon, philips or yamaha
they're very small but have a good sound
you can find them used for about $100 to $120 US, but theyre also found in package deals with small receivers for about $250 new in the US and UK
the main drawback is not a lot of bass
Nolan Foster
'scuse the mess. Lazy Sunday kicking back to some Taj Mahal.
Jordan Stewart
nice technics set
Alexander Parker
Appreciate the info, but as you implied, the flux design trumps magnet material. They sound different because of their varying conductivity -- higher means the magnet naturally acts as a shorting ring, lowering Le(x) and Le(i) induced distortion. Alnico is more conductive than Neo, which is wayy more conductive than ceramic etc., but they all pale compared to copper or silver.
So employ shorting rings, an all-out copper polepiece or any other flux/excursion management (differential drive or whatever), and magnet conductivity has only minor effect.
So maybe be honest with yourself: if you intentionally design for the magnet to be the sole source of shorting effect, then you're not really pursuing low distortion. You're encouraging extra distortion of a particular flavor. Embrace it, and you'll be able to design "to taste" much easier, without the charade of "low distortion". If low distortion really is what you want, stuff the fucker full of silver and move on.
Gabriel Torres
I can't say much about them, the brand isn't even sold here. But the Accuton drivers are tricky and requires some really good crossovers, and some people have complained about the metal grills infront of the drivers. And the bass-reflex port at the back looks somewhat undersized. They don't seem to have anything special to offer other than somewhat big woofers compared to the competition. A speaker like KEF Reference feels way more advanced in its construction and utilities proprietary technologies and parts.
Also, you mistook some user for me in the old thread about breaking in the LS50 :)
Jonathan Diaz
Aaron Smith
I think those florid comments are excerpts of an audiophile review and not of Genelec staff.
>10% distortion
Impossible to predict with just a number. As perceptual coding shows, a lot of distortion can be added into a track without sounding very poor. Detection of distortion products is frequency band dependent and relative to the band spacing from the signal.
In general, a lot of low-order nonlinear products can be tolerated in the low frequencies without any issue. 2nd and 3rd order products dominate typical loudspeaker nonlinearity, assuming nothing is defective.
So, 10-20 percent is probably a reasonable cutoff for bass distortion.
>how much of their coaxial innovation is novelty and how much of it is practice
It appears intended for near-field operation. The 19mm tweeter used would suggest that.
The attraction of the coaxial is blending the midrange and treble smoothly, so I think you take issue with the slot woofers or the small tweeter used.
>phase/decay
If you run the auto calibration, the decay will clean up some. Decay is a visualization of the magnitude-phase response, and the little wiggles in the magnitude can be removed.
The order of the allpass here (8th order crossover?) is not a priority as long as all channels have the same order of shift.
Neo magnet blends are effective at much higher temperatures than 70ºC and don't suffer on efficiency. You do need to avoid cooking the neo magnet.
Pricing and availability have been more problematic. There was a hard supply shock back when China locked down exports on rare-earths for a bit. Some woofers simply could not be made.
Mason Wilson
you can mod these?
Evan Watson
Owen Parker
generally all coax units produce lot of distortion
even TAD/Pioneer one which stands for highest quality coax unit ever made
David Myers
>he considers himself an 'audiophile'
>he's never been to an orchestra concert
Brayden Morgan
I know that the LSR 305 are praised basically everywhere, but has any of you tried the Tannoy Reveal 502? I'm looking for good active monitor speakers, they should be placed on the desk of my bedroom (see pic) and I'm interested into the Tannoy for their rear bass port, since I need to place them near the walls.
On a different note, are 5" woofer active monitors worth? or should I get a couple of Yamaha HS8 once I move to a bigger place?
Henry Davis
>I know that the LSR 305 are praised basically everywhere
By Harman Co. shills, yeh.
Josiah Edwards
Neodymium in the Special 40 tweeter and the weird practice of putting the voice coil outside
Luis Mitchell
it's hard to compete with lsr305 not only because they are very good speakers but they also have a shitload of independent measurements which show how good they are so when you choose between buying objectively good speaker with measurements and buying something because someone told you it's good then the choice is obvious
Camden Williams
>magnets killing a phone
Huurrrrr durrr
Isaiah Long
Thanks for the technical breakdown
>I think those florid comments are excerpts of an audiophile review and not of Genelec staff.
It's from thomas lund - chief technologist. This line in stuck out in particular:
"However, listening still brings out more contrast than expected. First time I did so, after just arriving at Genelec in 2015, sitting down with 8351 reminded me of a quote about another human marvel, the Sydney Opera House: "The sun did not know how beautiful its light was until it was reflected off this building.”"
A little funny, since the sydney opera house is infamous for its terrible acoustics. I was hoping for a more scientific explanation why the sacrifices made for coaxial point source are worth it in favor of conventional designs that measure better in most traditional metrics. It seems that this is as close to the answer is it gets:
"Hearing and seeing rely on movement, and what you get in return with the 1s is more coherent than with any other monitor. This is very noticeable at close range; but also at a distance in a semi-lively room, probably because direct sound and reflections both are less coloured than when drivers are dislocated."
So would such coaxial designs be less beneficial in treated or professional rooms? Would a conventional speaker design like the 8350 that measures better in time domain and phase response be better?
>If you run the auto calibration, the decay will clean up some.
But those measurements are from an anechoic chamber, I thought autocal would have a non-effect in such situations.
What makes the TAD/Pioneer unit so special?
Jackson Hernandez
>On a different note, are 5" woofer active monitors worth? or should I get a couple of Yamaha HS8 once I move to a bigger place?
get a 5 inch bookshelfs and a sub afterwards
the difference will be much bigger
Asher Flores
>>it's hard to compete with lsr305
When you want lots of noise and hiss mixed in.
Gavin Green
nobody has told me to get the Tannoy, I simply have thought that they might be better in my room since they have front bass port, whereas the LSR have rear bass port.
Austin Lopez
oh i hope youre jokin'
lsr mihgt be good for studio work maybe
not for listening to music and getting, instead, hiss when you turn the volume up to 40%
sold mine after three months because of the low level din and purchased some KEF 150
Gabriel Thompson
Nicholas Hill
I'm currently looking for "decent" desktop 2.0 speakers under 300 USD, that aren't too bass-heavy. any recommendations? an optical input would be favorable but necessary
Alexander Lee
Jace Lopez
maybe the micca meme + meme amp?
William Brown
going mini
Joseph Green
>empty walls
acoustics must be shit.
Hunter Hernandez
>le im distortion face
Jacob Murphy
going mini again
Josiah Phillips
>le you can't afford those anyway because youre an aging third world nigger
Jordan Baker
>you just can't afford it
sorry you regret your purchase earlet
Dylan Adams
>2 expensive 4 uuu hihihi
They're that bad huh?
Caleb Lee
>top tier B&W
I think they'll get over it.
Thomas Hughes
front ported options
David Jenkins
about TAD CST coax driver you can read here
audio-database.com
Tyler Rivera
Aiden Myers
Scalford Show 2014
"Next up is one of the most astonishing systems at the Show for me. Not because it had the best sound, although it sounded excellent. Certainly not because it was the most expensive – quite the opposite really. But simply because a vintage Sony powerhouse of an amp was exerting astonishing grip on a tiny pair of Q Acoustics 2010i speakers. An amazingly dynamic and rhythmically exciting sound that could play at high levels with ease."
Luke Richardson
Autocal flattens the measured low-frequency response. The non-uniform decay is an expression of the wiggles in the response.
>measures better in time domain and phase response
Linear frequency and time response are expressing one thing in different ways for convenient understanding. They are derived mathematically from each other.
Practice tends to show that phase shift is well tolerated monoaurally, definitely not a priority beyond anechoic listening. The phase shift in the 8351 is the result of high-order digital crossover filters used, not inherent to coaxials.
>better
Treated rooms are not totally dead, and the sweet spot is bound to be larger than non-coincident. Summing point is much closer with a coaxial as well. Many issues with coaxials (surround and horn design, modulations) are problems of 2-ways and are mitigated by designing for a 3-way.
But, treated rooms are less live than usual assumptions of listening rooms, and it still can't match the SPL of the 8350. The older 8260 would seem more of a straight "upgrade" to the 8350.
A subwoofer or two would be very useful in increasing maximum distortion-free output if you don't want to stick to near-field. This raises a bit of a question as to why you need a main speaker that has been severely beaten with EQ to extract deep bass response.
>TAD/Pioneer
Pioneer reserved its 3/4-way coincident drivers for high-end lines, mainly TAD.
They use beryllium tweeter domes and have a very impressive cabinet construction, almost unnecessarily sturdy and vibration damped. But most TAD designs have the on-axis issue that KEF has managed to work around as of late.
The modern Genelecs don't seem to be plagued by the classic on-axis cancellation of coincident drivers either.
Jack Bailey
2010i okay but 3020 got meh test results
Hudson Morales
Owen Lee
you never listen speaker strictly on axis
slightly off axis is preferable for all speakers
Connor Morgan
Lol McIntosh
Nicholas Torres
plus one thing
TAD sound better than KEF or genelec
so they have achieved nothing !
Chase Adams
I asked about foam behind my lsr305 in here before and was told that it's pretty much pointless, but I keep seeing it..
Nice setup btw :)
Adrian Rivera
absolutely not pointless for decoration
Mason Bailey
what do you guys think about the Presonus Eris e5?
Josiah Gonzalez
Cambridge Audio Topaz SR20 or Pro-ject Maia?
Leaning towards the Pro-ject Maia..
Jace Harris
it's a small lowest budget active speaker with a little more problematic port turbulence than the competition
Carson Wright
lol 600 watts
wtf
Dylan Harris
The perfect "miniset":
>Raspberry Pi, optionally with a HifiBerry DAC+, with Volumio to a pair of Edifiers
Completely poorfag yet doesn't sound any different from all the overpriced garbage you guys recommend to people.
Angel Moore
One is a reciever and one is an integrated amp.
Go for an topaz am5 instead
Nolan James
>Completely poorfag yet doesn't sound any different from all the overpriced garbage you guys recommend to people.
Ethan Turner
>port turbulence
please elaborate. The main reason why I'm looking forward to this rather than the LSR 305 is the front bass reflex.
Nathan Howard
>topaz am5
What dac would compliment this amp?
Evan Kelly
you mean like this
Liam Taylor
Anything that has reasonably good stats will work fine.
It's a clean amp, had mine since 2012 I think.
James Wilson
Hey guys. So I got this vintage radio in my store that works like a dream except when anyone walks by it or looks at it funny, really. But it works and it's the music for my store. I'm just so tired of the radio. It has a built in record player, but I don't own any 45s. I think it's 45s, the smaller records? How can I play music from my phone through this thing?
Liam Russell
ah interesting
does the back look like this
or take a detailed pic of the back
Jordan Hughes
anyone here use cork yoga blocks for speaker stands? do they look okay or cheap and shitty?
Jonathan Parker
Well... time to clean muh amp.
Angel Rodriguez
doze would be nice for woodsy spekrs like dis
Zachary Young
Vacuumed it but theres linty shit stuck in the crevice.
Carter Watson
Considering getting Topping's A30 amp and D30 DAC primarily for use with my Phonon 4000 but also my (pretty decent) harmon/kardon stereo+sub setup. Thoughts?
Jaxson Russell
Jacob Foster
Using my d30 with my lsr305's and 600's. It does what I want it to do, can't fault it. The amp isn't supposed to be very powerful though compared to others though. Magni 3 is better as long as you don't get annoyed by a potential scratchy volume knob, though you barely notice it through speakers compared to headphones.
Christian Wood
my speakers are white so i'm thinking they would look okay... just a bit hesitant to pull the trigger
John Allen
Anyone know some alternatives to this Monoprice 5 speaker wall plate?
monoprice.com
That's perfect but I might need something sooner than their ETA for it to be back in the stock. Parts Express didn't seem to have an equivalent. I don't want anything labelled.
Ian Anderson
Got the lint out.
Jeremiah Sullivan
hey guys, been looking at my cunts version of craigslist for a while now, looking for an amplifier.
Are there any things that I should look/out for, good brands, bad brands?
Bentley Wright
it looks like the Grundig has a DIN 5 socket for the record player and the tape in/out
you could try a DIN 5 to 3.5 mm jack connector to see if you phone has enough wattage to register any output
another option is to feed signal in through the tape recorder in/out -- im assuming it allows input via the DIN 5 -- but you may have to be careful to choose an amplifer that wont put too much power into your Grundig
or call Grundig and get some kind of manual or direct advice
Dominic Miller
Is there such a thing as a simple mp3 player with a screen that has no wifi/bluetooth/radio/mic or wireless connectivity of any sort?
All I want is a simple mp3 player with sd slot that I can take with me anywhere, and not care at all if it is lost/broken.
Adam Long
sansa clip+
fiio
walkman
Evan Morales
good: sony, pioneer, yamaha, denon (usually, can't go wrong), harman kardon
not so good: onkyo, unless much older
bad: kenwood, recent sherwood
not an iron-clad rule of thumb BUT if the amp or receiver is heavy, it likely has a larger transformer and more power
avoid all-in-one-systems
older avr receivers without HDMI may be very powerful for low cost
Bentley Turner
Back in business.
Isaac Powell
Chinese iPod Shuffle Clone, I got one from a sale at gearbest for a for less than a dollar and it works fine.
I haven't used it much so idk how long the battery lasts.
Ian Green
Dude! Thanks so much. Really appreciate it. I'll start looking into this immediately. I'll ship you some candy if you like candy and are in The States. Send a message on Facebook, we're ABC Candy and Designs.
Kevin Howard
C'mon Jow Forums
Best bluetooth speaker for general house use between £100 - £200
Jaxon Smith
Get a Sonos
Matthew Cox
i was one of those people.
i have foam and every wall in my room.
pic related is the same room opposite direction
Isaiah Brooks
>requires to be plugged in.
Need something I can move from room to room relatively hassle free.
Eli Lopez
thanks user, hopefully I can find something nice
Justin Barnes
hope it sounds good
Nathaniel Nelson
I wouldn't say it is pointless, but can grab a GIK panel for reasonable money and probably get more value.
I mean these are less than 200 bucks for three
gikacoustics.com
Austin Rodriguez
Can I suck your dick and watch you fuck your wife up the ass?
Daniel Brown
Hey gramps, its time to get off the Panera wifi and go home to your cat.