Neodymium or ceramic?

[scott fitlin]

I have been reserching 15in woofers, everyone makes them now with neodymium magnets! JBL, as well as others! There are a few different models, including JBL, that interest me.

My question for today is neo,s reliability! A few guys I have spoken to, sound contractors, have told me to stay away from neodymium magnet woofers because the magnets have a habit of becoming completely discharged if overheated! I knew this was in fact a problem with neo several years ago, and neo was only really used for compression drivers etc! But now every manufacturer has seemingly high performance, and lightweight woofer models available featuring neo magnets, so whats the real deal? Is neo a reliable magnet in a high power woofer, in commercial use?

An enquiring mind needs to know!

[Titanium Dome]

My...name...is...Neo!


Many of the issues have been addressed, but a neo magnet still has its inherent virtures and vices.

Here's what one manufacturer has to say about it and why his design modifications make it a great magnet.

http://www.euphonicaudio.com/2005/te...eo_magnets.htm

You can also check out the Gaussboys general warning about neos, including what heat and fracturing can do.

http://www.gaussboys.com/warnings.php

I always find musicians' discussion on these kinds of topics enlightening, if anecdotal, so you might enjoy this:

http://www.musicplayer.com/cgi-bin/u...5;t=011558;p=1

A brilliantly executed neo magnet is a remarkable thing, i,e,, heat sinks, liquid cooling, thermal dissipation casings, etc.

[Mr. Widget]

I am not sure if this is relevant, but I had a mishap with an imported compression driver with a neodymium magnet and it could not be repaired since no one here had a magnetizer powerful enough to recharge the magnet once the repair was complete. I believe one of our European members had a similar problem with a JBL neodymium compression driver and was told that it must go back to the factory for repairs.

I would assume the woofers would have the same issues.

Widget

[scott fitlin]

Thank you, Dome, good reading! I am aware there will be sonic differences between ceramics and neo,s, and its interesting to note that some find the mids of neos somewhat brittle sounding! I have no idea, I havent, as of yet, auditioned any myself! I was surprised that two different sound guys told me to stay away from neo,s! I know about the Aurasound 18 back in the 90,s, demagnetizing from extreme use, especially if they were blown, but would have thought since most manufacturers offer this as a regular product in their respective lineups these days, the heat issues have been solved!

Keep it comin, seems from the little bit Im reading, heat IS still an issue!

[scott fitlin]

I am not sure if this is relevant, but I had a mishap with an imported compression driver with a neodymium magnet and it could not be repaired since no one here had a magnetizer powerful enough to recharge the magnet once the repair was complete. I believe one of our European members had a similar problem with a JBL neodymium compression driver and was told that it must go back to the factory for repairs.

I would assume the woofers would have the same issues.

Widget

Well, then serviceability becomes an issue should the magnet be discharged! And, yes it is relevant, as it has to do with reliability!

Thank you!

[pelly3s]

I use Neo drivers in a lot of my boxes at work, all my monitors have 2255's and my double 18s are 2258's. I also use some EV Ndym 6 horns and I havent had any issues. As was mentioned though the magnetizer that we have wont even touch them. Im telling you I would rather take the chances then break my back moving the double 18s. Just my personal opinion. I know there are a lot of people out there who dont like them but i havent had any issues yet

[scott fitlin]

As I said, the neo woofers i am looking at are very interesting! Thus far, two sound contractors have told me to stay away from them! Thats why I am asking questions. OTOH, since Dome turned me on to talkbass.com, I have found some more interesting reading from the musicians! I feel bass guitarists put their woofers through more abusive use, than playback audio apps! So if they can withstand the rigors of live, uncompressed, sometimes highly distorted bass, they can withstand pre recorded music!

As to their sound? Well Im just gonna have to order two drivers and see for myself what they do or dont do!

But heres another interesting read > http://www.talkbass.com/forum/showthread.php?t=167954

The one thing I seem to have come across is they, ( neos ), do have a midrange bump! Some like, some dont, and this may account for the brittle sound some claim they have!

[scott fitlin]

I use Neo drivers in a lot of my boxes at work, all my monitors have 2255's and my double 18s are 2258's. I also use some EV Ndym 6 horns and I havent had any issues. As was mentioned though the magnetizer that we have wont even touch them. Im telling you I would rather take the chances then break my back moving the double 18s. Just my personal opinion. I know there are a lot of people out there who dont like them but i havent had any issues yet

Besides the lighter weight, whats your opinion of neo magnet woofers sound compared to the more traditional ceramics? Or at least can you compare the sound of the neos your currently using, to the drivers they replaced?