Magnet type in modern speakers

Most bass and bass mid drivers are ferrite, some are AlNiCo.

Tweeters are usually neodymium iron boron or ferrite.

The the pole / coil shape and presence or absence of a Faraday ring have more effect on the sound than the material from which the magnet is made.

Thinking about it, if you're going into this level of detail , then in addition to the drivers you should also be concerned about many other details that are not often published, such as...

Electrical Details...
Impedance vs frequency
Phase vs frequency
Type of cabinet wiring
Type of connectors used to connect to the crossover and drive units
External connectors

Cabinet details...
Cabinet structure
Methods of resonance control
Bass alignment
Q factor of the intenal damping vs Frequency

Crossover details...
The order of each filter
The electrical alignment of the filters
The acoustic alignment of the filters
The type of the core (if there is one) in the inductors
The type of capacitors

From experience all of these can have an influence on the sound.

Magnet type in my ATC's is HUGE.

Huge posted:

Most bass and bass mid drivers are ferrite, some are AlNiCo.

Tweeters are usually neodymium iron boron or ferrite.

The the pole / coil shape and presence or absence of a Faraday ring have more effect on the sound than the material from which the magnet is made.

Adding to the above, cobalt based magnets (e.g. AlNiCo) are  rare because of the increasing rarity and cost of cobalt. Meanwhile neodymium magnets are creeping into bass driver design.

tony123 posted:

There are always a lot of information about speaker membranes in reviews and manuals, but always ZERO info about magnet type. Is this some kind of secret?

All these magnets sound differently and would give better understanding about sound characteristics to potential users.

There have been suggestions of different sounds, but as Huge hints that may not be the magnet material per se, but the overall magnet assembly: The different magnet materials having different magnetic characteristics such as coercitivity and remenance, in turn allowing different dimensional characteristics of the whole assembly for any given voice coil gap flux density, as well as being capable of achieving different maximum flux densities.

In my experience looking at speaker drivers, most manufacturers do identify the magnet type. That reviews don’t mention may in part be because of far less relevance to the sound than the diaphragm characteristics, while the very review itself is trying to tell the reader the sound characteristics, so what the magnet is made from is rather a trivial detail. (Of course, the diaphragm construction is arguably is also irrelevant in this context, however reviewers have to fill a page with text, and so find something beyond the description of the sound to talk about, while providing a bit more interest to their reviews for those more technically minded.) Sales material and manuals are likely to mention where a manufacturer sees a potential sales advantage in drawing attention to the magnet material, perhaps arguing that their approach using material X brings particular advantages - and I have certainly seen that, though offhand I don’t recall any particular speaker or manufacturer. 

Klyde posted:

Magnet type in my ATC's is HUGE.

I deny it, I don't live in an ATC speaker.    

Klyde posted:

Magnet type in my ATC's is HUGE.

ATC’s sublime 3 inch dome midrange unit weighs something like 7kg in standard version (the high power ‘S’ version 2kg more)  - and that weight is mostly magnet and magnet assembly.  I believe it is ferrite. ATC’s most recent tweeters use neodymium magnets.

As examples of others, Scanspeak drivers, used by many loudspeaker manufacturers, I think are now all neodymium in the tweeters, while most of their bass units ferrite, though some neodymium (I don’t know about mids). Voxativ, making full-range drivers similar to (but said to be much better than) Lowther, are possibly unique in the range of magnets they use in different models, with ferrite, neodymium, AlNiCo, electromagnet and  neodymium combined with electromagnet!