Speaker magnets

Vintage Altec's and JBL's used large magnets for high density magnetic flux. Better control of voice coil movement! This is important for bass drivers which have large cones that need sufficient current from amplifiers to control movement!

@jasonbourne52

I have a pair of 8" Kevlar speakers with magnets that are 2/3 the diameter of the speaker, so presumably they will be better at low frequencies than my pair of 8" vintage Wharfdales that only have around a 2" diameter magnet, or is it more complicated than that? I can’t test as they are just the speakers, no cabinet. The reason for the questions is that I have access to a variety of speakers from 8" down, and thought I would do some reading (well a lot) and have a go at building some of them into a cabinet just for the fun of it, then experiment from there.

OP if you have any information on the drivers, that would help YOU build the correct size enclosure.

Second if you don’t have or can’t find the specs on your drivers, there are tools to help figure out certain thing about drivers. Parts Express has some great software and package deals to fix you right up..

Yes magnets wear out. In your lifetime probably not..
Some flake apart, they can loose their mojo, BUT there are some tricks..
There are ways to revitalize the magnets and even change them if you know what your doing.

Sound crazy, but I’m careful around very strong magnets or just a bunch warehoused in tight quarters. Weird vibes so to speak.. LOL

Regards

@oldhvymec3
I’ll have to go with your investigation suggestion as the speakers have nothing on them besides the Wattage and Ohms.

The 8" Kevlars are mental, if you get them stuck together they are one hell of a job to separate.

I believe the stronger the magnet the more efficient the speaker.
Also of interest is a technology called "Field Coil" speakers.
This technology uses the current from your wall outlet to create the magnetic field eliminating the magnet.
From dagogo.com: 
"A field coil speaker uses two coils; the voice coil and a field coil. Instead of a magnet, DC is applied to the field coil creating a magnetic field. This takes the place of the permanent magnet in creating the fixed magnetic field."