There is always a trade off. The magnet needs to match the designers goals. Large magnets do increase efficiency. They also roll off and limit low frequency extension (all other variables being equal).
Speaker magnets
Three questions:
1) The coil in a speaker when fed with current from the amplifier will produce its own magnetic field, presumably 4 layer coils more so. Over time does this ever have any effect on the characteristics of the speaker magnet?
2) Modern speakers have massive magnets compared with most vintage speakers. What advantage do they give a modern speaker over a vintage speaker?
3) Does the magnet in a speaker deteriorate to any noticeable amount just due to age?
1) The coil in a speaker when fed with current from the amplifier will produce its own magnetic field, presumably 4 layer coils more so. Over time does this ever have any effect on the characteristics of the speaker magnet?
2) Modern speakers have massive magnets compared with most vintage speakers. What advantage do they give a modern speaker over a vintage speaker?
3) Does the magnet in a speaker deteriorate to any noticeable amount just due to age?