Author Options:

How would a stronger magnet impact the performance of a speaker, and what impacts the overall quality of a speaker? Answered

Okay, so I had decided to build a sub-woofer for a speech topic for school, and I was wondering what it was that made speakers, or sub-woofers so loud an efficient. Granted, I know mine is far from great, while being made from ply-wood, duct-tape, and everything, but why is it that professionally manufactured speakers are so loud by them-selves with minimal power? I am using the circuits from my Logitech X-240 system, and the sub-woofer is always way louder than that of my home-made speaekr, with a significantly smaller ceramic magnet, it seems. Is it the geometry of the speaker itself, or what? What do manufacturers do in construction which improves the sound, or quality of speakers, and would using a neodymium magnet be better than using ceramic magnets? Any help is appreciated, and thank you in advance.


The forums are retiring in 2021 and are now closed for new topics and comments.

Best Answer 9 years ago

Three things ;
  1. The magnetic flux path.
  2. The air resonance chamber path.
  3. The electronic drive.
I know an audio driver expert who not only takes into account
the mass action of the speaker coil acceleration but he computes the
difference between the pull and push in his circuit design.

And that is performance ! ! !


Answer 9 years ago

Thank you very much for your help. I think I see what the electronic drive is- it is the amount of wattage, or power put into the voice-coil, or electromagnet, and the air resonance path is the general shape of the cone, making sure the most air is displaced if you will, and please correct me if I am incorrect. But what is the magnetic flux path? So in your diagram would it be best to have a coil which sits around one piece, and is surrounded by another?


Answer 9 years ago

You want to build the strongest magnetic density ( lines of force ) only in
the air gap where the voice coil moves between the metal walls.
The direction of the magnetic flux is most affective at right angles to the
wire with current flow.
Any diverging or branching flux is a wasted magnetic ability
( not helping to move the coil ).
See the purple magnet is passing all its flux through the gray magnetically
permeable metal and then the gap.  Permeable means it accepts magnetic
lines of force ( magnetic flux )  much better then air ( free space ) and
concentrates it to increase coil movement per milliampere of current.

Electrical power is only the top of the pyramid.  Consider a sine wave
and now you want to make the air move as a sine wave but the coil is
harder to pull against the cone, so the + power must be more then then
the - release power to make the air move as a true sinusoidal collumn
of air.  That is electronic design.

Air flow in the speaker cavity is as important as the other two.  Air is
compressible and temperature dependent.  Sound waves can reflect
and bounce undesirably in the wrong speaker enclosure.  There are
books on speaker cavity design.

I hope ths rates as Best answer for you.


Answer 9 years ago

It sure does. Thank you for the in depth help. It is greatly appreciated.