speaker magnet question

[dadydolas 10+ year member]

i was looking at the dd 3518 and the aq hdc3 15 and i noticed that the dd is rated at 1200 rms and the aq is at 1000. but the magnet on the aq is 340 oz. and the dd is 200 oz., i know these speakers are underrated, but what kind of performance differences, if any, would i see due to the different size magnents?

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[ballstothewall 10+ year member]

Looking at magnet sizes is pointless. You can't tell anything from it.

 

[dadydolas 10+ year member]

i know alot of cheap companies put big magnets for looks. but i don't think this is the case with aq, so i why so much bigger. is it made to be given more power and control the speaker more efficiently. i am just trying to learn a little more about how subwoofers work.

thanks

 

[dadydolas 10+ year member]

bump

 

[audioholic 5,000+ posts]

The magnet(s) are only one portion of the motor assembly, thus they are only one portion of th over-all performance of the driver. Imagine the magnet like your engine's pistons... you could say my buddy's car has bigger pistons, why is my car faster? Because there are more variables to account for.

Magnet force is only one portion of the motor's function, and the size of the magnets is only one aspect of deriving magnet force (Bl). Just as piston size is only one aspect of the engine's displacement and power potential.

Power handling comes in two forms, mechanical and thermal. Usually advertised manufacturer specs are thermal limits, because mechanical limits are so greatly determined by the enclosure size/type. Mechanical limits are how far the cone can move before things start going wrong... suspension bottoming out, voice coil bumping the backplate, etc. The larger the box, the easier this is to do.

So since the manufacturer has no way of knowing exactly which box you will be putting their speaker in, they give you the thermal limits of the speaker, which does not vary install to install as much as mechanical limits. This is how much current can pass through the coil before it melts.

Thermal power handling is generally handled not by simple magnet size, but by the size of the voice coil, shape of it, the material used in it, the speaker's cooling abilities on the coil, etc. One speaker could have huge magnets, and a tiny voice coil with poor cooling... while another sub could have much smaller magnets, but a larger coil and better cooling capabilities. And, the larger magnet does not even mean a 'stronger' motor. Magnet size, unless compared in very specific and understood terms, is all but meaningless to the average consumer. For you.... just ignore it.

 

[ItalynStylion 10+ year member]

^great post....I would rep you if we had a rep system on this forum