Magnet Question

[1ndatrunk 10+ year member]

Does the size of a subs motor effect the power handling or loudness of the sub? What exactly is the purpose of having larger motors on some subs as opposed to average sized ones on others? I have a mag from an 18 and wanted to know if it would be worth it to make it into a 12", and what the pos and neg of doing this would be

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[46panel 10+ year member]

I've wondered the same thing...like an 18" Fi Bl is around 37 pounds and a 15" Rockfod T2 is like 60 something according to their site, the T2 has a triple stacked motor where the Bl has a double, yet I hear the Bl gets louder. Hopefully someone can help you out.

 

[bunkerking09 10+ year member]

I've wondered the same thing...like an 18" Fi Bl is around 37 pounds and a 15" Rockfod T2 is like 60 something according to their site, the T2 has a triple stacked motor where the Bl has a double, yet I hear the Bl gets louder. Hopefully someone can help you out.

There is one major thing your not taking into account.

Magnet weight. Th RF sub may weight a lot more, but is it the magnet? Or the basket? Generally, yes the larger the motor the louder / more power it can take. Also just because the RF is "triple stacked" doesn't mean the motor is bigger. I could put 3 20 oz magnets together and say mine are triple stacked.

 

[helotaxi 5,000+ posts]

It depends. The magnet has practically no bearing on the power handling. That is dictated by the coil. The sole purpose of the magnet is to give the coil something to work against. The magnet size only needs to be adequate to saturate the motor. Bigger than that and all the extra magnetic potential is wasted. What is needed in the way of actual magnet material is dictated by the design of the steel portion of the motor and how it is meant to interact with the coil.

Magnet size and motor efficiency are a factor in the motor force of the sub. Motor force is part of what allows a sub to get loud.

 

[Corey69 10+ year member]

Does the size of a subs motor effect the power handling or loudness of the sub? What exactly is the purpose of having larger motors on some subs as opposed to average sized ones on others? I have a mag from an 18 and wanted to know if it would be worth it to make it into a 12", and what the pos and neg of doing this would be

pos

smaller

neg

less cone area

 

[1ndatrunk 10+ year member]

Makes since, I think.

 

[terra 5,000+ posts]

Magnet size will have almost zero bearing on power handling. its a combination of the suspension, coil and total design.

 

[audioholic 5,000+ posts]

Magnet size will have almost zero bearing on power handling. its a combination of the suspension, coil and total design.

The suspension will only affect mechanical power handling, which I assume is being ignored in this discussion, as its dictated easily as much by the enclosure as it is by the speaker itself.
A speaker works via electromagnetism. The magnet(s) portion of the motor is simply the fixed portion of the electromagnet. The coil being polarized by current flow is the moving portion of the electromagnet. Polarize the coil to repell one way or the other against the fixed magnets in the motor, and you have cone excursion. But as said above, its the coil size/shape/material/design/cooling/etc that affects how much current can pass through this electromagnet, not the size of the fixed magnets.

 

[1ndatrunk 10+ year member]

If I recone with btl parts does that mean I will have the same power handling and response as an original btl or will it be completely diff because of the motor

 

[bhsdriller 10+ year member]

If I recone with btl parts does that mean I will have the same power handling and response as an original btl or will it be completely diff because of the motor

what kind of motor is it. I don't think you can get btl softparts for any motor

 

[1ndatrunk 10+ year member]

Its an older Treo csx motor off an 18. Will that work or will I have to go another route?

It has a 3in coil also if that helps

 

[Haunz 10+ year member]

It's probably worth noting that a motor assembly does act as a giant heat sink for a voice coil... //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[helotaxi 5,000+ posts]

The motor assembly will sink some heat from the coil but the former and the air flow within the magnetic gap make a much bigger difference than motor size in cooling because the transfer of heat from the coil to the motor is horrible inefficient since they don't even touch. The magnet itself is a terrible heatsink material anyway, so the size of the actual magnet has no bearing on cooling.

 

[jdawg 5,000+ posts]

ALOT of manufacturers use a much larger magnet than actaully needed so it looks like a beast to the eye.

 

[DJ Nitrous 427 10+ year member]

Not all 3" coils are the same, slightly different inner diameters, different lengths, differnt thicknesses.