better understanding of motor mechanics

trewest

Member
2010-11-16 12:26 am
Hello all. I am working on a design for an actual sub woofer, not an enclosure just so everyone is clear. First and foremost the design I'm looking at is looking to be estimated at 2" one way x max (4" full excursion). However before I get down to exact measurements on anything, there is much info I need to acquire. Keep in mind, I not only want to achieve this but at a high efficiency rate, I don't expect say 96 spl, but I'm going for highest possible. I am not interested in talking about linearity or my purposes for trying to accomplish this or anyone trying to shoot down the idea, only looking for answers to the following questions for now. I apologize if that sounds rude, however on the last forum i posts all I received were negative remarks, not an answer to a single question. Also thank you very much for reading, and all info is greatly appreciated.

1. To reach this extreme excursion, along with the longer voice coil, does the top plate need to be thicker for the magnetic gap, or magnet, or neither?

2. Would flat wire be beneficial in keeping number of coils down for a faster response?

3. Does the magnetic pull need to be addressed compared to a sub woofer with say 2" of full excursion?

4. what would the equivalent neodymium magnetic mass be compared to ferrite?

5. As far as the spider goes, are there currently any out there that can acheive this in a 12" frame? If not, what is the best material, or combination to do this while being strong enough, extremely light weight, and highly flexible?

6. Is differential drive illegal for personal use?

this speaker design has no cost limit so these next questions can be answered with the absolute best in mind these questions are for in case something new is out there that I don't have any education on.

7. Surround material-I understand different for different purposes. However, what is best over all for flex, holding shape, strength and weight, under these conditions, I have an even need for all 4. It has to be efficient, and respond quickly, under the obvious heavy load.

8. cone material- same as above

9. i'm under the impression that a magnesium aluminum alloy frame is probably my best option for rigidity and weight, is this correct?

I might have more questions, not sure for now. I'm mostly an idealist and try to push the boundaries in concepts, i'm an audiophile at heart, and i got an idea so naturally with my hobby to tinker with electronics and mechanics, i had to dive in. Most of my weakness is in the chemistry of components.
And hey, if I get lucky and create something amazing (not likely, lol) I'll make sure to benefit those who benefited me.

Thank you again for your time, consideration, and help.

Tre
 

jbell

Member
2003-04-02 4:34 am
.
this speaker design has no cost limit so these next questions can be answered with the absolute best in mind these questions are for in case something new is out there that I don't have any education on.
Tre


If you are really serious about this, and there really is no cost limit -- contact dan wiggins, commission a custom sub to your specs, and in the process he may be gracious enough to provide the education you are looking for as well.

I personally think if what you are asking for was feasible, it would have already been manufactured.
 

sumit

Member
2005-01-07 10:13 am
delhi
Hi

"To reach this extreme excursion, along with the longer voice coil, does the top plate need to be thicker for the magnetic gap, or magnet, or neither " >> The thickness of the top plate will depend on the coil length. It thickness needs to be calculated after u decide on the TS specs u aim for.

" Would flat wire be beneficial in keeping number of coils down for a faster response " >> Faster response in a subwoofer is not a thing to aim for. But yes flatter wire will give more BL per inch as no air gap will be there.

" Does the magnetic pull need to be addressed compared to a sub woofer with say 2" of full excursion " >> Did not get his part.

" what would the equivalent neodymium magnetic mass be compared to ferrite " This is not a proper question as there are different grades in both. Comparing mass and designing motor is way to much off the track.

" As far as the spider goes, are there currently any out there that can acheive this in a 12" frame? If not, what is the best material, or combination to do this while being strong enough, extremely light weight, and highly flexible " >> May be there are, but buying in low quantities might not be possible. Making your own spider is a diff ball game. No significant knowhow with me abt how to do this.

"Is differential drive illegal for personal use" No its not.

" Surround material " >> Rubber as far as i can think

" cone material " >> Aluminum or Magnesium (if cost no bar )


" i'm under the impression that a magnesium aluminum alloy frame is probably my best option for rigidity and weight, is this correct " Yes, but there is a cost to performance ratio, which won't be very high for these type of baskets. Cast Aluminum is good enough.

best of luck