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Old 18th October 2013, 03:38 AM   #1
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Default Driver design: efficiency, mms, suspension

General questions to make a theoretical driver:

For argument sake, lets take any 4" paper cone driver.

1. We take this driver and start to soften its spider to the point where it is extremely soft. What happens to driver's parameters?
Fs goes down but what goes up? Vas? what happens to efficiency?

2. Now we reduce the weight of cone to reduce mms. Is it correct to assume that Fs will start to go back up? Efficiency? other parameters changes?

3. Now we reduce the weight of voice coil (wire thickness, length). Le goes down? What other changes?

thank you,
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Old 18th October 2013, 10:22 AM   #2
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Join Date: Mar 2005
Location: UK
If you have an interest in the design of moving coil drivers then I suggest you get hold of a few books treating the subject, which will give you a detailed background in the basics of their design.

These three will get you (more than) started:

Colloms, M. High Performance Loudspeakers (currently in 6th edn.)
Dickason, V. The Loudspeaker Design Cookbook (currently in 7th edn).
Eargle, J. Loudspeaker Handbook (2nd edn).
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Old 18th October 2013, 06:46 PM   #3
chrisb is offline chrisb  Canada
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of course a "theoretical" driver could be designed using materials and operating principles that defy all known and as of yet undiscovered laws of physics

- and before you laff, the audio tweaker's world already abounds with such products
"Perception is a highly non-linear function" - Earl Geddes
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Old 18th October 2013, 07:12 PM   #4
Frank40 is offline Frank40  Denmark
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Hey Herman

This is what happens if only on of the parameters are chanced at the time.

1. Vas will increase, the efficiency will be the same unless the spider gets lighter. Qm will increase.

2. The Fs increase, efficiency wil increase. Qm will decrease.

3. Efficiency will increase (due to lower weight), higher Qe. Note that less winding means lower BL (decreases efficiency).

Are you planing to design your own unit? Please tell

Take care
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Old 19th October 2013, 08:24 AM   #5
DrBoar is offline DrBoar  Sweden
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There is no free lunch only different compromises to make, and hopefully understand the system well enough to pick the right set of compromises for what you wish to archive.

The suspension is there to center the voice coil in the gap so idealy it should have great radial stability to center the vc but no stiffness at all along the axis of motion. But of course there is a link between these two features.
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Old 20th October 2013, 07:17 PM   #6
el`Ol is offline el`Ol  Germany
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