Voice Coil

[RedJacket]

How exactly does a voice coil contribute to the overall efficiency of a loudspeaker driver? In general, the smaller the mass and more temperature resistant it is, the better?

 

[Pyrrho]

No. If you are not designing speakers, forget about voice coils entirely. Just select a speaker based on how it sounds, on its actual performance. Nothing else really matters.

 

[shadyJ]

The mass of a VC isn't going to make much of a difference as far as I understand. I suppose the less weight, the better, but the mass of the VC itself is insignificant compared to the force generated by the interaction of it's field and that of the permanent magnet. Anything a VC can do to stay cool is better, as magnetic strength is lost as the temperature rises, and so efficiency is lost by heat. More VC mass isn't always better- it can give you more force in the excursion, but if you don't have enough permanent magnet to counter it it will create problems in fidelity ie lots of distortion from flux modulation and lots of inductance.

 

[RedJacket]

I see - so from a design perspective, the goal becomes to get as high as you can for the temperature resistivity (leading to less energy being lost as heat)?

 

[shadyJ]

I'm not really sure what you are asking here. There are a lot of different factors and goals in designing a driver, and thermal control is only one.

 

[RedJacket]

Well I'm saying if you were to strictly focus on the voice coil and only the voice coil, what would the biggest optimization be? I guess I'm asking, what properties would make the ideal voice coil?

 

[ski2xblack]

Narrow your question down a bit. Is the goal high sensitivity or wide bandwidth? High power handling, high output? Only knowing such things will inform as to which vc is the appropriate tool for the job, in the context of being a part of a more complex device. There is no ideal one-size-fits-all answer.

 

[RedJacket]

Narrow your question down a bit. Is the goal high sensitivity or wide bandwidth? High power handling, high output? Only knowing such things will inform as to which vc is the appropriate tool for the job, in the context of being a part of a more complex device. There is no ideal one-size-fits-all answer.

Let's say high sensitivity (getting more dB from 1 W at 1 m), and high efficiency (output/input)

 

[ski2xblack]

Let's say high sensitivity (getting more dB from 1 W at 1 m), and high efficiency (output/input)

Ok, take a look at this spec sheet paying close attention to the details of the vc. That is a fairly representative example of a high sensitivity, high power handling mid/woof.

 

[shadyJ]

If you just want more sensitivity, I think you would just put in more coil windings, so more voice coil mass, that way you get more current and more power. But, like I said before, a lot of voice coil give you a high le (inductance), this is bad for linearity and fidelity, but good if you want to win an SPL war. It also gives the permanent magnet a harder time controlling the moving assembly because the field created by the VC actually pushes around the field created by the permanent magnet, this is called flux modulation and is a major cause of distortion.

 

[shadyJ]

Ok, take a look at this spec sheet paying close attention to the details of the vc. That is a fairly representative example of a high sensitivity, high power handling mid/woof.

I really want some mains with some 2226s. Its why I have been salivating over some Pi Fours for some time. MKtheater has said the 2226s have had the best mid bass he has ever heard, and that guy has had his ears pounded by a lot of high performance mid bass drivers.