Thought maybe someone could take this one and explain why use a certain coil over another. Which material and what size fit what needs the best. etc.

I'm not ready for this yet

I am maybe 50% done a rather large article on all the different parts and the roles they play in a driver.

I was thinking along the lines of collecting a nice info listing for each major part of a driver, and amplifier. Would help others understand what each piece is doing and why or why not it is there.

Very interested in this topic. Past powerhandleing and increasing l in Bl.

Flat wound vs Round wound (besiges power handleing)

Low AWG windings vs Higher AWG windings.

Different Coil Formers

etc...

Very interested in this topic. Past powerhandleing and increasing l in Bl.

Flat wound vs Round wound (besiges power handleing)

Low AWG windings vs Higher AWG windings.

Different Coil Formers

etc...

I'll just touch briefly on this and will try to cover it in greater detail when I cover all of the parts of a speaker. The most important note is that despite any inherent differences between option A and option B, it is the summation of all parts that provides the final product.

A big part of power handling is the surface area to mass ratio. A flat wound coil has a higher ratio than a round wound coil. However, it also means that the windings are further spread, so BL drops more quickly as the coil moves out of the gap. Yes, fringe BL is higher, but the BL in the gap drops. This is an obvious example of flux modulation and generally leads to a degradation in frequency response.

Higher gauge windings are generally not a good thing. To give a real world example of how little this is used, ask yourself how many times you have seen 2 or 4 layer windings of the voice coil rather than an increase in wire gauge. Increasing the layering of the windings with a small gauge wire will add power handling without really sacrificing BL. A larger gauge wire will increase power handling, but also runs you into the flux modulation issue. Generally speaking, very small gauge wiring in several layers is the best option, hence why it is seen most frequently.

The coil former is an interesting part of the heat dissipation formula. When looking at dissipation of heat, you generally want power to go from the coil, to the former, from the former to the air, and then have this heat collect around the magnets or be pushed through any of the venting opportunities. The challenge is getting it from the former to the air, as air is not the greatest heat conductor. You can choose a highly conductive former to pull a lot of heat from the coil, but then you might damage the former. You can pick a former that isn't very conductive, but then you leave all the heat in the coil with a very small chance of transferring heat into the air. The best solution is often picking a relatively conductive former with a high melting point while using very good heat resistant adhesives.

Just food for thought.

Tungsten Carbide coil formers. That would be rather heavy.

It seems as in the quest for the perfect woofer it is big push pull and no one solution is perfect in every instance.

One piece machined Al former and cone. No adhesive needed at the T-junction, nice big heatsink, expensive as hell to do right. Lots of Al chips on the machine shop floor...

Ok, I hate you all. Now I have this crazy idea running through my head of how to put the whole thing together without any adhesive at all in the area of the former, including the spider attachment...