Coils

 

 

Introduction

There are many different types of coils, designed for a huge range of applications. What makes them so useful in crossover networks is the fact that they conduct AC current better the lower the frequency of the current is. Our comprehensive range enables you to choose exactly the right coil for each application. (You will probably find the section on vacuum impregnation particularly interesting.

 

Coil types and their uses:

 
1.

Air coils (i.e. coils without a ferro-magnetic core) are absolutely distortion-free, which on the face of it makes them ideal for all audio applications. The trouble is, their electrical resistance increases with their inductance. There are two solutions to this problem: One can either use very thick windings (this is why our standard range includes windings with wire up to 3mm in diameter) or coils with cores. Lower cost and smaller size are also common reasons for choosing cored coils.

 
2.

Ferrite core coils can produce high inductance values at low cost. They are frequently used as inexpensive bass coils and in oscillators and equalisers. We don't advise using these coils for mid-range speakers and tweeters, however.

 
3.

Aronit® core coils can also provide high inductance values at low cost. This core material produces performance that is closer to that of air coils than ferrite cores, but the electrical resistance is higher. They are also used as inexpensive bass coils and in oscillators and equalisers. Like ferrite core coils, these coils are not advisable for mid-range speakers and tweeters.

 
4.

Transformer core coils are high-performance bass coils. When you need inductance values of 5.6mH and higher there is really no other choice. They combine extremely high power handling capacity with low electrical resistance and good mechanical mounting facilities, delivering optimum value for money.

 
5.
Zero resistance coils are a special type of transformer core coil. The infinitesimal electrical resistance is made possible by special new manufacturing processes - in the past this kind of performance would have been unthinkable.