Generally, audio crossover inductors are manufactured as air coils. There is no solid core material in the centre of an air coil’s winding, just air.
This type of coil has two major disadvantages, these being it usually has a higher than desirable DC resistance, which results in a lack of efficiency. Secondly, the magnetic field is not contained. It spreads into the other air-cored coils in the cross over circuit and feeds undesirable frequencies into these coils.
The audio loudspeaker industry is generally very traditional and doesn’t like change. However, we have a lot of experience in coil winding and therefore saw a solution to the air coil’s lack of efficiency.
We produce crossover coils with a solid core material for use in loudspeaker products. The core materials are iron for the bass loudspeakers and ferrite for mid range and tweeters.
Using these materials gains the following advantages:
- The coils have low resistance, which creates fewer losses and a more efficient loudspeaker.
- The magnetic field is contained, so there is no spread to effect the other coils in the loudspeaker.
- The coils are also smaller, less cumbersome and easier to mount.
The AGW style coils are now in use by several of the top loudspeaker manufacturers and are receiving excellent reviews in the audio press.