do Harbeth use?
All Harbeth tweeters are made in Norway by SEAS, the masters of tweeter design. Some models use tweeters using a formed aluminum diaphragm; some use the Excel system with the soft diaphragm. There are advantages and disadvantages to both types: the aluminum dome is highly repeatable, reasonably priced and within its operating band is very linear with a piston-like performance. The softer dome material is a very advanced composite and offers a carefully contoured response right through the audio band with a gentle roll-off at ultrasonic high frequencies, but at a much higher cost. There is nothing inherent in the construction of these units that means that one technology is necessarily superior to another – so much of the perceived characteristics of a tweeter are in fact those of the crossover and integration with the bass/mid unit.