Initially the sound was a little disappointing. A gap in the upper-mid. Somewhat muffled. Treble was too strident. All in all, the owner of these speakers was dissatisfied with the way they sounded.
The task did not consist in making them over, for it would be easier and far cheaper to produce new speakers than to remake the old ones.
The objective was to improve the sonics to the uttermost at minimum cost, which would be impossible without replacement of the tweeter. The original tweeter was too crooked in measurement and repulsive in sound. We agreed upon installation of Heil’s air motion transformer Mundorf AMT21CM2.1-C
We had to adjust the filter to this tweeter. In the meantime we replaced the standard wiring by Van Den Hul. The speaking casing is made of medium density fiberboard which is quite spongy and thin to the touch. Very austere, I must admit. :) However, all units are carefully assembled. Nothing dangles anywhere.
Eventually, the made-over speakers came out as very balanced, and one will not feel ashamed to switch them on. The AMT’s have a great treble, pure and distortionless. In a perfect world, the mid-bass should have been replaced, but this is probably unnecessary.
Author: Timur Sheykhov