Dave Plowman (News) wrote:


These are distorting. The bass units appear fine, and I've had the HF

1300s apart to look at the coils - again ok. Any ideas about checking the

STC units? The distortion is most noticeable on some types of speech -

mainly female. If I roll the treble off it all but disappears.



** Examine carefully the underside of the crossover PCBs first, wires from the small crossover inductor for the Coles/STC 4001 may have become unsoldered at one end.

This would change the slope of the HP filter from 18dB/oct to only 6 and could produce distorted sibilance.


FYI: many years ago, I reworked a pair of B&W DM1s for a friend - the two oval EMI woofers had begun poling badly so I replaced them with KEF B200s, mounted on a new baffle board. The owner was very happy with the result and used them with a Goodmans 120 tuner amp.

DM1s have the same HF1300 and STC4001 tweeter arrangement and a similar crossover. See pic:

http://www.hificlub.co.kr/upn/1004/b...0/IMG_9003.JPG



..... Phil