Dave Plowman wrote:

In article ,
Oddjob wrote:

I opened them to find wharfedale super 8 / RS / DD drivers inside. A
friend has told me that they are 1970's with tweeters "built in" to the
woofer!


It's a so called wide range unit. But the standards required of HF
response in those days were rather different - I'd expect it to be perhaps
10dB down at 10kHz - and only that good directly on axis.

Home brewed designs for this sort of speaker would often include a
special amp with a tailored response to help hide the deficiencies, as it
were.


This could be what you are looking for:
http://www.geocities.com/thevenialcritic/w2.jpg

An advert from Practical Electronics, June 1966.

The standards required weren't so different.
It's just that many manufacturers were selling crap.

--
Roger.