The HF1300 tweeter can do some wonderful things in certain circumstances (the numerous BBC derivatives for example), but the Ditton 15 isn't the best speaker to hear it (it uses a more basic magnet assembly I think). I found the top end a bit "pinched" and "peaky" and ultimate extension is limited to a peak at around 14KHz followed by a swift roll-off, hence the "BBC" designs adding a super-tweeter by Coles, KEF or Celestion.
I think the Ditton 15 was of its time - the early seventies. By 1974 when I started in a serious HiFi shop, it was starting to sound very coloured by comparison with the likes of KEF Chorales and Monitor Audio MA7's for example.
I can't go on and I can't go back, I don't feel so matter of fact,
I tried and tried to make good sense, What's the good to try it all again?