Amazing how a little thing like quality new pads can make such a difference.
These headphone pads could be viewed as a trivial item but they are a perfect fit.
The headphones are the original white HD414s, were used many times through many changes in my Hi-Fi systems and the sound from the headphones had remained excellent, until I had to find replacement pads. However, all were of poor quality, painful on my ears and the sound was inferior. I even bought several pairs of new (better looking?) headphones but, even though reviews were good, the sound quality was reduced.
The new pads have made a significant improvement in the sound quality, are comfortable and I can now listen in peace.