David Looser wrote:
"bcoombes" bcoombes@orangedotnet wrote
Hardly necessary since what was missing was/is clearly audible. As it
happens I still have a Panasonic RQ-X20D cassette player which I've just
dug out of storage and had a listen to to confirm the effect and it's
totally obvious, with the Dolby on some of the 'music' is just plain
MISSING. My original 8k figure was a [mis]remembered estimate, it
actuallity it must be lower than that.
ISTR that Panasonic were established to be one of the manufacturers that
took a while to get the *new* Dolby technology right but the defect was
quite common for a while and was often commented on in reviews of cassette
decks of the time.

What you were hearing was dynamic expansion of the HF. The HF isn't
"missing" exactly, but it has been pushed down in level by up to 10dB,

Yeah that's right, it was only half as loud, maybe my choice of 'sliced' to
describe the effect was a bit OTT but it's the pushed down level wot I meant guv.

depending on it's frequency and on it's original level. The audible effect
is unpleasant IMO,

I quite agree, that's why I remembered it after all this time.

probably subjectively worse than the simple HF roll-off
you took it to be.

And I said something about HF roll-off where exactly?

I long ago gave up using Dolby NR on cassettes; I have a fairly up-market
Aiwa with auto bias and eq adjustment, but even with that I preferred to
sound with Dolby off. A little bit of tape hiss is pretty innocuous, far
less subjectively disturbing than hearing NR systems at work.


Currently I have a Denon 540 which sounds great to my (admittedly f***ed) hearing.

--
Bill Coombes