With this tape we can see an excellent response from 20 to almost 15kHz, but from that point there's a falloff of about 3-4 dB. This is probably caused by a bad calibration, showing that the assisted calibration system (which uses two tones auto-generated) doesn't always perform as it should.
Yes, it's not a big problem -at least to me-
as I cannot hear anything above 15kHz, but the real time analyzer shows that there is. This is why a RTA combined with pink noise can easily outperform a 2-tones internal calibration system. I could get a better calibration with pink noise, although it's not as easy or convenient.
Letting this problem apart, the response is quite plain, with just a small lift of the mid range from 500 Hz and up to 5-10 kHz of about 1 dB that still makes it perform great.
Let's move into a real winner: a SONY UX-S from the '92-94, one of the best chrome tapes and one of the best performance/values I've ever seen.
As it can be seen, the performance is close to perfect: almost like a straight line from left to right. Only a very slight rise of the high frequencies at 15 kHz and above is seen, but it's under 1 dB, so it's almost unnoticeable.
It's not easy to find a tape that performs that way, even into the high end ones.
Not only the performance is almost perfect at 10 dB, but also at -20 and even at 0dB, which talks a lot (good) about this tape. I must remember, though, that this tape is made from SONY and the deck too, so it's not hard to imagine that SONY engineers developed that tape with the best of their decks in mind, like this K909ES.
Now let's move on to a simple but still good SONY HF from the '90:
That's indeed impressive what this simple and cheap tape can achieve! Wow. It's linearity is better than a superb MetalXR, with a 1/5 of it's cost! Yes, the whole performance is not as good, but the linearity is remarcably good for such a cheap tape.
An excellent tape for doing recordings to listen with your walkman in the street or in not-so-quiet environment.
What a good job did SONY engineers do, indeed. Well, yes, there are also other things to score other than the linearity but this is indeed an excellent start point. The background noise in type I tapes is quite high compared to good chrome tapes, but with a good Dolby (like the 'S') the resulting performance can be truly good, especially if the music doesn't contain a lot of high frequencies.