Manual says 97 and they say it is 112...
I don't even know which is right now
There's nothing to be confused ... the tech guy who answred stand is wrong , i don't know if it's even a tech , peraphs just a low level comercial / secretarial departement , when he don't have the skill dispatch to real tech guys . he just look at sennheiser usa specs and brochure and that's all .
AGAIN let's look at innerfidelity numbers .
If it was 112dB/V or 107dB/mW , to achieve 90 dB we should have 0.08v and 0.02mW .
But innerfidelity get : 0.23v and 0.17mW . Differences are HUGES it can't be driveres variations etc
If we took HD650 numbers it match with innerfidelity numbers . 103 dB/V and 98 dB/mW
To get 90 dB in theory => 0.224v and 0.16mw
In practice with innerfidelity numbers => 0.205v and 0.13mW (drivers variations etc ) . The difference is not so huge .
So I replied to them with the following question. This should, hopefully, force them to give one answer.
Then which product sheet is correct?
Just thinking of the relative sensitivity compared to my HE-500's and other headphones on the same amp, I'd be inclined to believe the less sensitive spec. But them again, I'm not an SPL meter.
the english manual .
The french brochure .
The english and german manual say : 97 dB/mW same as french brochure .
Perhaps the person at Sennheiser that wrote the product sheet posted on the USA site was asleep at the wheel and the support technician that answered my email was sitting next to that person.