Thank you for your replies.
I have been using the same set up ( mouthpiece, reed and saxophone) for many years, so I decided to buy a box of different reeds.
@LostConn You are right. I hear some difference, but very subtle. Maybe two reeds of the same brand in the same box could be more different.
The strange thing is that I heard many differences while playing those two reeds.
But this is the proof that all differences were about the response and not sound.
I find the Hemke spreads the sound a little more, while the Vandoren is more "compact".
The articolation is a bit easier on the Hemke, but the subtone is better with the Vandoren.
But, overall, I agree that I sound like myself.
I am sure the difference between blue Vandorens and green ones would be greater.
@dexdex Thanks. You wrote "a nice part of buzz and grain in your tone". I don't know, I am not the most unbiased person to define my sound, but I think that I am more on the "dark woody side" rather than on the "buzzy" one, but maybe I misunderstood that word.
@KennyZ Yes, all reeds are Connected...