@BEC Thanks Bob for the help on the ti diaphragms of my kg4. Finally i took off the cotton and i got back your TI diagphrams on the modified kg4. It seems the titanium was not damaged yet. It took about 100 hours to settle down, with the sound passing slowly from a little harsh to very smooth, transparent and clear. The definition and the air around instruments is awesome. They became my reference speakers and now they are in the main system. They are sounding so well i bought them a pair of SET made by an artisan in Italy with 2a3 tubes and Tamura transformers. Now their sound is simply fantastic. Best set up i had in 45 years! Well, 300$ speakers driven by 40.000$ tube equipment and i dont regret any speaker i ever had. KG4 are incredible, and so much undervalued and misunderstood! A real surprise. I was so excited I bought a La Scala from 1973. Well, they will need work. Even recapped they don’t sound not even close to the kg4. I will need your advice again this summer to make them sing.