A Meyer 7 is open, but not WIDE open. you've still got a few facings to go before you're wide open. In contrast to a rubber 5, of course it's gonna require more air volume and higher pressure! First, the tip opening on a 5 is probably around .010 closer than on a 7. Second you're dealing with different materials. Metal mouthpieces behave differently than hard rubber. Here's a few good facing charts I have in my favorites. www.saxophone.org/facings.html www.bandandorch.com/catalog/facing.html Hope that helped, Wade