I think it would be safe to suggest you'd loose close to a 1000rpm with the Menz S prop. These prop's are not the quietest prop's either. However at the reduced rpm it should be close in noise level. You could always install a tuned exhaust system and pick up additional power. You may also want to consider a larger prop at a lower rpm. This will provide comparable thrust at lower rpm and be quieter yet.

What do 22/10 Menz S props sale for in Denmark? And how about the 22/10 APC 's?