HI all, before I start asking questions I want to remind you that I'm still green and I'm not a professional trumpeter at all although I've been playing it for around 8 years. So I need your help. I want to take it seriously now At the moment I'm doing long notes, starting from C and doing the same note over and over again, until I'm satisfied with the tone and sound of the note. Now my sister's boyfriend, who is quite a good trumpeter, gave me the Denis Wick 4E mouthpiece to try, since I was not happy with the previous mouthpiece (Vincent Bach 7E). Well, I've been playing with it for some weeks now, and to say the truth I find it better than the VB7E. But, now air is going out from the sides of the mouthpiece as well, so I can here that air sound coming from the side. I hope you understood what I'm trying to say. What could be the problem. Maybe I need to study more so my lips will get used to it or anything else? Mind that my lips are quite big. Not sure if it's a downside or not. But sometimes I notice when I'm playing the mouthpiece (the trumpet) will slide downwards usually. So I have to stop for a second and move it upwards again. Well, this was with the other mouthpiece actually, not too much with this one. I was thinking of trying one with a wider cup diameter. Does it make sense at all, since my lips are not the smallest ? I came to this whilst viewing this comparison chart... http://www.deniswick.com/dw_leaflet_06.pdf I know most of you are going to suggest finding a professional trumpeter as a teacher. Of course that would be nice, but at the moment I'm so so so busy that I can't add anything more in my lifestyle. For sure I will once I settle. But thaat's personal now, it's not going to make any difference for you Until it's the time, I will follow pros like you on this forum Well, thanks in advance until I get an answer .... continues long notes Daniel.