wireless speaker sound quality

I've got a macbook air late 2010. Recently i've bought the bose soundlink mobile speaker to listen music around my home. White the speaker sounds good with other device (a pc with window 7 for example) when the device is connected with the Air the sound is perfect for a limited time (about 30 minutes) so it began to be a lot of noise a full of craks. I then stop itunes a then again play and the sound turn perfect. I've found somewhere that i need to set a special terminal command to increase a parameter. I've done it but the issue remain. Is there any solution for this issue? thank you very much for any help