More volume from headphones on plane ...

[twvette]

I upgraded to a good set of Philips headphones that sound great from bass to hi's under normal use. However, when travelling on plane I have to run the Sansa at almost highest volume setting and if I use them on my laptop PC I cannot hear hardly any audio when playing a DVD etc. I think this is is kinda an IBM laptop thing (I am sure all settings are turned all the way up) as it is certainly much worse on my laptop than Sansa, but how do I get more volume ??? Does anyone make a inline amp or do the noise cancelling (also battery powered) also amplify the sound ??? Any input on headphone make/model to get me significantly more volume would be appreciated.