I have an original PSP, it's a great device but the big complaint I have is that it just isn't loud enough. On a bus or airplane you can barely hear it.

Does anyone know if the new 'slim' model allows for more volume?

I don't if I actually noticed any difference. I just use headphones when using it outside of home.

well, that's with the headphones.

well, that's with the headphones.
oh wow.. ok. I think yours may have some issues. I have always found enough volume with headphones. or perhaps your headphones are at issue (unless of course you tried more than one set). I cannot crank mine to the full volume.. it would hurt my ears. And if I use even a lower end set of earbuds, I have to set the volume even lower.

Make sure you don't have AVLS turned on because it limits the maximum sound level. I agree that in a very noisy environment it can be hard to hear through earbuds even at max volume. It also depends on the source, too, and I find that some podcasts' sould levels are lower than others.

My only other suggestion would be to invest in a good quality, noise canceling headset or ear buds. Keep in mind, even something that just covers over your ears is going to be better at blocking out other sounds than a basic earbud.

I think it was confirmed somewhere that there is no difference in sound volume between the 2 models, so I wouldn't take that into consideration for upgrading.