I tend to agree that headphones will make the biggest difference. However, for use in loud environments, like on an airplane, I have found the X100e to have the most powerful signal of all the machines I've flown with. I used an Echo Indigo PC Card with all prior laptops because even at full volume, I couldn't hear music or movies with an X22, X23, X24, X40, X41, X60s. However, with the X100e, everything is audible at about 50% volume level.
For excellent qualtiy, an add-on adapter, like the Echo Indigo, is your best bet.
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