The airplane is undoubtedly one of the best places to relax with an iPod or to watch a DVD on your PowerBook. The only potential problem is when you want to share them with a companion. Sure this is easily remedied with a simple $2 mini headphone splitter from Radio Shack, but splitting the signal tends to lower the volume and degrade the audio quality.
Enter the Boostaroo Revolution headphone amplifier and splitter, a US$79.95 device that not only boosts and splits the audio signal, but it also images surround sound into 3 channels. Depending on the ohm rating of your headphones, the Boostaroo Revolution will provide up to an 11.5 dB boost with no more than one percent harmonic distortion, according to the company.
Even though it adds to the heft of your iPod slightly, the Revolution is a slick way to share your music with a companion while giving the volume a boost at the same time. The Revolution is powered by two (included) AAA batteries and comes in black or white. Revolution improves upon the original by doing away with the pesky power switch. I would often forget to switch it off only to find the batteries were dead the next time I needed it. The Revolution turns on automatically when you plug in the included stereo-mini cable.
The only disappointing change from the original was that the Revolution dropped from three stereo mini outputs down to two. This is not a huge issue for me because I rarely share my tunes with two other people anyway. The battery door is a bit of a pain to open too, but this is hardly an issue.
My advice is to follow the included instructions: set your iPod on the lowest possible level before connecting your headphones then turn it up gradually from there. The Revolution increases the volume level by up to four times, so it's important to heed their warnings.
Keep in mind that your ears adapt to loud volume very quickly, avoid the temptation to keep turning it up. The rule of thumb is that if you can't hear yourself talking over your music then the volume is too loud. Tinnitus is a very serious injury to your eardrums with dreadful side effects (think suicide). See my previous article "Are iPods Making Fans Deaf?" for more on the issue.