T he best headphones can be tough to buy. Headphones have a basic function: to provide a closed environment for listening to audio. Then the differences are applied \u2014 such as how comfortably they fit and how good they sound being the most two important ones. But being usable as a pair of stereo speakers isn\u2019t part of their normal design. But it is for the Boomphones Phantom.\r\n\r\nThe Phantom comes in a well constructed hard box that contains a soft pouch that\u2019s good for holding the included accessories: a 3-foot mini-jack audio cable, another the same length but with an inline mic (for smartphone use), a mini-jack to headphone adapter and a USB charging cable for the rechargeable battery. Not charging the Phantom won\u2019t stop it from being used as a passive over-the-ears headphones, but without a charge amplifying the inside or outside speakers won\u2019t happen. Nor will there be any LED illumination.\r\n\r\nFirst thing noticed was the padded headset and the plastic-ringed earcups. I was pleased to see that the hinges for each cup had very little \u201cgive\u201d and looked to be solidly designed \u2014 I\u2019ve had 2 pairs of headphones in the past break off at these hinges. Controls consist of an On\/Off switch on the left earcup, with the mini-jack audio input below it, and the micro-USB port on the right earcup.\r\n\r\nI began by playing an episode of Japanese animation, \u201cKnights of Sidonia\u201d and was pleased to hear that the headphones could reproduce the slightly higher treble those speaking Japanese without any distortion. The fit of the headphones was tight, but the padded headset kept them from being painful \u2014 after wearing them for an hour, they weren\u2019t pinching my ears the way some other headsets did (probably due to the 40mm drivers requiring a larger cup).The tight seal of the cups also aided in the solidity of the bass response.\r\n\r\nWith the cups still on, I flipped the amplification switch \u2014 but other than it now illuminating the logo design on the outside of each cup with a solid white ring, the sound I was hearing became only marginally louder (less than 2 out of 10 if I had to put a number to it).\u00a0 I pressed against the right cup logo \u2014 nothing happened \u2014 but when I did the same to the left cup, the illumination became a solid blue\u00a0 ring and the amplification went way way up \u00a0\u00a0 \u00a0\u2014 I\u2019d say it tripled \u2014 because it was now playing through the outside drivers (yes, Boomphones was right in saying you should take them off first before going to the external amp). The quality was similar to that when listening with the cups on, in that there was no distortion or crackling\/hiss during playback. This continued even when I brought the volume up nearly to the 3\/4ths mark on the computer (keeping in mind that there\u2019s no volume control on the Phantom itself). Certainly the volume was loud enough to be hear by anyone within a 10 foot radius, and that included having the TV on and my wife\u2019s iPod dock playing some 40 feet away.\r\n\r\nOne of my favorite tests is Frank Zappa\u2019s instrumental \u201cPeaches en Regalia\u201d due to the layering of horns, constant bass, rotational drum-set and the more excellent guitar playing that anyone has the right to listen to. I wasn\u2019t disappointed with the Phantom in place over my ears one bit, although when I played it externally the sound at high levels did start to feel a bit \u201cthin\u201d \u2014 expected from the amplification and the drivers not being absolutely top drawer. Similar results occurred when I played both symphonic and rock music through iTunes. The Phantom is good enough to be considered moderately \u201caudiophile,\u201d although realistically they are nowhere as sweet as headphones using wood as part of the chassis (plastic resonating differently) or as succinct in detail as my high-end and expensive Sennheisers. But then it doesn\u2019t have external stereo speakers.\r\n\r\nBottom line: The Boomphones Phantom headphones provides good, solid sound when placed over the ears, but the addition of the boombox feature adds to its use in a unique fashion \u2014 especially when used with a smartphone outside where having others \u201clisten in\u201d is desirable. This doubles the value of the $149.99 headphones.