Imagine a set of compact headphones that produce Dolby 5.1 surround sound with great fidelity, portability, and ability to be used anywhere.

That was no doubt the vision of the folks at Sunnytech, who've produced the Mentor 5.1 headphones.

Though they've made strides on the central problem - how do you recreate the sonic sensations produced by a six-speaker array with two cups, each the size of a fist? - they haven't yet made a product that I'm willing to spend $139 on.

The sound is impressive under the right circumstances - when you're sitting at your computer with a DVD such as "The Animatrix," for example - but I don't want to watch DVDs on my computer. My 38-inch TV has a better screen, and I'd rather use my remote from my recliner than a mouse at my desk. So why not just plug the headphones into my main sound setup and get a long extension cord? Because the headphones have a USB connector, which works with Macs and PCs, but won't hook into a receiver.

Another drawback: These headphones are neither light nor small, and they have a controller box partway down the wire that adds to their weight. It's impressive what the controller can do, but I still wouldn't want to lug the things around.

If you have to have your surround sound but live within thin walls or worry about waking the baby, these phones might be for you. But at this price, and this weight, they're not for me just yet.