I occasionally receive e-mails from readers worried about loud music's potential for damaging their hearing. The concerns are very real; a recent study found that one in five adolescents now. How loud is too loud? If you regularly experience "ringing" in the ears, see your doctor!
Cranking the volume of your headphones up loud will (eventually) deafen you, unless you're using the new dB Logic headphones ($40). They use SPL2 technology to automatically limit the maximum volume to a safe level. Sure, there have been other headphones that promised to do the same thing with active (battery-powered) circuitry, but the dB Logic headphones don't use batteries. Simply plug in the headphones and enjoy the music; there are no switches or adjustments to fuss with. They just work.
Up to a moderate volume the dB Logics works like any other headphones, but if you attempt to blast your ears, they will gently lower the volume to a safe level (85 dB). The design is "smart" enough to let momentary loud sounds pass, but sustained high volume sound is hushed, so you can listen longer, without suffering ear fatigue.
I first found the dB Logic headphones only moderately comfortable; the ear pad pressure was a bit too tight for me. The earpads didn't sit flat, and they put more pressure against the tops of my ears than the bottoms. The faux leather ear pads made my ears feel hot over extended listening sessions. Bending the metal headband to reduce earpad pressure made for a much more comfortable fit.
The headphones are available in a variety of trendy colors: Barracuda Blue, Big Apple Red, Green Shamrock, Pink Valentine, Quick Silver, and Orange Tiger. The padded ear cushions are nicely done, and the skinny cable is 1.2 meters long.
The closed-back headphone's isolation from external sound is fairly good, and like most closed back designs, bass is deep and fairly potent. Sam Phillips' "Don't Do Anything" album has an interesting blend of acoustic sweetness and hard-edged electric, and the headphones reproduced both with equal skill. Sound quality is above average for headphones in this price range.
I listened to the on-ear dB Logic 'phones, but the company also offers an in-ear model, with the same SPL2 safe volume technology. Sometime later this month the company, which is based in Indianapolis, will offer SPL2 technology in an inline module that will work with any stock earbud (not in-ear headphones) to automatically maintain safe volume. Pricing for that unit has not yet been released.