If you really want to hear every last bit of music on your favorite recordings, headphones have it all over loudspeakers. The reasons for headphones’ sonic superiority are easy to fathom. First and foremost, the vagaries of room acoustics that play havoc with speakers’ sound matter not a nit to headphones. With a headphone squirting sound directly into your ears, there is nothing between you and your music. That sort of intimacy is impossible to achieve with speakers.

Next, where speakers rely on a maze of networks to route their sound through woofers and tweeters, headphones keep the sound whole, delivering everything from the deepest bass to the highest highs over a single driver. That may explain why headphones make even the most familiar music sound fresh.

So are they perfect? Not quite. Headphones cannot deliver the dynamic wallop of tower speakers or the rolling thunder of even a modest subwoofer. When you listen to headphones, the sound is all in your head. It’s a more cerebral, less visceral experience.

OK, there is one other thing: High-end components and surround processors with headphone jacks are exceedingly rare. The headphone amplifiers built into A/V receivers are, for the most part, merely serviceable. To really strut its stuff, a great headphone needs to be partnered with a great headphone amplifier. That’s why a good number of specialist manufacturers are jumping into the fray. One, Montana’s HeadRoom, has been perfecting the art of headphone amplifier design for 13 years. Its product range runs from teensy, battery-powered portable amplifiers (for use with iPods and laptops) to homebound, über-audiophile units. If there is a more passionate advocate for headphonia than HeadRoom’s chief honcho Tyll Hertsens, I have not met him.

HEAR NO EVIL

Hertsens sent three amplifiers for this review. The first is the cute little Desktop model that can be hooked up to a computer’s sound card or a DVD player. The second is another Desktop amp that looks identical to the first, but sports a souped-up "Max Module" internal amplifier circuit board. The third is HeadRoom’s ne plus ultra standard-bearer, the Max Balanced, which tops this field of headphone amplifiers. It is about the size of a high-end surround-sound processor.

The basic Desktop amplifier is no bigger than a thick paperback novel. It scores a massive improvement, however, over the sound available from the headphone jacks found on even the most upscale A/V receivers, which sound harsh and crude by comparison. Stepping up to the Max Module-equipped Desktop produces more nuanced gains in bass power and overall purity of sound. The Max Balanced reveals new riches of palpable details and resolution—you feel the sound as much as hear it. If you want to imagine what it would be like to get really close to Diana Krall or Madonna, the Max Balanced will take you there.

Hertsens and his HeadRoom cronies are continuously developing an ever-wider array of upgrades for all of the amps they manufacture in-house. You can, for example, buy the basic Desktop and add features down the line. The HeadRoom website also offers an enormous selection of other companies’ headphone amplifiers, headphones, and accessories. If it fits on your head and makes sound, there is a good chance it is available at HeadRoom.

FEED YOUR HEAD

Lucky for me, I am auditioning the HeadRoom amplifiers with three world-class headphones: AKG’s brand-spanking-new K 701, Grado’s RS-1, and Sennheiser’s HD 650. Each is, in its own way, remarkable.

The AKG K 701 is a very large, over-the-ear headphone. Its remarkably open sound will be hugely appealing for those of you who use headphones while watching DVDs. I find the K 701 produces a less in-your-head, more speakerlike sound than the Grado or Sennheiser. As big as they are, the K 701’s creamy soft ear pads are so darn comfy it is easy to forget I’m wearing headphones. No wonder the cognoscenti have already crowned the K 701 as the next big thing.Even in the heady group of contenders the Grado RS-1’s luscious sound scores an immediate "wow" response. The handcrafted, real-mahogany headphone belts out a technicolor-rich sound, although I would guess it is less accurate than the AKG and Sennheiser ’phones. Watching the Heartworn Highways documentary DVD starring Guy Clark, Steve Earle, Townes Van Zandt, and Rodney Crowell performing in kitchens and back porches, I feel like I am right there with the musicians. The RS-1’s foam ear pads may not be the most comfortable things, but over the months living with the three headphones, I gravitate to the RS-1 more than the others. I love these headphones.

On the other hand, or head, the Sennheiser HD 650’s modernist styling does not get in the way of comfort—you can wear these headphones for hours on end without ever feeling any clamped-to-the-head feeling. The sound is warm, the bass huge, and the treble range sweet; the HD 650’s low distortion lets me listen at louder volumes than the other headphones without fatigue. To get a fix on HeadRoom’s ultimate amp, the Max Balanced, I am using two HD 650s, one with the standard cable and one specially fitted with cables terminated with a pair of balanced XLR connectors.

The mighty Max Balanced can drive up to four headphones at the same time, so switching between the balanced and standard HD 650 headphones is a snap. The ’phones look identical, but the balanced HD 650’s dynamic kick feels more lifelike, and its stereo imaging is more precisely focused; the overall sense of lucidity is enormous. Keith Richards’ guitar heroics jousting with Mick Jagger’s bluesy athleticism are laid bare as never before. You’re there, and once you get accustomed to balanced headphone sound you won’t want to live without it.

What it all comes down to is this: Speakers capable of delivering even a glimpse of these three headphones’ astonishing clarity live in the stratospheric price ranges. Try a HeadRoom amplifier matched with one of these reference-quality headphones, ears cocked, and listen—really listen.

For even more headphone goodness, check out High End Headphone and Headphone Amp Roundup.

PRICE: HeadRoom Desktop $599, Desktop/Max $1,098, Max Balanced $3,999; AKG K 701 $399; Grado RS-1 $695; Sennheiser HD 650 $499.

CONTACT: HeadRoom, headphone.com, 800.828.8184; AKG, 615.620.3800, akg.com/us; Grado, 718.435.5340, gradolabs.com; Sennheiser, 860.434.9190, sennheiser.com