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S-Logic Enables Audio Depth, Clarity

Ultrasone's Proline 750 Surround Sound Headphones Trick Ear Into Thinking It's Wired for 3-D Sound

Ultrasone’s Proline 750 Surround Sound Headphones Trick Ear Into Thinking It’s Wired for 3-D Sound

Just when you thought headphone development had camped on a predictable technical plateau, along comes German manufacturer Ultrasone with its S-Logic Natural Surround Sound headphones. While it isn’t truly surround, it’s as close as you’ll get without having a hole in the back of your head.
Product CapsuleTHUMBS UP:

Unique design creates realistic “surround” effect

Requires less volume, so creates less fatigue

Easy to change ear pads (spare set included)

Coiled and straight cables included


1/4-inch to 1/8-inch plug-on adaptor

Pricey for daily broadcast needs

PRICE: $399

CONTACT: Ultrasone of America in Tennessee at (615) 599-4719 or
The Ultrasone Proline 750 is part of the S-Logic line. Its uniqueness comes from its offbeat – and off-center – earphone driver alignment. Where headphones traditionally place the drivers directly opposite the ear opening, the S-Logic design moves them down and a bit to the side.

What’s the point? According to company literature, the headphones use each individual’s outer ear anatomy to fool the brain into thinking it’s wired up to 3-D sound.

Sound perception

From the manual: “The sound first strikes the pinna and gets changed through the individual anatomy. This also works as a filter for different directions, which intensifies or weakens the frequency range. This frequency range will be processed by the human brain and then produces spatial listening.”

In other words, the listener’s hearing isn’t changed, only the perception of sounds.

To see how it works, just remove an ear pad. They’re designed for quick change, with just a small counter-clockwise turn needed to snap one off. The Proline 750 package includes a set of spares.

Once an ear pad is removed, the secret is revealed. Near the bottom of the cup, concentric circles of different sizes surmount the main driver. Five larger screened ports arc across the top of the cup. This alignment is critical, apparently, because the manual warns users to wear the headphone band directly across the top of the head to achieve the proper S-Logic effect.

Does it work? Yes – spectacularly – although it depends on your source audio. A potent test is provided by the included demonstration CD. It includes a broad spectrum of audio that gives the Proline 750 a workout.

In among the jazz and classical recordings I found a liturgical piece that was reproduced with such clarity I thought I heard vinyl pops. This is an issue with super-accurate monitors of any kind; any imperfection in the audio will be painfully obvious. A rumbling “Also Sprach Zarathustra” (also known as the theme to “2001: A Space Odyssey”) brought out a strong, undistorted bass.

Included was a piece played on bells and perhaps water glasses in which the sound seems to float and the highs are astonishingly true. You even hear the performer breathing.

In my test, the cut that really sold the S-Logic concept was one that simply involved flowing water. Yes, it’s one of the oldest stereo effects going but the Proline 750 reproduced it so well that it seemed as though water was sloshing in all directions, like a tidal pool.

Clean and clear

For RW readers, of course, the question is: how does the S-Logic surround technology work day-to-day in a busy studio?

I do voice work for clients all over the country and used the Proline 750 every day for a week on every job. That included growling station sweepers, bombastic car dealer spots and punchy voiceovers for a TV sports network. The Proline 750 handled everything with great clarity and cleanness, which should be true of any headphone but isn’t. I really enjoyed working over music and effects because everything sounded so clean.

As a bonus, I found I was running the headphone amp at a lower level than with some other “cans,” so there was less fatigue during long sessions. The company credits its 40 mm titanium-plated drivers and says the S-Logic Surround Sound technology “allows listeners to perceive the same volume at significantly lower sound pressure (3-4 dB), up to 40 percent less compared to (some other) headphones.”

In addition to spare ear pads, Ultrasone provides two sets of cables – one coiled, one straight – that plug into the left earphone cup by means of a 1/8-inch male plug. This is not the Achilles’ heel it would seem to be because that plug is threaded, so you plug it in then screw it tight. Cable strain is always an issue but it will be hard to yank out or short a cord on these headphones.

Oddly, with that much care taken at one end of the cable, there’s a concern at the other. A standard 1/4-inch to 1/8-inch plug-on adaptor is provided. While all connectors are gold plated, that is never a secure way to adapt plug sizes. Why not include a screw-threaded adaptor, like the plug at the other end of the cable? This has been a standard accessory for other headphones, notably Sony, for many years.

The Proline 750’s comprehensive accessory set, with spare ear pads and two types of cable, is welcome. The headphones also fold up for carrying in an included bag.

Ultrasone’s S-Logic Surround Sound provides a sensation of sound depth and separation unmatched in my experience with headphones. Whether you want or need this depth of sound quality – or can tolerate hearing things you never imagined were buried in your audio – is your choice. Keep in mind, too, that this is a high-end audio device and is priced accordingly at $399 list.

S-Logic is exciting technology. In a broadcast climate that is increasingly exploring the possibilities of surround from an RF standpoint, headphones like the Proline 750 could be the monitoring choices of the future.