The Hi-X65 headphones use their Hi-X Drive Technology that begins with a 44-mm (1.73-inches) diameter driver, a ring magnet system and a copper-plated aluminum voice coil. The low-mass diaphragm combined with the strongest magnetic field (in its class) coupled with an improved airflow means the driver is capable of high excursions. The ability to move air (for low frequency reproduction) and also fast transient response enables an overall linear frequency response. The inherent qualities of this design means the Hi-X65 provides excellent stereo imaging and low THD--total harmonic distortion measured <0.1% at 1kHz. The company claims THD measures up to a "three-times better" in the bass.

Using Headphones In Music Mixing

Headphones are another way to verify many details while mixing music--they could be your only other way to scrutinize your work to assure its quality. I find that a good set of headphones has become a necessity in my music mixing workflow.

I rely on headphones in the first part of my mix process for the "microscopic inspection" of the recording quality of individual tracks and for hearing extraneous noises and bad edits. By subtracting the acoustics of the room and the sound of your particular monitor speakers, listening on good headphones right on your ears is a more pure experience where flaws seem to be magnified. These are defects that have eluded me (or others) while listening on my main monitors.

Later on sometime during the mix, I use headphones more musically for things like checking the balance of the lead vocal level versus the backing track level. Mixing only on headphones is problematic (for me) with instruments, vocals, percussion and effects equally heard with no sense of foreground or background--the feeling of depth of field. This is why taking a break from the monitors and listening on phones is a necessity in my world.

Near the end of my mix process, it is easy to switch to headphones for checking and refining overall mix compression/limiting settings and any mastering EQ. It is probably more that just listening on another set of speakers (headphone drivers) just points out problems immediately.

Headphone Powering

I use a very typical studio setup system for headphones. It's the same system for both the singers and musicians I'm recording as well as for me listening at the mixing position. I have a 100-watt Hafler stereo power amp that drives a Simon Systems CB-4 headphone box out in the recording room and also a second passive headphone box I built myself located at my listening position.

I've found that using this amp and all-passive headphone boxes will drive any set of headphones of any impedance to full level. Unlike many powered personal headphone boxes, this system doesn't distort at any volume. This is noteworthy when overdubbing guitar players or drummers who demand loud phones when playing their instruments in the studio.

Comparing Headphones

I compared the Hi-X65s to my only other set of open-back headphones that cost about three times as much. I have been relying on them for music mix checks for about a year now and I know what they do. I am able to play both Hi-X65s and my other pair at the same time so I can just quickly swap them on/off my head while listening to the same section of a music mix playing out of Pro Tools HDX.

The Austrian Audio Hi-X65s were more sensitive (25-ohms impedance) and used a lower volume control setting when I first matched loudness; they require about 150mW and are 310g on my head. My other open-backs weighed in at 612g and required 250mW or more of audio power. Stereo imaging was excellent for both but the bass was more present on my other heavier pair. But the Hi-X65 has a flatter, truer and had a more even frequency response than the expensive pair.

I also thought the Hi-X65s were better made than my more expensive and heavier pair with the metal hardware and swivel mechanism more rugged. They adjusted and fit my head perfectly with newly redesigned memory foam ear pads that are replaceable.

The Hi-X65 comes with both 3-meter (9-feet) and 1.2-meter (4-feet) detachable cables with 3.5-mm connectors at both ends. I loved the shorter cable because my custom headphone box is located just to my lower left at the mixing position. You get a 1/8-inch or 3.5 mm to 6.3 mm or 1/4-inch threaded adapter and the foldable design that collapses nicely to fit the plush carrying bag.

My conclusions became clear the more I used the Hi-X65s. While I loved the sound of both pairs, the expensive ones have a hyped and "wonderful sound" but the Hi-X65 headphones were truer and are a better tool for professional mixing and mastering and critical listening.