Ultrasone PROline 750 Headphones Review

PROline 750 Overview and Build Quality

It was high time Audioholics picked up the ball and did some headphone reviews, so we contacted a few manufacturers and selected some products based on price and specifications that we thought would represent a more mainstream target for price-to-performance. Ultrasone's $399 PROline 750 headphones seemed to fit the bill and we quickly arranged for a pair to be sent to us.

Headphone Design & Build Quality

The Ultrasone PROline 750 headphones are a closed-back design. Closed headphones are modeled so that the music doesn't escape the headphone as with an open design, and is instead pumped directly into your ears. One advantage is that they also provide a level of noise attenuation from the outside ambience. In the case of the PROline 750's they reduce ambient noise enough to help isolate sound in loud environments (around 10dB or so). This is accomplished through having a tight seal around the entire ear with each headphone pad. The caliper pressure used was not uncomfortable, but I have to say, the experience of using closed headphones in general isn't for everyone and can be a bit disconcerting for the first few times. The velvet ear pads were easily removed with a simply twist and the inclusion of an extra set was a nice touch.

Taking a close look at the headphones with the ear pads removed reveals an off-center placement of the driver. This positioning is what, in part, makes up the S-Logic Natural Surround Sound system. The idea is that the sound will arrive at your ears in a method more consistent with external sound which interacts more with your ear's natural makeup. This is not a surround sound DSP system, mind you, but a method by which Ultrasone attempts to eliminate the "in your head" sound so often reproduced by headphones. The PROline 750s also have something called ULE technology which is comprised of MU Metal shielding in order to reduce magnetic field radiation caused when electrical signals are converted into acoustical energy. ULE is supposed to reduce 98% of that radiation compared to other headphones - something that professionals who are concerned with that sort of thing may wish to factor into their purchase.

The comfortable headband pad protects your head, while the nice velvet ear pads do well to make listening feel comfortable - even for extended listening sessions (though I never went over 2 hours at a time). The majority of the unit was made out of plastic, but it appeared durable and was nicely molded, so I really didn't see this as an issue. I would also not like to carry more metal on my head than necessary as weight lowers the comfort factor considerably - especially over time. The inclusion of a straight headphone cable as well as a coiled one (not to mention making them removable) was a nice touch and should be appreciated by those with special distance needs. Also, I suppose, those audiophiles who substitute the standard cables with cryogenically treated products coated with kosher chicken fat would be equally appreciative.

Packaging

The Ultrasone PROline 750 headphones arrived in a box which opened up in three directions from the center and contained the headphones, extra ear pads, the two headphone cables, a 1/4" TRS to 1/8" stereo mini adapter, bag, demo CD, and instruction manual. The packaging was nice (like something Apple Computer would come up with) and lent a feeling that they took great care in making sure that the ownership experience would be a pleasant one.

PROline 750 Listening Evaluation and Conclusion

I listened to a variety of music using the Ultrasone headphones and utilized a reference set of earphones we keep around that have a very flat frequency response in the 50Hz-16kHz range. The reference set is simply that - a reference - and not meant to be used in direct comparison within the context of a review. One thing I noticed early on in the review process was a tendency for the tonality of the headphones to change depending upon where they sat on the ears. For example, pushing the headphones farther forward yielded better upper frequency detail and clarity as opposed to allowing them to sit farther back towards my outer ear rim. Since everyone's head and outer ears are shaped differently, I am guessing that the effect may be different for each listener.

DVD-Audio: Lowen & Navarro Carry On Together (AIX 83044)
This track is a high resolution two-channel mix by Mark Waldrep of AIX Records. The key to these recordings is that there is NO added compression and NO EQ. The mics are carefully placed in the room and the room's natural reverb is captured to add depth to the mix. Having spent some time in recording studios, I can attest that this is no small feat. AIX Records produces some of the most authentic, high quality mixes I have ever heard. This track in particular came through the PROline 750s with full, enveloping sound. They were slightly muddied from what I am used to (as well as our reference earphones) making them a bit less intimate than they could have been. As I listened I was missing some of the vocal detail and the percussive attack of the acoustic guitars.

DVD-Audio: The Brand New Opry Another Time (AIX 80043)
The soundstage on "Lowlands" was slightly wider than I perceived with both my reference loudspeaker system and reference earphones. It features a folksy, harmonic presentation with acoustic bass, guitars, banjo and violin. Again, some of the upper midrange frequencies felt a bit lacking, but the bass was sufficiently present, though not in an overblown or dominating fashion as is the tendency with many headphones. By this track my ears were adjusting to the sound of the Ultrasone headphones and I felt that, while the PROline 750s were not necessarily the most accurate headphones I've heard, they were definitely pleasing to the ear.

CD: Little River Band - Greatest Hits
Little River Band's "Cool Change" had pristine lead vocals and a bright piano which marked the opening verse and chorus. The detailed guitar in the left channel was evident and lifelike; and when the drums came in during verse two, you understood that these headphones are a pleasure to listen to. Backing vocals were full and the strings in this track were one place in particular that seemed to maximize the use of Ultrasone's S-Logic system.

Two-Channel Orchestral: Star Wars Episode IV: A New Hope Soundtrack 
I decided to continue my listening tests with some two-channel orchestral music from none other than John Williams. I wanted to hear a full-bodied score and a source that was not quite as clean as newer material. In fact, on this disc you can hear, just above the audible noise floor, clear detailed movement of the players as they shifted in anticipation during quiet passages. I queued up track 3 "Imperial Attack" and began to get a feel of the potential bass response and the mix - which quickly led to full-on strings and percussion. Here the Ultrasone imaged much better - or more accurately, I should say. This was perhaps due to the different micing style associated with orchestral recordings. The sound was both full and robust and I could easily get lost within the score with these headphones.

Editor's Note: Dolby Headphone
Engaging Dolby Headphone in Pro Logic II: Music mode with the PROline 750s gave the headphones a chance to really show off. With Dolby Headphone enabled, the Ultrasone's took on new life and gave a very deep, very convincing soundstage. With this in mind, I moved on to movie playback to see how the PROline 750s would function in home theater use.

DVD: Finding Nemo 
Chapter 25 of Finding Nemo was a great place to examine in more detail the low frequency extension of the PROline 750s as well as the Dolby Headphone surround performance. When Darla taps on the glass in the opening seconds, there is a full-bass thump that does a great job of substituting for a subwoofer in its apparent depth. After this, Nigel the Pelican flies around the room and the ability of these headphones to track his movements was uncanny. It simply went on and on from there with one scene after another capturing realistic spatial imaging and positioning unlike anything I've heard in some time in a pair of headphones.

DVD: The Last Samurai 
Convinced that the PROline 750s were competent for those looking to reproduce movie soundtracks using headphones and Dolby Headphone DSP, I popped in The Last Samurai and sat back for the final battle sequences against the Japanese army. This scene was simply awesome in its richness of scope and compelling musical score 舑 all of which sailed through the Ultrasone headphones in a very pleasing and convincing manner. The dramatic battlefield sounds were compelling while dialogue was crisp and articulate. I was very pleased with the overall performance of the 750s for movies to say the least.

Portable MP3 Players 
I connected the PROline 750s to a Creative Zen Touch 20GB MP3 player to see how it would fare with lower level output voltage. What I found was that the stated 40-ohm impedance of these headphones was plenty to drive them to very loud levels using the standard 1/8 舡 mini plugs found on these players. While some may feel the need for more volume, I can assure you that, at least on this player, the loudest setting would have OSHA knocking at your door before you ran out of volume.

Conclusion and Recommendation

Ultrasone has a great pair of headphones with the PROline 750s. They are pleasing to listen to and seem to wear comfortably for at least reasonable amounts of listening periods. If you are looking for the most accurate headphones you can buy with your hard earned money these are not them. If, however, you want relatively accurate headphones with pleasing, but not overbearing, bass 舑 then these may be for you. At $399 retail, and not much in the way of street pricing discounts, we're thinking this may be a difficult choice for some. In any case they are definitely worth a listen and represent an option for those who want a compellingly enjoyable closed-back design.

Ultrasone PROline 750 Headphones
MSRP: $399
http://www.ultrasoneusa.com

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Build Quality
Appearance
Treble Extension
Treble Smoothness
Midrange Accuracy
Bass Extension
Bass Accuracy
Imaging
Soundstage
Dynamic Range
Performance
Value