Headphones come in all shapes, sizes and types. But with regards to full-size over-the-ear headphones, they fall into two main categories, “closed” and “open”, which refer to the acoustic seal in the ear-cups. In the case of open-back headphones, the ear-cup is open and there is no noise isolation from the surroundings and conversely the open ear-cups also leak some sound back into the surroundings. Generally speaking, open-back headphones can usually offer better and more dynamic sound than other types of similarly priced headphones. Open-back headphones are great if you need to remain aware of your surroundings or if you are in a quiet environment that does not mind the noise that the headphones will project outward into the surroundings. However, for times when you need to escape some low level ambient noise like a dryer or dishwasher, or if your surrounding environment is not interested in hearing what you are listening to, you will want to use a closed-back (sealed) headphone. The acoustic seal in the ear-cups works to provide noise isolation from outside noise and also limits sound escaping outward.

Headphones can offer an amazing music listening experience and even rival expensive loudspeaker systems at a mere fraction of the cost and space. The main reason for this is that headphones don’t have to deal with the listening room boundaries or reflections which can muddle the music. In recent years many improvements have been made to sealed headphones and some closed designs can sound nearly as good as similarly priced open-back headphones. In this group test we take a look at three closed-back circumaural (over the ear) headphones: a pair of the Shure SRH840, the Ultrasone PRO 650 and the Beyerdynamic DT 770 Premium (600 ohm version).

Shure SRH840 ($265 CAD)

Shure has been a leader of the in-ear headphone category for years and the SRH series represents the company’s introduction to the full-size headphone market. The Shure SRH840 is its top-of-the-line model and features plush oversize ear-cups. The ear-cups are padded in a soft leather-type material that appears quite durable and should withstand heavy usage. The earpads are replaceable, if they ever wear out, which is a great feature for those who plan to get heavy use out of the headphones – an extra set is included. The plush ear-cups combined with the fully flexible headband make the SRH840 headphones quite comfortable and well suited for longer listening sessions. These headphones are comfortable enough that you can fall asleep while wearing them. The headband is durable and built to last but also flexible, which adds to the comfort of the headphones. Numbered click-pull settings are used for adjustment of the headband. The ear-cups are hinged and fold up and inward towards the headband for compact, convenient storage. The ear-cups do not rotate so the headphones will not lay flat on a surface. Included with the headphones is a 3 meter coiled cord which is removable from the headset via a cable lock and terminated with a gold plated 3.5 mm jack. A locking (screw-type) 3.5 mm to 6.5 mm full size adapter is also provided. Visually the headphones have an all-black finish and have a somewhat bulky profile. Another goodie included with the headphones is a soft faux leather carrying pouch which can store the headphones when collapsed. The specifications note that the SRH840 headphones use 40 mm drivers and neodymium magnet transducers. The acoustic isolation of the headphones is noted as -12 to -16 dB. Putting the headphones on without any music playing, demonstrated that the SRH840 keep a lot of the external noise out. With music playing you likely will not hear anything from your surroundings. The nominal impedance of the headphones is 44 ohms and generally speaking the SRH840 can be driven reasonably well with a portable media player.

For a sonic evaluation of the headphones I used the headphone output of my Behringer SRC2496 A/D and D/A converter connected to the digital output of a computer. The Shure SRH840 are relatively easy to drive and a computer sound card or a portable media player or will do just fine, but you will want to use an amplifier to get the most out of the headphones. My test music included various lossless high resolution albums from HDtracks. With tracks that I would generally consider bright, the brightness was still there but not as forward. The upper-end response was neutral to laid back, without giving up detail or excitement, hence these headphones are not going to cause listener fatigue during long listening sessions. On tracks with heavy bass notes, the bottom-end response was commendable and sonically pleasing (especially for closed-back headphones). The SRH840 had superb instrument separation and despite the big bass response I could easily distinguish the bass drum from the bass guitar. Their great balance, full, low-end response and an overall accurate response makes the SRH840 suitable for both casual and critical listening, as well as home studio and monitoring applications. Since the SRH840 headphones are durable, easy to drive and fold into a compact package they can also make a great portable companion.

Ultrasone PRO 650 ($399 CAD)

I know that you shouldn’t judge a book by its cover, but right out of the box the Ultrasone PRO 650 impressed me with a much higher than expected build quality (at this price point) and their durable appearance. Holding the headphones in my hands I got an undeniable sense of great quality that put a smile on my face. The PRO 650 headphones, manufactured in Germany, are largely geared toward professional use but also well suited for discerning music lovers. The headphones are constructed on a plastic polymer headband which is fairly rigid. The underside of the headband is covered with a padded, plush leather to add comfort. The ear-cups are attached to the headband with a hinged, swiveling connection. This allows you to fold the headphones into a bundle for transport or storage and during use the swivel connection will allow them to lay flat on a surface. The large earpads are covered with plush black leather. The Ultrasone PRO 650 come as part of a fairly comprehensive package which includes a large hard-sided protective storage and travel case, an extra pair of earpads, a 6.3 mm to 3.5 mm gold plated adapter and two detachable cords, one coiled and one straight (each is about 3 meters long). The detachable cords plug into the left earpiece and are terminated with a full-size 6.3 mm gold-plated stereo plug. The black cloth hard-sided case measures about 220 x 220 x 90 mm and will offer a fair bit of protection during transport. A demo CD rounds out the accessory package. With the headphones on there is a good amount of isolation from the surroundings, but the seal is not complete so you can keep some sense of what is happening around you. During extended listening sessions I did find that the headphones became a little bit uncomfortable. The comfort level seems quite dependent on how you angle the ear-cups and adjust the headband extensions, so fine adjustments should maximize comfort. The Ultrasone PRO 650 headphones use large-element drivers and have a nominal impedance rating of 75 ohms, making these headphones best suited for use with a headphone amplifier.

To test the PRO 650 I used the headphone output of an NAD C162 preamplifier with an NAD CD player as the source, listening to various standard CDs from my collection. The PRO 650 are not a difficult load to drive, but are best mated with a headphone amplifier. From the very first note I was pleasantly surprised, perhaps even shocked with the deep, powerful and warm bass response. These headphones achieve an incredibly deep response from a closed-back design. If you enjoy music with deep bass you would likely be very happy with these headphones. Even with the big bass, the uppermost range remained clear, with plenty of fine details and no signs of harshness. The midrange was somewhat recessed and mellow around the vocals, but the overall response came across smoothly. This allowed for long listening sessions without causing fatigue. Ultrasone uses “S-Logic” technology in the PRO 650, which arranges the drivers in the ear-cups in such a way that places the image higher up in the listener’s head, resulting in an expanded soundstage and giving the headphones a sonic signature that sounds much like tower speakers would in a room. These headphones provide great value for the cost, with an excellent built quality and sound performance to match. The PRO 650 are great for use in a listening room, around the home or for rugged use in a studio.

Beyerdynamic DT 770 Premium – 600 ohm ($319 US)

German audio equipment manufacturer Beyerdynamic has been around since 1924 and its DT 770 headphones have existed in the company’s product line-up for many years, in one form or another. Today, there are three versions of the DT 770 headphones, identified by their nominal impedance; 32, 250 and 600 ohms. In this review I test drive the 600 ohm version, noted on the packaging as an “audiophile model”. The extra high impedance makes these headphones rather difficult to drive, so in order to get the best sound from them you will need to use a higher powered headphone amplifier. The headphones have light grey-coloured, round ear-cups that are padded with a plush velour material. They fit very comfortably around my ears and felt surprisingly light on my head for a pair of full sized headphones. The headband design is very flexible which minimizes the clamping force, giving them a slightly looser but more comfortable fit than the other two headphones in this group test. The underside of the headband is covered by a soft leather-like padding which is comfortable against the top of the head. Overall the DT 770 headphones are incredibly comfortable and thus well suited for extended listening periods. Fixed position aluminum alloy supports connect the headband to the large ear-cups so these headphones will not fold up or lay flat on a surface. In my hands, the headphones felt and looked luxurious but did not appear to be overly rugged so they are likely best suited for use at home. There is a fixed, straight 3 meter cable that exits from the left ear-cup, terminated with a threaded 3.5 mm gold plated mini stereo plug. Included in the headphone package is a full-size 6.3 mm gold-plated adapter plug and a nice faux leather storage/travel bag that is soft-sided and foam-padded. The acoustic isolation of the headphones is noted at -12 dB and this keeps a lot of the outside noise out.

To power the headphones I used a 6AS7 OTL tube amplifier with an OPPO BDP-83 disc player as the source, listening to various CDs and Super Audio CDs from my collection. The 600 ohm impedance of the DT 770 headphones makes them ideal for use with high powered headphone amplifiers like this OTL. High impedance headphones combined with a quiet amplifier will produce an extremely quiet noise floor which is great for critical listening or serious studio work. During my listening sessions, the bass response was full and well textured from the DT 770 headphones. While the bass was not as warm nor did it dig as deep as with the other headphones reviewed here, it was nonetheless impressive for a sealed design. The Beyerdynamic DT 770 truly shined from the mid-bass up. They delivered superb clarity, excellent detail, transparency and smooth, crisp extension well into the treble ranges. The soundstage was expansive in all directions and the overall sound was very impressive. The balance of comfort and performance make the DT 770 headphones an excellent mate for a high quality amplifier and perfectly suitable in the listening room for both casual and critical listening.

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