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AKG K271 Studio Headphones

Headphones are a vital part of a recording studio - either a professional setup, or the home studio. Their main role is for performance monitoring, but they are useful as a second point of reference when checking mixes and edits as any noise or distortion is more easily detected. The AKG K271 are a closed headphone ideal for performance monitoring as they isolate the sound leakage, both into and out of the headphone.

Background

"The new Studio Series headphones differ from one another mainly by their designs that provide four different sonic results. The K 141 Studio uses semi-open supra-aural earphones. The K 240 Studio is a semi-open design, too, but uses circumaural earpads. The K 271 Studio, successor of the famous K 270 Studio, use closed-back circumaural earphones. The K 171 Studio is a supra-aural, closed-back design."

At this point, it might be useful to take a look at the basic properties of each design.

Circumaural headphones are usually comfortable to wear because the earpads surround the ears on all sides. This provides a highly accurate sound so this design is an ideal choice for analytical listening. Supraaural headphones have smaller earpads so they take up less space in the van and are suited for mobile use as well. Since their enclosed air volume is smaller, their sound pressure levels are higher. Besides earpad design, the acoustic design of the earcups is another important feature. Semi-open designs use defined openings in the earcup shells that allow sound to pass from the outside to the inside and vice versa. These so-called "leaks" are used to  tune the frequency response, particularly in the bass range. Therefore, most semi-open headphones provide a well-balanced sound and are used primarily for hi-fi and analytical listening applications.

The distinguishing feature of the closed-back design, however, is its high attenuation of outside noise. This type of headphones is preferred by users who wish to isolate themselves from their acoustic surroundings or avoid disturbing others with noise from the headphones. Closed-back designs, however, have no leaks for acoustic tuning, so the bass range on many closed-back models is either too weak or too inaccurate for analytical listening. The two closed-back models AKG K 171 Studio and AKG K 271 Studio are exceptions to the above rule. They use a particularly sophisticated design that combines the well-balanced sound of semi-open headphones with the high attenuation of closed-back designs. More about that later."

Design

AKG K 171 Studio (exploded view):

1. XXL-speaker
2. Support Plate
3. Acoustic Resistors
4. Rare Cavity
5. Gimbal Cavity
6. Tube
7. Earpad
8. Earcup

Specifications

Type: Circumaural, closed-back headphones
Applications: Professional stereo-studio-headphones for live sound and studio monitoring
Frequency range: 16–28.000 Hz
Sensitivity: 91 dB at 1 mW / 104 dBV
Impedance: 55 ohms per channel
Power handling capability: 200 mW
Cable: Plug-in, 99.99% OFC single cable, approx. 3 m (10 ft.)
Connector: Gold plated stereo mini jack
Adapter: Gold plated mini to 1/4" screw-on adapter jack
Net weight (without cable): 240 g (8.5 oz)

Awards

The TEC Awards, presented annually by the Mix Foundation for Excellence in Audio and Mix magazine, recognizes new audio products that represent superior accomplishment in their respective classes. Products are nominated for TEC Awards by a selected panel of industry professionals and are voted on by over 40,000 subscribers of Mix magazine.

The K 271 Studio headphones have been internationally-acclaimed and accepted by audio professionals because of their outstanding sonic quality, excellent wearing comfort, gorgeous styling, and manufacturing excellence.

The PAR Excellence Award recognizes the K 271 Studio as being one of the best new products from 2003. The award certificate was presented to AKG Acoustics by John Gatski, Publisher/Executive Editor of Pro Audio Review at AES in New York. Each year Pro Audio Review magazine enlists the help of industry professionals to test hundreds of new products. At the end of the year, the reviewers nominate their favorites based on criteria of innovation, value and performance. Winning products are chosen from the following categories: Studio, Live/Contracting, Project Studio, Broadcast and Post-production. The PAR Excellence Awards are presented each year at AES to the best new products that offer the most potential to the pro audio end-user.

Usage

I would have liked to have written this article based mainly on my experience with the headphones as opposed to more about their specifications, however since I don’t have a many other sets to act as reference points; this would have been a very short review. A good review should base the results of a product against several others in that specific range. Daniel Rutter of dansdata.com provides a review that is based on the use of other headphones, and hence this will give a much more fair analysis of the K271s. Read it here. In addition, the Sound on Sound website has a small review here

Having said all of the above, I can still give you my opinions on the design and usage. I have, in the past, used a variety of standard heaphones such as the crappy in-ear type, the smaller portable types, and up to some better made Sony headphones, designed more for the musician. Whilst these may not be the best reference points, they can still offer people in a similar situation to me, a reasonable comparison. I had been using the Sony (no idea of the model number, but they were a Supraaural type set) along with my surround speakers (because I have no proper active monitors) to mix and edit my recordings.

Whilst these were fine for the occasional use, I really needed to get a set of higher quality, closed back headphones. As I said at the start of the article, these are a vital bit of kit. I ordered the K271 headphones from www.gak.co.uk and they cost £84 (including VAT but excluding the £10 delivery charge).

The delivery took just a couple of days, so I was happy so far. I opened up the box, and was impressed by the size and the quality of the design. My old Sony set sat on your ear and prolonged use became a painful experience. Sitting these K271s on my head was very comfortable. The wire band provided just enough pressure to keep the set in place, but not so much to cause it to be uncomfortable. I have sat for several hours with them on and not had any problems. The actual headband that makes contact with your head is also comfortable and wide, allowing the weight to be almost undetectable.

The headphone pads that sit over your ear are made from a soft fake leather, but as bad as that sounds, it’s far more comfortable that foam padding. This is also the material found on the top of the range wireless set, so it’s clearly not that bad from AKGs point of view.

The headphones come with 3 meters (10 feet) of cable, that terminates with a mini XLR connection at the headphone end, and a gold plated 3.5mm screw jack at the other. They also include a 3.5 (1/8") to 6.5mm (1/4") screw on adapter. The cable is plain, straight wire, but you can also purchase a spiral / coiled cable if you wish. Useful if you are always tripping over miles of wire. The connection is solid and well fitting with a proper metal push button release. Basically, the sound will not crackle if you wiggle the cable about.

On this same side, the headphones feature a microswitch. When you removed them from your head, the switch is reset and the audio signal is cut. This is important in a recording environment as whilst the headphones are on, the cups will seal the sound in. Taking them off would prevent this sound escaping and hence AKG adding a switch.

The headphones are designed primarily for monotoring. For this reason, if you use them for games or movies for example - you will notice a very different type of sound. They provide a "flat" sound - that is, with no alterations as you would get with speakers or other standard headphones. The signal that goes in, is the sound that you head. The technical specs quote a frequency response of 16–28.000 Hz which easily covers the full range of the human ear. Whilst this type of huge range is quoted by many manufacturers, it’s down to either how they sound to you, or for more accuracy, plotting a frequency response graph. This basically displays the power agains the frequency. Ideally, the hoeadphones (ie monitors) should produce a graph with a horizontal line at ± 0dB across the 20-20kHz range.

The graphs show the AKG K271 on the left, and a top of the range set by Beyerdynamic - the DT800. You can nitpick over this as much as you like, but the difference in price between the two sets will soon resolve these slight imperfections in the K271’s response.  Remember also that the AKG model is closed back, where the Beyerdynamic is open. Closed back headphones do not allow any air exchange and hence the response suffers.

The power output is also efficient at 91-SPL (sound pressure level) for 1mW of inpout power. This means that they will sound reasonable loud when connected to most audio devices. Smaller portable players may have to be turned up a bit higher to power the headphones - but again, these are aimed at studio use and not for plugging into your iPod (although you can!).

Overall

For just under £100, I have a set of very comfortable, well made headphones. I have read many good reviews about these, and the awards speak for themselves. So overall, you can’t go to far wrong, and the price is very reasonable. To pick out negative points, whilst the pads are comfortable, on warmer days the soft pads can cause your skin to sweat a bit as they don’t allow any airflow. Nothing too serious. Other than that, no complaints from me. Finally, the K271s come with a 2 year product warranty, as with all other AKG headphones.

Links

AKG Acoustics Product Page
Daniel Rutters Review
SoundonSound Review

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