World’s Best Headphone Review: AKG K701.

[caption id="" align="alignright" width="198" caption="Beautiful and round in the fashionable iWhite of the day. "][/caption] The AKG K701 makes the "World's Best Headphones" list because that's what they tried so hard to be, and though they didn't quite succeed, they did manage to make some running room for competition, and they did take the blush of the Sennheiser HD 600/HD650 rose. Prior to the AKG K701 introduction in 2005, the Sennheiser HD 600 and then HD 650 ruled the dynamic headphone roost, but AKG is no slouch when it comes to headphones and they intended to knock the king off the throne.  There are a number of ways in which the K701 brought competitive counterpoint to the top of the headphone heap. [caption id="attachment_1366" align="alignleft" width="180" caption="Careful: You'll void your warrenty, but here's how to open your K701. Use a tool with points in the grill hole to turn counter clockwise a small amount and remove."][/caption] The HD650 provides a warm and snuggly sort of fit, a hefty minority of users find them to tight on their head.  I've got a fat head and the HD 650 never bothered me in that way, but I'm also a sailor and don't mind confined spaces. The K701 by comparison is a roomy and light feeling headphone. [caption id="attachment_1367" align="alignright" width="150" caption="You can see the latching tangs on the grill here."][/caption] Large perfectly round earpads encircle the ear; the pads are asymmetrical in thickness with the thicker part going to the rear of the ear. The fit around the ear is spacious, and many will claim --- with good reason, I think --- that a good amount of space in the ear cup and distance from the driver tends to deliver a nice sense of imaging on headphones when done well. [caption id="attachment_1370" align="alignleft" width="150" caption="Remover the two screws under the grill, and then poke a sharp point into the tiny hole to release cap."][/caption] The cord is single sided in the K701 with the cable following convention and entering the cans on the left. Internally the left conductors go to the left drive, and the right conductors are soldered to two conductors that run through the two head bands over to the right side driver. Personally, I like a single sided cable, it seems to stay out of your way a little better than two sided cables for me, but it's not too big a deal. [caption id="attachment_1371" align="alignright" width="150" caption="Once one side is off, you may have to wiggle gently for the plastic tang on the other side to release."][/caption] HeadRoom does re-cable the K701 for balanced operation, and we continue to keep it single sided using the internal conductors through the headband. [caption id="attachment_1372" align="alignleft" width="180" caption="Here's the inside of one of our balanced re-cabled K701s. Maybe you'd like to recable your own if you've made it this far inside?"][/caption] Some other custom re-cablers drill a hole or purchase replacement plastic with the hole in it and re-cable the K701 with a two sided "Y" cord entry bypassing the headband conductors. Arguments could be made either way, but the K701 clearly benefits from recabling. I suggest a smooth sounding cable be used. [caption id="attachment_1375" align="alignright" width="284" caption="AKG's patented Varimotion two layer diaphragm is about the same size as the HD 650 and uses a flat wound coil."][/caption] The diaphragm of the K701 is about the same size and shape as the HD 650, and tries to compete with Sennheisers Duofol design with it's own patented version of two-layer material they cal "Varimotion," and by using a flat wound conductor and coil winding.  (More information about multi-layer plastics used as headphone diaphragms can be found in the HD 650 review.) Using flat conductors in the coil allows for better packing density of the coil and closer tolerance in the magnetic gap, and therefore higher magnetic flux density per unit volume of the coil.  In other words, you can make a stronger magnetic field in a narrower gap in the magnet, which creates a more power to drive the diaphragm. How effective this new coil is is hard to say, but one thing is certain, the K701 is a fast sounding headphone, and it takes a long time to break-in.  I'm not one that believes break-in is typically very important or that the sound of a headphone usually changes significantly with break-in, but the K701 certainly needs it. My experience, and the common wisdom among headphone audiophiles, is that the K701 is very bright and harsh out of the box, and that it needs about 200 hours to break-in to the point that it starts to sound reasonably smooth, and maybe 400 hours before it's fully broken in. Sound Quality [caption id="" align="alignright" width="298" caption="Both the K701 and HD 650 measure similarly well, with the overall tilt of the curve being the major difference."][/caption]If you read the review on the HD580/HD600/HD650 you'll know that while those models were considered very good, they began to get a reputation for having the Sennheiser veil --- a sound that was slightly missing the high frequencies and sounded "rolled-off" or "laid-back." The sound of the K701 goes in a completely different direction with a very quick and lively sound, much more intimate and up-front. Though harsh out of the box, once fully broken in the K701 smooths out significantly and settles into a level of articulate detail the handily surpasses the HD650. Where the HD650 is warm, intimate and close, the K701 is open, airy, and marvelously detailed. On the down side, the K701 has less low frequency energy than the Sennheisers and can sound a bit cold and sterile in comparison. One look at the frequency response graphs of these two cans shows clearly that that while they are quite similar and share the solid middle ground of where a headphone should be, they also differ in their overall spectral tilt with the 650 having a stronger and warmer tilt, and the AKG having a shallower and cooler sounding slant. At the time, and to this day, I would still have a hard time knowing which I would bring to a desert island with me. The HD650 would be a great can for long listening sessions, but the K701 brings excitement and microscopic resolution to your listening sessions. While I don't think AKG can claim to have taken the throne of best headphone for themselves when they introduced the K701, they may have certainly knocked Sennheiser off the throne by providing an alternative and in some ways superior sound to the high-end headphone world. Maybe the best advice at this point in time is, once you have a decent amp, buy both.  Then you'll have the opportunity to discover and play with the differences afforded by some of the world's best headphones. Please visit HeadRoom’s website to purchase your AKG K701 or AKG K701 with balanced cabling with our Best Price Guarantee.