Headphone Reviews

The Sound
It's pretty easy to take for granted a headphone that's been around for six years, so I'm very glad the folks at AKG sent me the Quincy Jones Q701 to re-experience. The sound of these cans is very good, and I'd forgotten just how good. No, these are not headphones for bass lovers; though the bass is well extended, it is not emphatic in the least. I'd say the Q701 is well balanced with a slightly less present bass than perfect. The low notes are, however, tight and nicely textured, and well integrated into the whole.

The treble has been the troublesome spot with these cans, being slightly too fast to my ears. The overall impression of the highs is open and clear. These cans image surprisingly well, and the sound is coherent and deep.

The mid-range is very good in the Q701, and is integrated quite well with the extremes of the spectrum. With the slightly emphatic treble, the mids do seem a bit lean in comparison, but only a bit. Overall, I find the Q701 to portray the music as a well integrated whole, and deliver an open and satisfying listening experience. These are very good headphones at their price point, I strongly recommend them.

Other directions to look for a similar can are: the Sennheiser HD650 is substantially more expensive, but has a more laid back sound; the Beyerdynamic DT800 600 Ohm is roughly the same price for a slightly airier presentation.

A Note: Break-in
The AKG K701 has long been considered by hobbyists to be a headphone that needs a lot of break-in time to sound its best. Numbers like 300 and 400 hours are commonly mentioned. I've been working on the measurability of break-in in articles here and here with the Q701 to see if there are measurable artifacts to back up this claim. So far, I can report that while there seems to be some evidence that the break-in phenomena does exist, it is small in terms of its measurable effect. I do think I've heard it on the K 701 previously, and recommend that if you get a pair, give them time to show you their stuff. Break-in your pair by playing music (or pink noise, if you have it) through them continuously at moderately loud levels for at least 100 hours (200 is better) before making a final decision on your purchase. Though they will sound fundamentally the same, my experience is that the "edginess" is markedly lessened with long break-in on these headphones.

Measurements
I've seen some questions and comments about the Q701 being voiced differently than the K 701, I've done some comparison measurements here and they look virtually identical to me.

Frequency Response

The graph above shows that the K 701 and Q701 are very similar in frequency response. The only artifacts of note are the slight differences in lumpiness between 900Hz and 2000Hz, and about 3-4dB lower energy above 10kHz on the Q701.

300Hz Squarewave Response

The 300 square wave response of both headphones is virtually identical. The leading edge spike may be somewhat higher than ideal, and likely leads to the subjective impression of these headphones as fast and detailed. The fact that they settle down quickly to a fairly noiseless top indicates goos control and likely contributes to the excellent imaging and clarity of these cans. The somewhat downward sloping tilt is indicative of headphones that are somewhat lean sounding, an observation that is born out in subjective listening tests as well.

Impulse Response

Here we can see the Q701 initial impulse spike is slightly lower, and settles into zero very slightly quicker, and with slightly less noise. This would indicate a slightly better controlled headphone, though I heard both headphones as essentially identical. The impulse response shown here is very good.

After seeing the measurement data I would say that other than the cosmetic differences, both headphones are identical. The slight differences observed could possibly be accounted for by the added "Q" badge on the outside of the earcup behind the driver, and improved manufacturing processes over time.

Here are the full measurement sheets for the Q701 and K 701. Resources after the video!

Resources
Wes Philips' review of the AKG K 701.
"Everything it Takes to Become a Classic" press release from AKG.
YouTubes on the Q701 by Quincy Jones, and totally weird, but quite good xtranormal K701 review.
Headphone purchasing study by NPD Group.
Recabling services for AKG cans by Moon Audio.