For today's post, let's have a listen and look at the two AKG headphone models above separated by about 25 years in age. On the left we have the AKG Q701 "Quincy Jones" Signature Reference-Class Premium Headphone which was released in 2011. I bought this one (I preferred the black rather than some of the funky colors like neon green) in late 2012.
The AKG Q701:
|Notice the tilt towards the front with the ear pads.|
How does it sound?
No need to say too much here I think. Lots of folks already have commented about the K/Q70X series of headphones by now. Basically, this is a good sounding "reference" AKG headphone. The open-back nature and the large earpads feel comfortable and the sound is spacious. While these headphones are lightweight, sometimes I find the lumps on the headband which are supposed to distribute the pressure can be a little uncomfortable but easy to overcome with reseating on the head.
A friend has the K702 headphones and although I did not have my Q701 to listen side-by-side, I think it sounds the same.
Yeah, I think the angled earpads do add a little "space" to the sound quality. A bit more "air" like the Sennheiser HD800 but not quite to the same extent - I'd like to say about "60-70%" if I have to guess. It pushes the center image like vocals forward from deep inside the head. I was quickly flipping back and forth between this and the K260 (discussed below) on Peter Cetera's "Even A Fool Can See" on World Falling Down and the effect was quite obvious when A/B listening like this. Note again that the effect does not sound anything like real speakers! While it's a nice effect, I would not say it's essential in any way (in fact, with the Dekoni Blue, I prefer the non-angled Elite Velour ear pads over the angled Elite Hybrid as previously discussed).
The AKG K260:
Although I gather not too many of these headphones were made (unsuccessful AKG seller, compared to the much more popular AKG K240), you see these mentioned once awhile on forums and I see that Moby used these for mixing much of his body of work - in fact, here's Moby's K260 listed for sale:
The upper treble was a little less "hot" compared to the Q701 above and certainly less than the Sennheiser HD800. Notice that at the same time, it did not feature that "dark" scooped frequencies from 5-10kHz seen in the Sennheiser HD650.
The waterfall plot looks pretty good as well. Not as smooth as the open headphones but we see -40dB decay within 10ms for all frequencies down to 100Hz. Electrical impedance is indeed high; these are spec'ed as 600Ω and I'm seeing more like 700-850Ω, with a driver resonant frequency at 130Hz. Voltage sensitivity of 89dB SPL/0.25V implies around 101dB/Vrms. Indeed, this headphone is not as sensitive as the Q701 with a significant difference being the "high" impedance load compared to the Q701's "medium" impedance of 60Ω (with ramifications as discussed before).
For an old headphone from 1987, harmonic distortion looks pretty good although notice that the bass distortion is higher than more modern headphones I've tested. Below 125Hz, THD is above 1%, the Q701 is better than this and a modern closed headphone like the AKG K371 likewise has lower distortion (as previously measured).
As a semi-open headphone, the noise isolation and sound leakage sits as expected between the open and closed designs. Here are the results for this headphone:
Since it's semi-open, the maximum sound leakage was from the rear of the ear piece near the openings. On average from 100Hz to 10kHz, leakage is 71dB SPL measured at 1", or 49dB SPL @ 1' - about 10dB better than the open Q701 above. Most of the leakage tends to be from 1kHz to 5.5kHz.
Let's look at some 100Hz square waves:
Very interesting "square" waves. I have not seen this kind of pattern with other headphones up to this point. Looks like a pattern of low frequency attenuation with a dip below zero before the next square edge transition. I've read comment about this as perhaps correlating with poorly controlled bass (not that there's much bass with these anyways). To me this might correlate with harshness as I'll discuss below.
How does it sound?
Well, once I cleaned out the headphone and old pads, these sound very good! What a neat experience to listen to an old headphone that is used but well cared for, made before I graduated from high school to get a sense of how "vintage" (almost 35 years old) transducers compare to modern devices.
While the build does leave much to be desired and the original earpads can be upgraded to modern replacements, the comfort is still good and I would have no problem listening with these for hours. Clamping force is relatively weak on these (less than the Q701), so can feel like they might fall off with vigorous head movements.
While the treble is nice and neutral, I found that it sounded a little grainy at times. Modern compressed pop like Taylor Swift's recent evermore (DR6 average) tended to show more of this in the highs (eg. guitar plucks on "Willow") and even her voice seems to be a little rougher, more "etched" than usual compared to headphones like the Q701. This sounded also very evident in The Greatest Showman soundtrack like the song "This Is Me". It almost seems like it's accentuating the peak-limiting in some of these productions. I wondered if the square wave performance above could be a reflection of this "graininess" on these "loud" dynamically compressed tracks. This could be beneficial in the studio to pick out anomalies like frank clipping.
The other issue is that bass is rather weak. Songs with a fair amount of sub-bass content like Malia/Boris Blank's "Celestial Echo" (Convergence) sounded weak compared to even the Q701 which itself is no great bass machine. The high end on this track sounds good, but again, a hint of excess graininess on the vocals and the synth percussion. I would say that these headphones are good for acoustic music without much deep bass, small classical quartets sounded great. If you listen to Go: The Very Best of Moby (speaking of Moby using these for production work) with these headphones, you'll miss some of the bass on many of those tracks!
"Soundstage" is mostly the usual right-left-inside-the-head affair. Sounds good with binaural like this or your favourite ASMR. ;-)
The sound basically is much better than the build quality would suggest. The treble graininess was a bit more than I would be happy with when listening for fun, and the bass roll-off made the sound less than "full bodied". I could not help but to think that if the treble quality here were to be transported onto the Sennheiser HD650 (sans graininess), that would have sounded awesome!
Thanks again linnrd for the opportunity to try out a vintage and relatively rare headphone!
To end, it's been awhile since I have read/listened to audiophile cables and power systems discussions. Overall, I've just been happy with my inexpensive 10AWG power cord with Hubbell plugs. ;-)
I see that there have been a couple of interviews with cable/power accessory people in the last number of months. Here's Caelin Gabriel of Shunyata and the San Francisco Audiophile Society (September 2020). And here's Garth Powell of AudioQuest and Audio Excellence Canada (May 2021).
I do not recommend watching the videos completely unless you're truly fascinated in this kind of stuff. As an observer of humanity, it is interesting watching people answer questions. The nonverbals like mannerisms and words selected give us an idea about character. Fascinating watching someone like Caelin Gabriel present his case and answer the unchallenging questions being presented by folks who seem to have consumed the Kool-Aid. There's an attitude that comes through and the way he has prepared (or not) for this interview also speaks to this. As expected, he keeps talking about noise and clock issues (eg. 56:30 - 60:00 for a few minutes taste) to push his products. At no point is he showing us any evidence that this is a problem or that his products are able to ameliorate issues. Sure, buy the US$8000 fancy power strip with hospital outlets, Stereophile says it's good. ;-)
As for Garth Powell, it's fascinating that he talks about using subtraction techniques (like this DiffMaker test, or more recent DeltaWave Audio Null Comparator) to detect differences with his power products. The problem is that he has zero data to show despite this clearly being presented as some kind of discussion about his measurement protocol for cables! It's all talk, and he throws out numbers like "20dB" differences with various AudioQuest Niagara products (is that down at something like -120dB noise floor? :-) It's quite amazing that he talks like this and throws out jargon (18:40) which could be true but there's simply no demonstration at all to put these hand-waving and hypothetical claims into a concrete example so anybody even understands whether his statements are referring to differences that could have audible relevance for humans. Is this good enough for audiophiles in the 21st Century? I think not.
I don't understand. Can they not see how poorly these interviews come across with claims of "profound effect" these days in the face of actual tests like the Audioholics test/critique of the AudioQuest cable? Guys, show a little more transparency, less talk (hot air), more demonstration of effect to actually show the supposed "research" being done! Last week, we talked about Michael Fremer and the Wilson XVX in his room. I guess that back in early March there was a need to highlight power products in the magazine and he wrote this article about his power issues after installing a natural gas generator and switch. Well, I seriously hope if the audible changes are real, rather than the usual hysterics, that Fremer would simply measure the problem and how something like an AudioQuest or PS Audio device can fix it; not gonna hold my breath on this though from him or Stereophile.
As for the interviewers, I appreciate that at least Audio Excellence Canada pushed Powell a little while remaining nice to the man. But wow, the San Francisco Audiophile interviewer and crew were totally "softball" or even delusional when it came to questions for Gabriel. Hilarious at 1:57:10 when the guy claims that Shunyata products used with a TV resulted in visual changes in brightness and "blacks darker" or something like that. Even Gabriel agrees and suggests using his cables for digital photographers to hook up to their computers to see a difference! Hmmm, maybe Shunyata should measure that and present the data. That would also open up the home theater and computer markets! Imagine how happy the sales guy might be to push a high-margin Shunyata power cable with that 8K 85" Samsung QLED TV purchase or the latest Apple Mac Pro. I don't know whether to laugh or cry thinking that the "head honcho" of the company can say these things with a straight face, or that the audience do not seem to be rolling their eyes.
I wonder if we look back at these interviews in 5 years just how well they will age. Will these individuals be seen as audio luminaries, or examples of guys pushing snake oil? I'm willing to bet it's very much the latter, and probably very obvious for many audiophiles already.
Alright, enough for a week! Originally I wasn't going to publish this article since Google/Blogger seemed to have pulled a few of my older articles and I would have needed to spend time restoring them this weekend. I know a few bloggers were complaining so I suspect something strange must have happened yesterday - some kind of bug/hack? Looks like this got fixed... Yay.
Hope you're all doing well and enjoying some wonderful music... Sunny, warm weather here in "Beautiful British Columbia"; time to get out!