AKG Q701 Vs. AKG K702 | Comparison & Review

[inter voice]

Quote:

Dear Kevin,
 
Wether your family member know headphones or not, a sighted test is a sighted test. I'm not arguing you or your family members are hearing something, my comment was wether this difference would still be present in a DBT. It was a personal comment, or a question to self if you will. Now let's put this to rest shall we ?
 
Back to the discussion, it seems to me the difference in the graph is essentially in the mids, or should I say, the biggest amplitude is in the mids. The graph of Inter Voice is actually different from Innerfidelity as it shows a second difference in the mid-bass region. I'm wondering if that would be repeatable, or if that's a single occurrence quirk. If you haven't already laid your eyes on it, and you have interest in seeing good heaphones measurements, you might want to have a read there :
http://www.innerfidelity.com/content/akg-quincy-jones-q701-sound-and-measurements
 
@Intervoice, please correct me if I'm wrong, but you did the test for each pair only once, right ?

Just to confirm that I took the measurements more than 10 times, on both right and left channels of the CAN.  I also shifted the mic a bit during the measurement and found the high freq. would drop if the mic was near to the bottom or at the top of the ear pad.  However the low freq. had not much change even the mic was shifted.  The plots I posted had the mic in its middle position just opposite the mini speaker.  I found that the FR of both Q and K headphones were very much the same.
 
If you look at the my plots posted up in my previous threads they were taken at two different dates and the trends for K702 were very consistent and looked very similar.
 
I believe the measurement equipment I used was different from Innerfidelity and that may explain why the curves were somewhat different.  My headphone amp. is Fidelity Audio HPA-200 (with very good freq. response curve and extremely low noise) http://www.fidelityaudio.co.uk/hpa-200.html, the mic is an omi-directional passive mic and the software used is Room Eq Wizard http://www.hometheatershack.com/roomeq/. I used a battery driven Notebook computer to carry out the measurements to avoid any humming noise being picked up.  IMHO the FR of my measurement is more realistic especially when you look at my plots for Senn HD650.  
 

 

[frenchbat]

@Chicolom
Yes I had that opportunity, but not in the best environment, unfortunately. Besides, I was probably more focused in analyzing the differences between the HD650 and the K. At the time the price difference between the Q and the K was also bigger than it is now. Couldn't care less for the design difference and went for the K.
 
@Intervoice
Thanks a lot for the confirmation. Obviously we cannot compare your results and Tyll's ones, different locations, equipment, etc ... The main reason why the curves are looking so different is the compensation algorythms used by both your equipement and Tyll's one. If you're interested, he has a very interesting article on his blog where he explains the methodology of his tests. Good stuff, really.
 
What interests me the most is that mid-bass slope your equipment detected. Since you made the tests with the same equipement, you should find similar results compared to Tyll's, i.e. Different looking graphs but essentially similar curves between the K and the Q, except for the mids. I'm wondering if the fact that you did the tests on different days could account for this. In Tyll's article on the Q's burn in tests, he showed that different time of day can lead to different FR graphs.
 
EDIT : Regarding the placement of the MIC, highs will suffer faster and from a smaller shift. That's why high frequencies are so difficult to get right in a headphone. One day you might be fine, the next day with a different placement on the head, you'll get shrills. Bass and mids are more consistant in that regard.

 

[LizardKing1]

Maybe someone has already suggested this, but I still think the driver is exactly the same. I can think of many reasons why the sound would be different. I do believe they sound different, but I wouldn't be surprised if there was an audible difference between 2 identical K702 or 2 Q701. Quality control just isn't that good to assure that it's all tuned within +/- 2dB of each other. I also thought the Q symbol on the grill could be one of the causes, but through your pics it's obvious that already had a plastic cover where that symbol was, and only a small part of the Q was not already covered by that plastic, so the effect would be minimal between both. All in all I don't expect them to sound the same, but I expect the driver to be the same. Good review by the way

 

[inter voice]

Quote:

@Chicolom
Yes I had that opportunity, but not in the best environment, unfortunately. Besides, I was probably more focused in analyzing the differences between the HD650 and the K. At the time the price difference between the Q and the K was also bigger than it is now. Couldn't care less for the design difference and went for the K.
 
@Intervoice
Thanks a lot for the confirmation. Obviously we cannot compare your results and Tyll's ones, different locations, equipment, etc ... The main reason why the curves are looking so different is the compensation algorythms used by both your equipement and Tyll's one. If you're interested, he has a very interesting article on his blog where he explains the methodology of his tests. Good stuff, really.
 
What interests me the most is that mid-bass slope your equipment detected. Since you made the tests with the same equipement, you should find similar results compared to Tyll's, i.e. Different looking graphs but essentially similar curves between the K and the Q, except for the mids. I'm wondering if the fact that you did the tests on different days could account for this. In Tyll's article on the Q's burn in tests, he showed that different time of day can lead to different FR graphs.
 
EDIT : Regarding the placement of the MIC, highs will suffer faster and from a smaller shift. That's why high frequencies are so difficult to get right in a headphone. One day you might be fine, the next day with a different placement on the head, you'll get shrills. Bass and mids are more consistant in that regard.

Just had a good look at Tyll's measurement method.  Without doubt he is more professional than me 

.  Tyll's article is very interesting indeed.
 
I took my measurements just with the ear pad sealed and the mic was put on a flat surface and it explained why the FR looked flatter.  (The FR looks very much like a FR curve of a speaker took inside a room.)   Tyll actually constructed a rig which included an actual ear structure, i.e. with ear channel.  According to Tyll the tubular channel amplifies the HF and the measurement reflects actually what you will hear (I hope Tyll's theory is correct).
 
As you said the most important thing is to compare the FR curves of both Q701 and K702 using the same measuring environment.  According to my measurement it appears to me that the drivers of both Q and K are very much the same.  The strange thing is that the two CANs actually sound somewhat different though by not much.  The more strange thing is that most people (including myself) can confirm Q is actually better than K.
 
 

 

[Kevin Brown]

Quote:

Dear Kevin,
 
Wether your family member know headphones or not, a sighted test is a sighted test. I'm not arguing you or your family members are hearing something, my comment was wether this difference would still be present in a DBT. It was a personal comment, or a question to self if you will. Now let's put this to rest shall we ?

 
I feel quite confident I could ace a DBT with the Q701 and K701.  I am telling you, the differences were not small !!  I have another pair of Q701's on the way.  If there's anyone in the SF Bay Area who has a pair of K701's they want to put up against them, we could most certainly do a SBT A/B/X test.  (Hard to do a DBT without an automated switching technique.)  Stats is my hobby, so I could even set the test up.
 
Also these measurements too:
 

 
Let say the Q701 actually sounded identical to the Q701.  Then we'd have equal numbers of people saying one or the other has more low end.  But that isn't the case, isn't it?  Multiple measurements say the Q701 has a beefier low end, and multiple people who have heard and compared both say the Q701 has more low end.  To be honest, I don't quite understand why there is still a discussion about this.
 

 

[lejaz]

Quote:

 
I feel quite confident I could ace a DBT with the Q701 and K701.  I am telling you, the differences were not small !!  I have another pair of Q701's on the way.  If there's anyone in the SF Bay Area who has a pair of K701's they want to put up against them, we could most certainly do a SBT A/B/X test.  (Hard to do a DBT without an automated switching technique.)  Stats is my hobby, so I could even set the test up.
 
Also these measurements too:
 

 
Let say the Q701 actually sounded identical to the Q701.  Then we'd have equal numbers of people saying one or the other has more low end.  But that isn't the case, isn't it?  Multiple measurements say the Q701 has a beefier low end, and multiple people who have heard and compared both say the Q701 has more low end.  To be honest, I don't quite understand why there is still a discussion about this.
 

Would be interesting if you or anyone else, could set up a reliable test. But to answer your last question: expectation bias. Someone reports more lows with the Q, and since it's what we all want out of the 70X, we expect to hear more lows, not less. Thus, we hear what we're expecting....and wanting.... to hear. Of course that's an oversimplification, but I had the same thing occur with a cable upgrade on the 702. Also, people are reporting a more relaxed treble on the Q, since that's what most people want and expect....where is the relaxed treble on the graph? If that graph is an accurate portrayal of the bass, then why is the treble not more relaxed? Perhaps a testing error?
 

 

[Kevin Brown]

I personally didn't hear much of a difference in the treble.  Just more low end, which might give the impression of a smoother overall impression.
 
But ... The Q701 certainly doesn't have as much output from about 2.5 kHz to 5 kHz in terms of just Headroom's data.
 
Why would the expected bias of the Q701 be more bass than the K701?  Why wouldn't anyone have the expected bias that the K701 has more low end than the Q701?  That doesn't seem like a real argument to me. 
 
And then from my previous posts ... I thought the K601 had more low end than the K701, and I thought the K501 had more low end than the K601.  (So I kept the K501 and sold the other 2.)  So then when I got the Q701, it had more low end than the K501, but the K701 had less low end than the K501.  (I still have the K501, so will be interesting again to compare that to the Q701.)  So ... I just imagined all those differences?  Expected bias? 

 

 

[lejaz]

Quote:

I personally didn't hear much of a difference in the treble.  Just more low end, which might give the impression of a smoother overall impression.
 
But ... The Q701 certainly doesn't have as much output from about 2.5 kHz to 5 kHz in terms of just Headroom's data.
 
Why would the expected bias of the Q701 be more bass than the K701?  Why wouldn't anyone have the expected bias that the K701 has more low end than the Q701?  That doesn't seem like a real argument to me. 
 

Just speculating, but perhaps because we want to hear an improvement when we're spend money on what we think is an upgrade.....or perhaps someone actually heard more bass, and once it was reported, others started hearing it out of expectation bias. But less upper mids on the Q might make them seem less bright, so maybe the graph is telling the truth. I was looking at the treble which I assumed started around 6k, but maybe I'm mistaken about that.
 

 

[Kevin Brown]

I do hear what you're saying, I just don't think it applies.
 

 
For example, if I had any expectation bias, why would I have chosen the K501's over both the K601 and K701?  Both of those are newer and more expensive.
 
I likewise chose the Grado RS2i's over the RS1i's and the Alessandro MS Pros and the GS1000's too.  And I like the SR225i's, the SR125i's, and the SR80i's all more than the SR325i's.
 
Also ... what's the forum consensus on the Beyer DT880/250 vs the 600 ohm model?  Most people like the 600 ohm model more.  I don't.  I like the 250 ohm model more.
 
I use my ears, and go from there.  Heck, I sold the Q701's and kept the K240 Mk II's because at that time, I liked the Mk II's better. 

  But that comparison had always been bugging me, so that's why my recent interest in the Q701's again.
 

 

[tdockweiler]

Same here with a possible DBT. In fact, if I had MY Q701 and K702 and even failed more than a couple times, I'd sell all my headphones and force myself to live with a KSC75 for life.
Here's the thing though..it entirely depends on music. If you take some music it will all sound very similar on many different balanced sounding headphones.
 
 
I even once found that some music sounded identical on the HD-650 and HD-600. It took some acoustic music with a larger soundstage to pick apart the differences easily.
 
Without a good source/amp/dac, maybe the difference isn't as large? I can use them even with my E9 though and it's still a large improvement over the K702.
I imagine from portable amps they might sound similar? Who knows..
 
You mentioned you found the K601 to have more bass than the K702. I did also. Better bass extension and more mid-bass. When I got my old K501 I expected it to have very little bass, but it actually didn't sound that way to me! I don't know if my old K501 had more bass than the K601, but i'd say no. Apparently there are two versions of the K501 floating around. The K601 I have still sounds like it has more mid-bass (and is warmer) than the Q701. With the Canare wire i'm using now, it's about the same level of warmth.
 
Since everyone believes copper is copper, nobody has compared the K702 vs the Q701 cables by listening to them. I did for 5 minutes, but maybe that wasn't enough. I'll have to try it again sometime. There's no reason a high capacitance wire can't make a headphone sound warmer. I mean basically anyone in a studio understands this..i've said it all along, but the Q701 cable sounds like Canare in many ways. Maybe the Q701 cable uses a higher quality or thicker wire. Both the cables look to be the same size.
 
When I got my Q701 I traded my K501 away and kept the K601 since I couldn't sell it. I'm so glad I did. It seems there's another guy on here who prefers the Q701, but not the K702 to the K501. I'm definitely one of those.
 
In the past I've always preferred the K601 to the K702, but did think the K702 was technically better. and had a clearer sound and more detail.
 
As for the treble on the K702 vs the Q701. The K702 annoyed my ears about 10-15% of the time due to this random weird treble peak. It drove my ears crazy. It was on any amp and on my receiver. Tried many different sources and gave them over 200 hours of use. When I got the Q701 it was GONE. I wish I would have found out what frequency this was, but it wasn't a case of poorly mastered garbage tracks.
 
I should point out that if the treble of the Q701 bothers me, it's the tracks fault. I can verify this by listening to the same track on my other headphones. They're just as bad on my HD-600 (with DHC) and KRKs. The HD-600 does tame them a little bit. Some may appreciate a headphone that tames bright sounding/bad tracks, but I don't. I keep around my HD-598 just for this reason. Sometimes it's nice. The HD-600 with stock cables does this!
 
Quote:

 
I feel quite confident I could ace a DBT with the Q701 and K701.  I am telling you, the differences were not small !!  I have another pair of Q701's on the way.  If there's anyone in the SF Bay Area who has a pair of K701's they want to put up against them, we could most certainly do a SBT A/B/X test.  (Hard to do a DBT without an automated switching technique.)  Stats is my hobby, so I could even set the test up.
 
Also these measurements too:
 

 
Let say the Q701 actually sounded identical to the Q701.  Then we'd have equal numbers of people saying one or the other has more low end.  But that isn't the case, isn't it?  Multiple measurements say the Q701 has a beefier low end, and multiple people who have heard and compared both say the Q701 has more low end.  To be honest, I don't quite understand why there is still a discussion about this.
 

 

 

[lejaz]

 
Quote:

I do hear what you're saying, I just don't think it applies.
 

 
For example, if I had any expectation bias, why would I have chosen the K501's over both the K601 and K701?  Both of those are newer and more expensive.
 
 

Probably because they're very different sounding headphones. When there's only a very subtle difference, or no difference at all, then we might question whether bias of one sort or another is influencing our preference. Sure, go by your ears... I'm just saying that sometimes our ears are influenced by subconscious biases, desires, reviews, price differences, appearance, etc., in addition to any actual differences in sound, if there are any. This subconscious stuff is going on all the time and we're usually not at all aware of it influencing our likes and dislikes. If we were aware of it it wouldn't be sub-conscious.....it would be conscious, duh... 

  

 

[frenchbat]

Lejaz is perfectly right, expectation bias is a very strong one. Just refer to the placebo and nocebo theories. What about the people that got better while taking only sugar instead of a real medication ? It's also their body isn't it ? So they should know wether they feel better or not, right ? The human brain is easily fooled, on purpose or not.

As to the graph from Headroom, these have actually been done by Tyll Hersten, who was the founder of Headroom, and the main writer of Innerfidelity, the page I've linked before. Those graphs are not as accurate as the ones he does with his newer test equipment. Just have a read at the page I have linked, you'll see there's no bass difference in the more accurate tests.

Right now, I guess CSD Plots would me more useful, by showing us how much energy the K and the Q are rendering, respectively. There might be a difference there, also I personally think expectation bias is more likely.

 

[chicolom]

Quote:

Since everyone believes copper is copper, nobody has compared the K702 vs the Q701 cables by listening to them. I did for 5 minutes, but maybe that wasn't enough. I'll have to try it again sometime. There's no reason a high capacitance wire can't make a headphone sound warmer. I mean basically anyone in a studio understands this..i've said it all along, but the Q701 cable sounds like Canare in many ways. Maybe the Q701 cable uses a higher quality or thicker wire. Both the cables look to be the same size.

 
I actually swapped the cables on them and listened to them.  If there was a difference in the sound after swapping, I couldn't hear it. 

 
Quote:

Probably because they're very different sounding headphones. When there's only a very subtle difference, or no difference at all, then we might question whether bias of one sort or another is influencing our preference. Sure, go by your ears... I'm just saying that sometimes our ears are influenced by subconscious biases, desires, reviews, price differences, appearance, etc., in addition to any actual differences in sound, if there are any. This subconscious stuff is going on all the time and we're usually not at all aware of it influencing our likes and dislikes. If we were aware of it it wouldn't be sub-conscious.....it would be conscious, duh... 

  

I agree.  For example, I don't think I can hear much if any difference between different opamps in my M-stage (it is also a pain to try and compare them, having to shut the amp down and swap the opamps out and the power it back up takes too much time

).  I would definitely fail a DBT with those.  I was expecting to hear differences between them based on what I've read on Head-fi.  I entered that comparison with certain bias, and what I read about them on Head-fi primed me to expect differences and then try to hear them.  But I admit I can't really hear them, even though I may want to.
 
After my experience with different opamps, I try to be careful about people's impressions on head-fi influencing my expectations too much.  Half of me went into the Q701 vs K702 comparison expecting them to sound the same or extremely similar.  I was ready to rule that people claiming differences between them existed were hearing what they wanted to hear and exaggerating the truth.  I mean, they look almost identical on the service manuals!  The other half was expecting to hear differences like others had described.  The latter is what I got.  Obvious differences that stand well above the threshold of placebo and bias and made DBT totally unnecessary in this case.  Similar to comparing AD700 and AD900, but an even bigger difference IMO.
 
Also, I should point out that I started out with the Q's and had never heard the K70x before.  When I got the Q701 and heard them (again my first pair of AKG  x70x) I was surprised about how people claimed the x70x were "thin" and "bass light" as that wouldn't be my description of the Q701s at all.  I thought they were freaking punchy!  All my posts right after I got the Q701s confirm this.  I didn't ease into the idea that they were punchy, or convince myself to develop that opinion over time.  It was my instant impression.  Right after I got them (in November 2011) I had a lot of posts defending them saying their bass was great.  I thought everyone on Head-fi must be bassheads to describe the AKG 70x so harshly like that

 
I can't defend the K702 though and say it's bass is great, having heard it now myself.  It's not "great."  Not bad *cough AD700*, but not great.  I will defend the Q701 though.  My pair at least (damn you manufacturing variation/quality control!!!! ).  I think that's why this discussion is still going, there is maybe some variation in the x70x that prevent this debate from being "solved"...
 
 

 

[lejaz]

Thanks for pointing that out about the graphs.....it totally slipped my mind about the newer ones... I saw those just little a while ago. I was a victim of expectation bias myself when I did a cable upgrade to the 702 about a year ago. I went into that particular experiment fully expecting to hear a nice improvement since it was reported by a couple of other forum members who I had been corresponding with. It was a result I expected AND wanted..  And I did hear an improvement......until I did some careful swapping back and forth of the new and old cables. Careful listening showed me I was totally fooling myself. Experiments with the ouija board are kind of fun. Who's actually moving the pointer....our subconscious desires/expectations, or a disembodied spirit? 
I haven't heard the 'Q' version yet. It would be interesting if someone could blindfold me and slip one over my head alternating with the 'k' version... without telling me which was which.... while I listened to some of my favorite tracks. I'm sure someone could arrange a SBT quite easily....and maybe even a DBT. 
Quote:

Lejaz is perfectly right, expectation bias is a very strong one. Just refer to the placebo and nocebo theories. What about the people that got better while taking only sugar instead of a real medication ? It's also their body isn't it ? So they should know wether they feel better or not, right ? The human brain is easily fooled, on purpose or not.
As to the graph from Headroom, these have actually been done by Tyll Hersten, who was the founder of Headroom, and the main writer of Innerfidelity, the page I've linked before. Those graphs are not as accurate as the ones he does with his newer test equipment. Just have a read at the page I have linked, you'll see there's no bass difference in the more accurate tests.
Right now, I guess CSD Plots would me more useful, by showing us how much energy the K and the Q are rendering, respectively. There might be a difference there, also I personally think expectation bias is more likely.

 

 

[tdockweiler]

Quote:

Lejaz is perfectly right, expectation bias is a very strong one. Just refer to the placebo and nocebo theories. What about the people that got better while taking only sugar instead of a real medication ? It's also their body isn't it ? So they should know wether they feel better or not, right ? The human brain is easily fooled, on purpose or not.
As to the graph from Headroom, these have actually been done by Tyll Hersten, who was the founder of Headroom, and the main writer of Innerfidelity, the page I've linked before. Those graphs are not as accurate as the ones he does with his newer test equipment. Just have a read at the page I have linked, you'll see there's no bass difference in the more accurate tests.
Right now, I guess CSD Plots would me more useful, by showing us how much energy the K and the Q are rendering, respectively. There might be a difference there, also I personally think expectation bias is more likely.

This is annoying and I don't understand how you can know this.
As far as I know, Tyll had probably left Headroom before the Q701 was released. I guess it's possible he did the Headroom graphs, but highly unlikely. How can one possibly know for sure if the Headroom graphs are less accurate or more accurate? Actually, I don't even care! For all we know, there could be two different versions measured.
 
It seems strange how the more similar graphs are the ones that are supposedly more accurate. How do we know for sure? Just a guess? Just because they're similar to the ones another member here posted?
 
I remember back when the Q701 was released everyone and their brother said they're both the same but never heard them. Out of curiosity I bought one and expected it to be exactly the same and return it if it was. I would have felt ripped off. The K702 I couldn't deal with for more than a month due to some weird frequency bugging my ears and other issues. The Q701 has been here since October 2011 without a single complaint or issue I had with the K702. Yet over and over people say it's all in my head or a variation in production.
 
It will be nice when this mystery is solved. No way AKG will ever tell us what causes the differences.