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AKG K712 Pro Review (Headphone)

Jimbob54

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You didn't answer one of my main points, which is that you have an inconsistent approach between boosting the 3-6kHz in both EQ's. You can see from your graphs that you boost the Harman EQ in that area by only about +7dB, see following pic #1, yet on the Reduced High Frequency "Harman Curve" EQ you boost that same area by a massive +11dB (see pic #2 further below) - which is ridiculously inconsistent and counter to the actual targets you're using, because you're boosting the 2nd EQ significantly more even though it has a lower target in that 3-6kHz - that is super illogical and really questions your understanding / logic & competence in this domain. See the red circled parts in the pics below.

Pic #1:

View attachment 168297

Pic #2:
View attachment 168298

My point also stand about my other main point I brought up, I really don't think you're labelling the difference clearly enough between your two curves to make it clear, if you can't see that or can't figure out a way to make it clearer then I don't quite understand how you don't have those communication skills.
Some might say its your comprehension skills failing more than their communication skills as the difference between the targets was clear to me and at least one other person. I'm also not sure why you need to go personal with condescending questioning about their understanding, logic and competence in the field. This is a fairly common tactic of yours but ad hominem challenges don't sit well with me.

Your question about the levels of boost to the 3K area is valid but your overall approach and attitude towards @Maiky76 in those 2 posts has no place on this forum IMO. If I had these headphones I would be free to try both EQ as well as any others available and make my own mind up. I suggest you let folks do just that as I dont believe you own them either.
 

Robbo99999

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Some might say its your comprehension skills failing more than their communication skills as the difference between the targets was clear to me and at least one other person. I'm also not sure why you need to go personal with condescending questioning about their understanding, logic and competence in the field. This is a fairly common tactic of yours but ad hominem challenges don't sit well with me.

Your question about the levels of boost to the 3K area is valid but your overall approach and attitude towards @Maiky76 in those 2 posts has no place on this forum IMO. If I had these headphones I would be free to try both EQ as well as any others available and make my own mind up. I suggest you let folks do just that as I dont believe you own them either.
Ok, I probably didn't need to be so dramatic about it. I'm glad you can see my point about the different levels of boost to the 3K area between the 2 EQ's. I still think everyone would benefit from Maiky's EQ's more if he were to be more clear re labelling when he decides to use a different or "slightly different" target to Harman, as that's in everyone's interest to avoid confusion & misunderstanding. A more consistent approach between the two EQ's also wouldn't go amiss, because the current approach doesn't sit logically with the targets used for both EQ's - as in the "non-Harman" EQ (EQ#2) would sound more Harman than the Harman EQ (EQ#1).
 

Robbo99999

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@Maiky76 , I've had a bit of a realisation, I want to apologise for the strong language & emotion I used against you earlier this morning - it just wasn't necessary or warranted, I should have instead just asked you why you chose to make the decisions you made with your EQ's and then just made my points rather than getting a bit aggressive/dramatic about it. You providing your EQ's is a positive here on this forum, and you're doing it off your own back & free of charge.
 

AdamG247

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1638030990024.gif
 
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Robbo99999

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GaryH

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Here is the rational behind the “taste” curve that I sometimes use when the HP has a lot of boost to be added (12dB+ and the corollary loss of dynamic range) in this case I feel that it is a lot already, plus Amirm who listens to the headphone did not fully compensate the HF so I did take that on board when I designed the EQ.
Anyhow let me try to be clearer:

“Factors that Influence Listeners’ Preferred Bass and Treble Balance in Headphones“ https://www.aes.org/e-lib/browse.cfm?elib=17940
View attachment 168278


Note that the HF modification starts @800Hz with significant change @3000 - 6000Hz and up.
I think you are familiar with high-shelf biquads from what we have done on the JBL 308…

" Segmentation of Listeners Based on Their Preferred Headphone Sound Quality Profiles” https://www.aes.org/e-lib/browse.cfm?elib=20289
View attachment 168279
This study, demonstrated according to S. Olive that:
•A 64% (the majority) of listeners prefers headphones with a frequency response that adheres to the Harman Target Curve.
•A 15% portion of listeners prefers 3 to 6dB more bass, usually younger males and less experienced listeners.
•A 22% portion of listeners prefers 2 to 4dB less bass usually older population, and biased towards females.

Based on this data one can roughly derive preference range, neutral being the default Harman curve:
•-3dB/Neutral/+3dB/+6dB as EQ for bass preference;
•-1.5dB/Neutral/+1.5dB for as EQ for treble preference;

That means that you can still be within the “taste zone” of the Harman target while not being completely on the “majority” curve. You just change the likelihood of the EQ to be optimal for the user, but still rather close to it...
A number of people will actually prefer that, it's also a major piece of knowledge that is often ignored.
A marketing department might even tailor the default curve to cater best for a certain audience…

@amirm is probably [email protected] [email protected] as I have already casually observed, but the listening material also have an influence…
Again these EQ are starting point as clearly stated, for about a third of the population it is not the ideal curve...

What I propose is not random. You can question it in the details but it is perfectly honest, logic, consistent, clear and founded as a whole.

Here's the problem with this rationale for including your additional "Default Harman curve [email protected] HF":

1. It's a single arbitrary curve in the 'taste zone' as you put it...
2. at one extreme of the treble taste zone no less, so unlikely to be applicable to many listeners...
3. based on your 'casual observation' of what you think is...
4. one particular listener's preference which applies specifically to them...
5. in their sighted, non-level matched conditions, so even if correctly inferred by you, may not match with true blinded, level-matched preference...
6. a target which @Robbo99999 has pointed out isn't consistently matched in the same way to as your Harman target EQ, as is the case with the EQ for this headphone.
7. All this accompanied by not scientifically valid adjusted 'scores' with this new target that have no basis in research that specifically uses the Harman target in the algorithm's calculation of the predicted preference score. You can't just change the target in the algorithm and expect that to be valid.

There's just too much arbitrary unscientific inference going on here for this curve (and the sometimes inconsistent EQing to it compared to Harman) to warrant being plucked out of the 'taste zone' and presented alongside the actual Harman target which has strong scientific backing behind it. Casual readers will see it as having some special significance, if not on a par with the Harman target, then at least more than other possible curves in the 'taste zone', which it really doesn't (and the accompanying adjusted scores as being valid predictions, which they're not). An approach such as Oratory's is better here - EQ to the Harman target, but carefully curate the bands to include some broad filters such that regions like bass and treble can be fine-tuned according to preference / headphone unit / listener anatomy / mixing or mastering variation.
 
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Maiky76

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Here's the problem with this rationale for including your additional "Default Harman curve [email protected] HF":

1. It's a single arbitrary curve in the 'taste zone' as you put it...
2. at one extreme of the treble taste zone no less, so unlikely to be applicable to many listeners...
3. based on your 'casual observation' of what you think is...
4. one particular listener's preference which applies specifically to them...
5. in their sighted, non-level matched conditions, so even if correctly inferred by you, may not match with true blinded, level-matched preference...
6. a target which @Robbo99999 has pointed out isn't consistently matched in the same way to as your Harman target EQ, as is the case with the EQ for this headphone.
7. All this accompanied by not scientifically valid adjusted 'scores' with this new target that have no basis in research that specifically uses the Harman target in the algorithm's calculation of the predicted preference score. You can't just change the target in the algorithm and expect that to be valid.

There's just too much arbitrary unscientific inference going on here for this curve (and the sometimes inconsistent EQing to it compared to Harman) to warrant being plucked out of the 'taste zone' and presented alongside the actual Harman target which has strong scientific backing behind it. Casual readers will see it as having some special significance, if not on a par with the Harman target, then at least more than other possible curves in the 'taste zone', which it really doesn't (and the accompanying adjusted scores as being valid predictions, which they're not). An approach such as Oratory's is better here - EQ to the Harman target, but carefully curate the bands to include some broad filters such that regions like bass and treble can be fine-tuned according to preference / headphone unit / listener anatomy / mixing or mastering variation.

1. It's a single arbitrary curve in the 'taste zone' as you put it...

It is not arbitrary, I have explained the rational behind it and if you have had a look at the curves, some versions of the of the target curves had lower output @HF and LF (trained listeners?). Here again:

Screen Shot 2021-11-27 at 10.52.13 AM.png

You can question the details of the rational, I am OK with that, but I don't think you can confidently state that the lower HF target is completely arbitrary.

2. at one extreme of the treble taste zone no less, so unlikely to be applicable to many listeners...

Well, again please read the graphs provided for yourself:
Screen Shot 2021-11-27 at 10.52.54 AM.png

Men tend to forget that half of them are women... Women tend to prefer -3.1dB. At HF alone [email protected] target (or -1.41 -1.5dB = -2.9dB) might be closer to 50ish% percent of the population preference. So not such a small portion of the population, is it?
In addition the more training the less HF (and LF) is preferred which may or may be representative of the of ASR readership.

The map and the country, or if you prefer, model vs reality.
The users must not comply with the target but the target can be adjusted to the user.
All the models are good approximations so most probably, in the details, every user has his/her own slightly different preference target.
Again from the study at least a third of the population exhibits significant deviation from the default target.
The whole "taste zone" is the "Harman target curve" for the complete population (with "normal hearing").
It may not matter if we are only ranking devices against each other (although it may, see hereafter) but it will matter when trying to EQ to the exact target. Readers need to understand that and I wrote it in my EQ preamble.

As a matter of fact, to me, one of the greatest outcomes of the study is that yes, differences exists between users but they are quantifiable and trends are clear to be seen.

How long before AIs will automatically adjust the EQ based on the material been listened to and your Facebook account?
Note that measurements for physical (anatomic, fitting etc.) variations is very much possible already (otoacoustic emissions and self/adaptive EQing products)


3. based on your 'casual observation' of what you think is...
4. one particular listener's preference which applies specifically to them...
5. in their sighted, non-level matched conditions, so even if correctly inferred by you, may not match with true blinded, level-matched preference...


I don't see the point here. I just stated that to my casual (note the importance of this word) observation based on quite a few EQ he devised for Headphones + loudspeakers Amirm seems to prefer; @amirm seems to be [email protected] LF -1.5dB at HF. That's all. He has on several occasions acknowledged this to me directly on the forum. What's the big deal?
According to you he may or may not know what he prefers but he seems to be rather consistently, not perfectly, exhibiting the same trend which is the crucial point to observe for a casual reader of Amirm subjective reviews.

6. a target which @Robbo99999 has pointed out isn't consistently matched in the same way to as your Harman target EQ, as is the case with the EQ for this headphone.

I have clearly explained why I did that for the first EQ. Amirm who listened to the HP did not feel the need to further EQ.
I took that onboard.
I very seldom do that, and it seems I should not have done it here for some reasons that escape me.
As you pointed there are other resources on the web, everyone is free to use them and prefer them to mine.
The second [email protected] iteration is a much closer to the target after @Robbo99999 "kindly" pointed that out.

Part of my concern is that if the EQ users are reading and buying their gear based on ASR reviews, they will have amps with plenty of headroom. Which is good, but even by loosing 12/15dB of sensitivity through EQ their system might still have more that enough power to damage their headphones.
So you say I should disregard that? well I usually do but do provide warnings...

7. All this accompanied by not scientifically valid adjusted 'scores' with this new target that have no basis in research that specifically uses the Harman target in the algorithm's calculation of the predicted preference score. You can't just change the target in the algorithm and expect that to be valid.

That's is the only point that I would gladly concede.
The weights in the score with a different target may or may be identical amongst other possible differences.
However the -1.5dB target scores 99.8 against the default target so yes different, lower (which should satisfy you) but not miles away.
That would need to be compared with the actual listening score error bar and other things to be judged.

I have observed that in some cases the EQ devised by Amirm would actually decrease the score while he reported a significant improvement.
The one simple way to get the score consistent with his rankings was to modify the target curve according to the trend that I have casually observed.
Assuming that Amirm is indeed roughly [email protected] LF -1.5dB at HF his actual preferred target is no longer the default curve so the scores/rankings derived from it are not completely accurate for him. It makes more sense to me to swap the target curve than modifying the weights of the metric.
But that is up for debate...

Nevertheless, the great news is that the model is good enough to detect the score vs listening ranking inconsistency with the default target.
This result tends to validate Amirm not been right on the default target curve BTW.
Plus while being rough, my fix reestablishes the correct score vs listening ranking consistency with the modified target.
The actual numbers not being that relevant in this case, I'll admit to that.
That's the way science works, 1. establish a model/theory 2. compare it to observations 3. adjust model/theory to fit the observations

I will definitively make it clearer that the scores are not comparable but again it is clearly stated that the target curves are different.
I can still however target something different but calculate the the actual score which may be consistent for some users but not for others.
In the AKG case I only modified it at HF to try to prevent over-boosting.

An approach such as Oratory's is better here - EQ to the Harman target, but carefully curate the bands to include some broad filters such that regions like bass and treble can be fine-tuned according to preference / headphone unit / listener anatomy / mixing or mastering variation.

As you pointed there are other resources on the web, everyone is free to use them and prefer them to mine.
But if you are referring to the magic band #3

Oratory's:
Adjust gain of band 1 to preference (bass)
Adjust gain of band 2 to preference (warmth)
Adjust gain of band 3 to preference (tonal accuracy)
Adjust gain of band 7 to preference (treble detail)


My answer it still the same:

What is stated here is quite tautologic in essence: if you change the system will sound different.
In particular band 3, I though we were looking for accuracy so I don't see how it can have different settings.
This band it is either accurate or not.... That is definitively not the apanage of a single band.

One more line of warning I put in my all my headsets EQs:
  • The EQs are starting point and may require tuning (certainly at LF).
I cannot predict the users taste so up to them to tweak. Expect a learning curve though.
I sometimes use Amrim's preference (documented as more bass and less HF) and modify the Harman curve to show that for him his EQ make sense. but that's all.

As a general comment my algorithm does not simply optimize for the curve fitting nor the score.
There is way more going on in the fitness function of the evolutionary algorithm and it is a WIP and it has been for years.
I welcome any feedback, good or bad, in order to improve it.

Oratory know what they are doing, there is no denying that, but it does not mean that others can't do a similar job.
We'd better leave it at that.


Furthermore if ANY rational or otherwise deviation from the default Harman curve is "arbitrary unscientific" then Oratory should not provide any facilities to encourage them either. I suspect we both understand the studies, just replace his "preference" by my "taste" we are advocating the same thing. The difference is that I went one step further (but not better) by directly proposing (the first) two EQs that for one takes into account Amirm's input and for the second ([email protected]) fits a different target curve to try to mitigate the boost at HF while been reasonably close to the default target.
 
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C. Cook

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One curiosity with the K712 is the insane price for replacement ear pads.
The headphone itself is 222€ in Germany right now and a new pair of pads will set you back another 100€.
LOL yep I noticed that too and it was 'way back' in 2015 when I bought a pair of the used Quincy Jones edition (the neon green as opposed to orange on this one) and wanted to replace the pads. It took me quite a while to find a reasonably priced pair of them, which I finally did via Amazon IIRC.
 

GeorgeH

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Great curve, thanks - with it the K712 Pro sounds much closer to my studio monitors inkcl. subwoofer (all Yamaha). I applied the EQ (on the HPh Out EQ of my REM Fireface UCX Audio-Interface) about 2-4 db less in the deepest and highest area, that seems more practical, otherwise the K712 Pro easily sounds a bit like distorting in the bass and fizzy in the heights at louder listening levels. Overall great for anybody who cannot make these measurements, big thanks to you!

Bildschirmfoto 2021-12-16 um 17.15.56.png
 

Luke Lemke

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Chinese version is more relevant, true.
but Austrian version would also be interesting, since the difference between them is a bit of a myth.
Just a quick update on the headphones I'll send to Amir.

After some consideration, I've bought two used AKG 701's, one made in Austria and another one made in China. They were both sent to Amir for a review. I thought about getting the K702 as @Robbo99999 suggested but my plan is to keep one of these cans and I really like how the 701 looks as opposed to the 702.

The pads on the 701 version are worn out, so that may be a point of concern. I think Amir will review them side by side, which should be pretty interesting.

If anyone is interested to buy one of these two cans after the review, I'll give you a decent discount. I'll keep the one that measures best, of course... LOL.
 

Robbo99999

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Just a quick update on the headphones I'll send to Amir.

After some consideration, I've bought two used AKG 701's, one made in Austria and another one made in China. They were both sent to Amir for a review. I thought about getting the K702 as @Robbo99999 suggested but my plan is to keep one of these cans and I really like how the 701 looks as opposed to the 702.

The pads on the 701 version are worn out, so that may be a point of concern. I think Amir will review them side by side, which should be pretty interesting.

If anyone is interested to buy one of these two cans after the review, I'll give you a decent discount. I'll keep the one that measures best, of course... LOL.
Might be worth trying to get some fresh pads on there before sending in for review, on my K702 that Oratory measured the difference between fresh pads & worn pads was around about a 2dB Low Shelf difference darker below 1kHz for the worn pads vs fresh pads. But, to be fair the difference between worn & fresh on the K701 is likely to be similar between that of the K702 given the similarities in the physical design of the cups & pads, so this is the difference between old & new pads on my K702:
K702 old pads vs new pads.png

I would imagine there might be some quite large differences between the measurements of the two K701 samples you send in as K702 has proven to have some quite large variances from unit to unit based on my 2 units I sent to Oratory, but of course it's only two units. K702 is really a great headphone with some great potential re soundstage & resolution abilities, wish they were a bit tighter on unit to unit variation as well as driver matching. I'm interested in any K702/K701 review that Amir may eventually do.
 

Luke Lemke

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This is the austrian made version I sent:
1641052343582.png


And here goes the Chinese made version:
1641052408557.png


Maybe Amir could use the pads of the Chinese AKG for both headphones when testing, but I guess that will be up to him.
 

Robbo99999

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This is the austrian made version I sent:
View attachment 175934

And here goes the Chinese made version:
View attachment 175935

Maybe Amir could use the pads of the Chinese AKG for both headphones when testing, but I guess that will be up to him.
If those were pics of the headphones relatively shortly before you sent them to Amir, then I think those pads aren't too badly worn. Those pads still look quite thick.....I know from my old K702 that after using them heavily for 5 yrs (thousands of hours) that the pads became visually thin in comparison to the new genuine pads I bought from Thomann. That ain't bad there for those pads of yours. Is a good idea though you have of using the same Chinese pads on both headphones before measurement, assuming you're saying that the Chinese pads have less wear.
 

Luke Lemke

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If those were pics of the headphones relatively shortly before you sent them to Amir, then I think those pads aren't too badly worn. Those pads still look quite thick.....I know from my old K702 that after using them heavily for 5 yrs (thousands of hours) that the pads became visually thin in comparison to the new genuine pads I bought from Thomann. That ain't bad there for those pads of yours. Is a good idea though you have of using the same Chinese pads on both headphones before measurement, assuming you're saying that the Chinese pads have less wear.
I've bought them both from eBay and sent them directly to Amir, so I never really saw them in person. Based on the pictures it seems that the Chinese version has "newer" pads, so I'll propose to Amir that he uses the same pads to review both. It's pretty easy to swap the pads, so I guess it wouldn't be a hassle :).

Both eBay sellers had 100% positive reviews, so I'm confident none of these cans are defective.

I've never listened to any AKG 701 in person, the only ones from "the family" that I tried were the K7XX and the K712.

I plan to keep one of them for myself and sell the other. I paid $105 for the Austrian version and $140 for the Chinese one, which has the box and accessories. I guess it wasn't a bad deal...
 

Robbo99999

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I've bought them both from eBay and sent them directly to Amir, so I never really saw them in person. Based on the pictures it seems that the Chinese version has "newer" pads, so I'll propose to Amir that he uses the same pads to review both. It's pretty easy to swap the pads, so I guess it wouldn't be a hassle :).

Both eBay sellers had 100% positive reviews, so I'm confident none of these cans are defective.

I've never listened to any AKG 701 in person, the only ones from "the family" that I tried were the K7XX and the K712.

I plan to keep one of them for myself and sell the other. I paid $105 for the Austrian version and $140 for the Chinese one, which has the box and accessories. I guess it wasn't a bad deal...
K701 is really quite similar to K702 in both physical structure & frequency response, with K701 perhaps being a bit warmer when comparing Crincacle measurements of K701 to Oratory & Crinacle measurements of K702:
K701 vs K702.jpg

So in terms of the K7 family, if you've got the K701 it's gonna be almost like a having a K702. I do think it's likely that the angled pads of the K702 & K701 stand them in better stead re soundstage vs the K712 / K7XX.
 

solderdude

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I've never listened to any AKG 701 in person, the only ones from "the family" that I tried were the K7XX and the K712.

The K7XX and K712 are kind of close in signature. The K712 being slightly better sounding (to me).
k712-vs-k7xx.png


Both sound substantially different from K702. (compared to K7XX below)
k702-vs-k1xx.png


Both sound substantially different from K701/K702. (within production spread)
k702-vs-k701.png

The K70* are bass-shy and clearer/brighter/more 'forward' sounding.
 
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Luke Lemke

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K701 is really quite similar to K702 in both physical structure & frequency response, with K701 perhaps being a bit warmer when comparing Crincacle measurements of K701 to Oratory & Crinacle measurements of K702:
View attachment 175937
So in terms of the K7 family, if you've got the K701 it's gonna be almost like a having a K702. I do think it's likely that the angled pads of the K702 & K701 stand them in better stead re soundstage vs the K712 / K7XX.
Interesting, I didn't know the K701 was bit warmer compared to the 702, that's more in line with my preferences. That being said, I'll EQ the 701 anyway. Regarding the angled pads, I also think that's a plus for the 701/702 compared to the rest of the family...
 

Luke Lemke

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The K7XX and K712 are kind of close in signature. The K712 being slightly better sounding (to me).
k712-vs-k7xx.png


Both sound substantially different from K702. (compared to K7XX below)
k702-vs-k1xx.png


Both sound substantially different from K701/K702. (within production spread)
k702-vs-k701.png

The K70* are bass-shy and clearer/brighter/more 'forward' sounding.
I've always thought the AKG K7 family was more or less the same headphones with slightly different tuning. Based on your measurements, that's not really the case, thanks for that.

I've read your review of the K701 and it seems it has a little bit more distortion than the K702 / K712. Is that really the case? I can't properly understand the distortion charts to be honest.
 

GaryH

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Based on the pictures it seems that the Chinese version has "newer" pads, so I'll propose to Amir that he uses the same pads to review both. It's pretty easy to swap the pads, so I guess it wouldn't be a hassle :).
Do you know the Chinese and Austrian versions use identical pads (when new) though?
 
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