AKG K701 Headphone Reviews (China and Austrian Made)

[restorer-john]

Its not that likly that this -5 db channel imbalance measurement is representative for other akg k 701. Its the worst we have ever seen for an k 701, like as far as i can tell really ever. Might be defective.

Or simply a totally messed up measurement.

The headphone would have never left the factory with an imbalance like that. The drivers themselves would have never seen the light of day, letalone be installed in products.

 

[oneman]

In the pic, that doesn't look like factory soldering.

Soldering - I found that photo on the internet so probably you are right.
But soldering is not an issue. As you can see there is no cable going from left to right driver. The signal to the left driver goes directly through a copper cable but to the right one it passes through a steel wire. Such a wire you can find in a product like on a picure below.
Just make an experiment. Turn on an amplifier and send a signal to your left speaker through a copper and to the right speeker through the hanger. Will it be sound the same?

 

[solderdude]

I actually measured the rods (in a Superlux) and its resistance is much lower than a piece of wire of the same length.

The only issue there is is the soldering which is a PITA because heating too long melts the plastic.

 

[oneman]

I actually measured the rods (in a Superlux) and its resistance is much lower than a piece of wire of the same length.

Do you suggest that there is no difference in sound when you plug the left spaeker to your amplifier via a copper wire and the right speaker via a hanger? If so, why all the audiophiles spend a lot of money on their super duper cables? Steel wires are a lot cheaper

 

[solderdude]

I know for a fact that the rods in the K7** series are lower resistance than a piece of wire or do you suggest the rods are of such high resistance and poor quality that the right side suffers in quality in all AKG and Superlux models.
If so please supply evidence of this.

The reason why audiophools spend a lot of cash on their wet dreams has literally 0 to do with it.
When you have any objective proof that headphone cables make a difference (as opposed to measurements I made) then please post that info here.

 

[Robbo99999]

I actually measured the rods (in a Superlux) and its resistance is much lower than a piece of wire of the same length.

The only issue there is is the soldering which is a PITA because heating too long melts the plastic.

Do you think it's likely to damage the drivers too during that process? I heated the rod enough so that the solder flowed into the wire rather than sitting as a blob. (It was my 2015 K702 that I sent to Oratory for measurement.)

 

[CedarX]

I know for a fact that the rods in the K7** series are lower resistance than a piece of wire or do you suggest the rods are of such high resistance and poor quality that the right side suffers in quality in all AKG and Superlux models.
If so please supply evidence of this.

The reason why audiophools spend a lot of cash on their wet dreams has literally 0 to do with it.
When you have any objective proof that headphone cables make a difference (as opposed to measurements I made) then please post that info here.

Honest question: isn't conceivable that a poorly-designed HPA could pickup EMI interferences fed back from the headphone cable, or K701-style rods? "Poorly-designed" HPA would be the key here, so the cable may make a difference but is not the culprit.

 

[Deleted member 23424]

FFS. A matter of days before my amp arrives and @amirm is on a mission to delete all the cans on my demo list.

K371 arrived yesterday, they'll do me fine as daily drivers, but was hoping these might tick the box for more critical listening. Not a chance based on those results.

At this rate my list will soon be down to 2 pairs of £1k+ headphones, a divorce lawyer and a bed for the shed.

 

[musicreo]

Or simply a totally messed up measurement.

The headphone would have never left the factory with an imbalance like that. The drivers themselves would have never seen the light of day, letalone be installed in products.

As the channel balance problem seems not to effect the listening test it is most likely that something went wrong with the measurement.

 

[PuX]

Just make an experiment. Turn on an amplifier and send a signal to your left speaker through a copper and to the right speeker through the hanger. Will it be sound the same?

has anyone actually done this to confirm scientifically?

 

[solderdude]

Do you think it's likely to damage the drivers too during that process? I heated the rod enough so that the solder flowed into the wire rather than sitting as a blob. (It was my 2015 K702 that I sent to Oratory for measurement.)

No way drivers can be damaged this way.

 

[solderdude]

Honest question: isn't conceivable that a poorly-designed HPA could pickup EMI interferences fed back from the headphone cable, or K701-style rods? "Poorly-designed" HPA would be the key here, so the cable may make a difference but is not the culprit.

A wire in the headband would pick up the same amount of RF.
Most headphone cables are not screened at all so a cable would pick up way more than the rods.

 

[Limopard]

Once upon a time when I had the Q701 (Quincy Jones Edition, lime green) I also cut off the headband bumps and glued a piece of pleather from an old pencil case over the "wounds" to make it look less butchered. I sold it some time later, it sounded somewhat off to me in the upper mids and treble.
Nevertheless, for the current price of appx. 120 EUR it's a "fine" headphone, especially since there are no bumps anymore.

 

[solderdude]

has anyone actually done this to confirm scientifically?

Cable myths: reviving the coathanger test

Today, in our speaker cable blind test we're going to try to prove one way or another whether or not high-end speaker cables make a difference for your equipment.

www.soundguys.com

 

[phoenixsong]

This is a review and detailed measurements of two versions of AKG K701 headphones: one made in Austria and one in China. They are on kind loan from a member and cost US $249.

View attachment 186515
Let's start with the China version. It is lightweight and doesn't impart feeling of a premium product. The large cups make them comfortable to wear though.

Note: The measurements you are about to see are made using a standardized Gras 45C. Headphone measurements by definition are approximate and variable so don't be surprised if other measurements even if performed with the same fixtures as mine, differ in end results. Protocols vary such as headband pressure and averaging (which I don't do). As you will see, I confirm the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers mostly in bass and above a few kilohertz so keep that in mind as you read these tests. If you think you have an exact idea of a headphone performance, you are likely wrong!

The K701 has a self-adjusting mechanism which makes it hard to put high pressure on the test fixture. There was fair amount of variability in how I seated the unit.

AKG K701 MK II Chinese Measurements
Let's start with our usual frequency response measurements:

View attachment 186516

No matter what I did, I could not get the weak channel to match the other. What is there doesn't seem too bad. Here is our relative frequency response for purposes of EQ filter development:
View attachment 186517

The highly irregular shape combined with difficulty of measuring this headphone means an exact EQ is going to be hard to develop. But I am sure we can improve on the stock sound.

I was disappointed in distortion measurements:

View attachment 186518

That spike at 2 kHz is where our hearing is very sensitive. Its narrow width though indicates it is likely a resonance.

View attachment 186519

Group delay confirms that a secondary resonance (of the case?) at the same frequency as above:

View attachment 186521

Impedance was on the low to medium side:

View attachment 186522

Sensitivity is below average but not crazy so:
View attachment 186523

AKG K701 Austrian Made Measurements
Let's start with a shot of the unit itself:

View attachment 186524

Notice that the headband has bubbles in it which I found more comfortable. And the cup has the designation of "Made in Austria). Otherwise they two feel the same.

Channel matching here was actually worse than the Chinese version:

View attachment 186525

That is whopping 5 dB difference extending to almost 1 kHz! It may be measurement error or fitment but still, we don't see large variations like this often.

Comparing the Chinese to Austrian we get:
View attachment 186526

Given the degree of accuracy we have in measurements, I say that they are "the same." Where they are not the same is in distortion measurements:

View attachment 186528

So looks like there are minor variations in the mechanical aspects of the headphone that causes resonances at different frequencies. Overall, I prefer the Austrian one (right above).

View attachment 186530

Group delay now looks better:
View attachment 186529

AKG K701 Listening Tests and Equalization
I did my listening tests and EQ using the Austrian one. Out of the box response is not offensive. It seems a bit upper bass boosted and the rest sounds kind of ordinary. Fixing the response errors wakes up the sound nicely:


View attachment 186531

Bass distortion was not audible until you cranked it up. Then it would crackle a bit and progressively get worse. But it never pops or make you scared that something bad is going to happen.

With EQ, I could sit back and enjoy the sound and take advantage of the comfort of the unit.

Conclusions
Common between these two AKG headphones is rather complex response error and resonances. EQ helps with the former to create much better sound. Our measurements and headphone variations are too large to say convincingly that one version is worse than the other. Taken at face value, I would say the Austrian one is a bit better in distortion department. But sadly had more channel variation.

I can't recommend either version of AKG K701 without EQ. With EQ, they are fine.
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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Thanks for the revealing review!

 

[Presently42]

Well! Colour me saddened! The AKG K701 were my first audiophile headphones, used in conjunction with a diy Beta22 amp, Sigma22 psu and Buffalo Sabre dac I'd made. Before I discovered eq, I thought I had the best system money could buy. I now see, that I was right - iff we base the metric on enjoyment of music. I ended up giving the K701 to a friend after I replaced them with the HD800. Anyway, many fond memories of music I have with them. I had them for ten years or so, so a lot of music (and my thought on how music should sound) is based on their sound. To wit, it took me several months to get used to the Harman target curve.

One thing I notice @amirm didn't remark upon in his review, were the spatial qualities of the K701: they have a reputation for having a delisciously large soundstage and whatnot. For my own part, they are only bested by the HD800 in that field, of the headphones I've heard. I still wish we'd a more solid metric for measuring soundstage!

 

[Yayoming]

K701: they have a reputation for having a delisciously large soundstage and whatnot. For my own part, they are only bested by the HD800 in that field, of the headphones I've heard. I still wish we'd a more solid metric for measuring soundstage!

True, funny enough HD800 seems to be natural upgrade path for them, kind of same sound but done better.

 

[Presently42]

True, funny enough HD800 seems to be natural upgrade path for them, kind of same sound but done better.

Indeed, that's why I bought the HD800!

Edit: also, I note, that you're a new member: welcome!

 

[amirm]

One thing I notice @amirm didn't remark upon in his review, were the spatial qualities of the K701: they have a reputation for having a delisciously large soundstage and whatnot. For my own part, they are only bested by the HD800 in that field, of the headphones I've heard. I still wish we'd a more solid metric for measuring soundstage!

Sorry I should have mentioned this. Without EQ I didn't think spatial qualities stood out. With EQ I got some of it but still not enough for impress me. BTW, shortfall in 1 to 3 kHz region is a sure of way of NOT having good spatial qualities in my experience.

 

[Yayoming]

Sorry I should have mentioned this. Without EQ I didn't think spatial qualities stood out. With EQ I got some of it but still not enough for impress me. BTW, shortfall in 1 to 3 kHz region is a sure of way of NOT having good spatial qualities in my experience.

Thank you for another review, this site is truly added value to community.

From many reviews it look like it is not easy to please Amir when it comes to headphones. Can you please recommend something reasonably priced with great spatial qualities?