[roBernd]

Quote:

 
And I just remembered sumthin'
A few weeks ago a friend of mine told me that his Q701s were significantly more efficient than his K701s.

Not possible.
 
Same Drivers, the only difference except for the color is the added dampening behind the back-grill (where the additional Q is located) which slightly changes the SQ.

 

[iim7V7IM7]

The K702s are a great set of headphones and portray jazz with great detail and a fine sound stage. Like yourself, I am a long time audiofile and ex-vinyl listener. Personally, I am not sure what to make of the lack of bass comments. In jazz, a piano bottoms out at 28 Hz, open bass string is 41 Hz (30 Hz on a 5 string), and a kick drum is about 50 Hz.

The AKGs frequency response is attenuated -8 dB at 10 Hz which is below where we can hear. At 20 Hz, they are at -5 dB which is definitely decernable with a test tone. Some organ notes can be this low, but not many things. By the time you reach 30 Hz you are at -2 dB which is very solid. From 40 Hz to 200 Hz the K702s are from neutral to + 3dB. This where most of the bass register music is.

The HD650s go from neutral at 20 Hz (vs-5 dB for the AKGs) to +5 dB at 70 dB and stay at this emphasized level through 200 Hz. Some listeners prefer this euphonic signature and others prefer the K702s. The AKGs are happiest with a low output impedance amp with decent power.

They are great HFs...

My $.02,

Bob

 

[juantendo8]

I think that the HD600 would be best here. IMO, it is one of the best dynamic headphones ever made. The K/Q701 is nice too, but it lacks a certain naturalness that makes itself known in classical music. 

 

[muad]

where did u get your numbers?
Quote:

The K702s are a great set of headphones and portray jazz with great detail and a fine sound stage. Like yourself, I am a long time audiofile and ex-vinyl listener. Personally, I am not sure what to make of the lack of bass comments. In jazz, a piano bottoms out at 28 Hz, open bass string is 41 Hz (30 Hz on a 5 string), and a kick drum is about 50 Hz.
The AKGs frequency response is attenuated -8 dB at 10 Hz which is below where we can hear. At 20 Hz, they are at -5 dB which is definitely decernable with a test tone. Some organ notes can be this low, but not many things. By the time you reach 30 Hz you are at -2 dB which is very solid. From 40 Hz to 200 Hz the K702s are from neutral to + 3dB. This where most of the bass register music is.
The HD650s go from neutral at 20 Hz (vs-5 dB for the AKGs) to +5 dB at 70 dB and stay at this emphasized level through 200 Hz. Some listeners prefer this euphonic signature and others prefer the K702s. The AKGs are happiest with a low output impedance amp with decent power.
They are great HFs...
My $.02,
Bob

 

[tdockweiler]

Quote:

Not possible.
 
Same Drivers, the only difference except for the color is the added dampening behind the back-grill (where the additional Q is located) which slightly changes the SQ.

 
The only difference? Hardly possible you would know unless you dismantled both or work for AKG. Sounds like you're just guessing without knowing for sure. None of us know the reason for the sound change. It's NOT the foam on the back of the grill. Someone has already tested this out and found it doesn't cause much of a change.

Definitely agree on it possibly being more efficient. Had an old K702 and it always gave me issues with my Total Airhead. Red blink/clipping light constantly went off and drove me crazy. On the q701 with the same setup it's almost impossible for it to go off. I would actually have to crank it to nearly 90% and t would take specific music for it to clip or give me the over-voltage blink.
 
You can take the K702 and Q701 side by side and I will bet you money the Q701 will get more volume at the same level on the amp. Someone can test this if they want. Buying a Q701 for portable use is still a dumb idea though.
 
Supposedly the HD-650's became easier to drive too after a silent update. I've also experienced this myself and so have others. The HD-650 is very easy to drive with some portable amps and even sound good.
 
My vote goes for the Q701. Much better than the K702. I had the K702 and K701 only about half a dozen times..I think the Q701 is even better than the K601, Sextett, K400 and K601! Previously i'd never ever put the K702 above the K601 or K501..not a chance. Not a fan of the K400..
 
Don't get me started on the HD-650. I loved many things about it, even over the HD-600.
 
You can also add the HD-580 to the list, which I've found better than the HD-600 and 650. HD-580 lately so far i've been liking even more than my 598 and Q701. The HD-580 and Q701 is a near perfect pair.
 
BTW I don't think the Q701 is any less neutral or any less balanced than the HD-600. The HD-600 has too much mid-bass and the Q701 has a little extra treble. Take your pick

I'm 100% NOT a believer that the HD-600 is really all that neutral.

 

[iim7V7IM7]

Which ones? The headphones come from headroom frequency response plots and the instrument numbers comes from general musical knowledge.

 

[ShamanSleeve]

My vote goes for the 702, the soundstage is awesome, and with proper amping I'm sure you would be really happy with them.

 

[Lorspeaker]

I recommend u fork out a little more n consider the LDMkIVse

I recommend u upgrade the cable of either can...

I recommend u buy each can and give them a go n sell the loser

I recommend u work overtime and do all the above

I recommend u listen to some star trek soundtracks

 

[Chris J]

Quote:

 
The only difference? Hardly possible you would know unless you dismantled both or work for AKG. Sounds like you're just guessing without knowing for sure. None of us know the reason for the sound change. It's NOT the foam on the back of the grill. Someone has already tested this out and found it doesn't cause much of a change.

Don't agree on it possibly being more efficient. Had an old K702 and it always gave me issues with my Total Airhead. Red blink/clipping light constantly went off and drove me crazy. On the q701 with the same setup it's almost impossible for it to go off. I would actually have to crank it to nearly 90% and t would take specific music for it to clip or give me the over-voltage blink.
 
You can take the K702 and Q701 side by side and I will bet you money the Q701 will get more volume at the same level on the amp. Someone can test this if they want. Buying a Q701 for portable use is still a dumb idea though.

 
You just agreed with me.
If the Q is louder than the K, than the Q is more efficient, assuming they are both the same impedance, which sounds like a fair assumption (I have never read anyone saying that the impedance spec on the Qs and Ks was NOT 62 Ohms).
 
If the Airhead clipped when driving your old Ks but does not clip when drivng your Qs then the implication is that your Qs are more efficient than your Ks.    I believe that you have also stated in the past that your Ks were much older than your Qs?    So maybe there was a production change to the drivers.

 

[Dubstep Girl]

akg, you will love them.
 
the hd 650s are fantastic headphones though too.

 

[obobskivich]

You just agreed with me.
If the Q is louder than the K, than the Q is more efficient, assuming they are both the same impedance, which sounds like a fair assumption (I have never read anyone saying that the impedance spec on the Qs and Ks was NOT 62 Ohms).

If the Airhead clipped when driving your old Ks but does not clip when drivng your Qs then the implication is that your Qs are more efficient than your Ks.    I believe that you have also stated in the past that your Ks were much older than your Qs?    So maybe there was a production change to the drivers.

Didn't AKG move the production and change tooling at some point in the last year, for all of their headphones?

Also, Tyll measured them, FWIW:
http://www.innerfidelity.com/images/AKGK701.pdf
http://www.innerfidelity.com/images/AKGK701SampleB.pdf
http://www.innerfidelity.com/images/AKGQuincyJonesQ701.pdf

I see more variation between the two 701s than to the Q. Maybe it's me. I've also seen the GE measurements between the 701 and 702, and they're different as well. FWIW.

Wouldn't be the first manufacturer to have inconsistent production runs.

 

[tdockweiler]

Quote:

 
You just agreed with me.
If the Q is louder than the K, than the Q is more efficient, assuming they are both the same impedance, which sounds like a fair assumption (I have never read anyone saying that the impedance spec on the Qs and Ks was NOT 62 Ohms).
 
If the Airhead clipped when driving your old Ks but does not clip when drivng your Qs then the implication is that your Qs are more efficient than your Ks.    I believe that you have also stated in the past that your Ks were much older than your Qs?    So maybe there was a production change to the drivers.

Major typo in my last post. I meant to say the Q701 was possibly more efficient. It's really interesting how difficult it is to get my Q701 to start clipping with my Airhead.
The last time I used my K701/K702 regularly with the Airhead was back in 2004 or so. Could be different productions runs. I remember coming to the conclusion that the K701 was just not worth it with portable amps.
 
I tested a K702 last year with my Airhead and don't remember if it clipped as easily.

 

[Chris J]

Quote:

Didn't AKG move the production and change tooling at some point in the last year, for all of their headphones?
Also, Tyll measured them, FWIW:
http://www.innerfidelity.com/images/AKGK701.pdf
http://www.innerfidelity.com/images/AKGK701SampleB.pdf
http://www.innerfidelity.com/images/AKGQuincyJonesQ701.pdf
I see more variation between the two 701s than to the Q. Maybe it's me. I've also seen the GE measurements between the 701 and 702, and they're different as well. FWIW.
Wouldn't be the first manufacturer to have inconsistent production runs.

 
I met a guy at a Headphone meet with a pair of K70x, problem is, I'm not sure whether they were K701 or K702, and I don't know what vintage they are.
And I don't know how to get hold of the guy
But they sure sounded similar to my Q701s!   They did not sound the same, but they were very, very similar, we both agreed on this.
 
I also know a guy with a pair of K70x and Q701, again, I do not know which K70x they are and I do not know what vintage they are.  But I trust him, and he very clearly told me that the Q701 was louder than the K70x.
 
So basically, I agree with you!  But I have no idea when AKG changed their production.
I know we change our product where I work for various reasons, quite often they are supplier related issues!
(I'm an EE working in the Power field).

 

[Chris J]

Quote:

Major typo in my last post. I meant to say the Q701 was possibly more efficient. It's really interesting how difficult it is to get my Q701 to start clipping with my Airhead.
The last time I used my K701/K702 regularly with the Airhead was back in 2004 or so. Could be different productions runs. I remember coming to the conclusion that the K701 was just not worth it with portable amps.
 
I tested a K702 last year with my Airhead and don't remember if it clipped as easily.

 
Yeah, I figured it was a typo!
You could argue that some Q701s are more efficient or more sensitive than some K70x.
 
You obviously know your 'phones!

 

[obobskivich]

I met a guy at a Headphone meet with a pair of K70x, problem is, I'm not sure whether they were K701 or K702, and I don't know what vintage they are.
And I don't know how to get hold of the guy
But they sure sounded similar to my Q701s!   They did not sound the same, but they were very, very similar, we both agreed on this.

I also know a guy with a pair of K70x and Q701, again, I do not know which K70x they are and I do not know what vintage they are.  But I trust him, and he very clearly told me that the Q701 was louder than the K70x.

So basically, I agree with you!  But I have no idea when AKG changed their production.
I know we change our product where I work for various reasons, quite often they are supplier related issues!
(I'm an EE working in the Power field).

The 701 and 702 are easy to tell apart - the 701 are only available in white, and the 702 are that blue/black color with the removable cord. I don't know if the 702s are serialized, but the 701s are - lower is older (mine was in the low 30,000s, and I bought them in mid-2008, they came out in 2006). The gentleman who bought them had no issues with them either - wish he posted more, he owns like 3-4 pairs of K701 and could probably illuminate this discussion a lot better than most of us.

I just remember hearing something about AKG shifting their factory to China in the last year or two, to combat rising costs, and I would suspect that means new tooling and new assembly lines, that could lead to some variation in the finished product. That's why I bought it up. Could be wrong though.

The weirder variation is that I've seen 701s and 702s measured for CSD and they can have different waterfall plots - some have a treble ridge, some don't. I'm not sure what to make of it. Here's an example:
http://en.goldenears.net/4138
http://en.goldenears.net/8281

Those are supposed to be "absolutely identical except for the color of the plastic" - :rolleyes:

So then the next question is - are we certain that all three colors of the Q701 are even the same?

The whole thing makes me curious as to what I'd get if I walked into a shop and bought a new AKG 700 series today...