fishski13
Member of the Trade: SolderWorksAudio
- Joined
- Nov 2, 2004
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Acix,
have you heard the Q701?
If the K701 had the bass that the Q701 has, I'd have kept them. That's for sure.
I got both HD 650 and K702 and in A/B test I found K702 has more highs while HD 650 got more prominent lows but lacks a bit of very high frequencies when compared with K702. To me HD 650 is wonderful for vocals (more sweet and warm) while K702 is more neutral and is good for jazz, acoustics and classics.
To my ears HD 650 sounds veil at high freq however having removed the foam grill the veil has gone (but the highs still cannot compete with K702) !!
To me the lows of K702 is not lacking at all while its highs are not causing ear fatigue and this headphone has honestly reproduced what is in the CD without added color. I have read with interests about the differences of Q701 and K702 and is interested to make the sound signature of K702 close to that of Q701. To this end I have inserted an acoustic foam piece of about 1/4" thick inside the 2 dooms of K702 and put another 1/4" thick round acoustic foam of just about 1-1/4" dia to cover the driver in additional to the foam already in place . To my amazement the lows of K702 are now more extended and the highs has been reduced by a small amount.
I then had another A/B test with both the modified HD 650 and K702 and now the two cans sound much closer. The lows of K702 is very closed to HD 650 though failed by a small margin. Overall I love the sound signature of the modified K702 more than the HD 650 even though HD 650 sound a bit more sweet with vocals. The soundstaging of K702 is bigger than HD 650 and the sound produced is cleaner and more clear.
Both cans used their stock cables on A/B testing and the foam used are acoustic foam (open cell) instead of normal foam (closed cell). K702 has a burn-in time of over 300 hrs while HD 650 is just over 100 hrs. The headphone amplifier used is Fidelity Audio HPA-200 http://www.fidelityaudio.co.uk/hpa-200.html
A lot of folks here expressed that K702 has a lean bass which I cannot agree with. According to the specifications from the two makers K702 has a freq. response of 10-39800Hz with 62 ohm impedance while HD 650 also got a freq. response of 10-39800Hz but with 300 ohm impedance. IMHO the main cause of lean bass is most probably due to insufficient current being fed to the headphone from the headphone amplifier. Just like driving a pair of power hungry speaker if your amplifier is unable to deliver sufficient current the bass will be greatly affected. You may wish to know that the headphone amplifier I used adopted a 250mA audio buffer in each of the channels (dual mono design) and that explains why I do not feel K702 is bass lean at all.
To my ears HD 650 sounds veil at high freq however having removed the foam grill the veil has gone (but the highs still cannot compete with K702) !!
The lows of K702 is very closed to HD 650 though failed by a small margin. Overall I love the sound signature of the modified K702 more than the HD 650 even though HD 650 sound a bit more sweet with vocals. The soundstaging of K702 is bigger than HD 650 and the sound produced is cleaner, clearer and more transparent.
A lot of folks here expressed that K702 has a lean bass which I cannot agree with.
I got both HD 650 and K702 and in A/B test I found K702 has more highs while HD 650 got more prominent lows but lacks a bit of very high frequencies when compared with K702. To me HD 650 is wonderful for vocals (more sweet and warm) while K702 is more neutral and is good for jazz, acoustics and classics.
To my ears HD 650 sounds veil at high freq however having removed the foam grill the veil has gone (but the highs still cannot compete with K702) !!
To me the lows of K702 is not lacking at all while its highs are not causing ear fatigue and this headphone has honestly reproduced what is in the CD without added color. I have read with interests about the differences of Q701 and K702 and is interested to make the sound signature of K702 close to that of Q701. To this end I have inserted an acoustic foam piece of about 1/4" thick inside the 2 dooms of K702 and put another 1/4" thick round acoustic foam of just about 1-1/4" dia to cover the driver in additional to the foam already in place . To my amazement the lows of K702 are now more extended and the highs has been reduced by a small amount.
I then had another A/B test with both the modified HD 650 and K702 and now the two cans sound much closer. The lows of K702 is very closed to HD 650 though failed by a small margin. Overall I love the sound signature of the modified K702 more than the HD 650 even though HD 650 sound a bit more sweet with vocals. The soundstaging of K702 is bigger than HD 650 and the sound produced is cleaner, clearer and more transparent.
Both cans used their stock cables on A/B testing and the foam used are acoustic foam (open cell) instead of normal foam (closed cell). K702 has a burn-in time of over 300 hrs while HD 650 is just over 100 hrs. The headphone amplifier used is Fidelity Audio HPA-200 http://www.fidelityaudio.co.uk/hpa-200.html
A lot of folks here expressed that K702 has a lean bass which I cannot agree with. According to the specifications from the two makers K702 has a freq. response of 10-39800Hz with 62 ohm impedance while HD 650 also got a freq. response of 10-39800Hz but with 300 ohm impedance. IMHO the main cause of lean bass is most probably due to insufficient current being fed to the headphone from the headphone amplifier. Just like driving a pair of power hungry speaker if your amplifier is unable to deliver sufficient current the bass will be greatly affected. You may wish to know that the headphone amplifier I used adopted a 250mA audio buffer in each of the channels (dual mono design) and that explains why I do not feel K702 is bass lean at all.
Not yet, but I'm aware of AKG changing drivers during the production time to the same individual model.
If I were you I will forget HD 650 unless you mostly listen to POP and Rock music. As a matter of fact HD 650 is relatively easy to drive but the overall sound quality is not as good as K702. Since you already have the K702 and according to my personal experience it would be more effective to buy a GOOD DAC with GOOD headphone amplifier of sufficient output to drive your K702. With that I am sure you can hear a great improvement in sound quality and hear a lot of bass.
This why I was never interested in the 650...they sounds like under the water (scuba dive). The K702 sounds like a free fly over the puffy clouds with a cleaner and transparent view.
Source?
Hi Intervoice, thanks for the comment. Do you have the possibility to post pictures of your mod here ? Fishski, and then myself, have been trying to work with some tape and felt for some time, and I'm curious about this open foam thing. However I'm not visualizing it very well, would you mind giving us a little more info ?
Thanks.