[lejaz]

Quote:

Didn't headfiers claim that Sennheiser updated the HD650 drivers even though Sennheiser didn't explicitly say that they did? So following your logic, the most practical marketing strategy for Sennheiser was to market the new HD650s as the new improved HD650 Rev.2, but they never did that. Why?
 


 

Maybe they were afraid to alienate those who liked them the way they are, but don't ask me ...ask the people at sennheiser. If I was in charge I'd have advertised it if I thought it would bring new customers, which was obviously the aim of AKG with the 'Q' versions..

 

[lejaz]

Quote:

I got the bass heavy DT770s, and Zombie got the same months later. I highly doubt it was just a select few. I got my Q701 considerably later than Chicolom, and it's obvious to me it sounds different from the K701 I had.

I don't doubt they sound different to you. What could account for that remains to be determined. . Unfortunately AKG is silent on the issue and there's no obvious physical difference that could account for the change in sound....only a small bit of foam behind the outer grill, which some claim makes no noticeable difference. . . 
 

 

[megamagic]

And now I present, the AKG K701 Tissue Mod!
 

 
As you can see it's a really quick mod for testing purposes...
 
It's to simulate the foam/grill on Q701.
 
So briefly how does it sound? I believe I did notice a very slight increase in weight of the sound (less thin) compared to the original. It does seem to sound closer to the Q701 although I didn't do any AB comparison yet.
 
My guess is that restricting airflow to the drivers does have an impact on the resulting sound of the AKGs like in many other HP. For example you can find a number of closed HP with decent near sub-bass, ie. M50, D7000. Also if you look at a subwoofer, it's not totally vented on one side, but restricts the airflow though the use of "bass ports."
 
Anyway...anyone feel free to try this mod and report your results. Or maybe you can progress this mod some more 

 

[Mad Lust Envy]

If the K701 had the bass that the Q701 has, I'd have kept them. That's for sure.

 

[lejaz]

OK, but people actually swapped the foam piece out of the 'Q' and put it behind the rear grill of the 'k' and noticed no difference. I tried taping over the rear grill but didn't notice a significant change. The 'friend or foe' mod of the 'k' makes a more noticeable change in the 'k' version as far as I can tell. 
 
Quote:

And now I present, the AKG K701 Tissue Mod!
 

 
As you can see it's a really quick mod for testing purposes...
 
It's to simulate the foam/grill on Q701.
 
So briefly how does it sound? I believe I did notice a very slight increase in weight of the sound (less thin) compared to the original. It does seem to sound closer to the Q701 although I didn't do any AB comparison yet.
 
My guess is that restricting airflow to the drivers does have an impact on the resulting sound of the AKGs like in many other HP. For example you can find a number of closed HP with decent near sub-bass, ie. M50, D7000. Also if you look at a subwoofer, it's not totally vented on one side, but restricts the airflow though the use of "bass ports."
 
Anyway...anyone feel free to try this mod and report your results. Or maybe you can progress this mod some more 

 

 

[megamagic]

Or the cause might not be restricting airflow, but instead a having a "sound shield".

 

[megamagic]

Quote:

OK, but people actually swapped the foam piece out of the 'Q' and put it behind the rear grill of the 'k' and noticed no difference. I tried taping over the rear grill but didn't notice a significant change. The 'friend or foe' mod of the 'k' makes a more noticeable change in the 'k' version as far as I can tell. 
 


 

Interesting. I hadn't seen that mod before. Maybe I need to try it sometime if this doesn't work.
 
I will decide what to do in a few days depending on if my K701 ends up inside my filing cabinet... 

 

[EinZweiDrei]

what about the other grill.
k701 has 2 grills right? the small silver cap with holes and the plate with holes around it.
maybe there's foam under the outer grill in the q701.
i dont have a q701 to compare

 

[tdockweiler]

Don't forget the K701 and Q701 also use different part numbers for the foam behind the pads.
The K702 and Q701 share the same foam pieces.
 
Can anyone check your foam on the Q701 and tell me what it looks like? Are they both very sparkly and rough?
The K701 pieces should be somewhat softer and not sparkly. K701 and K601 share the same foam.
My stupid Q701 look like it had both K701 AND Q701 foam installed! What the heck..probably no difference.
 
Does anyone want to be my test dummy?
 
One thing I noticed is that the every single copper cable (other than stock) I've tried with the Q701 makes it sound thinner than it should be. Still sounds good, but a tiny bit different than the stock cable. The Q701 stock cables sounds almost like Canare and it could be that the Q701 cable uses a higher capacitance making it sound warmer (lower should technically sound brighter and not as warm). It just seems that when I use an alternative cable on the Q701, it loses some of the things I like about it. It took me many, many hours to realize this. It's especially noticeable in games like Skyrim. The Q701 is just not it's old self with any other wire than stock.
 
I know someone tried it, but try the K702 cable on the Q701. It may require listening to an entire album and then switching back. Probably a huge placebo effect, but maybe someone with golden ears can tell the difference more easily. Even though the K702 and Q701 cables are the same thickness they could be slightly different. Please don't tell me copper is copper. Already heard that a hundred times

 
The changes could be a combination of the button, cable and two foam pieces. There's also the internal wires going to the drivers that could be slightly different or maybe a higher gauge of wire is used. Probably unlikely and wouldn't change much.

 

[megamagic]

Listening now and actually I think the sound might be a bit over-damped with the amount/proximity of the tissue. Someone else should try this out to confirm what effect it might have.

 

[EinZweiDrei]

Quote:

Listening now and actually I think the sound might be a bit over-damped with the amount/proximity of the tissue. Someone else should try this out to confirm what effect it might have.

tissue might not be a proper damping material.
maybe something with cotton or sponge like texture will do better

 

[tdockweiler]

Quote:

what about the other grill.
k701 has 2 grills right? the small silver cap with holes and the plate with holes around it.
maybe there's foam under the outer grill.

There isn't on the Q701 (outer grill)) since you can see through it if you take off the pads. Never realized this before. I imagine the K702/K701 is see-through also. I know the K601 is.

 

[EinZweiDrei]

then akg might have change the driver a bit.
slightly upset that i got the k701 over the q701 because i thought they were the same phone except cosmetically.

 

[nsx280ps]

As i stated earlier in the post, I myself was not able to hear the differences between the K701 and the Q701.... I had some issues with build on the Q701 and returned them to get the K701... The K701 seems to be a very recent batch with serial No. 728xx..... Im not sure if its the case, just a theory, could they have made changes to the K701 throughout the production runs to make it sound like the Q701 today that we couldnt see easily?  Seeing how they also changed the headband from 7 to 8 bumps over time..

 

[megamagic]

Quote:

There isn't on the Q701 (outer grill)) since you can see through it if you take off the pads. Never realized this before. I imagine the K702/K701 is see-through also. I know the K601 is.

I think there is something under the Q701 small (middle) grill since it's hard for light to pass through. The K701 seems to be open.
 
 
Also how to open K701 grill here: http://www.head-fi.org/t/225819/guide-to-the-balanced-akg-k701-recabling.
 
edit: weird could not open mine yet. I wonder if it's glued now on new versions ><