[Saraya]

Yes, agreed. I always got the impression Dolby virtualization, like any synthetic surround was bound to be a bit tasteless and tacky. However on these cards, it seems particularly bad.
You're suggesting use Razer to EQ and leave Xonar in pure analogue (with 8 channels?)
 
I will set it back to high gain/current then.

 

[elwappo99]

 
Actually I'm not after more bass. I just happened to be listening to a bass test when I noticed the buzzing.
 
I did as you said, and I appreciate the cans more when in a basic stereo analogue environment, though it sounds centered and claustrophobic to me.
 
Questions : 
 You do not mention anything about the amp. Where does this fit back into the equation? And should it be on high gain/high current?
 Is Dolby not meant to be used for these type of headphones? 
 What Sample rate am I meant to use in Windows and Xonar?

 
I see. It could be the buzzing was a result of "over equalizing then". No harm intended on the "more bass", I'm just trying to speculate based on previous experiences with users. 
 
Great! Glad you're appreciating the basic stereo. It should sound centered, and claustrophobic, is hard to truly compensate for. Some people claim that after "burn in" they will sound a bit more open, but nothing like the artificial sound of a dolby headphone environment. This should be a good starting place for you. I would make small changes in EQ, "virtual surround", etc, and see how each one affects your listening and if you enjoy it more. 
 
The Fiio E11 may not be best suited for the K612. It may actually "bottleneck" the sound from your Xonar. In fact your Xonar has a amplifier of sorts built in already, which might be better for the K612 than the Fiio.
Dolby headphone is meant for any headphone. I rarely use it, and when I do it's basically for gaming only. I find the weird reverberations and echos to just sound too bizarre for music listening. Again, play with it, and see if you like it.
I would suspect 90% of what you'll listen to is 44.1K. You can find audio that is a higher sample rate (for example HDtracks sells their music at up to 192KHz). If you select to play at a higher rate, it won't adversely affect anything. I believe the Xonar DG does have some capabilities of what is called "upsampling" but that's a long path I don't want to get too much into, as you're just starting out. Like everything else, play with it, pick what you like best. Chances are you won't hear much of a difference at all.
 
I would suggest giving Mad Lust Envy's guide a read if you haven't (at least the beginning when he looks at the surround sound stuff). FWIW, when you get to ratings, I'd place the K612 really close to the K702 65th anniversary.
 
http://www.head-fi.org/t/534479/mad-lust-envys-headphone-gaming-guide-updated-1-27-2014-monster-dna-pro-added-edits

 

[Saraya]

Thanks a lot.
 
Yes, I thought the EQ might be causing the bass distortion, but now on pure analogue it's still there.
When I use the EQ from the Fiio, it gives more punch to the bass and doesn't muddy it much. The rattle stays the same instead of increasing. 
 
As for E11 vs the sound card. It was suggested to me that a medium range ohms output(32-64) on the card  + the amp would be a better quality drive, than just the sound card alone because of the high current option.

 

[kman1211]

  Yes, agreed. I always got the impression Dolby virtualization, like any synthetic surround was bound to be a bit tasteless and tacky. However on these cards, it seems particularly bad.
You're suggesting use Razer to EQ and leave Xonar in pure analogue (with 8 channels?)
 
I will set it back to high gain/current then.

That's what I found. It can become tolerable with games but that reverb is just strange. I got better results by simply changing it to 8 channels and/or using razer because they don't mess with the sound too much. Basically. I often just change it to 8 channels and that works fine for me. Sometimes I get razer going.
 
I had some distortion and rattle with the bass at times when I first used the K612, it went away after a few days of use. It's just something odd I noticed.

 

[elwappo99]

  Thanks a lot.
 
Yes, I thought the EQ might be causing the bass distortion, but now on pure analogue it's still there.
When I use the EQ from the Fiio, it gives more punch to the bass and doesn't muddy it much. The rattle stays the same instead of increasing. 
 
As for E11 vs the sound card. It was suggested to me that a medium range ohms output(32-64) on the card  + the amp would be a better quality drive, than just the sound card alone because of the high current option.

 
The fact the bass is still there is a little concerning. Does it exist at any volume? I would take the earpad off and closely examine the driver. Maybe a hair got caught in there and it causing a vibration. Is it just the bass or other frequencies as well? Did you ever push a ton of volume into them?
 
If you want to use the E11, that's also what I would recommend. I don't have experience with the E11, so if it sounds better with the E11, then go for that. If you like straight from the sound card, you can use either gain. Part of the removing the E11 is to see how much of a difference it makes with the bass rattling. 

 

[Change is Good]

Try the bass shaker on this headphone test and reprt back...
 
http://www.audiocheck.net/soundtests_headphones.php

 

[Saraya]

 
That's what I found. It can become tolerable with games but that reverb is just strange. I got better results by simply changing it to 8 channels and/or using razer because they don't mess with the sound too much. Basically. I often just change it to 8 channels and that works fine for me. Sometimes I get razer going.
 
I had some distortion and rattle with the bass at times when I first used the K612, it went away after a few days of use. It's just something odd I noticed.

 
 
Yes, something never quite right with Dolby. 
So far with headphone/analogue as elwappo suggested, it sounds alright but definitely needs EQ. I tried it with my Xonar EQ and Razer EQ and decided to use one or the other only. The Razer comes out better overall it would seem and you get a bit more flexibility/options.
 

   
The fact the bass is still there is a little concerning. Does it exist at any volume? I would take the earpad off and closely examine the driver. Maybe a hair got caught in there and it causing a vibration. Is it just the bass or other frequencies as well? Did you ever push a ton of volume into them?
 
If you want to use the E11, that's also what I would recommend. I don't have experience with the E11, so if it sounds better with the E11, then go for that. If you like straight from the sound card, you can use either gain. Part of the removing the E11 is to see how much of a difference it makes with the bass rattling. 

 
Lesson learned, never test with Youtube songs. Rattling does not exist when hearing that same song locally.
 
Interestingly though, with Dolby enabled it manages to mask the rattle in the Youtube version. 
 
 
I cannot really tell if it sounds better with the E11, or it just gives more volume. 
At the moment I am enjoying 32-64 gain on Xonar, EQ with Razer and through the E11 amp.

 

[Change is Good]

 

[elwappo99]

   

   
The fact the bass is still there is a little concerning. Does it exist at any volume? I would take the earpad off and closely examine the driver. Maybe a hair got caught in there and it causing a vibration. Is it just the bass or other frequencies as well? Did you ever push a ton of volume into them?
 
If you want to use the E11, that's also what I would recommend. I don't have experience with the E11, so if it sounds better with the E11, then go for that. If you like straight from the sound card, you can use either gain. Part of the removing the E11 is to see how much of a difference it makes with the bass rattling. 

 
Lesson learned, never test with Youtube songs. Rattling does not exist when hearing that same song locally.
 
Interestingly though, with Dolby enabled it manages to mask the rattle in the Youtube version. 
 
 
I cannot really tell if it sounds better with the E11, or it just gives more volume. 
At the moment I am enjoying 32-64 gain on Xonar, EQ with Razer and through the E11 amp.

 
Perfect! I was concerned that it was happening with ALL bass, pointing to driver defect. Hearing a bass distortion on one portion of a specific song generally indicates a flaw with the recording itself, or the music file.
 
Like I said, play around with it. You may find you like specific settings for different situations. Sometimes for fun I put on dolby digital headphones with my "more bass" headphones while I play a game. Either way, do what you enjoy most! 
 
happy listening!

 

[Saraya]

   
Perfect! I was concerned that it was happening with ALL bass, pointing to driver defect. Hearing a bass distortion on one portion of a specific song generally indicates a flaw with the recording itself, or the music file.
 
Like I said, play around with it. You may find you like specific settings for different situations. Sometimes for fun I put on dolby digital headphones with my "more bass" headphones while I play a game. Either way, do what you enjoy most! 
 
happy listening!

Aye indeed, much appreciated. 

  Try the bass shaker on this headphone test and reprt back...
 
http://www.audiocheck.net/soundtests_headphones.php

All ok with bass shaker!

 

[Saraya]

Headphones are a bit big on me ( can't imagine what the 550s would have been like). They sit ok on the ears for the most part, though the head band is lacking. I think the removal of the pad on the new K models really cut out some of the necessary friction and grip.
 
Any suggestions on a DIY way to make it better?
 
I have a few pads from HS800 creative headsets that I can detach and maybe use. Not sure if the curvature will cause problems though.

 

[Change is Good]

Headphones are a bit big on me ( can't imagine what the 550s would have been like). They sit ok on the ears for the most part, though the head band is lacking. I think the removal of the pad on the new K models really cut out some of the necessary friction and grip.

Any suggestions on a DIY way to make it better?

I have a few pads from HS800 creative headsets that I can detach and maybe use. Not sure if the curvature will cause problems though.

Order some K702/Q701 angled pads from AKG

 

[Saraya]

I was unable to find the pads you mentioned. I think I get the part code right but I'm not sure. If you have it to hand, please share.
 
In the meantime, I took a headcushion from a spare HS800 and put it onto the K612.
It works extremely well. I do however have to pull the headphones downards a bit to get the cups around my ears now. I hope this doesn't stretch the bands too much.
 

 

[conquerator2]

  I was unable to find the pads you mentioned. I think I get the part code right but I'm not sure. If you have it to hand, please share.
 
In the meantime, I took a headcushion from a spare HS800 and put it onto the K612.
It works extremely well. I do however have to pull the headphones downards a bit to get the cups around my ears now. I hope this doesn't stretch the bands too much.
 

Looks like something that should have been there from the start

 

[Saraya]

Yes, maybe.
 
Resting, with no extension, the side bands measure 3cm
On my head, with no Hs800 cushion, they are about 4cm extended.
With the cushion, they measure about 6cm extended.
 
Anyone else get around 6cm or 2 inches when wearing them normally?
I am concerned that by using the Hs800 cushion, that it will stretch the bands unnecessarily, and make them weaker.