[alpha80]

  I was somewhat impressed that the Mod actually works.
 
To summarise things,
 
Pros:
Extra 2-3db of Bass
Bass still detailed
Mids are more detailed or just emphasised
Highs still extends well and are no longer fatiguing
Has a Warm and Fun Sound as compared to it's previous clinical state (Although I like the original)
Changes how the K701 plays rock and metal songs.
Somewhat like an HD700 now.
Soundstage seems wider
 
Cons:
Bass isn't as tight as it used to be.
That extra bass is there for most tracks, but there are some, for some reason it didn't turn out so well, as I think the Bass wasn't tight enough and didn't have sufficient body for it.
That extra detail retrieval or whatever it is on the mids, can be bothersome. I'd rather have the HD800 etc for doing those.
For a Fun headphone, you have other headphones that could fill this gap. Unless you just want the mids of this headphone. But i'd say, just get the K712.
Lacks Instrument Separation now.
 

As someone with a K701, Q701, and K7XX, I'm finally convinced about trying this mod, since it's reversible.  Might even try it on the Q701's....
I'll report back once I have enough free time to do it, and test it.

 

[Chris J]

What didn't you like about it, if I can ask?

Ummm, the bass?

I know you didn't ask me, but I thought the bass mod made the bass excessive.

 

[alpha80]

  Now I have compared my modded k701 to the Hifiman he-500 using my Audio gd compass2. I listened at quite high levels of output to be sure the he-500 didn't fall behind the always clear and fast k701. Orthos do in general need a bit higher listening levels to shine through. Btw the k701 and the he-500 requires almost exactly the same amount of power. 
 
Bass level is the same as the he-500 with velour pads. I couldn't hear any difference in level or extension between the two, the k701 went just as deep as the he-500 and was just as powerful. The k701 was even a bit faster(more speed) and a tad more punchy due to the overall more clear presentation and this includes the bass. The texture or "surface" on the bass-notes was every bit as good on the k701 as it was on the he-500.
So if you think the bass level, detail, texture and extension is on a high level and is good in the he-500, then you will like the bass performance in the modded k701.
To my big surprise the bass performance in the modded k701 is just as good and is right up there with the high rated he-500. I thought the he-500 would beat my k701, but this is not the case. I was a bit shocked when I started comparing the two. The k701 is indeed a wild bargain. 

Good to know. Performing this mod today !

 

[econaut]

Very curious about your impressions.

 
Got the gel pads but won't keep them. Actually I already sold them.
 
- I don't have jug ears, but since the pads are slimmer than the velour ones my right ear touches the center of the headphone now
- in combination with the bass mod the sound is too warm and bassy for me now, almost muffled in direct comparison
 
In combination with a fusty / unventilated smell of my used ones I only checked them out two hours and decided very quickly not to keep them.
 
If you have any specific questions regarding the sound be quick since I will send them off tomorrow. I won't reverse the bass mod, though.
 
My hearing and vocabulary regarding sound is not that sophisticated, please excuse that.

 

[Shaffer]

Thanks very much for the update.

 

[turbobb]

If there was ever any doubt whether the bass mod makes a difference, I'm now fully convinced after running my Q701's via: http://www.audiocheck.net/Audio/audiocheck.net_headphoneshaker.mp3

I haven't used these much after I moved so still didn't upgrade the left cup yet and it's day and night difference in the sub bass on right cup until about 6 seconds. Of course it's much more subtle when listening to normal tracks unless of course your music only consists of sub bass... ^_^

 

[DangerClose]

 
Pros:
Extra 2-3db of Bass
Soundstage seems wider
 

 
I don't have any frequency measurements, but I was eq'ing the lows around +10db to get even close to the bass mod.  The mod made the soundstage sound less wide, or maybe just less airy and less detailed giving the impression of less wide.  I eq'd it down, the notes got thin and "analytical" again, and the soundstage had that wider, airy sound back.  EQ'ing 10db in either direction is probably not recommended for sound quality, but I'd have to A-B them to be sure of the difference, but I only have one K701 and one Q701 at the moment, so they're similar but not the same.
 
Some people said the mod doesn't affect the highs, but I think it does.  The mod makes the low end boomier, but it also makes the high end boomier.  Everything gets more diffused, or maybe just details are covered up more from the warmth.  Both sounds have their positives and negatives.

 

[HaruHaruHarHar]

   
I don't have any frequency measurements, but I was eq'ing the lows around +10db to get even close to the bass mod.  The mod made the soundstage sound less wide, or maybe just less airy and less detailed giving the impression of less wide.  I eq'd it down, the notes got thin and "analytical" again, and the soundstage had that wider, airy sound back.  EQ'ing 10db in either direction is probably not recommended for sound quality, but I'd have to A-B them to be sure of the difference, but I only have one K701 and one Q701 at the moment, so they're similar but not the same.
 
Some people said the mod doesn't affect the highs, but I think it does.  The mod makes the low end boomier, but it also makes the high end boomier.  Everything gets more diffused, or maybe just details are covered up more from the warmth.  Both sounds have their positives and negatives.

My Bass was certainly a lil more boomier and less tight. But it wasn't a huge difference. As for Clarity, the Bass sounds wobbly for some tracks but when I compared it to the Stock K701 and K702. It sounds it has a slightly larger soundstage, perhaps just because of the laid back vocals and toned down highs. Although, for you, it might have been the lack of Instrument Separation. It gives a sense of no focus. But overall, it's A lot more Warm and Musical in comparison to the stock. I kept both the Stock and Mod

 

[alpha80]

   
It'd be hilarious if the K712 bass port was open.

I think bassheads would be shocked that they may find their grail if they bass port modded the K712, or K7XX.  And they might be so take aback by their newfound airy AKG soundstage and detail, that it may convince them the Abyss or Audeze line aren't the grails they imagined they might have been !

 

[Flipjack]

  I think bassheads would be shocked that they may find their grail if they bass port modded the K712.

Yes! I liked the K701 five years back, but sold it due to too little bass weight and it was too airy for my taste. The K712 Pro with the bass mod checks about all of the boxes for me it seems, so far (bought them 1 week ago). The K712 Pro's have me tapping my feet - a feat that the K701 never offered.

 

[JulianPard]

Very interested in this. All the pros states sounds like what I'm looking for. Especially that the highs will be less fatiguing, as I am experiencing that with my K7XX's.

 

[JulianPard]

Aaaaand after finally finding a screwdriver small enough, I'm done with the mod. Haven't listened to my cans for too long, but it's safe to say there is a mild bass difference. Warmer sound also seems apparent. Fun little mod

 

[Shaffer]

Very interested in this. All the pros states sounds like what I'm looking for. Especially that the highs will be less fatiguing, as I am experiencing that with my K7XX's.

I'm surprised you find the K7XX's highs fatiguing. They're very warm sounding headphones compared to K701/2, which respond very well to the mod. The K7XX has more bass to begin with. Coupled with its warm presentation, the bass seems even more present and fleshed out. Their bass needs control, as in a good amplifier.

 

[ExistentialEAR]

assuming this works with K702's I would be interested.

 

[Shaffer]

assuming this works with K702's I would be interested.

It does. My K702 is modified, K7XX is not.