[Ashade]

That is probably why this mod sounds so natural on the k701. That subtle increase in the lower mids makes the transition from lows to mids more harmonic and smooth I guess.

This is by far the best mod I've tried to date in a headphone.

 

[papamogl]

Thanks for all the feedback. Now we only need to get this mod measured. I've already written Tyll Hertsen when posting the mod here, and he said he might measure it when he finds the time. Maybe if some more people asked him, he could be more tempted to do it.

 

[Rob80b]

Quiet day in the shop (being -20 and all) so I thought I’d do the bass port mod on my K701s, first listened to a few tracks from Bill Laswell, Underworld’s "Dubnobasswithmyheadman”, Pandelis Karayoris Trio and Rammstein "Reise, Reise" and then play them again after the mod.
All I can say is “merde”, I’m running them off an old Technics 25 year old receiver in the shop but…… where’s that distant shallow sounding stage and limp bass, holy schmolly, almost a totally different phone but in a good way!!
Also listened to Stockhausen: Bass Clarinet & Piano to make sure the sound staging and depth was still there, now even better than I remember.
The mod FWICT helps to fill in the mid-range and adds a bit of space from front to back by actually making separation much clearer.  With the fuller lower midrange and bass the K701s also now sound a lot less plastically and also richer overall with no added bloat.
I would say this mod does change the K701s personality somewhat but from what I can tell in no negative way unless one doesn’t like a little added richness in their lives.
I’ll need to try them later at home off the Bryston BHA-1/BCD-1 combo, hope they sound horrible and it's just a placebo (but I don't think so) as I just got my new pair of Sennheiser HD700’s.

 

 

[Ashade]

  Quiet day in the shop (being -20 and all) so I thought I’d do the bass port mod on my K701s, first listened to a few tracks from Bill Laswell, Underworld’s "Dubnobasswithmyheadman”, Pandelis Karayoris Trio and Rammstein "Reise, Reise" and then play them again after the mod.
All I can say is “merde”, I’m running them off an old Technics 25 year old receiver in the shop but…… where’s that distant shallow sounding stage and limp bass, holy schmolly, almost a totally different phone but in a good way!!
Also listened to Stockhausen: Bass Clarinet & Piano to make sure the sound staging and depth was still there, now even better than I remember.
The mod FWICT helps to fill in the mid-range and adds a bit of space from front to back by actually making separation much clearer.  With the fuller lower midrange and bass the K701s also now sound a lot less plastically and also richer overall with no added bloat.
I would say this mod does change the K701s personality somewhat but from what I can tell in no negative way unless one doesn’t like a little added richness in their lives.
I’ll need to try them later at home off the Bryston BHA-1/BCD-1 combo, hope they sound horrible and it's just a placebo (but I don't think so) as I just got my new pair of Sennheiser HD700’s.

 

 
I recently got the HD700, and I can tell you that after the mod, the Q701 and the HD700 are more similar than different. I need to listen to them a little bit more, but I think the HD700 is still a bit warmer and more detail. The bass impact on the HD700 is still bigger. Again, they are still very similar.
 
I still don't know if I'll keep the HD700 or return them and go for the HD800 directly. The HD800 is a real upgrade.

 

[Rob80b]

   
I recently got the HD700, and I can tell you that after the mod, the Q701 and the HD700 are more similar than different. I need to listen to them a little bit more, but I think the HD700 is still a bit warmer and more detail. The bass impact on the HD700 is still bigger. Again, they are still very similar.
 
I still don't know if I'll keep the HD700 or return them and go for the HD800 directly. The HD800 is a real upgrade.

 
Not having another stock K701 on hand I of course had to rush out and get my HD700s for comparison.
Direct comparison obviously showed the differences in tonal characteristic of each manufacturer but after a few minutes either phone was happy on my ears, the Senn HD700 still had the better linear sound stage but the differences were not as great as before, the mod added a bit more body to the AKGs midrange.
Lower bass was also much more in line, where previously the K701s could be slightly disappointing with some music.    
Any definite comment requires long term listening and the ideal would be to have an unmodded on K701 hand, but so far I like what I’m hearing.

 

[Rob80b]

   
I still don't know if I'll keep the HD700 or return them and go for the HD800 directly. The HD800 is a real upgrade.

Funny you said that as I was just asking myself the question after I did the mod, but any decision this early on  would be a bit premature, don't want to get too carried away you know.

 

[Ashade]

  Funny you said that as I was just asking myself the question after I did the mod, but any decision this early on  would be a bit premature, don't want to get too carried away you know.

 
I need at least a week more of comparison... After that, I'll have to decide.
 

   
Not having another stock K701 on hand I of course had to rush out and get my HD700s for comparison.
Direct comparison obviously showed the differences in tonal characteristic of each manufacturer but after a few minutes either phone was happy on my ears, the Senn HD700 still had the better linear sound stage but the differences were not as great as before, the mod added a bit more body to the AKGs midrange.
Lower bass was also much more in line, where previously the K701s could be slightly disappointing with some music.    
Any definite comment requires long term listening and the ideal would be to have an unmodded on K701 hand, but so far I like what I’m hearing.
 

 
I have two Q701s and at some point I had one modded and the other one unmodded. Both ended up modded, I bet you can guess why.

 

[Rob80b]

I'm curious as to how they'll sound later this evening off my main setup, right now at work I'm using a 25 year old receiver with an Imac. With the Bryston combo producing overall better sound with wonderfully tight and lower bass the gap may narrow even more.

 

[Rob80b]

   
I need at least a week more of comparison... After that, I'll have to decide.
 
 
I have two Q701s and at some point I had one modded and the other one unmodded. Both ended up modded, I bet you can guess why.

Hi Ashade
 
Wish you luck, after a few more hours of comparisons at home, the mod has really come close to leveling the playing field, and has definitely taken away the thinness of the central imaging and fleshed out the stage presence with the AKGs
The Sennheiser HD600s and HD700s were an easy choice if I needed to choose a phone with music that needed more bass, it’s no longer the case from what I’ve heard so far.
Obviously if you are indeed thinking of getting the HD800 the decision should be a little easier but not necessarily as the AKGs are brighter than the HD700s which are darker than the HD800s.
The only thing I can say right now is that tonally the K701s (assuming the Q701s are very similar) are more akin to listening to speakers in a livelier room and the HD700s are like listening in a room with more furnishings and carpet, both very good…  but different.

 

[Ashade]

Hi Ashade

Wish you luck, after a few more hours of comparisons at home, the mod has really come close to leveling the playing field, and has definitely taken away the thinness of the central imaging and fleshed out the stage presence with the AKGs
The Sennheiser HD600s and HD700s were an easy choice if I needed to choose a phone with music that needed more bass, it’s longer the case from what I’ve heard so far.
Obviously if you are indeed thinking of getting the HD800 the decision should be a little easier but not necessarily as the AKGs are brighter than the HD700s which are darker than the HD800s.
The only thing I can say right now is that tonally the K701s (assuming the Q701s are very similar) are more akin to listening to speakers in a livelier room and the HD700s are like listening in a room with more furnishings and carpet, both very good…  but different.

They indeed hold some differences but the Q701 after the mod plays definitely in another league. I like the HD700 but it's a little but dark for my tastes. When I heard the HD800 I felt that WOW factor I have not had since the first weeks with the Q's (first stock, them modded). The HD700 is slight step up but the HD800 is just about the perfect sound signature I've been searching for. I will be getting them eventually but first I need to give some more chances to the HD700.

 

[ThurstonX]

They indeed hold some differences but the Q701 after the mod plays definitely in another league. I like the HD700 but it's a little but dark for my tastes. When I heard the HD800 I felt that WOW factor I have not had since the first weeks with the Q's (first stock, them modded). The HD700 is slight step up but the HD800 is just about the perfect sound signature I've been searching for. I will be getting them eventually but first I need to give some more chances to the HD700.

 
I forget, have you heard any planar magnetics?  Just wondering how you compare them, esp. to the modded Q701s, esp. the HE-500s.  Pretty sure you've mentioned the HE-500s, but maybe were a little unsure about their sound...?  For me, both modded to varying degrees, they are quite complementary.  And while I doubt you'd like the HD 650s, they offer a third complementary point (can "complements" come in more than two?  Too lazy to check atm
 
HiFiMAN is "debuting" two new cans at CES.  Thread is here.  No real reports in yet, though one reviewer mentioned they compare favorably to stats, which tend to have killer highs, or so I've read.  Maybe these odd looking new HFMs might suit you.  Or maybe you just want me to leave you alone 

 
Also, I hope you're in TX now, and not Spain! 

 

[Ashade]

   
I forget, have you heard any planar magnetics?  Just wondering how you compare them, esp. to the modded Q701s, esp. the HE-500s.  Pretty sure you've mentioned the HE-500s, but maybe were a little unsure about their sound...?  For me, both modded to varying degrees, they are quite complementary.  And while I doubt you'd like the HD 650s, they offer a third complementary point (can "complements" come in more than two?  Too lazy to check atm
 
HiFiMAN is "debuting" two new cans at CES.  Thread is here.  No real reports in yet, though one reviewer mentioned they compare favorably to stats, which tend to have killer highs, or so I've read.  Maybe these odd looking new HFMs might suit you.  Or maybe you just want me to leave you alone 

 
Also, I hope you're in TX now, and not Spain! 

 
Hi ThurstonX! The truth is that the HE-500 is a headphone I'll have to eventually own, but I didn´t get to audition them yet (nor any other planar magnetic). I don´t want to get them without auditioning because that FR scares me a bit (they look warm...) and the thing on the weight... I need to attend to a Head-Fi meeting or another nice audio event to listen to them, or maybe I should wait for the HE-560 that looks that sexy! Thank you for pointing out that thread, I read the rumors but I missed that one.

 

[Punnisher]

I just performed the mod, and I'm very pleased. I always had a hard time swallowing the k702's forward nature. Much more balanced now it seems. Thanks for posting this.
 
It makes perfect sense now that I think about it. AKG has been doing this exact tweak for many years, since the 1970s. Each headphone they made would be tweaked slightly using ports in the driver. I'm used to seeing it in the k240 sextett, monitor and studio as well as k270/k280 dual driver units so I never thought about the modern phones having the same types of ports. Some months ago I performed the exact opposite tweak (blocking the port on the k240 studio) and was impressed. Less midbass and gobs more clarity and detail.

 

[Rob80b]

Here's the other mod which addressed the side ports, although it did not fly as well, probably because the driver needed to be removed.
 
http://www.head-fi.org/t/374455/k601-701-bass-increase-mod-also-applicable-to-k501-500-etc
Quote:

Here's your k601\701 driver(actually pics of k701 driver, by head-fier superkuato, from this thread)

From the other side, there're two opening, covered but sticky white tape:

To allow more driver movement, simply take away one of this sticky white tape pieces, thus allowing more bass to come out. Also, this is highly tunable: if you take both pieces off, the amounts of bass will be simply intolerable, so your best best is to try and find your own balance. Maybe for some it'll be enough not to pull the whole sticky off, but just make some tiny pokes in it(be careful, not poke the driver too! %) ), this will bump-up the bass only slighly.
This is fully reversible as long as you accurate. Even if you poked the holes, you can easily replace those white stickies with other adhesive tape.

BTW. Disassembling those AKG is pain in the butt. One of the most stupid, complicated constructions.
Have fun!

 

[wink]

I have tried the bass mod twice on my K702 and, frankly, I am not impressed at all.
 
It does nothing for the bass escept to make it halfway what Beats do, Wooly to the max.
 
It also fuzzes the treble to the point that it's aggravating, in that the clarity is compromised to the point that it almost stoops down to iBud lack of quality.
 
My K702 is now permanently back to standard.