Kameleon in-line filter from G1217!

My experiences are similar. With the HE-560 module I initially had to check if the filtering was turned on because I really couldn't detect any discernible differences. It was only when the sub-bass kicked in on the track I was listening to and I had a holy smokes (may not be the exact word I used) moment that the the penny dropped. And then when I switched the module back off all of a sudden a whole raft of previously unnoticed little nuances start to reveal themselves and I could appreciate things better.

Which brings me on to the HE-560 and those impressions that I promised.

Really for me the HE-560 does more right than any other headphone I've owned so when I approached Frans regarding the possibility of a module I did so with a mixture of hope and trepidation. Not because I don't trust Frans' judgement but I was concerned that even sympathetic 'enhancements' might result in the headphone losing some of its character.  Sometimes its those little imperfections and quirks that give a headphone its charm. 

To my ears in stock form the 560 is quite a neutral and linear sounding headphone with very good treble and bass extension. Detail is excellent as is timbre. However, whilst capable of very deep bass and excellent bass quality with many recordings the quantity is lacking and it feels like the bass has gone awol. Then with other recordings, sadly too few, it suddenly rears its head and can be surprisingly powerful.

That aside the only other real complaints I have is that it sometimes has a tendency to sound a touch thin and the upper mids (or lower treble) can sound a bit peaky and grating.

After a few PMs to make sure we were on the same wavelength Frans set about making a module for me. Please note the production module may differ very slightly from mine (Frans may confirm) but I think mine has been set as follows:

+5dB added to sub bass and +2 or 3dB to the low bass

+ 1 dB at 2kHz

- 5dB at circa 5kHz (tames quite a large peak)

+ 1dB at 15kHz

Using the module the bass quantity is close to perfect to my ears. Recordings that previously sounded good don't feel like they have become overpowered but those that were a bit anaemic now have satisfying bass quantity. The bass now sounds more palpable and has great sub bass rumble. Very moreish.

The increased bass quantity also seems to have the knock on effect of influencing the wider sound too as the thinness I mentioned is no longer evident and music has much greater body / fullness to it now and seems more 'rounded' (3 dimensional) in nature. It's strange because although the width doesn't appreciably change, when I switch off the module the HE-560 now sounds really small by comparison.

Having addressed the 5kHz peak instruments that sounded a bit too sharp or shouty now seem considerably tamed but not so much that they feel neutered.

There also seems a greater sense of balance and cohesion to the sound now.

All in all I'm very happy with the changes that have been introduced and I really don't think I could go back to using the HE-560 without the filter or some form of equalisation now. I think tunkejazz is spot because although the changes are often sublte it is almost like switching from one headphone to another.

I agree Mark, you don't want the 'soul' sucked out of the headphone and as Frans says, some adapt better than others. I think you found that with the dt990 which you felt lost its character.

The effects really are subtle until you turn it off!! For me, the Senn hd650 sounds terrific once filtered, but mediocre when not filtered. It's not until you've heard it that you appreciate what the previous 'unidentified' problems were with your headphone. Suddenly, the problematic areas become very noticeable.

The Kameleon got me searching for something better than the hd650 since I can now hear its problems far too easily!!

Jeremy posted a couple of days back about this so pics are likely coming soon: diyah.boards.net/post/22757/thread

'Soul' is a good word for it Ian. Both the HD650 and HE-560 retain their soul when filtered so you get the best of both worlds. More of the same only better. As I said to Frans a while back changes are subtle but profound.

For me personally the filtered DT990 might just have been too much of a departure from stock form but then again it's a headphone that probably needed a lot more knocking into shape than some!! Don't get me wrong it sounded great and if I hadn't had a module for the HD650 I'd have greatly appreciated having the option of flitting between the two different sounds; one flat the other fun. But when you have both it's clear that filtered HD650 > filtered DT990. No shame in that as the HD650 + module is a formidable pairing.
 

Say his name 5 times in the mirror and he will appear 

Now wash his face and comb his hair and you have a Kameleon!

Still tinkering - I dig it A little funky and out of our norm - but welcoming at the same time.

- Left side switch, a heavy duty slide switch turns the filter on / off. The right side switch turns Kameleon on / off which also turns your amplifier on / off (Good stuff Frans!)