Headphone Correction Filter board

I heard the LCD2 and HE500 side by side and personally preferred the LCD2 over the HE500, like I prefer the HD650 over a K701.
This does not mean the LCD2 and HD650 are similar and K701 and HE500 are similar though, they aren't by a long shot.

The LCD2 simply had certain qualities over the HE500 which I preferred, such as the quality of bass and mids which is stunning and tighter than that ot the HE500 which is relatively a tad more 'wooly'. The HE500 did sound 'brighter' and more 'detailed' which the LCD2 lacks a bit. The extra highs on the HE500, however, is simply a peak in the FR which the LCD2 does not have. That peak in the HE500 did give it more brightness but a bit 'artificial' as only a small portion of the treble range is 'highlighted'. When listening to music I rather have no highlights but slightly 'skewed' sound instead of the other way around.

Just like the K701 is artificially bright and the HD650 is 'warm' while both are excellent headphones they cannot be compared.
The D7000 is in-between those, warm full lows and brighter in the highs but not too artificial.

The LCD-2 with a filter and HE500 with a filter will be difficult to tell apart as the FR will be closely the same AND they are both ortho's. The HE500 with filter would measure almost ruler flat while the LCD-2 would be a 'rolling off' very slightly in comparison. It would only become obvious when heard side by side perhaps and even then will be difficult to tell apart.

The difference between a filtered LCD2 and stock one will thus be bigger than between a stock HE500 and filtered HE500.

The filter could be constructed so it is almost perfectly flat but as you liked the signature of the LCD-2 that has a 10dB drop in the upper mids to the highs it has a signature. A bit too much of it though. The filter will increase the levels so it will be just below perfectly flat thereby retaining the LCD2 signature a tiny bit. It will sound noticeably brighter and have plenty of 'air' with the filter. These are the only issues that need fixing.

I do not know a single (affordable) headphone that has the complete perfect sound package. IMO you need something that comes close, is comfortable to wear (I find both HE500 and LCD-2 a bit heavy in weight) AND is easy to correct so it DOES come close to an ideal headphone.

my time now must be spent looking for an enclosure for my filter.
i do like the look of the ones John Kenny uses on his products. is anyone familiar with these and know where you get them from?

"The filter could be constructed so it is almost perfectly flat but as you liked the signature of the LCD-2 that has a 10dB drop in the upper mids to the highs it has a signature. A bit too much of it though. The filter will increase the levels so it will be just below perfectly flat thereby retaining the LCD2 signature a tiny bit. It will sound noticeably brighter and have plenty of 'air' with the filter. These are the only issues that need fixing."

have also got the "tonal balance" option on my stagedac, so will still have the option to tweak sound slightly.

below is the explanation from the manual.

"Tonal balance
Psychoacoustic studies have shown that our sense of direction is mainly determined by the sonic components with frequencies upto 2 kHz. To keep the sonic signals as much as possible in their originial state the crossfeed filter does not effect signal components above this frequency.
In headphone mode signals that are no longer present in one channel only but are now more evenly distributed over both channels will be less isolated and become a more integrated part of the soundstage. They no longer stand out and this may feel as if the energy in the frequency range below 2 kHz is slightly reduced. This can be compensated by the first switch to the front right side of the STAGEDAC. In its lower position no frequency corrections are made but in its middle and in its upper position frequencies below 2 kHz are slightly elevated to correct the tonal balance."

i do not use the crossfeed, but the tonal balance still warms things up slightly.

a wider version would be preferred... depends on what you might need on space (in the back) or find aesthetically pleasing.

You do have to figure out a way to mount the PCB so something where the top plate can be removed could be handy.
The PCB has 4 holes that can accommodate for M3 bolts so you can mount it on some studs or spacers (a few nuts on top of each other)

It doesn't have to have RFI shielding but recommend all metal enclosures.

about 40 left !

They do have a habit of making what's already very good much better...
You can adjust it to your taste if needed.
The filter was calculated to compensate the 'Paradox' so could be tweaked a little if needed.

The HE-6 and LCD-2 can also be improved but the filter action isn't that obvious there (at least not for the HE-6) but still an improvement.
Hope to get some feedback about LCD-2's as they also need some 'freshing up' of it sound while retaining it's lovely bass and mids.

page 35 of the July 17th manual.
Jeremy may have altered some values as he personally would like to have a tad less highs and a bit more bass.
As the highs increase the bass becomes relatively less so that could make sense.

Really flat isn't every ones cup of tea (it is mine though)

If I get feedback it should be changed I can alter it in the manual.

Hey Mo,

Frans answered for me...Thank, Frans.

Jeremy put it in a nice aluminum box with a 3-position switch: Filer On, Mute, and Bypass Filter.

@frans: What is the best way to use the Trim Pots and ensure the channels remain balanced? Maybe mark them and their current position on the board?