First off, it is very easy to take apart the 668B. The logo caps on each ear piece pop off with a sharp knife blade and the remaining disassembly is simple.

Using the AKG K240/270 velour pads, I used a closed cell foam weatherstrip approx. 3/8" x 3/8" cross section (self adhesive, graphite gray color) and ran a strip around the perimeter of the cup, under the ear pad and applied to the plastic cup. This gives a little spacing so one's ear is not resting against the driver grill. I have tried increasing this distance and it only enhances the discontinuity I hear between the bass and upper ranges, even after full break in. Increasing the distance also harms the balance in the upper mids, creating too much of a "V" sound.

Too much to go into detail here, so please PM me for more info. I am sorry for not taking pics along the way!

I use good 'ole Mortite hand-applied caulk rope to damp all the "in-between" spaces around the face of the driver grills (behind the ear pads). I appreciate that Mortite is heavily mineral filled and very acoustically dead. Other rope caulk brands are too lightweight and are not as efficient (in killing resonances). Because of how I modify the 6 vent holes around the driver grill (behind the ear pad), I could not use something similar to Dynamat. To do so would make a mod irreversible.

Except for my method of rewiring the left ear cup all the operations are simple.

VERY IMPORTANT: The internal "yoke" that allows the articulated movement and holds the driver in place, as well as other areas inside the cup, need damping. Without internal damping of these items, the entire frequency range - especially the bass - will greatly suffer. This I accomplished by using a simple formula of 1 part grout (the "filler" between ceramic flooring tiles) and 3 parts liquid electrical tape (or vinyl dip used for coating tool handles to create a better grip). I applied this with a fine, stiff bristled artist brush. Several coats are required but each coat dries quickly.

I rewired with Mogami W2534 quad microphone cable and Techflex sheathing and regret using the Techflex - it is very noisy when rubbed. Also the Mogami is very heavy for such a lightweight 'phone. Though I "cheaped out" in my choice of cable because this has been an exploratory project with no proven outcome, I highly recommend one uses their favorite/best quality cable because I have discovered the 668B truly deserves it.

I especially wish to thank audiofil for his helpful direction and sharing his experiences with the Superlux HD-668B.

From what I understand, he started to have an interest in buying a headphone to pair up with his iPod touch 2G 8GB after listening to a friend's Sennheiser HD-202. Sadly, there store he went to didn't have any stock of the said headphone for months, and shortly after that he heard of superlux, and was very interested in HD668B. Soon after, he was considering between:

1. Superlux HD668B
2. Superlux HD662
3. Superlux HD662B
4. superlux HD669 ---> (He's glad that HD669 came out just in time, or he would've bought 662B/668B.)

First off, he mentioned that HD669 is airtight. Guess it pretty much holds tightly to your head. Something like that.

"who says - john mayer" => I guess he says there's some audible hiss, but still awesome bass and treble. (Not confident whether the hiss he mentioned is in English or an Indonesian word which is unknown to me.)

"lady gaga" => Eargasm inducing boomy bass but still with clear treble.

"you rock my world - MJ & some other slow songs form sabrina, michael buble & olivia ong." overall, the quality is very good. bullet bass (I'm guessing he's saying tight bass), treble, n good vocal separation. He personally prefers this model over other superlux.

HD668B => similar impression, but less "airtight". He further mentioned that the bass is less boomy/tight probably due to the semi-open design.

HD662 & HD662B => These 2 are similar, but 662B has more bass, but still pale in comparison to HD669. EDIT: It was also mentioned that the 'airtight' feeling is similar to HD669.

The HD669 is still in burn-in period, and will report if there's any changes afterwards.

PMP used for audition is iPod Touch 2G 8GB, EQ setting = Jazz, volume = 90%

He invites all to test it themselves for a more accurate review, for he's new to the audiophile world.

He finished with saying that is review is purely his personal opinion, and to each man his own poison.

He agrees. It feels hot due to how tight it's pushing to the head. When he first started using it, the ears starts to feel hot after an hour non-stop usage. Separation and vocal details is similar to 668B, and IMO, the only difference is the bass and 'airtight' feeling.



"cobain de bro... cocokan mana 668B sama 669nya" (I don't get what he's saying.)

Yeah, you'll get 15% discout at 'bos kantong' (probably a store's name or a place)

"mantap lah bro entry level kualitas dolby surroundnya THX XXI.. wwkwkkwk (hiper)" (don't really get it, but I think he's saying it's comparable to an entry level Dolby Surround and THX. Or he's saying that this entry level headphones which is superlux is comparable to dolby surround and THX.)

"btw testing maen tekken 6 di PSP vol full --->> SADIIISSSS!!! (apalagi pas screen menu awalnya, lagunya tambah kereeeennnn)"

Complete satisfaction or eargasm when using his PSP to player Tekken 6 at full volume.

He's poisoned into getting a 662.

Why he chose 662 instead of 668B

1. 668B (and 669) need an amp for maximum SQ which is not his thing.
2. 668B and 669 vocals are more recessed, where it sounds slower compared to the instruments, which is very significant to him, but YMMV.
3. 662's has a better soundstage and separation.
4. 662's sound feels more real. Then he went on about how violins should sound which I don't really get. Something about violins should have some 'roughness' feeling to its sound, where it isn't present it 668B/669. In 668B/669, violins sound too smooth for his taste. (and supposedly too smooth for how violins should sound.)

662F, the 'roughness' is more than 662, but sounds a little 'thinner' than it should. Then again, in overall 662F have a better SQ. (in the context of violin's sound?)

He went on with saying that in the end, an audition should always be done personally. (SR60's bass is clearly as good as the review, SR80 is more suitable for him than MS1, HD595 is miles ahead of HD555 etc)

But then again, with such a price, whichever of the previously mentioned is bought, he might regret it.

He have auditioned cans for quite some time, so, his writings are (parts that I don't understand), but he have to say that in terms of SQ and price aside, he'd prefer HD662 over:
1. HD555
2. SR80 / MS1 non i. Overall, MS1i is better, but lost in terms of soundstage. I don't understand the rest.
3. Hippo Shroom (He's more inclined to VB though).
4. PX100, Porta Pro, iGrado. And again, I don't understand what he means by "dkk mah lewat lah ya"
5. Ultrasone Zino which was recently audition, unknown burn-in time.

Then he mentioned that he's yet to talk about IEMs. He just tested some IEMs F and B (maybe 381F and 381B), and says that if it wasn't for him owning the Hippo VB and Shroom, he'd would have get the F(probably 381F). The sound of the tested IEMs are simply amazing.

Rigs used:
Source: Zen Neeon 2
Songs:
Jamie Cullum - Mind Trick
Sister Duke - Kreyzie
Sister Duke - Selamat Tidur, Teman
Jamiroquai - Too Young To Die
Timbaland - Give It To Me
Arctic Monkeys - Brianstorm
Écoutez - Percayalah