[lei111]

Interesting.  Which one is MX2 then?
 
Looking through their products.  Any experience with the AT series?  http://www.nbisk.cn/productsDisplay.aspx?v=119&nid=222  Look at the velours.
This one looks good too.  http://www.nbisk.cn/productsDisplay.aspx?v=52&nid=229
 
http://www.nbisk.cn/productsDisplay.aspx?v=61&nid=229, this looks like Takstar HI2050.

 

[bhazard]

  Interesting.  Which one is MX2 then?
 
Looking through their products.  Any experience with the AT series?  http://www.nbisk.cn/productsDisplay.aspx?v=119&nid=222  Look at the velours.
This one looks good too.  http://www.nbisk.cn/productsDisplay.aspx?v=52&nid=229
 
http://www.nbisk.cn/productsDisplay.aspx?v=61&nid=229, this looks like Takstar HI2050.

That's the thing. There are so many, and so rare outside of China, that it would be very hard to find someone that has heard all of those models.
 
I don't think the MX2 came from this OEM. Maybe it did and they haven't updated the website? Very hard to truly know.
 
If you want to give them a shot, I can find aliexpress or Taobao sellers of them for you. I ordered the 580 model, which looks very similar to a Superlux 681. $20
 
The MX2 is awesome though. I feel it is better than the TH-02, and addresses the TH-02's flaws.

 

[lei111]

Any reason you picked HP-580?  How would you choose among closed, open, semi-open?  Does the AT-5000 spec look good to you?  Open, 60 ohms, 95±3dB, 15Hz-30kHz, 600mw.  Is 60 ohms too high for portables?

 

[bhazard]

  Any reason you picked HP-580?  How would you choose among closed, open, semi-open?  Does the AT-5000 spec look good to you?  Open, 60 ohms, 95±3dB, 15Hz-30kHz, 600mw.  Is 60 ohms too high for portables?

 
It would do best amped.
http://www.mistertao.com/beta/pages/item/14522250297.html
 
Around $33 after commission and shipping if you want to try it and compare to the tascam. My wallet is empty currently.

 

[lei111]

Any experience with this website: http://www.easy-taobao.com/taobao/view/id/14522250297 ?  Seems like the same seller.
 
Have you heard of Plextor/PLEXTONE D500?

 

[hans030390]

As measurements have shown, these are truly great for $30. Good response, not too much resonance or ringing, at least past 2KHz, fairly low harmonic distortion, good square waves, etc. Purrin clearly demonstrated these greatly benefit from some simple mods.
 
The HM5 pads work really well. I couldn't get a seal with the stock pads, nor were they comfortable. The HM5 pads fix that. All you really need is a bit of dynamat to control housing resonance (and maybe an adhesive foam or felt to cover it if it has the reflective top), cup damping, and some material in front of the driver if you find the treble a bit hot. 
 
The below is my mod and some brief notes that I mostly copied/pasted from another part of the intertubes (some slight edits):
 
My current configuration is on the warmer, laid-back side of things, but still not lacking much in detail and openness of the sound. The spacial cues and openness are actually surprisingly good at times. Fairly clean sounding overall despite the warmth and what I sometimes detect as additional bass (might just be harmonic distortion). I don't mind the dip around 4-5KHz, as it makes it easier for me to listen without fatigue. It's much better than having a peak around that area for me. I can handle 7-10KHz peaks more easily, and thankfully the slightly peaky treble is within the bounds of my tolerance. My configuration is as follows:

1. Layer of Dynamat in back of cups
2. Layer of Creatology foam on top of the Dynamat (in case you're wondering, it's purple)
3. 4 inch-ish long strips of Creatology foam and 2 half-inch-ish strips on the next area above the bottom of the cups, pushed into the corners (it's around half way up to the top of the cups)
4. Fairly thin disc of acoustic stuffing (feels sort of like polyfill) in bottom of cups
5. ~1/2 inch thick disk of what feels to be a medium density packing foam on top of that
6. Dynamat on back of driver magnet, covered with a layer of Creatology adhesive felt (non-stiff kind)
7. Ring of Creatology foam around driver on front side baffle, with a disc of foam or felt on top of that (glued at edges to the foam ring)
8. HM5 pads

I'm very impressed with this headphone and driver, and I'm enjoying what I'm hearing. It's headphones like this that make me wonder why I bother spending more on headphones sometimes. I also wanted to note that for whatever reason, it sounded better to me to put the acoustic stuffing under the foam disk than vice versa. I also had to use very little stuffing with the foam disk in there. I also don't remember exactly where I got the fabric/felt disk I placed in front of the driver. I think it came with a spare pair of ear pads I ordered a while back, but I've ordered too many different ear pads to know which pair it was. Or it came from a stock set of ear pads that I swapped something else for...

 

[lei111]

Where did you order the pads?  Any pictures?  Thanks and Happy Thanksgiving.

 

[Jay_WJ]

  Purrin clearly demonstrated these greatly benefit from some simple mods.

 
I do not think his measurements before and after a mod demonstrated that the entire mod would be worth the effort. Basically, what his measurements tell is that the ringing (4 to 9 kHz) is the driver's nature. Based on my experience of acoustic measurements of transducers, I seriously doubt the observed, major difference between the before- and after- measurements---i.e., lowered 7-8 kHz resonance (and corresponding 2nd harmonic product at 4 kHz) relative to the midrange amplitude below 1 kHz---is because of the dampening of the housing. It is most likely due to the toilet paper in front of the driver. Even that effect is not significant. When looking at his measurements, do not be deceived by a naive observation that the absolute amplitude of the ringing at 7 kHz is decreased by 10 dB, from -10 to -20 dB (or the second harmonic product at 4 kHz from -46 to -57 dB). You need to take into account the test tone's amplitude difference shown in the graph in the 100 Hz to 1 kHz range between the two conditions, which is about 6 dB. All in all, the effect size is about 4-5 dB. Assuming that I will apply EQ, the only mod I would perform is adding an acoustic screen in front of the driver (like toilet paper). After EQ'ing, the benefit will be a decreased harmonic distortion product, which is somewhat filtered by the screen. Will it be worth it? I think so, considering the ease of the mod. Will it be audible? Not sure.

 

[hans030390]

Suit yourself, but the measured changes from purrin's basic mods were of the magnitude that you'd be able to notice an audible difference, even if the effect was truly only 4-5dB in the end as you claim. Seems like there are little to no downsides to the basic mods, so there's no real reason to not do them. Applying EQ along with that can only help further, if you want to do that.
 
Unfortunately for me, I could not get a seal with the stock ear pads. The HM5 pads alone probably produce a larger effect on sound than all the other mods have, most noticeably in that they easily seal and actually provide comfort. I can't directly compare my results because of this, nor do I have measurements of my particular mod.

 

[Jay_WJ]

I think my negative tone about headphone mods in general may have misrepresented the main message of my post. The primary contents of the post was:
 
1) Purrin's measurements do not tell that all the mod components (baffle, cup dampening / filling, and toilet paper screening) have significant effects. He did not test each independently.
 
2) The major effect (i.e., lowered treble ringing, and more importantly, lowered harmonic products in the treble region) is most likely due to just the screen.
 
3) The size of such an effect is about a 4-5 dB (it is not my claim but what the measurements show).
 
My intermediate conclusion based on his measurements is that the TP mod may have some value,  but not others. But personally, if I were NOT EQ'ing, I would not keep even that mod since I like treble---I'd take some treble ringing rather than making the already laid-back headphones more so. If EQ is applied to make the FR flat, the benefit of the TP mod will be somewhat lowered harmonic products. Will a 4-5 dB derease in harmonics be audible? A 4-5 dB decrease in fundamental tones will be audible, but I am less certain of the harmonics.

 

[c61746961]

I don't think purrin's CSD analysis windows are long enough to display the effects of cup damping in the midbass-to-mids range, same as with the T50RPs graphs which indisputably benefit from the extra damping. Maybe I can pester him to do an in-depth analysis on such effects. Maybe you could try them yourself, too.

 

[Jay_WJ]

I don't think purrin's CSD analysis windows are long enough to display the effects of cup damping in the midbass-to-mids range, same as with the T50RPs graphs which indisputably benefit from the extra damping. Maybe I can pester him to do an in-depth analysis on such effects. Maybe you could try them yourself, too.

 
In fact, his measurements of FR and CSD are a mystery as I cannot find info about an exact procedure for obtaining them. With a minimum phase system (a headphone is, especially w.r.t. its high frequency behavior such as ringing, resonances, breakup), a non-heavily-smoothed FR plot derived from a properly windowed impulse response has ALL the information about the system's linear distortions. There is no additional information that a CSD plot can provide. If there are things visible in CSD that do not appear in the FR, they are processing artifacts most likely due to windowing. It is a general consensus among audio scholars that CSD plots are good only for attractive advertising and magazine graphics. For an in-depth analysis of linear distortions in narrow frequency bands, looking at Linkwitz-style, shaped tone burst responses will be better:
 
http://www.linkwitzlab.com/frontiers_2.htm

 

[bhazard]

MX-2 > TH-02 to me. Really strange to not see much info or hype on them.

 

[c61746961]

I'd really love to try a pair, but alas, they haven't reached here yet.

 

[Grayson73]

  MX-2 > TH-02 to me. Really strange to not see much info or hype on them.

Post something in the discovery thread and see if it catches on.