Orthodynamic Roundup - Page 5

I took the liberty of putting that photo on Tyre's Headphone Driver Pics thread, but I confess I can't tell how the diaphragm is attached, as good a photo as it is. We need an intrepid British-type person such as yourself to go over the top and get those photos showing the Wharfedale's flip-flap action.

[screams like a little girl] Glorioski! the mark of a true ribbon! Holy cannoli!

EDIT: Well, the Wharfedale Isodynamic driver is almost a true ribbon. A true ribbon would have the magnets standing off to the sides, not facing the diaphragm. But the motion of the diaphragm is pretty much the same in both cases.

.

Thanks to FV for posting good high-rez photos. They were a tad dark so I brought 'em up in value / boosted the Y channel / whatever you like, so you can see the construction. Here's the PMB 100's Jecklin-style "earcup":



Wow, looka them vents!


And here's FV's experimental vent-blocking tape:



Notice the slits are still open.

.

Whoops, I Didn't Answer FV's Question..

Good question: What, besides allowing backwave leakage (bass, but also midrange and some treble), are those holes doing to make the headphone sound good? Nothing. The controlled addition of antiphase signal, in this case acoustically via those holes and slots (though it can also be done electronically), is the basis of any "enhanced stereo/surround" circuit you might find on anything from a boombox to a DVD player. It's part of what made the Sennheiser HD 414 such a knockout back in the day. It's what gives the AKG K340 and K501 their famous soundstage. Taking advantage of the way the ear-brain interprets phase and arrival times, you can "steer" a stereo image out beyond the headphones or speakers. It's one of the oldest psychoacoustic tricks and has been used for decades, notably for CBS' SQ quadraphonic system more than 30 years ago. See if you can find anything on the interweb by CBS' resident antiphase maven, Benjamin Bauer.

So take a page from the K501 playbook and add a layer of felt (the denser the better) to the back of all those holes and slots. See if that gives you a better compromise than the yellow tape.

Ideally, what we'd like to happen is to keep all bass backwave away from your ears and only allow midrange and treble direct access. We can do this using the signal-delaying techniques I mentioned earlier in this thread. It's the midrange and treble antiphase leakage that's giving you the good vibes and the spaciousness; leakage of the antiphase bass is doing nothing but killing your bass, although Jecklin, following Sennheiser's lead, placed the driver as close to your ear as possible to minimize this, just as Yamaha did with the YHDs and Sennheiser did with the HD 424 (thinner pads than the 414).

.

Maroon's swoony. Setmenu likes his too.

The only difference I can see between the YH-1 and the YH-2 is the size of the driver "sandwich" (46mm vs. 55mm) and, because of that, lower power handling/ultimate output level. I'd expect the YH-2 to have a little less bass reach too. But an increase in diaphragm compliance could change that equation, as the YH-100 teaches us.

Now I'm going to say something shocking: Don't touch that $2 YH-2. It's not that the damping mod is risky. The riskiest part is unscrewing and rescrewing the baffle, what with the teensy cheapskate selftapping screws trying to grip '70s plastic and the fear that you'll strip the threads, such as they are. No, it's that for $2 you'll be able to hear past the underdamped diaphragm to catch a glimpse-- and it's only a glimpse-- of this driver type's capabilities. Well worth the price of admission. Then later, when you want to hear the real thing, get a YH-100 and finish it. It's not really a mod, it's completing a design that was left unfinished. Think of the Orthodynamics as kits, or, if you will, Headphone Helper. Just add damping, and voila, good sound for the whole family in minutes.

PS: Chris, ever tried Trung Nguyen coffee?

.

You never sold 'em? Dang. [EDIT: He finally did sell 'em.]

I haven't taken mine apart; I've only seen your disassembly photos. Is there any damping material, some foam maybe, jammed against the back of the driver? If not, you might try adding some. But not too much, since as I recall, the T40 sounds pretty good as is. The rule is, if the undamped 'phone sounds bassy and dull, adding lots of damping, which pushes the natural resonant frequency of the diaphragm upward, is a good thing.

If you have a 'phone that sounds like the resonant hump is smack in the middle of the midrange (like the T40, iirc), adding lots of damping will push the hump upward in frequency while reducing its height and increasing its width, and you could end up with a 'phone with a long slow rise in the 2--3kHz region and a more-or-less forward or bright sound. This, to a lesser extent, is what happens with the Realistic Pro30, and what makes it a good monitoring headphone. The YH-100, on the other hand, starts out bassy and dull and ends up sounding pretty much right.


.

Welcome to the madness, brewdog. I still haven't heard the YH-1000 and I haven't heard from anyone who currently owns one til now, so I don't know if Yamaha finally paid attention to the damping problem or not. On paper, the YH-1000 looks like the best Orthodynamic Yamaha was able to make. In real life... well, you tell us.