Orthodynamic Roundup

[setmenu]

Quote:

Originally Posted by wualta First, thanks for your story about the Wharfedales. No design exists in a vacuum-- someone has to buy it and appreciate it. The little bombshell you dropped with this ribbon business makes me go whaaaaa? They only fixed it at two ends, as far as you know?? Omigod, here we go again with yet another diaphragm design. When you get a chance, we need closeups of that driver, stat. I gotta go sit down.

Here is a pic of the transducer:

http://www6.head-fi.org/forums/attac...4&d=1019480031


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[wualta]

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.

Quote:

Originally Posted by smeggy If you look at the pictures of them dismantled you see... the magnets were shallow arcs to let the film flap about between the end anchors.

[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.

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[facelvega]

Notice the many round holes, curved rectangular driver mount holes, and the eight straight slots at the top. On a stock pair of MB floats there is a thin layer of foam over the entire center panel (everything but the eight slots). The panel is a unibody part of the main housing, while the rest of the earcup around it can be removed.



and then my attempted electrical tape mod with almost all tape in place:

 

[wualta]

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.

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[wualta]

Quote:

Originally Posted by facelvega So how can this be? It seems Willi's warning was right, but how do we explain it technically? What besides allowing in a bass backwave are these holes doing to make the headphones sound so good?

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).

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[facelvega]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif ...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...

Genius. I bet this is actually going to do the trick. Also many thanks for the antiphase explanation, it makes perfect sense now that I think it over. I will report back here once I finally find some felt. I'll also try to stick a little felt behind the driver, to see which works better. Many thanks.

 

[Coffeegeek]

Sorry to once again resurrect this thread


So I was at the thrift store the other day, and found a pair of Yamaha YH-2 Orthodynamics for the princely sum of $2. This is the first time I've ever found a semi-decent pair of headphones at a thrift store, usually they are all junk.

I haven't had time to do any serious listening, all I could really do was try them in a cd changer they also had at the store, but I could tell they weren't junk. I couldn't find much out about them here, but I'm assuming they are the second tier to the YH-1. One difference is that they are a maroon color. They padding is a little beat up, but I'm looking forward to giving them a listen.

Any other suggestions? Should I dissect them and attempt the damping mod?

Chris

 

[facelvega]

have you seen this thread? If you fail to do the damping mod, Wualta will likely haunt your house in a very unconvincing ghost costume, leaving glowing discs of otherwordly felt in his path.

Nice find. I like the maroon of the YH-2.

 

[wualta]

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?

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[RedLeader]

so... any suggestions about what to do with some really old Fostex T40RP? I've got a pair that sits in my closet...

 

[wualta]

Quote:

Originally Posted by RedLeader /img/forum/go_quote.gif so... any suggestions about what to do with some really old Fostex T40RP? I've got a pair that sits in my closet...

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.


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[brewdog52]

hello all,

I'm new to this forum and hoping for a little info. My dad recently gave me his old yamaha yh-1000 headphones he recently found that were packed away for years. He doesnt quite remember how old they are, he's guessing he bought them in the mid-late 70's. The earpads were missing on both sides so I made some using 1'' semi hard packing foam, which seem to work pretty well. I don't have to much experience with headphones, but in my novice ear they sound pretty good.

I searched around on google and came across this site and noticed the yh-1000's mentioned on this thread, so my question is how do these old headphones compare with the new headphones sold today?

Any information on these would be greatly appreciated, Thanks all.

 

[wualta]

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.

 

[brewdog52]

Thanks for the reply waulta. Well I can't really compare these with any other headphones other than my usual stock or cheap phones that come with cd/mp3 players, but I'm pretty blown away with how these sound the more I listing to my favorite songs. The detail in my novice opinion is really good and no distortion at all even with my player maxed out, background instruments stand out way more than I'm used to and some I didnt even know were there. For being almost 30 years old I was impressed, but it probably would'nt of been hard to impress me since I'm used to cheap headpones. The only bad thing is I just bought a pmp and spent days putting 1000's of songs on it encoded @ 192kbps now I have to put them back on as pcm wav or flac since I can tell the difference now

I'm glad my dad dug these up for me, he saved me quite a bit of cash I think. How would I tell if theres a damping problem or not waulta? -take care all

 

[facelvega]

Brewdog, would you mind taking a couple of close-up photos for us? Careful with those things, they're rare and extremely valuable, in principle if not monetarily. What's more, it's perfectly possible that the potential sound quality on your Yamahas (I say potential in case the damping needs to be sorted) may be competitive with the best dynamic headphones now in production.

Another key question, though, is whether that copper coil material makes them easily driveable by your player, or if an amp is adviseable. In my experience, the bass and midrange presence on an ortho is always vastly improved with good amplification. Also, if you can give us dimensions on the earpiece width, we can likely tell you where you can get earpads that will fit (though probably even then you'd need to use something to adhere them to the surface fo the earpiece).

Here's the easiest thing you can do to test the sound quality: get a pair of Koss KSC-75 to compare them to. They're maybe the fundamental bargain audiophile headphone, and a Head-fi institution. If you shop around, a pair will run you about $15 shipped. If the Yamahas don't sound definitely better, then you probably have a damping or amplification problem. Also, when you have a pair of KSC-75, you can keep the Yamahas safely at home for serious listening, and use the Koss while on the go.

best, FV