The Headphone Driver Pics Thread
Nov 2, 2023 at 3:59 AM Post #2,116 of 2,345
And the reason for that is?

Also, according to service manual it's not a good idea to open up 700's until absolutely necessary:

"More than 30 minutes's exposure of a high polymer diaphragm used in the SE-700 will affect its property, resulting in impairing the tone quality. Also never touch the diaphragm directly with the fingers, it will go ineffective. With these things in mind, be careful when disassembling the SE-700 for replacement of the cord, for example."

Interesting.

April 1975 changes notes say L and R headphone “drivers” have been updated for better sound.
The difference is
the 2 small holes in the foil on the newer models.
Additional black foam on the inside of the inner grill.
seen in 1975 https://user.xmission.com/~alhaz/img_1022-crop.jpg


The diaphragm is exposed to the ear side just behind mesh, so maybe it’s talking about the lack pressure from the foam when the covers are unscrewed. The translation from original Japanese maybe a bit off in the service manual.

I suspected that finger oils and acids would eat away at them over time so didn’t touch the foil. There is a previous post somewhere that did similar and didn’t report any issues. I guess you could measure the capacitance before and after to see if they have degraded.

I have only wiped the foil with 99.95% ethanol via a small ball of tissues wrapped in another tissue, so under as little pressure as possible.
Had to make sure nothing is growing on it since they are a little stale smelling. The spiders couldn’t get foil only into the outer area so that was good.

I’ve had them refitted with foam and cover in place most of the time while sitting waiting for parts to arrive or when not cleaning or drying the outer parts. Mainly as was worried if knocked or dropped the foil would get damaged.

The covers needed a deep soak and dry so they have had maybe 4 hours without the foam clamped. They have some material between the plastic and outer metal mesh trim so needed a very good dry before
The foam was still sitting on them for all but 2 hours where the foam was in the sun to make sure it wasn’t mouldy. Not that I can see anything.

I even gave up on the idea of removing the driver to soak and clean the inner grills. The glue is rock hard after 49 years so didn’t want to risk breaking them. I suspect this is possibly the exposed part of the manual, as it shows pulling the foil assemble out.

Had to soak a folded stack of tissue in ethanol and let the grill sit on that to get the crud out. Then Sellotape to get the rest out. I’d say 95% cleaner overall but far less risk.

They sounded fine before tear down if you could get the cable to work and wrapped paper towels around the headband and earpads to stop the flaking.

They were very flat but clear, can’t say the detail was there like HD800s but it was very pleasant sound. They may have needed more power and some better sealing pads.

Will find out in a few weeks when everything will hopefully be fixed.

I’m also building 2 of the junction boxes j21 or whatever it was and will run them from a little 40 watt class AB amp. The old parts look to be rated to 10 watts max input, So about 7.4% with its 8ohm and 100ohm resistors.
Modern components without speaker switch should be about usd$40 including small case.

Thread in DIY section with details and progress
 
Last edited:
Nov 15, 2023 at 8:34 AM Post #2,117 of 2,345
JVC HA-DX3 - 1999
- The first time this driver has ever been seen before online! (you lucky sausages) - 🥳

_DSC0010.jpg_DSC0011.jpg_DSC0012.jpg_DSC0013.jpg_DSC0014.jpg_DSC0015.jpg_DSC0016.jpg_DSC0017.jpg

The last photo shows the driver with the rear damping removed.
I had to do this because the headphone sounds broken (and measures broken) with it on.

JVC HA-DX3.jpg
JVC HA-DX3 - Without driver magnet damping.jpg


I'm leaning towards wondering if this was done exclusively for the Western market, since there is one graph of the DX3 online from Japan which looks totally different, even smoother than the 'fixed' one on the right.
It's a huge improvement, but this still doesn't sit right with me.
I can't imagine JVC releasing something this broken (stock form).
 
Nov 15, 2023 at 8:38 AM Post #2,119 of 2,345
Dec 16, 2023 at 12:03 PM Post #2,125 of 2,345
Takstar XY-E1 from "XY-1 Pro Recording Webcast Kit"

_DSC0195.jpg_DSC0196.jpg_DSC0198.jpg
Not too shabby. Upper mids and treble is a bit weak.
Takstar XY-E1.jpg
 
Dec 16, 2023 at 12:51 PM Post #2,127 of 2,345
Greq why did you deleted ratings from you site? It was very informative :) Did you plan to change it to numbers instead of emoji?
I think most of my ratings were far too subjective and overly simplistic.

Some examples...
• A 5/5 closed back might have smaller or worse staging/soundstage than a 4/5 open-back (even though they are generally not really comparable)
• Some ratings were affected by wearing comfort and build quality etc...
• Some high ratings were given due to the high sound quality with regards to historical position (something sounding amazing from the early 70's for example).

Ane none of those differences can be conveyed properly on a website that ONLY covers their frequency response.
Instead of going over every single rating and sticking to only ONE factor (sound quality) I feel it makes more sense to remain neutral and let the reader draw their own conclusions.

After all, you won't know how a headphone REALLY sounds until you actually try it.
To give one very specific example:
There are two graphs on my website, one from a closed-back studio-type headphone and another from a consumer on-ear headphone.
The graphs overlay ALMOST PERFECTLY... but of course they sound quite different.

So, every graph needs to be read within it's own context (on-ear, closed-back, planar, dynamic, electrostatic, etc etc) and properly informed preliminary conclusions can only be made when making reasonable comparisons (like HD580 vs HD600 vs HD650).

I don't have any plans to redesign or re-create the ratings system as that would have to be divided better into separate segments (sound, build, soundstage, imaging, timbre etc), and those can't simply be summed up in one generalized rating - I don't feel that generalized ratings are fair to the headphone or the reader.
Also, many of those headphones are no longer in my posession that it would be impossible to recall accurate ratings for every aspect.

It was not an easy decision to make, but I think it was the correct and most responsible one.

I was thinking of making pages with links to headphones of similar types, like one page with all of the studio-headphones, one page with all 2-way coaxial headphones, etc etc... I think that might be more informative/helpful, but right now I'm giving most of my focus/attention on my YouTube channel.
 
Dec 16, 2023 at 1:03 PM Post #2,128 of 2,345
I think most of my ratings were far too subjective and overly simplistic.
Understandable. I see your points. For me it's rather sad because you've had listened and measured stuff that is harder to obtain so any subjective note separated from objective measurments would be very welcome. Even something simple under the graph like:
Sound subjective: 76/100
Comfort: 67/100
Build quality: 90/100
Or even just updated list of 10 best (subjective) closed backs, 10 open backs.
Still it is my point of view and many thanks for the response :)
 
Jan 16, 2024 at 6:26 AM Post #2,129 of 2,345
Time for another "you saw it here first"...

VICTOR (JVC) HP-1100 - 1979
50mm (diaphragm is more like 40mm)

One of the earlier examples of a dynamic driver that has the classic dynamic driver dimensions and appearance.
Might be the earliest example I know of with this 'wide type' of 'corrugation' pattern that has survived decades.
Sony had earlier corrugations, but they were much thinner.

(foam is ready to turn to dust from the lightest touch)
_DSC0773.jpg_DSC0774.jpg
VERY CHONKY magnet
_DSC0775.jpg_DSC0776.jpg_DSC0777.jpg_DSC0778.jpg
Rubber gasket!!! (Victor being awesome as usual)
_DSC0779.jpg
 
Jan 16, 2024 at 6:28 AM Post #2,130 of 2,345
Time for another "you saw it here first"...

VICTOR (JVC) HP-1100 - 1979
50mm (diaphragm is more like 40mm)

One of the earlier examples of a dynamic driver that has the classic dynamic driver dimensions and appearance.
Might be the earliest example I know of with this 'wide type' of 'corrugation' pattern that has survived decades.
Sony had earlier corrugations, but they were much thinner.

(foam is ready to turn to dust from the lightest touch)
_DSC0773.jpg_DSC0774.jpg
VERY CHONKY magnet
_DSC0775.jpg_DSC0776.jpg_DSC0777.jpg_DSC0778.jpg
Rubber gasket!!! (Victor being awesome as usual)
_DSC0779.jpg
That's an amazingly modern design
 

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