Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › My new Joseph Grado HP2i & HP2is
New Posts  All Forums:Forum Nav:

My new Joseph Grado HP2i & HP2is - Page 11

post #151 of 173
Quote:
Originally Posted by Nik View Post

Because they are the first HP1000 (preseries), on which then began the production of the headphones...

Not to mention that these would be the only HP1000 that were built by Joe himself without John's involvement. They are truely unique! wink.gif 

This is not to belittle John Grado. John did the listening test on all the HP1000 and he has exceptionally good ears according to Joe.

post #152 of 173

Still, it begs the question why Joe would knowingly change future production models to sound "worse"?

 

 

<snip>personal comments edited out<snip>

post #153 of 173

.


Edited by devouringone3 - 9/30/12 at 4:19pm
post #154 of 173
Thread Starter 
Quote:
Originally Posted by jpelg View Post

Still, it begs the question why Joe would knowingly change future production models to sound "worse"?

What I say about my HP2is corresponds to the letter that Joseph wrote to me when he sent the headset. Does anyone know things better than him ... (???)
post #155 of 173

i just recently bought hp1000 used and its very old and there are many scratches

 

if you get an old hp2 restored/upgraded for $1200 or more, do you get practically a brand-new/like-new condition hp2 with new drivers?

post #156 of 173
Thread Starter 
Yes, of course you can contact Joseph and refurbish your HP2. Also I have done this the first time with an old HP2 bought on eBay ...
post #157 of 173

I'm not sure he would change your metal parts for less scratched ones, but he does replace the drivers with like-new ones (he does it in the upgrade but he also offers the service alone, for 600$; still a hefty amount).


Edited by devouringone3 - 10/2/12 at 12:13pm
post #158 of 173

i just noticed something with my hp2

what's the black circlish cone thing in the center of the driver?

post #159 of 173

(1 back)                                                                   (2 back, with "magnet plate" removed)

 (3 diaphragm / front)

 

(looking at the top left image, #1)

 

I'm not sure, the centermost circular textile in the depression must be some kind of air filter. What is under that black cover (#2: blue dot), well, is what you see in this picture; looks like a ring shaped magnet (or not, I'm not an expert).


Edited by devouringone3 - 11/13/12 at 11:28pm
post #160 of 173

do you think the black cone thing in the center is a part of the driver? i mean does it actually make sound vibrating together the outer ring?

or are the drivers of hp2 simply ring shaped like the ones in the hd800?

 

thank you for the pics BTW i have been dying to see the inside


Edited by goohsm - 11/14/12 at 2:02am
post #161 of 173

You're welcome :-)

 

If the magnet is bonded/attached to that black part then yes, loosing both implies loosing powerful magnetism that creates 100% of the sound.

 

But if I end up being right about the HP-1000 driver making use of a ring shaped magnet, this black part (that is being removed in the little storyboard above, an image I think it was Larry@headphile.com posted here a while ago) would be only "structural" and not required for sound-producing. More than for just structure it's also for long term protection from dust and airborne particles "inside" of the driver beneath the diaphragm.

 

So yeah my theory is that this (in gray):

1000

Would be the neodymium, rare earth, I-don't-know-which type ring magnet of the HP-1000. Not a ring radiator no, you can use the whole HD800's ring radiator as a wedding ring and it would still playback music, not the HP-1000's; so its not a "ring radiator".

 

When I manipulated my HP-1000's driver while cleaning the inside of my cups... well I forgot to measure the depth of this hole (in red, making up for the "cone" you're speaking me of right?):

1000

I could have compared my measured depth to the 14.8 mm width of the driver and told you if yes or no there could be a non-ring "regular" magnet lying between the "black part" and the diaphragm.

 

Basically I think the "Black Star" in the HP-1000 drivers is only the "small circular black filter" we've been talking about, that we can see through the transparent diaphragm. So not a magnet on a plate like in John Grado's driver. Here's better picture that I absolutely love (it was my Facebook cover for one hour until I realized none of my friends knew what these were):

 

It kind of looks like the same filter on the back seen from the front. So according only to that the HP-1000 driver magnet would really be a ring magnet... I'd say I'm 94% sure of it

 

The HP-1000's driver sure are is an interesting fellow, with a finely rippled diaphragm and from what I can tell a unique star formed in the center dome.


Edited by devouringone3 - 11/14/12 at 3:01am
post #162 of 173

i appreciate your enthusiasm for my simple curiosity

 

i have a very interesting result after some exploration

 

you know how sometimes you can visibly see large speaker woofer drivers move/vibrate if the volume is high enough?

 

i tried to make that happen with my hp2 drivers to see the both outer transparent part and black part in the center

 

i was kind of afraid because i have an experience of sending my rs1 for repair after killing the drivers this way but i usually do whatever it takes to know what i'm curious about

 

anyways i managed to turn the volume high enough to make the visible vibration

 

and i have witnessed that is the black part in the center move/vibartes together with the outer part

 

if you ask me if there is any chance that the black part isn't really an actual part of the driver and the only reason moves is just because of too much air flow inside of the driver with that high volume?

 

what i see is that the black part vibrates with the same power(only visibly though) as the outer ring

 

i dont know too much about drivers and all the technology related things but i agree with you that hp1000 drivers are very unique design
 

if my assumption is right and the black part is actually a part of the driver

 

i guess grado designed the driver this way obviously because there are benefits that the maker knows of using two different material

 

what an incredible journey i had!! i would have killed my own hp2!!

post #163 of 173

Well, curious is a splendid quality to have.

 

I have never asked myself such question about that black part that sticks out a lot from the rest of the driver's aspect. And me that took for granted that I knew the HP 1000 driver good!

 

Quote:

Originally Posted by goohsm View Post

what an incredible journey i had!! i would have killed my own hp2!!

 

Rofl! Actually I do think headphone drivers in general can survive music this loud, but I'm way too conservative to recommend anyone trying it with discontinued HP 1000 drivers! even for the sake of curiosity... but I'm quite happy you did it, I find it VERY INTERESTING too! so thank you

 

 

It is a " "known fact" " on Head-Fi that the drivers for the HP 1000 were manufactured by microphone Japanese company Primo, as commissioned by Joseph Grado to make them to his own specs. Apparently it is written Primo right on top of the driver (source: Rhydon [http://www.head-fi.org/t/269488/grado-drivers/15#post_3431274]).

 

http://www.primomic.com/products/ is a list of many of their products/schematics/patents? including their headphone drivers code named "DH-XX" (with XX as numbers), some of which quite intricate and complex in design. The HP 1000 driver looks based off the DH-57, but the dimensions do not match, the HP-1000 drivers (named "DH-40", according to the same source) have a 46.2 ± 0.3 mm outer diameter (my own measure), and not 48.4 mm.

 

What you're telling me you saw implies that this joint (in between two red lines) would be some kind of living hinge/edge, as opposed to a cement or glue, that lets the black back body vibrate along...

 

1000 (I'm a visual)

 

Vibrate along with what, in reaction to what? I see three possibilities here, either (1/3), like you said, the black body vibrates held "in the air" only by the "living edge", as a reaction to higher volumes of air being pumped by the diaphragm... personally I think it would confuse/mess up the sound more than it would serve any positive stabilizing(?) function.

 

Either (2/3) the black body is attached to the actual diaphragm by those "Mysterious layers" (as shown in the above picture) serving as a solid bridge, bonding together the two parts, unifying together the front and the back of the driver. Though I wouldn't know more about the advantages of such configuration/feature, compared to previous scenario, this time the diaphragm-black body ensemble would vibrate in a more unified/"coherent" way. 

 

And (3/3), the magnet, instead of being attached to the white capsule, resides in the black body, and floats with it... but that would make no sense at all, so let's forget about 3/3.

 

 

Quote:
if my assumption is right and the black part is actually a part of the driver

 

If your assumption is right, the black body is actually an important part of the HP 1000's sound!

 

I should report your discovery in the "Headphones' drivers" thread and ask if they would know why it's like that, serving which purpose, and if they know of other drivers doing that.

 

 

*edit: I think I recall reading an old thread on Head-Fi where people in it made allusions to the fact that this black part could be mobile. The context was that Larry@headphile.com (Xanadu something on Head-Fi) had received a seemingly never disassembled HP 3 in which the drivers had some kind of sponge cemented on their back (actual image of one of the drivers in question, next to a normal HP 1000 driver):

 

At the time, not knowing exactly what a HP-3 were, the people believed that this mod was done at Grado Labs and were some kind of failed experiment, giving explanation to both the 100$ reduced MSRP and the fact that HP 3 were made in such limited quantities. Yet, this is not a characteristic of the HP 3 at all, because that model is said in the official documentation to be identical in shape to its better matched drivers HP 2 and HP 1 counterparts, just like this HP3 proves to be:

 

400400 (left picture, identical in appearance to a HP-2, nothing appended on the back of its drivers)

 

So it's definitely the job of a modder... Purrin did something similar in his HP 1000 too (http://www.head-fi.org/t/596028/joe-grado-hp1000-modifications/75#post_8322637)

 

Anyway back to that old thread with Larry in it and how it matters to us: Larry did felt like this added ring of acoustic foam changed the sound a lot, if not dramatically. And I think, though I'm unsure, that it is at that point (that I can't recall precisely) in the thread that someone suggested that the black body was a mobile resonating part, which's movement were being impeded by the spongy thing.

 

 

Photos:

 we see through the white "podium" a change in color, I wonder why that is... could the magnet be so large?

 

 the ultra-wide bandwidth cable; the strands of copper are twisted around a plastic tube/cylinder... this copper is the same as the copper used for the voice coil of the HP 1000 driver and throughout the HPA-1 and -2, as Joseph wanted them to match perfectly.


Edited by devouringone3 - 11/15/12 at 12:43am
post #164 of 173

d3, do you happen to know what it is that makes the JGUWBC so special?  I've always supposed that it is all marketing fluff.

post #165 of 173

John Grado is the one who has been associated with marketing plots and disproportionate claims on Head-Fi :P. Joseph uses words more simply and literally, and it's quite apparent when he's exaggerating (like the "400% more details" about his upgraded flat pads).

 

Take this quote from Nikongod (relating his experience of opening a JGUWBC) which was posted on a headphone forum I'm not allowed to link:

"[...] the ultrawide bandwidth cable is a piece of work. the individual wires are not bundles of strands as is common, rather there is a solid core of plastic (about 0.5mm) around which the strands are wound. then of course there is an insulating jacket. The 4 wires are all in the main jacket with a few strands of cotton thread between each, and another strand of similar plastic down the center. The overal construction is similar to cardas "clear tubular litz" except there is only a sinlge layer of strands over the core, and the core is solid.

 

Anyone who replaces this cable for any reason other than it being broken is an idiot. ANYONE! Whoever designed this cable spent a ton of time thinking about how to put it together."

 

(the Laboratory Standard Cable is bundled strands though, no solid plastic core)

 

 

And just to give you the source when I stated that the copper of the cable was the same as the one being used in the HP 1000 driver's voice coil--> padam posted right after Nikongod in the same thread:

"Grado HP-1000 Signature Series Drivers
--------------------------------------
Transducer type: dynamic
Operating Principle: Open Air
Frequency Response: 18-24 kHz
Nominal impedance: 40 ohms
Drivers matched: 0.05 dB (HP-3 drivers are described as "not matched as closely")
Notes: The UHPLC used in the voice-coils of the HP-1000 drivers was also used in the connecting cables. [d3: which I think, was confirmed more than once by Joe] I've read that the factory-equipped Ultra-Wide Bandwidth Grados also used this cord in the voice-coils. This seem to indicate that there may have been as much as three types of drivers (one for every type of signal cord [d3: Ultra-Wide, Standard Laboratory, Blank/RS-1 cable]). Some people have stated that there are drivers with inscriptions on the back (i.e. "Joseph Grado Signature Products") and some without any inscriptions. Some Grado SR-200 and SR-100 headphones use the same drivers as the HP-1000 Signature Series."
 
...I don't think "one different type of driver for each cable", but the later ones that came in the Prestige Series Grados are definitely different. They have an thin layer of black color plastic over the rippled area (some with the "- Joseph Grado Signature Products +" inscription and some not [example]). I suspect these to have 45 ohms or higher impedance because they are slightly but significantly less sensitive. Though I tell people the two, black and white version HP 1000 drivers sound the same, others generally say that they are alike, but that the white ones that came inside HP1-2-3s are better, and that they prefer it. Frankly I don't have such a clear cut preference between the two.

Edited by devouringone3 - 11/15/12 at 1:49pm
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: High-end Audio Forum
Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › My new Joseph Grado HP2i & HP2is