My new Joseph Grado HP2i & HP2is - Page 12

Hum I've opened one of my HP 1000 and held the drivers while touching the mysterious black body with my thumbs, it didn't seem to vibrate at all at reasonably high volumes.

I tried to meekly wiggle and push the part toward the inside and while one the left channel it did move a slight bit in reaction to that, the other channel's stood in place and did not move at all. None of this seemed to affect the sound quality while I did it (and yes, they still sound the same now that I re-assembled them and put on my head).

Quote:

Originally Posted by devouringone3 

Hum I've opened one of my HP 1000 and held the drivers while touching the mysterious black body with my thumbs, it didn't seem to vibrate at all at reasonably high volumes.

 

I tried to meekly wiggle and push the part toward the inside and while the left side did move a slight bit in reaction to that, the other driver's black body was steadily staying in place and not moving at all. None of this seemed to affect the sound quality while I did it, and my headphones still sound the same now back on my head (not that I expected it to break or anything).

Hi devouringone3

were you be able to open the driver so that the bare driver can be seen?

teach me how to do that

at reasonable volume, you might not able to feel anything just by touching it.

once i was bored and have opened the grills of my two way speakers to try to feel the drivers.

i could feel the vibration on my fingers on the woofers at reasonable/high volume.

but i could feel nothing on tweeter driver even at high volume.

another way i was able to tell the movement/vibration of the the black body in the center of driver was that

while my hp2 is playing, i pulled a strand of own hair, stuck it in through the silk so that it touches the driver.

when it touches the black part, it vibrates the hair and makes weird sound.

its the same sound when the hair is touching the outer/transparent part.

Yes, you unscrew the 6 hexagonal screws a bit, the driver falls right off.

You're right, I did not pushed the volume beyond reasonable levels (at least not to the point of seeing the diaphragm going up and down like you did, lol ;).

So if I understand what you say, both the black piston part (in the back) and the diaphragm (that "transparent part" in the front) made your hair vibrate as to produce a sound that was similar between the two parts/tests. That's so cool.

Good idea the trick with the hair !

That driver in the HP 1000 is possibly the only one to feature such a "passive diffuser" in its dampening scheme / body construction.

''Good idea the trick with the hair !'', yeah... well, i'm afraid that ship as already sailed, now where is that darn cat...here kitty!

I don't know what you're referencing here Slacker, lol

Hey Goo, I found that isolated passage told by a Stereophile reviewer of the HP 1 :

Quote:

Originally Posted by devouringone3 

I don't know what you're referencing here Slacker, lol

 

Hey Goo, I found that isolated passage told by a Stereophile reviewer of the HP 1 :

 

 

"The rear of each diaphragm doesn't

radiate completely freely, however. It is resistively

damped in order to equalize pressure on

both sides of the diaphragm when the headphones

are in use."

 

Though I don't understand this fully, "resistively damped", maybe he is referring to that special black part in the back of the driver?

 

(from Stereophile, May 1991 - "GRADO HP l PROFESSIONAL RECORDING MONITOR HEADPHONES" - Gary A. Galo, http://www.mediafire.com/?gnhuo3on64zi1dz)

I was refering to a previous post where someone used one of his hair to see how much the diaphragms vibrates in his headphones, and since i'm bald and that my cat can spare a few well...

And by the way, it's Stacker, not Slacker

Lol! Hahaha, sorry!

So it's STacker... as in, SpeedStacking right? :P

No, it's Stacker45 as in 45 ton container Stacker, and yes, that's me in the red T-shirt and yes, i use ear protection