[Rhydon]

Does anyone ever look at the back of the drivers inside the mesh of their Grado's? Im trying to figure out why they place a black goop on some models and not others.

Its black, hard, kind of bubbly looking, and its covering one of the 3 holes in the back of the driver (holes are aranged ->(O- O -O) Black goop covers the middle hole on the button-top of the driver.

So far ive noticed this on the RS-1's, MSPRO, RS-2, and ive just seen it on a modded SR60 or 80. I have NOT however seen it on my old SR225's, MS-1's, SR325i's or some SR60's and 80's.

Seems like an aftermarket mod John does to some of the drivers after production.

Anyone else know anything about this?

 

[recstar24]

good question - i have always wondered about this. I have noticed they weren't there on the ms2's i owned, but its there on the rs-1's and ps-1's.

 

[NaOH]

Is there any way you could see if it changes the sound in any way (its presence or absence, that is)?

 

[seeberg]

I get the feeling that if removing the model number buttons on your Grados doesn't change the sound, neither will removing whatever globs of goo lie inside the earcups. I could be wrong though.

,
Abe

 

[NaOH]

Quote:

Originally Posted by seeberg I get the feeling that if removing the model number buttons on your Grados doesn't change the sound, neither will removing whatever globs of goo lie inside the earcups. I could be wrong though. , Abe

Well, but the button is fairly far away from the drivers, whereas this seems (at least if he described it well enough) to be right on the drivers, leading me to believe it would have greater effect.

 

[kramer5150]

ARGH!! My RS1 is less than 2 days old and you want me to pull em apart and do a "black goo mod"?

I really got to get away from this place.

Garrett

 

[jerb]

one person in another thread one about replacing the grills on the SR60's iirc) suggested that it was a dynamat like product to possibly dampen the driver?

whatever it is, I do think that there's a reason for it only being on the upper headphones

 

[allenf]

Tuning/resonance/damping issues I would guess.

 

[fureshi]

i wonder if a small piece of dynamat would make any difference on the grados without the goo. i don't want to take apart my hf1 yet tho. i fathom that this would make more of a difference than removing the button from the grill on a lower end grado.

 

[seeberg]

Whoawhoawhoa! Don't anyone take apart your expensive woody Grados just yet! Is there anyone that has already disassembled their Grados that has this goo in them? If so, perhaps they could give some insight into this matter.

,
Abe

 

[fureshi]

a head-fi member in this thread has done it but unfortunately the period between modding and listening was too long for him to discern any differences.

 

[kontai69]

Quote:

Originally Posted by fureshi a head-fi member in this thread has done it but unfortunately the period between modding and listening was too long for him to discern any differences.

That would be me.

The goop that Grado uses appears to be a sticky tar-like substance. I used a long sewing needle to gently poke at it through the metal grills. I noticed it on both my RS-1 and MS-Pro. I wonder if the PS-1 has it also?

My guess is that this stuff dampens the resonances on the back side of the transducers. What effect it has on the sound, I don't know.

When I modded my SR-60, I used Dynamat Xtreme, which is a similar material (butyl-based). Like fureshi said, I couldn't really assess its effect. In order to validly do so, I would have to do an A/B/A comparison which would be very difficult. Dynamat is very sticky and hard to remove. I put it on figuring it has to have some positive benefit, otherwise Grado wouldn't bother using it.

 

[aerius]

And now you know the cause of the brand new Grado smell!

Serious answer. Nothing on the back of my 225, but my guess is it's some kind of damping or resonance control measure.

 

[Jahn]

Uh oh, I'm sensing a new Grado diss nick - move over, Pizza Box, here comes the Grado Goop!

 

[Rhydon]

I remember back when i had my Bose QC2's (they were my dads, and it was before him or i saw the light lol), i totally took them apart, there were 4 holes on the back of the driver, i remember my MSPRO's having the goop, and i was interested to see what would happen if i plugged one of the holes with my finger. Well, it completely changed the sound, there was a considerable difference in the sound, less bass energy, less overall energy to the sound. I thought at the time that only alessandro headphones had the goop mod, cause that would explain the difference in their sound, but aparently the John Grado's have them as well. Im sure its a resonence controll measure, that was what i was hearing when i plugged the back of the QC2 driver.

Tho i still wonder why that SR60 link that fureish posted, why does its drivers have goop on them?

And, why not talk to the producer of the drivers, ask them to design the driver with 2 holes instead of one. I can stop thinking about how this goop seems to be a unprofessional quick fix to tailor the sound.



Rhydon