[Armaegis]

Cool beans, much appreciated 

 

[Armaegis]

So I found this roll of roofing repair material in the garage...
 

 
I don't know the exact name of the stuff, but it's probably some variant of "peel 'n seal". Anyhow, this kind of stuff has been used as a cheap alternative for vibration damping in cars (the thicker variety of course). I think it's an asphalt based adhesive with a plastic/rubber backing. Just peel the paper off and stick it on. The thin stuff I've got seems just right for headphones. Therefore...
 



 
Cutting this stuff was actually rather difficult. The material itself isn't hard to get through, but it sticks to your scissors and makes a mess of things. You have to be careful it doesn't bunch up behind the scissors and pull itself back into the blade as you're cutting.
 
So anyhow, I cut a ring out and applied it around the edge of the baffle front. 
 
Sound impressions? Bass is cleaner, but yikes I think it got louder too. 

 

[DigitalFreak]

Quote:

So I found this roll of roofing repair material in the garage...
 

 
I don't know the exact name of the stuff, but it's probably some variant of "peel 'n seal". Anyhow, this kind of stuff has been used as a cheap alternative for vibration damping in cars (the thicker variety of course). I think it's an asphalt based adhesive with a plastic/rubber backing. Just peel the paper off and stick it on. The thin stuff I've got seems just right for headphones. Therefore...
 



 
Cutting this stuff was actually rather difficult. The material itself isn't hard to get through, but it sticks to your scissors and makes a mess of things. You have to be careful it doesn't bunch up behind the scissors and pull itself back into the blade as you're cutting.
 
So anyhow, I cut a ring out and applied it around the edge of the baffle front. 
 
Sound impressions? Bass is cleaner, but yikes I think it got louder too. 

Ummm I'm hopefully wrong about this but if that's a real old variant of roofers tape (pre 1990)  it could have asbestos in it. I would highly recommend you not use that just to be on the safe side. Usually if the backing is really gummy feeling and has a slight tar like smell to it it probably has some asbestos in it. If it's really thin and has a very smooth surface you're usually OK.
 

 

[Armaegis]

No, pretty sure it's just a year or two old from when my folks had some "repairs" done. I say that with quotes since those guys my mom hired did a piss poor job. I'm not a roofer but even just crawling up on the roof I could tell right away that it was wrong. Just a mess of tar and tape everywhere; cripes I still can't believe she paid them money for a job like that.

 

[DigitalFreak]

Good to hear and sorry about your bad roofing job.

 

[nick n]

Quote:

Note to self for future modding projects: put micropore tape over the blutak... felt that gets mashed into the putty is messy stuff and makes life difficult

X2 Excellent advice. It's a gong-show otherwise. Wish i'd thought of that beforehand on some stuff.
 
Also is there a reason that you didn't just remove the MONO PCB section completely, to get it out of the signal path and make it easier to damp inside? Or do you use it to test them with?

 

[Armaegis]

Yeah, the first time I opened them up and saw the fibres sticking all over the place I had the "aw $%^& this is going to be a mess" go through my head.
 
I didn't remove the mono pcb because I don't like making permanent changes. Plus it's such a tiny thing with short wires that I just didn't want to bother. I hate trying to solder tiny thin wires.

 

[Byakushiki]

Quote:

Haha, an unintended benefit to putting tape over the bass vents is that the whistling sound from wind while walking outside has been decreased (probably because, well, now there aren't holes for wind to whistle across).

I need to do this with my HDJ500's. They have vents too, which causes really annoying whistling from the wind. Annoying when everyday, the wind is at 10-20mph.

 

[Armaegis]

I keep wondering if I should pick up a pair of HDJ-500 and experiment on them as well...

 

[Vanhornmp]

Nice work

 

[jfunk]

 
Quote:

I need to do this with my HDJ500's. They have vents too, which causes really annoying whistling from the wind. Annoying when everyday, the wind is at 10-20mph.

I don't think the HDJ-500 have vents but the hinge where the earcup joins the headband does leak a bit. If you remove the driver ( 3 screws under the ear pad) you can tape over the plate that covers the hinge inside.

 

[brent7109]

i was wondering how i could do this to my hdj 1000s and what you would reccomend?

 

[Armaegis]

I've never taken apart the HDJ-1000, but general damping principles to try:
1) mass load and/or vibration damp the baffle: generally some putty or plasticine near the driver, this should improve bass response overall
2) fill in any large crevices in the cup, add light filler like polyfill; gets rid of odd resonances and treble peaks and the filler might improve bass
3) of if you want to experiment with damping, try putting some felts or open cell foams in the cup; this can alter overall frequency response

 

[Byakushiki]

Image dump so you can see the vents I'm talking about. HDJ500 has 4 of them, 2 per side.


I think you can get away with just stuffing some foam or something there. Might help with noise reduction.
 
Edit: I did just clean out some dust from the tiny vents before I took that picture. Might be a placebo effect, but I swear the soundstage is ever so slightly wider.

 

[jfunk]

Quote:

Image dump so you can see the vents I'm talking about. HDJ500 has 4 of them, 2 per side.


I think you can get away with just stuffing some foam or something there. Might help with noise reduction.
 
Edit: I did just clean out some dust from the tiny vents before I took that picture. Might be a placebo effect, but I swear the soundstage is ever so slightly wider.

AH I did not spot those hidden away. If you did want to block them up then you would be better doing from the inside. The hinge at the centre of the cup has a channel that goes through the the inside of the cup so even if you stuffed something into the holes you may still get the whistle as the wind blows through the hinge. You could safely tape over the inside and it wont spoil the look