Grado closed: where did the bass go?
May 22, 2005 at 11:44 AM Thread Starter Post #1 of 14

stewtheking

Headphoneus Supremus
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Just got myself a pair of nice new grado sr60's, and i am rather happy with them. However, just now i was playing with them to get a nice fit on my head, and happened to close my hands over the vents on the back, which somehow instantly killed all of the bass response until i removed my hands.

What is this madness? Surely if the cup is closed, then all the bass points at my head rather than out into the wilderness!

Confused

Stew
 
May 22, 2005 at 1:23 PM Post #2 of 14
Quote:

Originally Posted by stewtheking
Just got myself a pair of nice new grado sr60's, and i am rather happy with them. However, just now i was playing with them to get a nice fit on my head, and happened to close my hands over the vents on the back, which somehow instantly killed all of the bass response until i removed my hands.

What is this madness? Surely if the cup is closed, then all the bass points at my head rather than out into the wilderness!

Confused

Stew



cuz the driver can't push the sufficient amount of air to reproduce the bass notes
 
May 22, 2005 at 1:24 PM Post #3 of 14
Hey stewthe, I am not going to claim that I know anything about this, but here is an answear from someone that claims to know nothing.

When you cuped your hands over the housing of the SR60 driver you created a semi-sealed enclosure for its driver. On the universal side of the SR60 driver, the side that is oposit to the individual side or the side that points in towards the user, you created an acoustic dampaning chamber just like speakers that you use in your home theater have. Obviosly your hand is much less air tight than say a well sealed wooden enclosure, but it works quite well in changing the acousitc propertys of the driver none the less. The creation of a type of enclosure on the universal side of the driver means that the driver is no longer a "free-air" infinate baffle transducer but rather a restricted device that can no longer function in its occilation in a free way. Its movement is not only impacted by how much power you are feeding it through say your iPod & how stiff its various suspension parts (spyder, surround) but also the presure that is created in the chamber that now exists when said driver occilates back and forth. There is a heck of a lot of mathamatics and physical equations involved for finding out the exact resonce of the driver in a newly created enclosure (no matter what side of the driver that enclosure is on) but for now all that is important is that creating an enclosure on one side or both sides of a driver impacts the way that driver resonates. (both with & without signal coming from a source)
 
May 22, 2005 at 1:25 PM Post #4 of 14
Quote:

Originally Posted by Fr_eak
cuz the driver can't push the sufficient amount of air to reproduce the bass notes


and this is an effect of all that stated above
 
May 22, 2005 at 2:48 PM Post #5 of 14
Isn't this the same theory behind opening the membrane in the back of the Sony Eggo's to create more bass?

For some reason there are a few people who adamantly deny that this would have any effect.

The Eggos normally are "semi-closed" (nearly totally closed), and opening the membrane makes them "semi-open". I would think that this is similar theory applied in reverse.
 
May 22, 2005 at 4:45 PM Post #6 of 14
Quote:

Originally Posted by xluben
Isn't this the same theory behind opening the membrane in the back of the Sony Eggo's to create more bass?

For some reason there are a few people who adamantly deny that this would have any effect.

The Eggos normally are "semi-closed" (nearly totally closed), and opening the membrane makes them "semi-open". I would think that this is similar theory applied in reverse.




Its the exact same physical effect caused by physical laws which are (in this case) demonstrated by a reversal of the circumstances of enclosure presence, yes.
 
May 22, 2005 at 5:00 PM Post #8 of 14
Quote:

Originally Posted by Quad
Its fun to do. Cup, uncup make the band sound bad. Oh what we do to entertain our simple selves.


Just be careful, if you get too good a seal, you might damage the driver. All closed dynamic driver headphones I know of have a port in the driver housing to keep that from happening.
 
May 22, 2005 at 6:24 PM Post #9 of 14
In addition to increasing back pressure on th driver.... you most likely are creating midrange resonances, inside that cupped volume of air. My SR40 was like that till I modded them. Had some Honk-ish midrange resonance around 1000Hz. The closed earcup around the driver really excited some nasty resonances and it overwhelmed the bass.

Now theyre a dead ringer for an SR60... Smooth

Garrett
 
May 22, 2005 at 6:31 PM Post #10 of 14
Quote:

Originally Posted by S_Dedalus
Just be careful, if you get too good a seal, you might damage the driver. All closed dynamic driver headphones I know of have a port in the driver housing to keep that from happening.


Even the DT770 has tiny drilled bass ports.
evil_smiley.gif
 
May 22, 2005 at 6:43 PM Post #11 of 14
Bass, in speakers as well as headphones need some type of escape, or else you will create a "slapping" effect, where the low frequency sounds will eventually cancel themselves. Put a woody on a HD 600 series can and you will have the same effect (as I have found out). These cans were designed to allow frequencies to escape, to create the sound that the manufaturers were trying to achieve. You are altering that, good or bad.

On a side note...has anyone while sitting on a tall chair or couch, while listening to speakers, ever tried to cup your hands behind your ears? The results are quite interesting.
 
May 22, 2005 at 9:53 PM Post #12 of 14
Quote:

Originally Posted by immtbiker
Bass, in speakers as well as headphones need some type of escape, or else you will create a "slapping" effect, where the low frequency sounds will eventually cancel themselves. Put a woody on a HD 600 series can and you will have the same effect (as I have found out). These cans were designed to allow frequencies to escape, to create the sound that the manufaturers were trying to achieve. You are altering that, good or bad.

On a side note...has anyone while sitting on a tall chair or couch, while listening to speakers, ever tried to cup your hands behind your ears? The results are quite interesting.



Remember those leather elephant ear things they used to sell? I think called "ultimate listeners" or somesuch. The hung on your ear to give you free hands while you cupped your ears. Made the K1000 user look normal and sane. I wonder if they now have a surround sound version for movie theaters. Combined with 3D glasses it would make a fetching looking audience.
 
May 23, 2005 at 2:52 AM Post #13 of 14
oh crap, I gotta stop doing it then when I listen to music to create strange effects.

seriously it damages the drivers???? Welll there goes my rs-1's and ps-1's up the spout
rs1smile.gif
 
May 23, 2005 at 2:56 AM Post #14 of 14
Quote:

Originally Posted by GoRedwings19
oh crap, I gotta stop doing it then when I listen to music to create strange effects.

seriously it damages the drivers???? Welll there goes my rs-1's and ps-1's up the spout
rs1smile.gif



I'd call you goofy, but I'm the one who fried my first good pair of cans.
 

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