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bilavideo said:

It isn't just the number of holes punched out that gives the GS1000 its huge bass hump.  The PS1000 has the same number of holes punched, yet it has a significantly reduced bass hump.  The GS1000 has that huge muffin top made of mahogany.  If you read the sales literature for the PS1000, the thinking behind its hybrid use of aluminum for the muffin top is the desire to shorten the decay rate, particularly for instruments like brass.  
 
I don't want to say more about it this at the present time.  Suffice it to say that the problem with mid-bass and upper-bass  is more related to the quality of the shells than it is to the number of holes in the back of the driver.

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I believe you are probably correct. I think the large wooden air chamber acts sort of like an empty Christmas wrapping roll that your voice booms when you talk into it.
 
I'm considering getting rid of all my headphones, quitting my job and just studying materials and drilling holes in everything, and maybe coming up with a concept for a completely different headphone design. I'll bet I come up with something worthwhile before BP caps that oil leak. I encourage every member here to go for long walks with an empty shopping bag, and pick up every scrap object you find along the way, bring them home and drop each one onto the kitchen table and note how each sounds or resonates.
 
Eddie, I experimented on an old pair of SR125. At first I thought I got more bass but after a while I discovered it was mud.
 

I was going to give it a go with my old SR125i but think I will avoid that now. Anyway, with the MS1 and jumbos, there is no added mid bass from the hole mod - and I do know the difference having been fighting it with both some bass monster HP50-S and ATH-M50 with velours. Just clean sub bass with the MS1 as bilavideo reported with the Sr60.

Quote:

beagle said:

I believe you are probably correct. I think the large wooden air chamber acts sort of like an empty Christmas wrapping roll that your voice booms when you talk into it.
 
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Eddie, I experimented on an old pair of SR125. At first I thought I got more bass but after a while I discovered it was mud.

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What did you use to damp the inner walls, magnet plate and button back?  Once you increase the air flow, the limitations of the plastic chambers become more apparent.  I found it helpful to damp these sources of resonance.  The difference between vented and relatively unvented drivers is revealed by holding your hands up to the rear grills of the plastic Grados.  In their original state, these headphones don't change much - if at all - when you cup the grills.  That's because there's just not that much "venting" going on.  When fully vented, the difference is enormous.  So, what you've been hearing - with your vented SR125 - is the plastic air chambers.  You can do two things about it.  You can either damp the air chambers or chuck 'em since plastic sucks.  You can use it as a cheap bracing material, but a plastic air chamber is like a plastic violin.  Cover it or cut it off.

i was going to purchase the koss porta pros till i found grado's. i remember hearing about them long time ago and as i kept reading more and more reviews and watching all the youtube reviews. i decided to go in and demo both SR60i and SR80i. i was skeptical going in but the more and more i listen to both, i decided to go with the SR80's for the bass. i bought them home and been listening to them for 6hrs straight and i love them. they make my monster beats solo hd sound like trash. the grado's SR80 are the most comfortable headphones i've ever worn and the open air earphone i've ever own and damn do they sound good!!