A quick question, are the drivers used in the SR60, SR60i, SR80 and SR80i identical? The SR80 isn't known for being bass anaemic or anything of that sort, right? Because I just bought an SR80 driver from BobSaysHi to replace my busted SR60 one, and the contrast between the two couldn't be greater. The bass on the SR60 practically booms compared to the SR80, which has practically every bass frequency cut off, by more than 10dBs or so. The rest of the frequencies seem fine though.
The official word from Grado, and the unofficial word from the Grado surrogates on Headfi, is that each driver in the Grado lineup is different. What they mean by "different" is some kind of state secret. Having taken apart the iGrado, the SR60, the SR60i, the SR80, the SR80i, the SR225, SR225i, the SR325i and the SR325is, I can't give you any meaningful difference between them. The mylar is the same shape and thickness; the magnet is the same size and weight; the frame is the same plastic, with the same felt. If there's a difference, it's in the grill cloth, any doping used on the driver (none of which I ever noticed), the materials of the shell, the use or non-use of damping on the magnet back, the type of cushion used and the amount (and quality) of the wire used in the cable.
I've always thought that they were identical, however something is obviously different between the drivers. I know that Grado matches their drivers at the factory, that might account for the difference. Maybe Bilavideo will chime in, he's been offline for a couple weeks now.
Do my drivers really sound bass anemic? They've always sounded like that.
I had that happen to a pair of MS1s I was working on. One morning they were fine; the next, they weren't. I couldn't tell why they were not performing properly but I'd suddenly found the bass cut off. That was before I went irate and destroyed the driver. Expensive tantrum.
Those holes are the original holes in the driver that were later covered by paper/felt.