After following this thread closely, I finally found the courage to take apart my 325is and do these mods. I have to commend you for your extremely detailed explanation and pictures which makes these mods possible for people like me who are a little bit of a coward (paranoid if you will) when it comes to taking apart the cans. Having done it now, I can only say that it was actually easier than it appeared but would not have been possible without your detailed sharing.
I did the driver venting, damping and grill cloth removal mods. I am not sure why in the hell I went ahead and vented 8 holes without trying out 4 first. 8 was definitely too much for me. It brought out some mid bass which I didn't appreciate so it went back in and covered 4. With just 4 holes, the sound was every inch perfect to me and the 325is is now a very very different beast altogether. I just can't keep it off my head :)
I meant to ask you one other thing - as you already know, the 325is has this plastic ring in the aluminium chamber. I presume it is there to prevent the drivers from being pushed too far into the chambers. I understand from one of your posts that you had this ring removed. Three questions:
1) How did you remove the ring?
2) How does it sound after that? Is the difference gained worth removing the ring from the chambers?
3) Without the ring in the chamber, how would you know how far you can push the drivers into the chambers?
I am very keen in removing those rings but the above questions are what preventing me from doing so at the moment. I thought I should write to you and get your views before attempting. Thanks a heap for your time and your effort in sharing these wonderful mods. Because of them, I found a new love in my 325is :) Have a great one dude!
Thanks for the kind word. I appreciate the encouragement and am glad these mods worked out for you. In the "more is not necessarily better" category, I think a lot of Headfiers who've tried the mod like four holes better than the full 10. It's what Grado does on its big cans. Like you, I went for the full ten - probably out of sheer curiosity. One good reason to go easy on the venting is to prevent a bit of overkill that would make it perhaps too easy to get all that bass. At one end of the extreme, the bass is always playing catchup with the treble. At the other end, bass is beautifully full on bass-anemic tracks but there's always an issue of cone breakup. I'm hesitant to dope the drivers, but there may be a case for doing so with all the holes vented. On the DT770, all eight holes are vented but the driver is covered in a rubbery substance that was probably sprayed out of a can.
With regard to the ring in the SR325, it's evil. I'd get rid of it. Some say it's there to prevent the plastic from being pushed in too far. Maybe. It may be there to keep the grill, which isn't welded in, from slipping back. Whatever the case, it affects the sound. Get rid of it and the sound will improve. It is the source of some form of resonance because when I took mine out, the presentation was smoother - and addictive. Yes, I really like the SR325 with these problems stripped away. It really does give its big brothers a run for their money.
The SR325 can and will survive the loss of this plastic ring. Like a lot of design elements, it's probably the brainchild of somebody who was thinking about it "on paper." If the aluminum shell were too big for the plastic front cup, a ring would definitely be useful for preventing a shift beyond a certain point. But the coupling between the plastic and the metal is pretty snug. It took some doing to remove them. That same tight fit will resume when the two are put back together. If you want more anchoring, apply some hot glue. Just get rid of that ring. A conspiracy theorist would suggest it's there to keep the SR325 in its place, below the woodies. Whatever the case, the 325 definitely sounds better without it.