- Aug 25, 2004
ok siddhartha talked, "I saw the sign, and it opened up my eyes I saw the sign". (wrong quote?)
in 3 words, I was wrong!
in more words + graphs:
I used another tip to show how much the trebles could be impacted. I believe it's one I got from the re400 but I'm not100% confident, I have a lot of tips.
B stands for bass setting.
the one scientifically labeled "crap tape" is the thinnest thing I could find, if one can vibrate with the driver this is it. an I put it on and off of my table a few times to make it a little dirty and less adhesive. sorry I didn't find paper based tape. but ultimately we could go with all kind of tapes or even just put some fabric that wouldn't close the vent but dampen it more or less. at that point it's all variations of the same thing.
oh and "strong tape" is the aluminum stuff I use, it's pretty thick and very adhesive so it's closer to something solid sealing the vent perfectly.
obviously you notice that I was wrong and siddhartha was right, the bass setting still has an impact after being taped.
here is compared to no no tape so that you can estimate the changes from adding tape.
doesn't change my own use, as what I was measuring is what I was using, but I'm glad you planted the seed of doubt in my head. I learned something today.
now don't ask me why it behaves like it does, I don't have a clue. maybe the bass setting changes the air volume inside the IEM? maybe something there is a gremlin inside? I really have no idea. but the behavior seems steady so I doubt Senn used gremlins.
I hope apart from self shaming, it can help a little. ^_^
Well, let me happily join you in having been wrong, even though I rightly guessed that vishnusiddharth's observations may have some merit.
Alas, I did guess right for the wrong reasons...
In short, your measurements prompted me to take another look at the construction of the IE8/80. Like pretty much everyone else, I assumed the bass dial was a rear vent, since it's located at the backside of the housing. (That much for the power of expectation bias lol However, these pics, that have been out there since the IE8 hit the market in 2009, show clearly that this assumption is wrong and that the bass dial is in fact an adjustable front vent:
So, basically, in turning the bass screw from 'max' to 'min', you gradually open up an air passage between the front and rear side of the driver, which leads to acoustic short-circuiting and a drop in bass level. And because of that, the tape mod's effect is only loosely related to the bass dial, since it only seals off the rear chamber and has next to no influence on the internal airflow between the front and rear side of the driver.
Bottom line, thanks to @vishnusiddharth's fine ears and @castleofargh's dedication to unearthing the truth via measurements, a long-standing misconception of the IE8/80's bass dial has finally been debunked. (... and btw, you guys at Sennheiser may stop laughing yourselves silly about us wannabe-modders now.)
Ok, it's been some time since we talked about the IE80's bass dial and its inner workings. However, it got me thinking that perhaps front venting to the outside instead of the inside might be worth exploring further. Based on prior experience with my JVC FX850/1100, I tried different ways to open an air duct large enough to counteract the IE80's bass hump and give its mids more room to shine. So, here's my suggestion to the curious at heart, who love to experiment and try out new things: the...
IE8/80 Paper Napkin Mod
What you'll need:
- a paper napkin
- a pair of scissors
- 5 - 15 minutes time, depending on skill
What you'll gain:
- better balanced / less obtrusive bass
- more forward / clearer mids
- more open feel / no more occlusion effect (due to air pressure equalization of the ear canal)
What you'll lose:
- sub-bass extension below 30Hz
- about 10-20% of isolation (rough estimate)
1. Set the bass dial to max and apply the tape mod at the rear side. We'll need all the sub-bass we can muster.
2. Use a common paper napkin like this:
3. Cut two pieces of about 1" x 1" (25 x 25mm):
4. Twist and roll the pieces between your fingers until they look like small sticks:
5. Stick them through your tips:
6. Now put the tips on. The result should look like this:
7. Pull at the rear end until the front end disappears inside the tip:
8. The result should look like this from the side:
Now listen to a tone generator, or your test tracks. You should hear a significant decrease in bass and better balance across the spectrum.
Side note: the IE8/80 have a treble spike @5kHz, which will become more noticeable with less prominent bass.
Leaving a bit of protruding paper in front of the nozzle (see figure 7) will have a slight smoothing effect on treble.
9. If you want the clearest / most forward treble, pull at the rear end until the front end sits flush with the nozzle.
10. If you're happy with what you hear, trim the rear end and you're done.
(Disclaimer: I've found this mod to be safe and easily reversible. Nevertheless: try at your own risk!)