Originally Posted by castleofargh
the impedance of the 334 is lower in the bass region (compared to medium), so increasing the source impedance will simply mean less volts on the bass. and so indeed less db in those frequencies.
I was talking about getting a bad damping ratio. using more than 30ohm on the 16ohm bass region of the 334 isn't an ideal scenario of tight controlled bass. (without regard to frequency response changes)
but as I said in my silly trial with the hifimedy, all in all it seems like it doesn't change too much the behavior of the bass driver.
doing the same on my IE80 (dynamic driver) doesn't alter the signature at all, but the bass get bloated past the fugly point.
Rin suggested 33ohm. in any case more would start killing the treble too much IMO.
do you guys know where we can find more values for impedance adapters? I would like to have some like 2, 3, 5ohm when I try some daps so I could compare 2 daps with around the same impedance and be sure I'm not blaming a colored sound on the dap when it's just the IEM getting altered by impedance changes.
Oh got it. Well you overlooked the fact that when increasing source impedance you are reducing the damping across the whole frequency range, not just the bass region. There'll be less dB on the bass presumably (theoretically, not exactly the case when it comes to different IEMs), but the rest of the spectrum is also skewed at the same time.
I guess there's some slight misunderstanding here. By increasing load impedance by 30 ohm on a 16 ohm load, you are also increasing damping by 3 folds so it translates into better controlled bass (and mids and highs as well). How that comes about was explained in my previous posts. That's why you see a much tamed curve in the bass region in the graph I posted earlier due to the fact the rod inside the BA doesn't swing all the way as much compared to when it's less dampened.
Can't speak for the IE8. BAs are way more sensitive to voltage changes compared to dynamic drivers. Not to mention there are heaps of types of dynamic drivers out there.
Oh well better stop here. The mod sure won't like it if I turn this thread into another science one.
Btw if you want to get a good, cheap adaptor that comes with whatever value you want to play around with, it might be a good idea to drop by the DIY box. There's a massive thread there where folks post their cabling work (which is very well done) and there'll surely be someone near your area. Drop him a pm about what you want and see how it goes.
Edited by tranhieu - 10/21/13 at 7:49pm