Oh you are pairing it with IM02? I was thinking of the IM03 as I heard they are more friendly to high output impedance than the IM02?
Yeah. I haven't noticed any issues with the A17, I prefer them with it to Clip+, with <1ohm output impedance. I think on the big review thread earfonia mentioned that they are brighter at higher impedances. It has been a while since I did direct comparison, and I don't remember them seeming particularly brighter with the A17, but then again my listening preference also leans that way.
Still, the 02 has 36-ohm impedance and the A10 is something like 3-ohm, which falls within the "1/8th" rule of thumb... though I don't know much about that stuff.
For me the main downside is that they pick up on the hiss- I've never noticed it while music is playing, but I still cant forget that it's there
http://en.goldenears.net/49122 at the bottom you have an impedance graph(impedance being the bottom line), as expected the official impedance is the value at 1khz and nothing more.
but don't get scared by the shape of the impedance curve, as soon as you're above the 1/8th ratio, you kow that you'll never get above a 1db difference whatever the value, so it almost doesn't matter.
here with the A17(4ohm), the IM02 can expect to lose about 0.7db in all the low end, and get about +0.5db at 7khz. that compared to a 1ohm clip+. really not as dramatic as the graph might make it look. and as always, some might actually prefer the sound into higher impedance sources, that's a matter of personal taste.
now as far as the source itself is concerned, you're also helping it when you try to respect at least 1/8 ratio for impedance, so while it doesn't always matter, when you can, try to follow up on that rule. and as soon as it's a BA driver or a multidriver, you may want to try and find out how low the impedance curve can go.
ok, as long as I like the sound I don't care about any rules or measurements or what people. But I tried somewhen the IM03 on my A17 and I liked it. Some people still telling me with the 4 OHm output impedance I am limited to dynamic or SingleBA IEMs or I have to use a portable amp.
you're never limited to anything, as I say above, it's more of a simplified rule for when you don't know enough about the IEM specs. dynamic drivers tend to usually have a relatively flat impedance curve so the signature change will be limited whatever the source's impedance. same for single BA drivers, they usually have impedance that rises like mad in the trebles, but they tend to not have much trebles after 11 or 12khz so you won't hear a lot of change in many instances.
on the other hand a multidriver will always have some impedance wobbling so the signature may or may not change a lot depending on the source's impedance, and the change often doesn't go the pleasant way.
as long as you can listen to the combo and like the result, you obviously don't have to care about all that. but you get piece of mind by following those rules when you can't listen.
