Originally Posted by theKraken11
Some IEMs come with an in-line volume control, but not all of them. If I were to buy a low-end model (or even a high-end model) to compensate for the ones that don't, are there any general compatibility issues I should look out for? Is there a chance the sound quality would suffer?
attenuation, on its own, cannot hurt sound quality.
what does affect things is what happens when you send audio thru a ganged pot (stereo pot). there is a triangle like curve on the RMAA test suite (or any audio analyser program) and as you go up in frequency, the separation goes down. this is due to the parallel tracks in a typical pot and as you go up in frequency, the tracks 'work off each other' and you lose separation (channel bleed thru). as frequency goes down, the effect goes down. you can see it on any amp you put thru RMAA that has 2 mono atten controls vs a single stereo control.
stepped attens and other things like that don't have this problem and don't hurt sound at all.
a pair of resistors in a series/shunt config is quite find and harmless to your sound. this will also not have the 'pickup problem' that pots have.