Would I be right in thinking that EQ can be good unless you EQ right at the crossover point of multiple drivers (where applicable)? I feel crossover points are the areas that should be handled very carefully.Digital EQ is not an inherently lossy process. Most would not alter the data even one bit if set to on without settings. Your brain is playing tricks on your ears.
Hell, I can't find one single set of transducers in the world that DSP can't improve on, loudspeaker or earphones, so I guess I would find the sound mystically inferior, whenever I see the EQ button off, even if nothing's been dialed in for the EQ yet?
The main reason for that is the high Q resonance peaks found on almost all IEMs above 4kHz (which may or may not show up in coupler measurements which have smoothing applied to them). Which physical mods can in most cases do nothing about, unless you can live with a long cork of foam in your nozzles together with foam eartips to make sure that no sound waves bounce back. And then, good luck getting a good tonal balance from such a configuration without EQ
Of course, one cannot use EQ to negate such resonances, unless one knows how to listen for and tune them out via interactive tone generator testing, so maybe this doesn't apply to most people.
(the above are personal opinions only, not representing that of any company)
How do we know where those XO points are? We don't. But my guess would be that you'd be safe to EQ, say, a DD in a hybrid/tribrid setup up to 200hz without any adverse effect on other drivers.
I might be linking this too much to my car audio experience.
