There's gotta be something in the impedance curve or whatever. I'm not an audio engineer nor do I really know much of anything when it comes to the numbers, but let's put it this way: Trinity IEMs all seem to quote about 16Ohms impedance, but all the ones I own take 2-3 clicks more on my iPod Touch 5g to sound the same volume as my Earwerkz Supra or JH16 Pro FP. Relatively speaking, in a quiet environment, I can have the Supra at 1 volume click, the JH16 at 1-2 volume clicks, and the Trinity IEMs at maybe 3-5 volume clicks and all would sound roughly the same volume. The Supra is a 23Ohm quoted impedance and the JH16 has an 18Ohm quoted impedance. So why so much more power to get the same volume with the Trinity IEMs? I mean, I'm not measuring my sound level meter so I'm by no means being all that exact, but still.