**roguegeek**

I need help understanding something. I have certain headphones and IEM that sound like absolute crap with the Magni, but other that are equally efficient that sound fine. A Porta Pro sounds fine through it. A PX 100-II or XBA-3 sounds like crap. I know this has to do with a low impedance headphone not being able to work with a high output impedance amp. Bottom line, I don't get it. Is there something someone can point me to that will help me understand this concept or can someone give me a simplified answer? Also, what's the math that needs to be done in order to know if a certain can will work with a certain amp?

Ok. I think I may have it. Headphones work best with an amp when the amp output impedance is less than 1/8th the headphone impedance.

My Porta Pro has an impedance of 60 Ohms. 60 / 8 = 7.5

0.1 Ohms output impedance of the Magni is less than 7.5 Ohms, so my Porta Pro should sound just fine on a Magni, and it does.

My XBA-3 has an impedance of 12 Ohms. 12 / 8 = 1.5

0.1 Ohms output impedance of the Magni is less than 1.5 Ohms, so my XBA-3 should sound just fine on a Magni, yet it doesn't.

My PX 100-II has an impedance of 32 Ohms. 32 / 8 = 4

0.1 Ohms output impedance of the Magni is less than 4 Ohms, so my PX 100-II should sound just fine on a Magni, yet it doesn't.

What am I doing wrong here?