Headphone Impedence

[jspoon]

I just purchased a set of jolly roger headphones and am waiting for them to arrive, my question is I just noticed there 16 ohm and all the better phones are like 150 ohm, will I be missing something by not going with the higher impedence? My manual for my M6 recomends 60 ohm.

 

[Rob (IL)]

MXT: 230
The manual says 60 ohms or HIGHER. The output impedance of the M6 is 230 ohms like the MXT. I use Rat Phones which are 300 ohms.



So let's review a few points:

1) To get the highest volume and efficiency, match the headphone impedance to the machine impedance.
2) Mono detector phone speakers are in parallel. So 150 ohm speakers will make 75 ohm phones, on ANY machine.. Minus a little (or a lot) wasted by the controls.
3) If you use true stereo phones, this is a special case. The speakers STILL end up in parallel, however the manufacturer will spec the impedance in ohms per side. On machines other than Minelab or Garret, 100 ohm per side stereo phones will end up at 50 ohms seen by the machine. But on Minelab and Garret, the wiring in the machine puts stereo phone speakers in series. In that case, 100 ohm per side stereo phones will now become 200 ohm phones.


Ratphones use 300 ohm speakers resulting in true 150 ohm total impedance delivering more power to the speakers and match a wider range of machines. They will be 150 ohms on ANY machine at all frequencies.