Will someone explain to me what ohms are?

[Il Mostro]

Don't forget that the impedance of a headphone or speaker is stated in terms of *nominal impedance*. In the real world, impedance swing is a critical factor in an amplifier's ability to drive things. For example, my first generation Martin Logan CLS's run from <4 ohms to 32 ohms (this is the nature of ESL's) -- an absolute beast to drive.. Subsequent versions of this will drop down to <1 ohm at 20kHtz but do not rise nearly as high (having a less severe swing). So in matching amps/speakers/headphones, this factor is crucial to success.

 

[roadcykler]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif For voice coil dynamic headphones, ideally the output impedance of the amp should be vanishingly small, low single digits of ohms.

So if I understand this, my Bellari VP-130 with 8 ohms at the headphone output should work well with my 701's that are rated at 62 ohms or is there more to it than that?

 

[xkRoWx]

Like many people have stated before, impedance is not the only factor that can affect the drivability of your headphone. Sure, the higher the impedance, the more current/power it needs to be happily driven to full potential. But you have to also factor in the sensitivity level of the driver itself as well. The higher the sensitivity, the louder the signal a headphone can output.

Say you take two 32 Ohm headphones, one with <100dB/mW, and the other with >100dB/mW and compare them side by side with the same volume on your source, the higher sensitivity headphone will sound slightly louder than the lower one.

If you put two headphones of the same sensitivity, but different resistance, like 80 Ohm vs. 600 Ohm on the Beyer models, the 600 Ohm headphone will sound much more controlled at higher volume, given its higher resistance.

That's my 2 cent.

 

[nullstring]

Quote:

Originally Posted by xkRoWx /img/forum/go_quote.gif Sure, the higher the impedance, the more current/power it needs to be happily driven to full potential.

Actually, I am pretty sure that high impedance means that more voltage is required for proper driving... The current through the high impedance phones shouldn't be high at all.

Thats what makes driving HD600's, which are 300 ohms, a very different situation than driving the K701's, ~60ohms

Both are inefficient phones. The wattage between the two phones should be relatively the same, but the higher resistance phones should have much less current, where as the low impedance phones would have current in excess.

 

[xkRoWx]

Quote:

Originally Posted by nullstring /img/forum/go_quote.gif Actually, I am pretty sure that high impedance means that more voltage is required for proper driving... The current through the high impedance phones shouldn't be high at all. Thats what makes driving HD600's, which are 300 ohms, a very different situation than driving the K701's, ~60ohms Both are inefficient phones. The wattage between the two phones should be relatively the same, but the higher resistance phones should have much less current, where as the low impedance phones would have current in excess.

Sorry for the confusion. I usually get the terms messed up.