[HernandezNUFC]

I am completely new to this, I learned about impedance today. I was wondering when the difference between output impedance and the headphone impedance becomes noticeable. I have heard of the 1/8th rule but is it really that simple?

 

[obobskivich]

Zout will interact with (attenuate) the load based on how reactive or stable the load is. If the load is a straight-line stable (like a planar magnetic) it will attenuate the signal more or less evenly, while a reactive load (like the HD 650) will result in uneven attenuation which means changes to the FR balance. In terms of what this means for the end-user, roughly 2 dB of change to FR is where you'll start noticing changes. The amplifier's handling of load impedance (voltage/current output) also matters here.

High Zout is not universally a bad thing, is basically the take-away.

 

[Tjj226 Angel]

Quote:

I am completely new to this, I learned about impedance today. I was wondering when the difference between output impedance and the headphone impedance becomes noticeable. I have heard of the 1/8th rule but is it really that simple?

A good rule of thumb to make your life easy. 32 ohms is pretty much standard. You don't really need to worry about it too much. Anything above 32 and below 50, check the sensativity rating of the headphones. If the sensitivity is close to 110db then you will have slightly quieter sound coming but nothing that anyone would really cry about. Anything above 50 to 60 ohms, start thinking about getting an amp. 60+ Ohms get an amp. 

 

[obobskivich]

A good rule of thumb to make your life easy. 32 ohms is pretty much standard. You don't really need to worry about it too much. Anything above 32 and below 50, check the sensativity rating of the headphones. If the sensitivity is close to 110db then you will have slightly quieter sound coming but nothing that anyone would really cry about. Anything above 50 to 60 ohms, start thinking about getting an amp. 60+ Ohms get an amp. 

"Get an amp" over what? Nominal impedance is a bad indicator of "ease to drive" without more context.

 

[proton007]

@HernandezNUFC
Check the thread : http://www.head-fi.org/t/607282/headphone-amp-impedance-matching-basics-you-need-to-know

 

[HernandezNUFC]

Thanks everybody.