[imackler]

I'm out of place in the sound science section and in need of your help, please. 
 
The sensitivity of the SRH1840 is 96dB/mW and the impedance is rated at 65 ohms. Is my Ipod Classic 7th Generation powerful enough to give the SRH1840 what it needs to function as designed or should I buy an external amp to make up for my ipods inadequacies? 
 
I'd love to have the scientific answer before hearing how it needs yada yada yada to sound its best. 
 
Thanks! 

 

[mikeaj]

It always depends on how loudly you want to listen.
 
Also the output specs of the iPod Classic 7th gen, which I do not know offhand (or where to find the information). However, I seem to recall most of these iDevices doing 1 V rms and not clipping into something of 32+ ohms or so, so that should be voltage limited and thus 15.4 mW of fairly clean power (108 dB SPL given 96 dB / 1 mW sensitivity).
 
That's likely enough for most people unless listening to recordings with high dynamic range and wanting the loud parts to get very loud.

 

[imackler]

  It always depends on how loudly you want to listen.
 
Also the output specs of the iPod Classic 7th gen, which I do not know offhand (or where to find the information). However, I seem to recall most of these iDevices doing 1 V rms and not clipping into something of 32+ ohms or so, so that should be voltage limited and thus 15.4 mW of fairly clean power (108 dB SPL given 96 dB / 1 mW sensitivity).
 
That's likely enough for most people unless listening to recordings with high dynamic range and wanting the loud parts to get very loud.

 
Thanks a ton for taking the time to answer. I can't find any more details about the ipod classic than what you have there. I don't listen to music very loud so it should probably be fine... I suppose the test will be, as always, classical music which is mastered at lower volumes and can have a high dynamic range. 

 

[cjl]

If it's voltage limited, it shouldn't ever clip (note that this isn't generally true with amps, but should be true with a portable player if it is well designed), so the question simply becomes this: does it get loud enough with the volume all the way up? If so, you almost definitely don't need an amp. If not, you might want one.

 

[stv014]

  If it's voltage limited, it shouldn't ever clip (note that this isn't generally true with amps, but should be true with a portable player if it is well designed)

 
It can make sense for a portable player to have some excess gain and allow for clipping, since very quiet recordings may never reach the full scale digital level. Also, if a track with a high dynamic range is not loud enough, it might be an acceptable compromise to occasionally clip a few peaks. Although the majority of consumers who buy portable players probably listens to "loudness war" compressed music.

 

[cjl]

   
It can make sense for a portable player to have some excess gain and allow for clipping, since very quiet recordings may never reach the full scale digital level. Also, if a track with a high dynamic range is not loud enough, it might be an acceptable compromise to occasionally clip a few peaks. Although the majority of consumers who buy portable players probably listens to "loudness war" compressed music.

That's a fair point. It all depends how the gain structure of the portable player is designed relative to the maximum output level (and I don't know how that's set up for an iPod/iDevice).