[iphone3g]

How are these umamped straight out of a laptop or mp3 player?

im asking because they are 65ohms

 

[J_C_Denton1]

No need for amp. If they are below 100 Ohms laptop and MP3 player can drive them without any problem.

Plus I found interesting discovery that my HD25 is louder at the same volume level compared to KSC-75, which is at 60 Ohm.

 

[Nagasaki_Kid]

The hd25 sp is kinda inefficient as a portable headphone and is 85 ohms not 65 ohm. They do however provide more isolation than anything I have except the hd280. The sp version is much less efficient

 

[1Time]

The Ohms (impedance) and sensitivity of the headphones should be considered, not just the Ohms.

Sennheiser shows the HD25-SP II at 60 Ohms, 114dB.

The KSC75 is 60 Ohms, 101dB.

And so the HD25-SP II would be louder at the same volume setting.

 

[Nagasaki_Kid]

The sennhieser site clearly indicates that the hd25 sp is 85 ohm and 100dB. I think you are looking at the specs for the hd25-II

 

[1Time]

Quote:

Originally Posted by Nagasaki_Kid /img/forum/go_quote.gif The sennhieser site clearly indicates that the hd25 sp is 85 ohm and 100dB. I think you are looking at the specs for the hd25-II

No. here is the link to the HD25-SP II at Sennheiser, and it shows the specs that I posted above.

 

[1Time]

.

 

[Nagasaki_Kid]

that's strange this page indicates they are 85 ohms and I was going mostly by the the specs of the hd25sp Sennheiser USA - HD 25-SP II - Product Details My pair of hd25sp doesn't sound as efficient as the non US sennhieser site makes it out as,

 

[1Time]

Quote:

Originally Posted by Nagasaki_Kid /img/forum/go_quote.gif that's strange this page indicates they are 85 ohms and I was going mostly by the the specs of the hd25sp Sennheiser USA - HD 25-SP II - Product Details My pair of hd25sp doesn't sound as efficient as the non US sennhieser site makes it out as,

Anyone interested should probably contact Sennheiser regarding the discrepancy to determine the correct specs.