Headphones and mp3 player - what's happening?

[Angilion]

I have a cheap media player. It came with awful earbuds (replacements are 79p, which says everything about the quality), so I replaced them with some fairly decent Sony earbuds.

They're still earbuds, so I've tried my headphones on the media player. My old Goldring DR100 sounded great, but they drained the battery very quickly. So I tried my Panasonic HTX7, which sound great connected to my PC. Much to my surprise, they were rubbish with the media player, worse than earbuds. The sound was thin, with no bass to speak of and poor quality across the board. Why such a large difference between PC and media player with the HTX7 when there's none with the DR100?

 

[IronWarrior]

Well, the sound chip/card on the PC can drive the headphones better then the mp3 player.

So connect it to the mp3 player and it sounds bad, but connect them to the PC which has better sound then the headphones can be driven a lot better and therefore sound better.

 

[Angilion]

Well, the sound chip/card on the PC can drive the headphones better then the mp3 player.

So connect it to the mp3 player and it sounds bad, but connect them to the PC which has better sound then the headphones can be driven a lot better and therefore sound better.

True, but it doesn't answer the question I asked:

Why such a large difference between PC and media player with the HTX7 when there's none with the DR100?

 

[joeyjojo]

Hmm. Well the specs are Panys 40 ohm 99 dB/mW. Goldring are 32 ohm 105 dB/1Vrms = 90 dB/mW.

So to drive the panys to 105 dB say requires 4 mW of power (0.4 Vrms 10 mA), for the goldring 105 dB comes with 31 mW (1 Vrms and 31 mA). This is all from an excel spreadsheet calculator I made the other day.

This explains why it drained the battery perhaps, the goldring use much more power.

As for the panys sounding thin, I can't answer that one atm. It needs far less juice to sound good according to the specs...

 

[hux]

Could be to do with the output impedance perhaps?