Will 32 ohm earphones lower volume and reduce hiss?

hiss is somehow related to sensitivity of the earphone.  Not the impedance.
 

Quote:

Originally Posted by esbenm 

For serious listening I use a Sony NWZ-A829 with Ety ER6I. For commuting and at work I use my HTC Desire with Sennheiser CX300. I have two problems with the Desire:

 

1 the ER6I and the CX300 are too loud, even with the phone at lowerst volume.

They are also loud with the Sony which I set at volume 3 or 4, but volume 1 on the Desire is like volume 5 on the Sony.

 

2. the baseline hiss is killing me.

 

Would a pair of 32 ohm earphones reduce the hiss and not sound as loud either?

 

Can you recommend any 32 ohm earphones? I prefer semi-sealed design like the CX300 but better SQ. I would also like them to have a clip and possibly a volume control (in case the answer to question 1 is "no").

Some Sony DAPs are notorious for hissing with most IEMs (excluding Sony brand IEMs, ironically enough)

This hissing is worse with the HTC Desire?

Actually my Sony hisses badly even with the Sony earphones. The only earphones that I detect very little hiss with are the 100Ω ER4S. Everything else is hiss heaven. I've learned to just grin and bear it because there is nothing shy of using the line out and an external amp that will reduce the hiss of the thing. Eventually, if you use anything else, you'll miss the hiss!

But Ω rating alone means very little for hiss - it DOES mean something for drivability however as the output of your Sony is probably around 10-16Ω (properly), so earphones that get lower than that can cause it to lose resolution and drive up other artefacts. 

My 55Ω Audio Technica CK10 hisses like mad with any Sony. Grin and bear it.

I mean that there is a signal - the audio signal - that is composed of: bass, mids and treble and that when a very low Ω earphone is applied to the headphone output, if that earphone exceeds the limits of the headphone output (for instance it is 6Ω and the HPO measures at 10), then the DAP will not be able to drive that earphone very well where the earphone drops below 10Ω. All earphones fluctuate to a certain degree as they travel from 20Hz to 20 000Hz. Many multi-armature earphones fluctuate violently within that range and they cause the headphone outputs to stutter. Most drop bass performance (that also happens with low Ω earphones of less than 80Ω with most DAP's on the market. But dynamic earphones don't fluctuate as greatly; armatures, on the other hand can go as low as 4Ω (or so) up to 50Ω or more even though they are rated for 22Ω. That causes terrible strain and mismatch to the headphone output.

A very very few players are able to almost perfectly keep up with the fluctuation: Sansa Clip, Sansa Fuze, S:Flo 2. I own all three plus a few Sony units. Sony players traditionally have kept up quite well with low Ω earphones, but my new A845 did not and actually reeled in its anchor at 16Ω with a dnynamic earphone. 

The good news: most people don't know or don't believe. They think that a high Ω earphone is just so much harder to drive when it isn't. It is harder to get the same volume out of, but most players have enough overhead to get the same volume out of the player, even if the volume has to be raised to 80%. Past that, though and most don't have the guts to drive without clipping and distorting. That said, the ER4S does achieve 90dB (louder than should be listened to) without clipping from a lowly iPod shuffle 1G. Many go louder than that and people still complain. 

An amp is best used to fix the problems of impedance mismatching or reducing hiss, not for making earphones unbearably loud.

Output impedence will be well below 1 ohm. I think you mean minimum comfortable drive impedence. If it's to low, you loose damping factor and pull too much current. On some phones, they may appear more effecient but they also clip at a lower V setting so it's not really the case. Static hiss may be higher but hiss level relative to music should be that same for 2 phones with the same efficiency. Of course, ratings are all over the map and frequency response differences may mask or enhance the noise.