IE7 Hiss

[schalliol]

I have a few different headphone sizes to work with and notice that the new Sennheiser IE7s I just picked up seem to communicate a fair amount of his at low volume level, regardless of the source, whereas I experience a little with my on ear Sennheiser PX120, and none with my 580s. I have heard that impedance could have something to do with this, but I don't know if there's any way to solve it. Ideas?

 

[mark2410]

an attenuator, should remove that no prob

shure do a reasonable one, think they call it their inline volume control or something like that

 

[schalliol]

Thanks for the response!

Interesting, so in that case, do I use the amp to drive the signal at a relatively high gain and then drop it in the inline control? I would be interested to learn what it is doing or how best to use it.

 

[aimlink]

Quote:

Originally Posted by schalliol /img/forum/go_quote.gif Thanks for the response! Interesting, so in that case, do I use the amp to drive the signal at a relatively high gain and then drop it in the inline control? I would be interested to learn what it is doing or how best to use it.

Is the inline control removeable, and if so, have you tried the IE7 without it?

How much does the hiss get in the way of listening? My ears ring just a tad in absolute silence. It makes no difference when listening to music... at least not that I can appreciate.

Finally, if that's really your pic in the avatar, you look a LOT like Travolta!!

 

[mark2410]

as to which way round is best, attenuator then amp or amp then atenuator i cant say i remember there being a huge difference, but its not something ive often used. try both see which you like better

 

[Nocturnal310]

first amp then attenuator i think...because the link between the Amp out and IE7 is causing the hiss

 

[schalliol]

Thanks for all these thoughts. This is helpful. The amp first would be easiest for me because one of my amps has a built-in DAC.

Can someone help me understand why adding the attenuator works? I certainly believe you, but I also like to understand what is going on. It seems like amplifying a signal and then attenuating it would not reduce noise, and actually increase it. I look forward to learning!

...and you're not the only one who thinks I look a little like Travolta. Not sure if that's good or bad

 

[fyu]

In very basic terms. The hissing is very low. The attenutaor increases the impdeance. Thus in order for anything to come through it has to be cranked higher. If the hissing isn't in the recording or somehow attached to the volume control it won't be able to get past the higher impedance.
Basically a crappy filter.

But you need to located the source of the hissing first. Is it from the DAP? DAC? AMP? heck it maybe in the recording (though looking at your other headphones, I doubt it).

 

[schalliol]

That info helps, and explains why the 580s are silent. Basically I hear the hiss plugged into one of many sources, even if no source materials is playing. The hiss is less on my Ultra Micro Amp, but there nonetheless. It does indeed sound like it's the impedance issue. Those of you with similar headphones, if you plug them into say a computer minijack output, do you hear the noise I hear?

 

[chi2]

This
ETYMOTIC ER4P TO ER4S RESISTOR ADAPTOR (3.5MM PLUG) - eBay (item 300299659310 end time Mar-17-09 18:42:52 PDT)

may solve the problem with hissing, too, as it adds 75 Ohms. It may, however, affect the frequency response as with the Etymotic ER4P which gets turned into an ER4S with its characteristic more pronounced/forward high and very high frequency range. And your (internal amp of your) source or your external amp must be able to drive the higher load.

 

[schalliol]

I emailed Sennheiser and they're going to send me some sort of adapter to raise the impedance (no charge).

We'll see how that goes.

 

[fyu]

Quote:

Originally Posted by schalliol /img/forum/go_quote.gif I emailed Sennheiser and they're going to send me some sort of adapter to raise the impedance (no charge). We'll see how that goes.

awesome. I wonder what it is. I've never seen a sennheiser volume control or attenuator.
keep us posted.

 

[schalliol]

Will do! I'm guessing it's like that one on eBay or similar.

 

[mark2410]

how very nice off them

 

[schalliol]

Quote:

Originally Posted by mark2410 /img/forum/go_quote.gif how very nice off them

I thought so. I guess we'll have to see whether it's the right thing and does the trick! I'll report back!