[Zasboy]

Hi,

So, I'm enjoying my nead Sennhesier HD 497's and wanted to try it out on difference sources. Sounds fine on the sound card. Next tried on the home receiver and it's sounded awesome. Now, I plugged into a boombox(Sony CFD-440) and I instantly get a hissing sound. I'm not playing any music and instead I got this terrible hissing sound. Even the volume is the lowest you can get, the hissing won't go away. I was confused so I did some more experiments. I took out two PCDP: A Coby and a Panasonic. I plugged the headphone into the Coby and the damn hissing sound was there. Took the headphone out and plugged into the Panasonic and no hissing sound but if you really really paid attention, you can hear a slight hissing but once you set the volume a little higher, you can't hear it. For the Coby, I had to turn the volume pretty high to get rid of the hissing sound and I couldn't stand the high volume. So, here I am wondering what could be causing the "hissing" problems. Even if the volume is at 0 or the lowest possible, there is this hissing sound until you crank up the volume.

Any suggestions, advices, comments, etc...would be helpful.

-Thanks

 

[dd3mon]

To my knowledge hissing is either caused by an impedence mismatch (headphone jack intended for either much larger or much smaller impedence than the headphones you're current using), or the equipment is just noisy.. In the case of a Sony boombox, it's probably just noisy.. Most mass market consumer electronics are not constructed of great components, the result is poor performance like you see here. Most PDCPs that I've heard have a hiss to them as well, my older Panasonic does have a slight hiss when the volume is high, especially noticable with lower impedence phones.

-dd3mon

 

[Zasboy]

Hi,

Was reading on impedence mistmatch and was wondering if an amp would help? For say, if I got a META42 portable amp and use that inline with the PCDP and headphone. Will the hissing sound be gone because the amp will correct the impedence mistmatch on the PCDP so that it will match the impedence on the headphone?

-Thanks

 

[dd3mon]

I'm not sure how the impedence matching with an amp would work out - there are many more qualified here than myself to answer a question like this..

However I'm inclined to repeat the old saying "garbage in, garbage out", meaning with crappy sources like a Sony boombox, an amp may even bring out the hiss more - I don't believe you can eliminate noise from a signal once it's introduced (at least not with just an amp, that's for sure..).. This is not, however, meant to downplay the usefulness of an amp, most amps will definitely increase the quality of sound from a given source.

-dd3mon

 

[skippy]

the hiss is coming from your noisy equipment.

it's not really an impedance mismatch. the thing is, high impedance headphones require a higher voltage swing, and if the hiss coming from your equipment is at a certain voltage the hiss will be lower with high impedance headphones. for example if you have a hiss at 0.1v and you use high impedance cans and the signal is 2v. then you use low impedance cans and they only need say a 1v signal to reach the same volume, but the hiss is still 0.1v. the hiss will be louder. this only happens in some equipment.

 

[Zasboy]

Hi,

The Sony Boombox is my temporary computer speakers and I was using it to test out the headphone. Basically, I will use these headphone on the Panasonic CD-player so I don't care much about the hiss problem because it's almost non-existance on that source. The reason I created this thread is because I was worry that something was wrong with my headphone or my ears

I am considering a META42 amp for my next purchase, but not sure if it's going to help the 497's dramatically. My ears are still trying to adjust to the sound quality of the headphone. Once they do, then when I get an amp, I can really tell if the amp made a difference or not. Until then, I'm just going to wait out until it's time for an amp.

-Thanks