[JimBob1971]

Both my Super.fi and Triple.fis came with a sound attenuators for use on planes. I've seen folk on here talk about attachments to change impedence.... Is that what these things do? If so, is there any benefit sonically to using these type of adapters? I know they can sometimes reduce hiss, but are they known to alter the frequency response?

Sorry if this is an obvious question, but I'm pretty new to all this.

Cheers!

 

[appophylite]

Those flight jacks work just like a 1/8-->1/4 jack. It just converts your existing 1/8 headphone jack into one compatible with the airline audio jack on most planes. I don't believe they significantly alter the sound signature of the headphones being used, but if they did, it probably wouldn't matter too much because the audio coming out of those seat units is never the best.

 

[JimBob1971]

Quote:

Originally Posted by appophylite /img/forum/go_quote.gif Those flight jacks work just like a 1/8-->1/4 jack. It just converts your existing 1/8 headphone jack into one compatible with the airline audio jack on most planes. I don't believe they significantly alter the sound signature of the headphones being used, but if they did, it probably wouldn't matter too much because the audio coming out of those seat units is never the best.

Thanks for the reply Appophylite. The attenuator doesn't alter the size of the jack, it simply makes the phones quieter so that the pilot talking during the movie doesn't blow your eardrums! However, I was just wondering if it is an impedance thing, and whether it would change anything other than volume whenn used with a quality source.

 

[ericj]

resistive attenuation alters the sound signature a few different ways.

First, the high resistance will significantly impede high-frequency noise - especially ultrasonics. This may make a headphone with "harsh" highs sound less "harsh". Using steel wire in the cable like Sennheiser frequently does will have this effect to some extent as well, and for the same reason.

If the source lacks series output resistors, the attenuator will add some series resistance that protects the output stage of the amp from nasty feedback from the capacitance of your cable and the inductance of the coil in the drivers. This may allow it to slew faster, which may make the combination sound more 'detailed'.

By sheer force of ohm's law, the increased impedance also lowers the amount of power the headphones are pulling from the source. This decrease in current load may improve the clarity of the bass response in the respect that, not having to pull as much current from the power supply, the amp may do a better job of servicing large transients.

 

[iPatcH]

I've noticed that the adaptors remove ALL hissing from my Super.fi 3 pros that comes from my laptop, but I sacrifice pretty much everything I bought them for, that is, the quality sound they give off.... I really need something cheap to fix that damn hissing!

 

[radioactive28]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif resistive attenuation alters the sound signature a few different ways. First, the high resistance will significantly impede high-frequency noise - especially ultrasonics. This may make a headphone with "harsh" highs sound less "harsh". Using steel wire in the cable like Sennheiser frequently does will have this effect to some extent as well, and for the same reason. If the source lacks series output resistors, the attenuator will add some series resistance that protects the output stage of the amp from nasty feedback from the capacitance of your cable and the inductance of the coil in the drivers. This may allow it to slew faster, which may make the combination sound more 'detailed'. By sheer force of ohm's law, the increased impedance also lowers the amount of power the headphones are pulling from the source. This decrease in current load may improve the clarity of the bass response in the respect that, not having to pull as much current from the power supply, the amp may do a better job of servicing large transients.

Woah, thanks, ericj =)
It's the first time I've seen someone explain this topic so technically.
Enlightened =D

 

[JimBob1971]

Yeah, thanks Eric. Certainly answered my question

 

[appophylite]

Ah my bad. I thought you were talking about one of those jack adapters, I didn't realize you were talking about an actual attenuator.