Noob question about headphone impedance.

[Anarchist420]

I have an hk3490 that I'd like to use headphones with. Problems are that my Sony 24ohms impedance headphones kind of died and I'm not sure why... and that the headphones i do have are some Polk headphones that are 16 ohm, they don't sound that good and they really don't fit that easily.

Does anyone here know what impedance rating for headphones is ideal for the hk3490 circuitry? I have no idea as to whether 24 ohms is ideal for it, but if it is, then I'd just get another pair of the Sony headphones that sounded so great and that fit so well. However, if my hk3490 killed them because the impedance was too high, then I'm out of luck I guess.

 

[SyndromeOCZ]

You just had them hooked up to the headphone port correct? If you had them there then the impedance wouldn't have been what caused your damage. The headphone port on those receivers can take a wide range of impedance headphones. Generally you only run into issues with very low impedance(16 ohm) and very high impedance(300+ ohms).

 

[Anarchist420]

You just had them hooked up to the headphone port correct? If you had them there then the impedance wouldn't have been what caused your damage. The headphone port on those receivers can take a wide range of impedance headphones. Generally you only run into issues with very low impedance(16 ohm) and very high impedance(300+ ohms).

yes.
Thanks

Perhaps the fact that my Polk headphones are only 16 ohms is why they don't sound good on something without uber high quality headphone circuitry. I've always wondered what my receiver used for its headphone circuitry, even though it's obviously not special like the loudspeaker amplifier circuitry is.

The hk3490 is pretty damn awesome, although surprisingly it isn't hk's very best 2 channel receiver... the hk990 is, but I can't afford one of those and I don't have speakers that I would notice a benefit with it over my hk3490. HK did kind of cheap out on the dac for the hk3490 (only 94 db SNR rated), but at least it is well grounded/shielded and does 24b 192 kHz.

 

[SyndromeOCZ]

If your 16 ohm headphones sound good on other devices, then you can buy/build an 'impedance adapter'

This is basically just a cable extension or adapter that has some resistors in-line to boost the ohms. Having a higher impedance can help alot to remove some of the noise created by the electronics in your amp, ipod, or other sources.

 

[darkswordsman17]

yes.
Thanks

Perhaps the fact that my Polk headphones are only 16 ohms is why they don't sound good on something without uber high quality headphone circuitry. I've always wondered what my receiver used for its headphone circuitry, even though it's obviously not special like the loudspeaker amplifier circuitry is.

The hk3490 is pretty damn awesome, although surprisingly it isn't hk's very best 2 channel receiver... the hk990 is, but I can't afford one of those and I don't have speakers that I would notice a benefit with it over my hk3490. HK did kind of cheap out on the dac for the hk3490 (only 94 db SNR rated), but at least it is well grounded/shielded and does 24b 192 kHz.

Actually most receivers will just step down the speaker amp using resistors. Unfortunately output impedance could be all over the place, so generally the higher impedance your headphones, the better they'll work with a receiver.

But yeah, 16 ohm headphones are pushing it as there's quite a lot of electronics that aren't great for driving them due to stuff like impedance mismatching which can cause wild swings in the frequency response. Unfortunately very few companies (including headphone amp makers even) list the output impedance.

Oh, and make sure and check for extra processing (surround modes, tone controls, EQ, etc) which could screw with the sound.

 

[_Rick_]

Actually, I'm quite unhappy with the headphone output on my HK3490, getting a subtle (constant with volume) noise on it, which changes in characteristic slightly when I switch Dolby Headphone mode. It's not really noticeable once I actually have a signal playing, but might impact very silent parts in pieces.
It's also completely independent of source.
So yeah, I prefer a dedicated headphone amp.

 

[darkswordsman17]

Actually, I'm quite unhappy with the headphone output on my HK3490, getting a subtle (constant with volume) noise on it, which changes in characteristic slightly when I switch Dolby Headphone mode. It's not really noticeable once I actually have a signal playing, but might impact very silent parts in pieces.
It's also completely independent of source.
So yeah, I prefer a dedicated headphone amp.

Do ya have IEMs? Their very high sensitivity tends to make them hiss with noisier setups and makes them a pretty poor match for receivers.

 

[_Rick_]

Just got some Sennheiser HD558s and 555s. They aren't overly sensitive. My hearing isn't that exceptional either, as far as I can tell. Maybe I got a bad model....
Should probably hook it up to a line in one day and send a sample to H/K

 

[sygyzy]

I have no idea what you are trying to say, Rick.

 

[_Rick_]

I have no idea what you are trying to say, Rick.

It was a reply to whether I have in-ear monitors as headphones. Should probably have hit quote instead. Sorry about that.
As for the last line, that was about recording the noise on the amplifier's headphone output, and send a sample to Harman/Kardon to let them figure out whether this is within specifications.
Not sure which of those confused you