What is the ohms mean?

Ohm is the amount of resistance between say the headphone and the source. More Ohms means generally that the headphone in this case is harder to drive, so the source need to supply more current in order to drive it effectively. Something like that.

One might ask, why have high ohm headphones, when low ohm rated headphones are easier to drive with no amp needed. The more ohms a headphone has, the more the drivers can be tuned, and the more detail can be had from doing so. Also I read that low ohm headphones can make any noise in the signal seem worse, whereas high ohm phones can mask the noise.

If I am incorrect, someone will correct me. :)
 
Thanks. Yes, i thought something like this. But I dont understand how a 100watt amp can easily drive some 120watt B&W 603 floorstanders to the point of the house shaking down, yet it cant drive some 300ohm headphones properly. Unless of course wattage is not realated to current?

So does the ohm in headphones generally mean that high quality headphones have high ohms? Would be interesting to find a chart with current headphones and their ohms, or even a list of the main ones like Grado, Sennheiser, Goldring and some others like Technics, Sony, Pioneer and Denon

Cheers
 
In your average hi-fi amp or receiver, the circuitry driving the speakers is not the same as the circuitry driving the headphones. Normally one of two things is done. Either there is a seperate amp circuit for driving the headphones or there is some sort of conversion circuit.

Even very expensive hi-fi speaker amps aren't always any good for driving headphones (some aren't bad though but spending a lot by no means guarentees that they'll be good for driving headphones).

Headphones themselves can be quite different. Most people think of high impedance headphones as being hard to drive. It's not quite as simple as that. High impedance (ohm) headphones benefit from an amp supplying higher voltage. Low impedance headphones can benefit from higher current. So one headphone amp won't necessarily drive all headphones well.

The Goldring NS1000s that we both have, in passive mode, seem to be very 'picky' with amps. They're somewhat demanding in both voltage and current. Thankfully, the built in amp required for noise cancelling to work allows them to be easily driven from all sources in active mode (albeit with some hiss related to the noise cancelling)

I have to say, I'm very surprised that you bought an ST, which has one of the best headphone amps that can be found built into a soundcard, without knowing why headphone amplifiers were important.

A bit more info: http://www.headphone.com/learning-center/how-do-i-know-if-my-headphones-need-an-amp.php
 
Last edited:
I should hope you're not driving the headphones from the speaker out.

Speakers tend to be 4-8ohms, headphones I think are about 50ohms upwards?

The power output from the headphone socket will be much less than the speaker outputs.

edit - beaten to it by Uriel, nice write up.
 
Marsman said:
Ohm is the amount of resistance between say the headphone and the source. More Ohms means generally that the headphone in this case is harder to drive, so the source need to supply more current in order to drive it effectively.
Click to expand...
Current is movement of the electric charges, and that won't happen without voltage. Higher impedance needs higher voltage input for drawing same current. Power itself is again function of both voltage and current (P=UI) so current doesn't need to be kept at same level for same output power.

Interference tolerance is increased because inducted interference has fixed voltage when voltage of real signal increases with load's impedance resulting increased signal to noise ratio despite of same level of EMI.
But need for higher output voltage again becomes problem for devices with low operating voltage (especially anything battery powered) so it's not without its disadvantages.
 
Uriel said:
I have to say, I'm very surprised that you bought an ST, which has one of the best headphone amps that can be found built into a soundcard, without knowing why headphone amplifiers were important.
Click to expand...

I don't really use headphones that much and have always just had them connected to my amp, headset from my audigy 2 was connected to the soundcard. (which i only ever used in BF2)

mr_x_plosion - No, im not driving headphones from speaker out. Xonar essence has phono connections for speaker out so cant anyway. On my audigy 2 card i always did though, i just had a splitter from the speaker out that went to speakers and my headset.

If i did manage to connect my headphones to the speaker out (by a dual male phono > 3.5mm female adapter) then what would happen?

Also what would happen if i connected my amp and speakers to my headphone out on the soundcard by using a 6mm male > 3.5mm female then 3.5mm male > dual male phono to my amp?
 
Guest2 said:
If i did manage to connect my headphones to the speaker out (by a dual male phono > 3.5mm female adapter) then what would happen?
Click to expand...

Say good-bye to your headphones.

Guest2 said:
Also what would happen if i connected my amp and speakers to my headphone out on the soundcard by using a 6mm male > 3.5mm female then 3.5mm male > dual male phono to my amp?
Click to expand...

You'd hear whatever the puter was playing :p
 
Also, i know it a bit off topic but when i connect to phono on my amp instead of aux1, aux2, or cd and play some music. It sounds like a shower of crap coming out of my speakers. Is this normal?

Works find when i plug into cd, or aux
 
because phono stages arent designed to handle the input of a stereo rca, they are designed to work with the input from a record deck which is much lower in power.
 
Last edited:
arhhh, thanks guys. So in theory i could connect headphone out on soundcard to phono on back of my amp. Then plug my headphones into the front of my amp and switch it to phono

I'm going to take a guess at mud coming out of the headphones and then possibly breaking
 
Guest2 said:
arhhh, thanks guys. So in theory i could connect headphone out on soundcard to phono on back of my amp. Then plug my headphones into the front of my amp and switch it to phono
Click to expand...

In theory yes but it would sound rubbish. Headphones run at closer to line level than phono level

Worst case scenario is you might damage the phono stage on your amp (but I doubt that would actually happen).

Edit: What I think you need is something like a SENNHEISER HZR62 or HZR6 (google them). They're audiophile headphone volume controls with extension leads. It would allow you to use your ST's headphone amp to drive your headphones, provide an extension cable and an easily accessible volume control. There are cheaper options that do the same thing. I don't know how good they are in comparison.
 
Last edited:
^ I had a look into the sennheiser HZR62 but ' Not recommended for hard-core audiophiles, however, since the device tends to add a slight background noise floor (line-level hiss) to the audio signal.'

thats not what tha wants!

Think ill just go for the belkin one on -jungle store- for a fiver

edit - will this add hiss and be crap?

Headphone Extension Cordwith Volume Control. £6

* Extender lead for headphones
* Suitable for all personal stereos
* Add a volume control to your existing headphones
* Pocket clip for easier portability

Back to Top
Technical Specification

Specifications:
Cord length: 0.9 metres ± 10%
Connector: L-shaped 3.5mm nickel-plated stereo plug
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom