headphone impedance

[gigpiglet]

ok so whats the deal with headphone impedance.
what do i want?
why?

im looking to buy some new headphones for the studio, but they also need to work for me on location.
ive always used beyer, and id like to stay that way.
im familier.
and ill still have the old ones, so like the idea of things remaining in the same "family"

ive used DT770 a few times (from another engineer i work with) and think they sound pretty damn great.
but they come in like 4 different impedance models.. 32, 60, 80 and 250 or something like that.

guidance?
thanks

[gigpiglet]

to get my numbers right... the options are 32, 80, 250 and 600
rob maybe?

[Wiz]

My understanding (until rob gets here and gives you the right answer 8 ) )


Low impedance headphones like the 32 ohms are for low power devices such as MP3 players.

Higher impedance headphones are for studio use, where you might end up having multiple headphones (in parallel) across the same headphone amp.


It would, I guess depend on your headphone amplifier set up.

In reality, I have 4 different types of headphones here and 3 different headphone amps.

I just plug em in, and turn them up... Some I have to turn up more than others... I use the same set 99 % of the time and the other headphones are for other people.

I find the different connection ends more a pain in the ass than the impedance differences 8)

[Chinagraf]

I remember learning somewhere in the past that higher impedance ones have a better sound and less distortion due to being able to have more winds of wire in the coils of the speakers, but your amp/device needs to be able to drive them properly, like a studio amp would be fine but an mp3 player will sound crappy. Hence the smile when hipsters brag about their mega high end headphones they are going to buy for their ipods.

[Mark Bassett]

Check out the tech section of this post

http://nwavguy.blogspot.ae/2011/02/headphone-impedance-explained.html

[Text_Edifice]

Gareth I have the DT770 pro 250ohm, I've never had a problem with getting enough juice to them and they're served me very well. They're not 'flat' but they work great once you know them and now I know them find they're a great alternate reference when working in unfamiliar rooms. Have generally found clients really like them for tracking too fwiw.

[gigpiglet]

thanks dave
exactly my experience from my mate who has them
and i have cheaper beyers in the studio that have always been fine... though getting to the end of their life.
appreciate the opinions/ experience

[Sammas]

DT770M's might take your fancy, Gareth. They sound ever so slightly thinner than standard DT770's, but offer 35dB of isolation which is great if you are monitoring sources in environments with lots of ambient noise.

[rob]

that article linked to by Mark is a good source of info.

As a broad rule things like iphones etc can only put out a small voltage and thus the lower impedance headphones will suck more current to give the power ( volume ) you want.
Higher impedance headphones require more voltage for the same power and thus require headphone amps able to put out a higher voltage, such as "proper" headphone amps.... ( like the ones ProHarmonic and JLM make )

[Linear]

Impedance is a tricky concept.

When I was studying mechanical engineering, many of our lecturers liked to put electrical concepts into mechanical terms - such as looking at an electrical circuit with a water analogy.

Anyway, one lecturer compared impedance to pedalling a bicycle. Good impedance matching = good power transfer - A quick trawl of the interwebs found this:

"For a mechanical analogy, consider riding a bicycle that has many
choices of gears. If you are in too low a gear, your legs will spin
with little effort, but you will move forward slowly. The pedals
present a very low impedance to your feet. If you are in too high a
gear, your legs will feel the "resistance" of the gears (high
impedance), and you will move forward slowly because it is difficult
to grind out any progress. But a gear that is not too big and not too
small--just right--allows you to maximize the power transfer from legs
to wheels, and allows you to make the greatest progress.

Sometimes you want the driven system to have high impedance (e.g. an
oscilloscope), sometimes you want the driven system to have low
impedance (e.g. current-carrying coils), and sometimes you want the
driven system to be well matched to your signal source (e.g. bicycles,
or audio speakers) in order to maximize power transfer. Improper
impedance matching can have damaging effects: for example, your
speakers may have had a 4 ohm impedance, while your amplifier was
expecting 8 ohms of impedance--if this were the case, the amplifier
will have delivered a lot of excess current into the speaker coils,
possibly heating something up and destroying the speaker. In the
analogy of the bicycle, you may have spun the pedals so rapidly that
the chain falls off the chainwheel, rendering the bike useless."

It sure helped my small mechanical brain!

[Sammas]

Rob wrote a great article on impedance for Audio Technology as well.