Low Impedance vs. High Impedance? Huge Difference?
Sep 12, 2011 at 9:50 AM Thread Starter Post #1 of 32

Corbet

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I've had "expensive" headphones for 5 or 6 years now and I've always purchased low impedance headphones so things like laptops can drive them. I currently own the D2000s, which has a really low impedance of 25 ohms. 
 
What advantage do high impedance headphones have? Are they really that much better sounding? Am I missing something by only owning low impedance headphones? I'm getting that 2-year itch to buy a new pair of headphones and I'm not sure if buying higher impedance cans will really make a difference.
 
Sep 12, 2011 at 9:52 AM Post #2 of 32

Croozer

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It's just personal preference.

 
Sep 12, 2011 at 9:58 AM Post #3 of 32

BotByte

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If you have a very powerful setup and put a low impedance can to it, something will blowup. Really, I've seen this before.
 
If you have a cheapy setup and add a high impedance can to it, either you won' hear anything or hear horrible sound.
 
If you don't have a amp, aim for 32ohms or lower
If you have a good headphone amp, go under 250ohms
If you have a powerful one, it's nice to hang around the 600ohm+ cans.
 
EDIT: there is no sonic differences
 
Sep 12, 2011 at 5:35 PM Post #4 of 32

MalVeauX

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Heya,
 
Impedance really is a reflection of past hardware, and the concept of high impedance as 'audiophile' grade reflects people having old hardware (mind, still good) with different power outputs, noise floors, etc. These days it doesn't even matter as much because a lot of modern desktop amps are made to be able to deal with low impedance and high impedance, so you can just get a decent amp and plug basically anything into it.
 
Most headphones under 250ohm impedance will play fine out of a normal discreet soundcard on a PC (note, that does not include onboard sound necessarily). If you're at all worried and have a desktop, the Xonar DG is $30, that's a good enough amp for most 250ohm and below in general. If on a laptop or something, consider an inexpensive small amp like the FiiO E11 or go a bit more and get a simple E9 and you're set for virtually any headphone in the mid-tier and under range.
 
Very best,
 
Sep 12, 2011 at 6:55 PM Post #6 of 32

MalVeauX

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Quote:
If there are no sonic differences, why they don't just make headphones with appropiate impedance for most situations?
 
 


Again,
 
Due to hardware. And most headphones these days, including high end stuff, is starting to be low impedance because of the digital revolution and the mass spreading of portable devices. Basically because of Apple. There's far more low impedance stuff than high impedance stuff. We just talk a lot of about particular headphones here with high impedances often.
 
Very best,
 
 
Sep 12, 2011 at 7:35 PM Post #7 of 32

Uncle Erik

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If you have a very powerful setup and put a low impedance can to it, something will blowup. Really, I've seen this before.
 
If you have a cheapy setup and add a high impedance can to it, either you won' hear anything or hear horrible sound.
 
If you don't have a amp, aim for 32ohms or lower
If you have a good headphone amp, go under 250ohms
If you have a powerful one, it's nice to hang around the 600ohm+ cans.
 
EDIT: there is no sonic differences


You have no idea what you're talking about.

I wonder if you just made this up.

Low impedance headphones will not "blow up" if connected to a "powerful" setup.

Impedance is important related to the output impedance of the amp.

Low impedance does not mean something is easy to drive.

Google the Apogee Scintilla speaker. It has a 1.2 Ohm impedance. So if low impedance means easy to drive, then how come the Scintilla has a terrible reputation for overheating and literally melting lesser amps?

Impedance has to be considered along with an amp's output power, an amp's output impedance, and the headphone's sensitivity. You take the output power, consider how the output impedance and headphone impedance interact (there is a formula for this) and then you get the amount of power that comes through. Use that resulting power figure with the headphone sensitivity and you can calculate how loud the headphone will get.

If you only have the headphone impedance, you cannot call it a "tough" or "easy" load. That's like saying that x + y + z = n. If x is 3, find z. You can't. There isn't enough information.

When it comes to headphones, you generally want an output impedance lower than the headphone impedance. This is called the "Damping Factor"; look it up if you don't know what it is. Generally speaking, only solid state and output transformer-coupled tube amps have a low output impedance. OTLs have a high output impedance. Do not listen to OTL manufacturers when they say it will drive "anything," that's not true. They will make sound with anything, but an output impedance higher than the headphone impedance loses control of the bass. The only commercial OTL that does low impedance is the Zana Deux, and that's mostly because of its 6C33C tubes. If you don't see 6C33C tubes in an OTL, it probably has a high output impedance.
 
Sep 12, 2011 at 8:02 PM Post #8 of 32

jupitreas

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There are some advantages to a headphone with high impedance. A higher impedance allows for more turns of wire to be used in the voice coil of the driver. This can improve how a headphone sounds and is the reason why Beyerdynamic's higher impedance models sound slightly better than their low-impedance versions.
 
With this said, with today's technology, low impedance phones sound awesome and I don't think there is any real advantage in using a higher impedance headphone anymore. If you have a choice of impedance (Beyer) and have a nice amp, you should go for the higher impedance model but otherwise you shouldnt worry about this. 
 
Sep 12, 2011 at 8:37 PM Post #10 of 32

grmnasasin0227

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Quote:
If you have a very powerful setup and put a low impedance can to it, something will blowup. Really, I've seen this before.
 
If you have a cheapy setup and add a high impedance can to it, either you won' hear anything or hear horrible sound.
 
If you don't have a amp, aim for 32ohms or lower
If you have a good headphone amp, go under 250ohms
If you have a powerful one, it's nice to hang around the 600ohm+ cans.
 
EDIT: there is no sonic differences

Well I know whose advice I'm never taking anymore...sheesh do you understand anything about circuits?
 
EDIT: I see I was beaten by Uncle Erik.
 
Sep 12, 2011 at 8:48 PM Post #11 of 32

Dubstep Girl

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Quote:
There are some advantages to a headphone with high impedance. A higher impedance allows for more turns of wire to be used in the voice coil of the driver. This can improve how a headphone sounds and is the reason why Beyerdynamic's higher impedance models sound slightly better than their low-impedance versions.
 
With this said, with today's technology, low impedance phones sound awesome and I don't think there is any real advantage in using a higher impedance headphone anymore. If you have a choice of impedance (Beyer) and have a nice amp, you should go for the higher impedance model but otherwise you shouldnt worry about this. 



thats what i thought, it seems to add better control making for less noise and better sound quality (slight improvement its not super super big over low impedance headphones)
 
Sep 12, 2011 at 8:55 PM Post #12 of 32

BotByte

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Quote:
You have no idea what you're talking about.

I wonder if you just made this up.

Low impedance headphones will not "blow up" if connected to a "powerful" setup.

Impedance is important related to the output impedance of the amp.

Low impedance does not mean something is easy to drive.

Google the Apogee Scintilla speaker. It has a 1.2 Ohm impedance. So if low impedance means easy to drive, then how come the Scintilla has a terrible reputation for overheating and literally melting lesser amps?

Impedance has to be considered along with an amp's output power, an amp's output impedance, and the headphone's sensitivity. You take the output power, consider how the output impedance and headphone impedance interact (there is a formula for this) and then you get the amount of power that comes through. Use that resulting power figure with the headphone sensitivity and you can calculate how loud the headphone will get.

If you only have the headphone impedance, you cannot call it a "tough" or "easy" load. That's like saying that x + y + z = n. If x is 3, find z. You can't. There isn't enough information.

When it comes to headphones, you generally want an output impedance lower than the headphone impedance. This is called the "Damping Factor"; look it up if you don't know what it is. Generally speaking, only solid state and output transformer-coupled tube amps have a low output impedance. OTLs have a high output impedance. Do not listen to OTL manufacturers when they say it will drive "anything," that's not true. They will make sound with anything, but an output impedance higher than the headphone impedance loses control of the bass. The only commercial OTL that does low impedance is the Zana Deux, and that's mostly because of its 6C33C tubes. If you don't see 6C33C tubes in an OTL, it probably has a high output impedance.


Did I ever mention I'm not good with amps?
 
I'm not. I understand that my T50RP are 56ohms and pull on a amp pretty hard.
 
 
Actually, that taught me a lot. I thank you.
 
But for someone starting out, it's easier to tell them that there are cans that need a amp and those that don't. We see about two dozen people asking for amps for Grado and others that don't need a amp. It's simpler to tell them either go for a can that needs a amp because of a the Ohms which is a easy (but confusing and unreliable) dictation or go for a can that has low Ohms. But then there are headphones like the T50RP, Dj100 and several others that run extremely low power and need amps regardless.
 
I admit, I do dramatize my writing a bit, it's in my nature. But I have seen sparks fly from a receiver before. My guitar teacher is an idiot.
 
 
Sep 13, 2011 at 1:16 AM Post #13 of 32

khaos974

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To make it simple, all headphones require a certain amount of power to be driven at a certain acoustic level, this is the sensitivity of the headphones, it's expressed in dB/mW (decibel per milliwatts).

Considering P = U^2 / R = R * I^2 (Power = Voltage squared divided by impedance = Impedance times Intensity squared) and headphones with the same sensitivity:

- with low impedance headphones you need more current to achieve the desired acoustic level.
- with high impedance headphones, you need more voltage to achieve the desired acoustic level.

In addition to that, there's always the damping factor to consider (headphone impedance / amplifier impedance), it's usually recommended to have a damping factor greater than 10, ie. with 300 ohms headphones, use an amp with a maximum output impedance of 30 ohms.

In short, with high impedance headphones, you need an amp with more voltage swing and with low impedance headphones an amp with more current capacity and a lower output impedance.

 
Mar 17, 2014 at 3:58 AM Post #14 of 32

newave

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25 ohms is quite high for sound try 8 ohms it has a much lower and deeper base .
low ohm impedance for sound waves are one thing.
For amplification. low or high ohm impedance is a totally different thing.
Don't go out to the local electronics store and ask the gut the difference they are low paid idiots
 They will always ask you what you are looking for first . Then pretend they have the perfect thing.
Make you feel dumb and pressure you into a sale . Just google everything
 
Newave
 
Jun 19, 2014 at 2:42 PM Post #15 of 32

bjh00

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To make it simple, all headphones require a certain amount of power to be driven at a certain acoustic level, this is the sensitivity of the headphones, it's expressed in dB/mW (decibel per milliwatts).

Considering P = U^2 / R = R * I^2 (Power = Voltage squared divided by impedance = Impedance times Intensity squared) and headphones with the same sensitivity:

- with low impedance headphones you need more current to achieve the desired acoustic level.
- with high impedance headphones, you need more voltage to achieve the desired acoustic level.

In addition to that, there's always the damping factor to consider (headphone impedance / amplifier impedance), it's usually recommended to have a damping factor greater than 10, ie. with 300 ohms headphones, use an amp with a maximum output impedance of 30 ohms.

In short, with high impedance headphones, you need an amp with more voltage swing and with low impedance headphones an amp with more current capacity and a lower output impedance.
 

 
I follow the technical details provide in this and other responses yet I must say there are aspects that seem counter-intuitive to me coming from home audio (with speakers).
 
So for example with speakers it is axiomatic that low impedance speakers are thought to be harder to drive, i.e. the current demand with some speakers that drop below 4 ohm can be a real issue even with SS amplifiers. So why is it that in the headphone world this seems turned on its head with low impedance designs apparently targeted to portable usage; portable solution are better at providing relatively high current demands? ... seems odd to me.
 
Then there was the post about high impedance allowing/implying more (wire) turns in the voice coil. Ok fine, but seeking and analogy in home audio I can't but help think of MM v. MC phono cartridges, in particular the generally conceived superiority of MC due to fewer windings; or high output v. low output MCs for the same reason. Again it just seems that the rules are turned on their head in the headphone world. 
 

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