# Headphones and impedance question



## MusiquedeReve (Apr 1, 2022)

I just ordered a new audio interface and the headphone impedance is 27Ω

I have done some research and found it is recommended that headphones should have approximately 8x the impedance of the output, which would mean that I should get headphones that have an impedance of ~216Ω

Is this true? I am, quite possibly, misunderstanding and would appreciate any help

Thank you and be well


----------



## sumskilz (Apr 1, 2022)

Yes, it's true if you want the least amount of distortion. The closer you get to that target, the less distortion there is. With a few exceptions, it seems interface manufacturers don't bother with bringing their output impedances down to a level suitable for a wide variety of headphones. In contrast, dedicated studio headphone amps typically have an output impedance of less than 1Ω.

Off the top of my head, an industry standard set of headphones that meet your recommended minimum are the Sennheiser HD 650s at 300Ω.


----------



## sostenuto (Apr 1, 2022)

Many good choices out there. Recently chose Beyerdynamic DT990 Edition - 600 ohms.
Very comfortable. Spoke directly with Beyerdynamic tech rep _ in detail _ prior to purchase.
Very pleased.
Driving with Schiit Audio - Asgard Headphone Prea, /Amp. Should be even better for OP ??

Beyerdynamic offer 250 ohms as well .... same affordable cost point. 









DT 990 Edition


Hi-fi headphones (open)




north-america.beyerdynamic.com


----------



## MusiquedeReve (Apr 1, 2022)

sumskilz said:


> Yes, it's true if you want the least amount of distortion. The closer you get to that target, the less distortion there is. With a few exceptions, it seems interface manufacturers don't bother with bringing their output impedances down to a level suitable for a wide variety of headphones. In contrast, dedicated studio headphone amps typically have an output impedance of less than 1Ω.
> 
> Off the top of my head, an industry standard set of headphones that meet your recommended minimum are the Sennheiser HD 650s at 300Ω.





sostenuto said:


> Many good choices out there. Recently chose Beyerdynamic DT990 Edition - 600 ohms.
> Should be even better for OP ??
> Beyerdynamic offer 250 ohms as well .... same affordable cost point.
> 
> ...


Thanks - I guess my Audio Technica ATH50X at 38Ω are not going to cut it


----------



## sostenuto (Apr 1, 2022)

MorphineNoir said:


> Thanks - I guess my Audio Technica ATH50X at 38Ω are not going to cut it


Maybe not, but since already ordered, at least try _ to check results. May only reduce volume some. _Granted_ _ distorted results would be unacceptable. 
Had similar situation for long time with solid Focusrite Saffire Pro14 Audio I/F driving older Sennheiser HD497 _ 32 ohms. Worked acceptably for long time prior to recent upgrade .... _imho_


----------



## MusiquedeReve (Apr 1, 2022)

sostenuto said:


> Maybe not, but since already ordered, at least try _ to check results. May only reduce volume some. _Granted_ _ distorted results would be unacceptable.
> Had similar situation for long time with solid Focusrite Saffire Pro14 Audio I/F driving older Sennheiser HD497 _ 32 ohms. Worked acceptably for long time prior to recent upgrade .... _imho_


I didn't order the AT headphones, those are the ones I happen to already have

I guess I can wait and see how they sound once the new interface arrives next week then reassess


----------



## sostenuto (Apr 1, 2022)

MorphineNoir said:


> I didn't order the AT headphones, those are the ones I happen to already have
> 
> I guess I can wait and see how they sound once the new interface arrives next week then reassess


Understand. Was referring to Audio I/F and hopefully may be acceptable.
Have benefit here of running (2) Win 11 Pro desktop PC DAW(s).
Chose to use Schiit Audio - Asgard HDfone amp _ their Modi DAC,  + Rode AI-1 Mic Amp _ on DAW 2 _ _versus_ Audio I/F.
Pleased now and will re-evaluate later as notable PC rebuilds now needed for Win11 Pro requirements.

Good luck, going forward.


----------



## Nick Batzdorf (Apr 1, 2022)

I use 600Ω headphones (AKG K240M), and they sound fine in pretty much all built-in headphone amps.

But then these kids on my lawn today listen on cellphone earphones, so I guess headphone mixing is a little different.


----------



## MusiquedeReve (Apr 1, 2022)

Nick Batzdorf said:


> I use 600Ω headphones (AKG K240M), and they sound fine in pretty much all built-in headphone amps.
> 
> But then these kids on my lawn today listen on cellphone earphones, so I guess headphone mixing is a little different.


I will use them for tracking, not mixing (nobody wants to hear my mix of anything lol)


----------



## AceAudioHQ (Apr 1, 2022)

sostenuto said:


> Driving with Schiit Audio - Asgard Headphone Prea, /Amp. Should be even better for OP ??


Schiit has had huge supply problems for a long time, in europe you can’t get any at all since the USA Office wont supply them die to lack of components. Their last shipment was feb 2021


----------



## MusiquedeReve (Apr 1, 2022)

sostenuto said:


> Understand. Was referring to Audio I/F and hopefully may be acceptable.
> Have benefit here of running (2) Win 11 Pro desktop PC DAW(s).
> Chose to use Schiit Audio - Asgard HDfone amp _ their Modi DAC,  + Rode AI-1 Mic Amp _ on DAW 2 _ _versus_ Audio I/F.
> Pleased now and will re-evaluate later as notable PC rebuilds now needed for Win11 Pro requirements.
> ...


How would I hook an external headphone amp to audio interface?


Here's another question - on these high impedance headphone amps, if the headphones are supposed to be 8x the impedance of the amp, are there really companies making 4800Ω headphones -- I think I am not understanding all of this properly


----------



## sumskilz (Apr 1, 2022)

MorphineNoir said:


> I guess I can wait and see how they sound once the new interface arrives next week then reassess


Unless you’ve spent some time recently listening on a really good monitoring setup, the distortion won’t necessarily be obvious. The headphones will probably sound fine, but accuracy will suffer. There will be some bass roll off as well as reduced clarity and transient response in the low end, but these are issues we’re all used to hearing because it’s so difficult/expensive to acoustically treat low end in a home or home studio environment and many monitors don't have great low end response anyway. The obvious advantage of headphones is that they take the room out of the equation. If your low end is distorted and muddy, it isn’t as obvious because our ears aren’t as sensitive to detail in that range and we aren’t used to hearing detail under typical listening circumstances. Although every imperfect listening environment is muddy in the low end in different ways, so that’s why having as accurate of monitoring as possible helps mixes translate better since accuracy is the midpoint from which various distortions deviate.


----------



## sostenuto (Apr 1, 2022)

MorphineNoir said:


> How would I hook an external headphone amp to audio interface?
> 
> 
> Here's another question - on these high impedance headphone amps, if the headphones are supposed to be 8x the impedance of the amp, are there really companies making 4800Ω headphones -- I think I am not understanding all of this properly


Line-out(s)s from dedicated preamps /amps to I/F Line-in(s)

Defer quickly to 'audio' heavyweights here ! Have several times inquired, or grumbled, that Audio I/F providers do not seem to provide specifications _ which can be compared 'directly' to those from headphone preamp/amp and microphone preamp providers. 
Have not been able to 'verify' frequent user-posted statements that top I/F(s) just as capable as individual components.
Happy to acknowledge personal deficiencies, yet continue with comparing apples to oranges when evaluating options.
Main concern is sorting potential duplication of microphone /headphone amp cost _ built into I/F(s) _ if dedicated preamps /amps are truly superior.


----------



## fakemaxwell (Apr 1, 2022)

Judging a pair of headphones by their ohms is like measuring how fast a car can go by counting the number of cupholders. The only thing you should be worried about re:ohms is "do these headphones get loud enough with my interface?"

If you can get a good level without cranking the gain to 100%, you're in the clear and can judge the headphones purely on their sound.


----------



## Nick Batzdorf (Apr 1, 2022)

fakemaxwell said:


> Judging a pair of headphones by their ohms is like measuring how fast a car can go by counting the number of cupholders. The only thing you should be worried about re:ohms is "do these headphones get loud enough with my interface?"
> 
> If you can get a good level without cranking the gain to 100%, you're in the clear and can judge the headphones purely on their sound.



My name is Nick and I endorse this post.


----------



## sostenuto (Apr 1, 2022)

Get the point _ _but_ _ individuals' ability to judge 'sound' can be wildly discrepant. In OP's case, perhaps valid way to judge.
When choosing headphones, amps, mics _ for purchase _ would only 'trust' narrow range of sources, _yet then_ _ knowing their hearing is far different from mine.
What I like is key point for some choices. For others _ prefer trustworthy, 3rd Pty testing, and comparative results.\

My name is Thom and I know my ears are _seasoned _!! 👂🏻 📯


----------



## sumskilz (Apr 1, 2022)

fakemaxwell said:


> Judging a pair of headphones by their ohms is like measuring how fast a car can go by counting the number of cupholders. The only thing you should be worried about re:ohms is "do these headphones get loud enough with my interface?"
> 
> If you can get a good level without cranking the gain to 100%, you're in the clear and can judge the headphones purely on their sound.


Accuracy is an objective rather than subjective measure, but impedance mismatch issues aren't about the quality of a particular set of headphones, but whether or not those headphones will function properly with a particular amp.


----------



## Nick Batzdorf (Apr 1, 2022)

sumskilz said:


> Accuracy is an objective rather than subjective measure, but impedance mismatch issues aren't about the quality of a particular set of headphones, but whether or not those headphones will function properly with a particular amp.


As I said, headphone amps are a lot more forgiving than one would think. Modern audio equipment - meaning anything from the past 40 years - is designed to work with a wide range of inputs and outputs.


----------



## rhizomusicosmos (Apr 1, 2022)

Headphone impedance is not flat across the frequency spectrum (unless they are planar magnetic or similar design), so it presents a varying load to the amplifier at different frequencies. This can cause a shift in frequency response that is much more pronounced if the amplifier output impedance is high relative to the headphones nominal impedance. Whether this is subjectively significant to you is another matter.

Julian Krause explains this fairly well at around 5:20 in this video.


----------



## PaulieDC (Apr 1, 2022)

Funny, I just watched a video by Julian Krause, reviewing the Babyface Pro FS, and he explained the outputs vs headphones and actually answered your question which I also had. In the screenshot the red arrow is the output of the BabyFace ¼" and 3.5mm headphone jacks. The ohm specs are this:

¼" - 10.13 ohms
3.5mm - 0.25 ohm! (accommodates super low-ohm headphones like my cheap walkman style)
The graph gives us our answer. As you move across the headphone list to higher ohms, you see the output. The blue arrow are my 300 Ohm HD 650s, running on a 10.13 Ohm jack... not as loud as a pair of 150 Ohm cans, but that 35.90mW output I'm getting is enough to hurt my ears volume-wise.

I haven't read the whole thread so maybe this was mentioned, but a decent number of Studio Headphones fall in that 150-300 Ohm range which will work great for your 27 Ohm output. If you go 600 Ohm, you'll probably need a headphone amp.

I found it interesting that the 3.5mm jack at 0.25 Ohm, which is designed for consumer headphones, puts out amazing power at 16 and 32, fizzles at 150 and is unusable at 300 Ohm. I wouldn't plug my HD 650s in that jack anyway, but I'm glad to know this or I would have thought the Babyface was busted, lol. But for my cheap $7 Panasonic Walkman headphones which I can wear all day for non-critical stuff, it's great! Finally, Ohm mystery is now less of a mystery.






Here's the segment where Julian discusses headphone/jack ohms and power, if interested.


----------



## PaulieDC (Apr 1, 2022)

rhizomusicosmos said:


> Headphone impedance is not flat across the frequency spectrum (unless they are planar magnetic or similar design), so it presents a varying load to the amplifier at different frequencies. This can cause a shift in frequency response that is much more pronounced if the amplifier output impedance is high relative to the headphones nominal impedance. Whether this is subjectively significant to you is another matter.
> 
> Julian Krause explains this fairly well at around 5:20 in this video.



LOL! I was writing about the same guy when you posted. Haven't seen this vid yet, I'm on it! Finally understanding the mystery.


----------



## sostenuto (Apr 1, 2022)

rhizomusicosmos said:


> Headphone impedance is not flat across the frequency spectrum (unless they are planar magnetic or similar design), so it presents a varying load to the amplifier at different frequencies. This can cause a shift in frequency response that is much more pronounced if the amplifier output impedance is high relative to the headphones nominal impedance. Whether this is subjectively significant to you is another matter.
> 
> Julian Krause explains this fairly well at around 5:20 in this video.



........ emphasis on amp output impedance. RME Babyface state theirs (Phone) at 10 ohms.

Not finding that spec for Sennheiser HDV 820, yet this statement: For an optimal listening experience, Sennheiser recommends using high-impedance headphones and cables with a length of 3 m.

_Brief examples of potential difficulty for users /purchasers trying to make careful choices._


----------



## rhizomusicosmos (Apr 1, 2022)

But to put it into context, the frequency response variation in the example that Julian Krause shows in the video is about 1 dB. This may not be particularly audible and subjectively you may be happier with the louder output of low-impedance headphones. YMMV


----------



## rnb_2 (Apr 1, 2022)

rhizomusicosmos said:


> Headphone impedance is not flat across the frequency spectrum (unless they are planar magnetic or similar design), so it presents a varying load to the amplifier at different frequencies. This can cause a shift in frequency response that is much more pronounced if the amplifier output impedance is high relative to the headphones nominal impedance. Whether this is subjectively significant to you is another matter.
> 
> Julian Krause explains this fairly well at around 5:20 in this video.



I literally went back to that exact video earlier today to refresh my memory on impedance - I watched so many of Julian's videos when I was buying my two interfaces in 2020/2021 to make sure my headphones and interfaces were good matches.


----------



## PaulieDC (Apr 1, 2022)

rhizomusicosmos said:


> But to put it into context, the frequency response variation in the example that Julian Krause shows in the video is about 1 dB. This may not be particularly audible and subjectively you may be happier with the louder output of low-impedance headphones. YMMV


Very true. If I graduate from bedroom wannabe composer to having to deliver audio files to some entity of importance, I'll get a headphone amp more for the frequency response than the volume. I'm used to the 650s and listening to them against the Neumann monitor system I run, but I'd want a better signal into the 650s. And a reason to justify an amp.


----------



## vitocorleone123 (Apr 2, 2022)

One of a couple reasons I upgraded from a 6i6v2 to a 4pre Focusrite is power output. The 6i6v2 couldn't keep the 250ohm DT 880Pro loud enough when making music (since I'm not making music at 0db). The Clarett4pre has no issues, though I do sometimes still end up at 75% volume output or so before reconfiguring some things, like boosting a track volume or the master output etc. to get it back toward 50%.

It's not just raw power that matters, of course, since it can be "dirty" power with a higher THD.

Side note: I can't wear Sennheiser cans because I have a round head and wear glasses - the clamping force on the Sennheiser cans are ridiculously painful. The Beyerdynamics, on the other hand, are very comfortable. So fit matters, as well - clearly something bonded to your skull around your ears will have less leakage, but, if you can't wear them, what's the point?

Speaking of which, then there's closed/semi/open back cans and what that does to sound. Or the environmental noise. Or....


----------



## Pier (Apr 2, 2022)

rhizomusicosmos said:


> But to put it into context, the frequency response variation in the example that Julian Krause shows in the video is about 1 dB. This may not be particularly audible and subjectively you may be happier with the louder output of low-impedance headphones. YMMV


Exactly. 1db is negligible except for the most critical applications. If you care about a single db then you will probably buy an amp that perfectly matches the headphones you're using.

In fact if you measure many rooms (home studios or even pro studios) the response on the low end will have peaks and valleys *much* higher than +-1db (combination of speaker and room acoustics). A perfectly flat response is very difficult and expensive to achieve.


----------



## cel4145 (Apr 2, 2022)

rhizomusicosmos said:


> Headphone impedance is not flat across the frequency spectrum (unless they are planar magnetic or similar design), so it presents a varying load to the amplifier at different frequencies. This can cause a shift in frequency response that is much more pronounced if the amplifier output impedance is high relative to the headphones nominal impedance. Whether this is subjectively significant to you is another matter.
> 
> Julian Krause explains this fairly well at around 5:20 in this video.



Here is another good explanation for those that would rather read instead of watching a video.








Headphone & Amp Impedance


INTRO: The output Impedance of headphone sources is one of the most common reasons the same headphones can sound different depending on wha...




nwavguy.blogspot.com


----------



## sostenuto (Apr 2, 2022)

cel4145 said:


> Here is another good explanation for those that would rather read instead of watching a video.
> 
> 
> 
> ...


Partial read and will revisit in morning. My earlier post mentioned $2,000. + Sennheiser HDV 820 with printed manual info _ stating Output Impedance @ 10 ohms. Yet this is impedance and varies with frequency. 
Just restating ongoing frustration trying to use _range_ of manufacturers' provided 'specs' to make valid decisions for headphones - preamps /amps _ audio I/F(s). 

_Often like watching fast food hamburger tv ad _ then trying the pathetic 'real thing' _


----------



## sumskilz (Apr 2, 2022)

rhizomusicosmos said:


> But to put it into context, the frequency response variation in the example that Julian Krause shows in the video is about 1 dB. This may not be particularly audible and subjectively you may be happier with the louder output of low-impedance headphones. YMMV


In my opinion, the improper damping associated with impedance mismatch is a bigger issue than the frequency response deviation, since it results in reduced clarity and transient response in the low end. This is because the speakers continue moving when they shouldn't and don't react fast enough when they should. As previously mentioned, this smearing effect is usually much less pronounced than what you'll hear on monitors in an untreated or undertreated room. However, I dislike that it somewhat compromises one of the main advantages of headphones — the clarity that comes from taking the room out of the equation.


----------



## MusiquedeReve (Apr 3, 2022)

I am wondering if I this might be my solution:









Rupert Neve Designs RNHP 1-channel Precision Headphone Amplifier


24V Stereo Headphone Amplifier with +4dBu Line, RCA, and 1/8" Stereo Inputs




www.sweetwater.com


----------



## sostenuto (Apr 3, 2022)

RNHP 1 _ one of better choices considered. Simply beyond budget for DAW #2. 
Schiit Audio Modi /Asgard combo was acceptable and works well now. 
Saw comment on availability, which is ongoing issue with many components these days.

Best of luck with solution(s).


----------



## sumskilz (Apr 3, 2022)

That Schiit Audio combo looks great for someone who just needs inexpensive good quality monitoring (no other interface required in that case).

Another inexpensive headphone amp with good specs is the Cranborne Audio N22H. Output impedance is 0.33Ω. They're $149 at Sweetwater. Thomann usually has them as well, but it looks like they're currently sold out. It's not the most aesthetically pleasing piece of gear for a desktop, but you can bolt it somewhere that works with its rack ears.

Here's a Tape Op review: https://tapeop.com/reviews/gear/145/n22h-headphone-amp-cast-breakout-box/


----------



## cel4145 (Apr 4, 2022)

sumskilz said:


> That Schiit Audio combo looks great for someone who just needs inexpensive good quality monitoring (no other interface required in that case).
> 
> Another inexpensive headphone amp with good specs is the Cranborne Audio N22H. Output impedance is 0.33Ω. They're $149 at Sweetwater. Thomann usually has them as well, but it looks like they're currently sold out. It's not the most aesthetically pleasing piece of gear for a desktop, but you can bolt it somewhere that works with its rack ears.
> 
> Here's a Tape Op review: https://tapeop.com/reviews/gear/145/n22h-headphone-amp-cast-breakout-box/


The problem is that audio equipment specs like that are very unreliable.

For those that might want to know what they're getting for certain, rather than relying on manufacturers to provide accurate specs, Julian Krause's YT channel is great for pro USB interfaces. And Audio Science Review measures a lot of consumer headphone amps and dacs.

So between those two resources, there are plenty of products to consider that have been independently verified that they perform well.

And personally, I would be wary of a reviewer like Tape OP who reuses the marketing prose from the N22H that it is "reference grade" in the very first sentence of his review. Without independent measurements, one cannot know if that device is reference grade. lol

Best to rely on reviews that have independent measurements.

BTW: if one is in the US, an excellent budget option is a JDS Labs Atom Amp+ or Schiit Heresy amp for $100. Search ASR, and you'll find that the measurements show both of those are easily arguable to be noise and distortion-free within the range of human hearing.

Pair one of them with a $9 US version of the Apple USB-C dongle (the EU version has substantially lower voltage output) to use as a DAC. It measures very well









Review: Apple vs Google USB-C Headphone Adapters


This is a review, detailed measurements and comparison of Apple's USB-C adapter to the current and last version of Google Pixel headphone adapters. The Apple adapter costs just $9 including one day shipping for free. The Google dongle costs $12. Not that any of these are large by any stretch...




www.audiosciencereview.com


----------

