The Effect of Glasses on Headphone Frequency Response

Not long ago a reader asked me if I would experiment with how glasses effects headphone measurements. Having measured a lot of headphone and knowing how important the seal is I kind of knew how this would turn out: very varied. Some headphones are very sensitive to seal, and some aren't. Generally speaking, the more leaky or open the acoustics in the chamber between the driver and the ear, the less sensitive they are to a seal.

The problem is that the amount of seal in the ear cup is not typically apparent in the measurements I do. I would say the only time it is, is when you can see the headphone sometimes sealing and sometimes not in the measurements. For example, in these Master&Dynamic MH40 and KRK KNS8400 measurements.

Headphone101_InterpretingFrequencyResponse2_Graph_MasterDynamicMH40Headphone101_InterpretingFrequencyResponse2_Graph_KRKKNS8400

Both headphones were having troubles getting a good seal in the measurement, and when the seal was broken the measurement would be dramatically different. So, while I can tell how tightly a headphone seals and how sensitive it is to a seal breaking, I will often times be able to adjust the headphones carefully so that it's not actually apparent in the final raw data. Only when I'm having problems getting the seal will I intentionally allow the measurements to wander, as that reflects a real trouble with the headphones.

What I'm driving at is I see a wide variety of sensitivities to seal in the headphones I measure and as I try to get a good series of measurement on a headphone it will make that sensitivity to seal less and less apparent. But I can tell how sensitive to seal they are when I do the measurements. Bottom line: I can show you the typical variety of responses of wearing glasses with headphones by doing the experiment, but I can't tell you how to predict when a headphone will be sensitive to glasses based on the measurements. Sorry.

The Experiment
It was pretty simple really, I picked five headphones that I knew would have a representative variety of responses to the seal being broken by the glasses. I used the: Philips Fidelio X2; Audeze LCD-2F; Focal Spirit Pro; Audio Technica ATH-M50x; and Master&Dynamic MH40. I measured the raw response of the headphones on the head without glasses, and then with two different glasses I have here—one with thick arms and one thin.

150610_Blog_Glasses_Photo_glasses

I then averaged the left and right channels together for each measurement and created a plot comparing the measurements with and without glasses.

Results
Results, as expected, varied quite a bit. Let's start with the open headphones...

150610_Blog_Glasses_Measurements_PhilipsX2

The Philips Fidelio X2 above is an open headphone and ear pad seal shouldn't have too much effect on response, and indeed it didn't.

150610_Blog_Glasses_Measurements_AudezeLCD2F

The Audeze LCD-2F is an open headphone, but the seal between the driver and ear is actually pretty tight. Still, the glasses didn't seem to have as much effect as I thought they might. Just a slight roll-off below the pad resonance.

150610_Blog_Glasses_Measurements_FSP

The Focal Spirit Pro is a sealed headphone, but the glasses didn't seem to have much effect. Perhaps it's because these pads are a bit small and they may be sealing partly on the ear as well as around the ear.

150610_Blog_Glasses_Measurements_ATHM50x

I would guess the effect of glasses on the Audio Technica ATH-M50x is probably close to average. Here there's a clear loss of bass energy, and just breaking the seal is enough to do the job—the thick and thin frames had similar effect.

150610_Blog_Glasses_Measurements_MH40

I knew the very tight seal of the Master&Dynamic MH40 would show up strongly on this test. Often times with a headphone having this strong a seal, I will put a piece of felt between the ear pad and the side of the head. This mimics hair and will provide a controlled leak that is often more representative of how the headphone normally sounds. (I was taught this trick by a professional headphone engineer.)

Summary
I'm sorry I can't tell you how to predict the sensitivity of a particular pair of headphone by looking at the measurements. But I know this subject has come up before and simply showing you the measurements will satisfy some of the curiosity out there.

Thanks for reading!

COMMENTS
kongmw's picture

maybe this has been discussed in the past but to me (a glasses wearer), unless the material with which the dummy head is made of can be compressed and deformed and contour to the frame of glasses like human flesh does to an extent, it would be hard to interpret the data.
but in the end it would appear that in 4 out of 5 pairs tested only the last pair kinda responded negatively enough so i digress...

Impulse's picture

But I don't think my head compresses or deforms much around my glasses. :p What's more, my Oakley glasses definitely sit away from my head much more and make less contact overall with it than thinner frame glasses... I wear some thin Flexon frames at home tho, because they don't deform if I fall asleep with them on and roll over them etc. :s

Smiling Kev's picture

Very interesting report, Tyll. Thanks! Reading it just now and tapping this response out on my iPad, I'm wearing my medium frame reading glasses and listening to Daft Punk's "Random Access Memories" via my iPhone 6+. It is running the Teac High Resolution player app, feeding a Teac HA-P50 portable headphone amp/DAC, and immersing me in the effortless musicality of the Shure 1540s I bought after reading your review. [Again, "Thank you!"]

As I slide my reading glasses off and on, the temples slip under the 1540's pads, with almost no effort or friction, to a comfortable position behind my ears. Try as I might, I can detect no difference in any particular passage as a function of having the glasses on, off, or in the process of being changed. I may be naive, but I think a major reason is that the pads of the 1540 are so supple and malleable that I can almost slip my index finger behind my ear without breaking the seal, as long as I move slowly!

[Quick break to dig out my "sentimental favorite" headphone.]

Now I'm wearing my old standby and first "real" headphone: the Sony MDR-V6. It has much smaller (but still circumaural) pads that are thinner and, while comfortable, a bit harder and less malleable than those on the 1540s. I can't correctly position my glasses without leaving a slight "leak" in the seal. The pads can't accommodate the frame's width sufficiently to allow the glass's temples to be "absorbed" and the seal to be reestablished. My very tentative impression is that when I'm wearing the glasses, the bass response of the MDR-V6 is slightly compromised. Would I have noticed the difference without being prompted to check for it by your test report, Tyll? Nope. Does the apparent difference persist, call attention to itself, and tarnish my enjoyment of the MDR-V6 and Daft Punk? Again: Nope. In other words, the difference doesn't really make a difference to me in this case. You have not ruined my evening . . . yet. Just don't reply to this comment with some hooey about Santa Claus not being real and everything will be just fine!

Seriously: I think that the materials, pliability, and other characteristics of the headphone's pads might be variables that are as - or maybe even more important than - the dimensions and shape of the glasses that are worn in combination with them. I'll be interested to hear others' experiences with glasses and the headphones they typically use while wearing them. Thanks again for an interesting report and the careful attempts to measure what might be happening.

Keep listenin' and keep,smilin'!
Kev

JC77's picture

I think the earpads are the biggest factor.

One test I would like to see is of the M50 and the M50X both with and without glasses. I chose those headphones because they are very popular so almost everyone knows the sound signature, and Audio Technica made improvements to the pads in the X version which does make them softer and not as stiff.

If one wanted to, they could even put the regular M50 pads on the M50X (or the X pads on the M50) for a more accurate test.

tony's picture

ideas.

I read this and remembered having this issue over the decades dating back to my Ham Radio phones in the 1950s.

I just now checked my Sennheisers to realize they don't have problems here.

I do recall not liking Headphone Meet headphones for some sort of "not fitting my head" sort of issue, I can get the vague feeling of the darn things don't seem to work well for me.

My HD580s have that "old shoe" kind of comfort that keeps me having them as my No.1 "go-to" headphone if I'm not using my Wireless Sennheisers.

Thanks for doing this, from now on I'll be keeping my eyeglasses in mind as I try a new Phone.

On another issue here:

I purchased an aftermarket headphone cable for my Sennheiser HD580s, it "was" only 1.2 meters in length. It sounded kinda powerful and aggressive but the 580s fell to the floor and pulled the little wires right out of the connector. I just threw the new cable away as a failed attempt to improve my lovely 580s.

Still, I'm hopeful of the new Hifiman Phones using the standard little connectors instead of the exotic device and systems we see on nearly all good headphones.

I am anxious to hear about Hifiman's latest offerings, I may become a Hifiman fan now that I've learned how to make nearly any quality transducer sound beautiful and to my personal hearing parameters. I give you credit for pointing me down this direction and Professor Bob Katz for reinforcing your hintings.

Nice to see you're "young pup" doing good postings. I wish him well.

Tony in Michigan

gummydogs's picture

good god... no wonder why I thought my HP50 had no bass. curse the glasses!!

jasonhgross's picture

I actually had to get rid of my NAD HP50s due to lack of a good seal with my thicker rimmed glasses (worn all the time). I went to IEMs: Sure SE215 and Etymotics instead, as I can wear them all the time both with and without glasses. Perhaps I shall try the Shure Over Ears based on the other commentator's advise. I have no issues with Sennheiser Wireless headphones while watching TV, though I dont use those for critical listening.

rasmushorn's picture

Can you be sure glasses do not have an effect on Etymotics? I have heard some say they lack bass as well.

jasonhgross's picture

I am sure they have no effect.

hanshopf's picture

Just a suggestion: why not devote some time to probably more relevant questions?
- how do the different crossfeed functions on the market (hardware as well as software) compare?
- how about some articles dealing with EQ-correction? I for example sent my HD800's to Sonarworks in Latvia for measurement and got a correction curve, which transformed them into an unbelievably accurate tool (never understood the remarks of guys like David Mahler finding them to be neutral. In fact they are very far from neutral in their natural state - and this is not a matter of taste). This to me seems more up to date than fumbling around and writing about some hardly effective "Anaxilus"-mod etc.
- how about testing applications which even go one step further like the Smyth Realizer?
I believe that the three points mentioned are too much neglected on this page, but are more relevant for the present and future of headphones than many articles like the one above about wearing glasses... .

tony's picture

So right you are.

Tyll mentioned that he "had" to measure, test and evaluate without Eq., which tipped me off about the significance of using Eq. devices.

Nearly all the little Asian Digital Audio Players feature a Eq. ability.

Bob Katz mentioned his use of various techniques to correct frequency response.

I reciently discovered that using a professional 31 Band Equalizer in my Schiit/HD580 circuit transformed my Sennheiser performance ( to great results).

And I've discovered that my own personal Ears and Brain have their own response curve that my Audiologist tests and reveals.

Now I know that I can "correct" nearly any headphone to wonderful performance levels, although they retain their sound signature. ( I seem to love the Sennheiser Sound Signature ) .

Of all the various Headphone Journalists out there , Tyll and his team are by far the most aggressive about reporting these things. I can look at Tyll's reporting on nearly any transducer response curve and adjust my Eq to bring that device into nearly ideal.

In the world of personal audio Tyll, Joker, Bob Katz, Grandberg and hopefully the new lad are our high level Think Tank for headphones, the other sites are mostly presenters of IMOs & IMHOs, nice photos and simple observations but not anywhere as "useful" as what we find here at Professor Tyll's Innerfidelity.

Tony in Michigan

hanshopf's picture

Thanks Tony for your insightful comment! My criticism was not meant to neglect the achievements of this page. I am just not so sure about the different directions its trying to head at.
On the one hand it somehow wants to be innovative or at least be reflective about innovations but at the same time does not do many - if at all - reviews of innovative products implementing crossfeed, EQ-correction, individual HRTF etc etc. and discuss their merits and/or drawbacks. On the other hand there are not many classic headphone reviews here as well. If it really wants to focus on headphone reviews, there should be more of them, I think. If on the other hand it wants to be less conservative, there should be more about innovation.
That's at least my impression. I can imagine that times are hard to finance such a page, but I am not sure if every article here is suitable for bringing in new readers. Therefore my suggestions.

hanshopf's picture

Thanks Tony for your insightful comment! My criticism was not meant to neglect the achievements of this page. I am just not so sure about the different directions its trying to head at.
On the one hand it somehow wants to be innovative or at least be reflective about innovations but at the same time does not do many - if at all - reviews of innovative products implementing crossfeed, EQ-correction, individual HRTF etc etc. and discuss their merits and/or drawbacks. On the other hand there are not many classic headphone reviews here as well. If it really wants to focus on headphone reviews, there should be more of them, I think. If on the other hand it wants to be less conservative, there should be more about innovation.
That's at least my impression. I can imagine that times are hard to finance such a page, but I am not sure if every article here is suitable for bringing in new readers. Therefore my suggestions.

tony's picture

I think Tyll has covered the Crossfeed devices.

There are plenty of them nowadays.

Tony in Michigan

hanshopf's picture

Ok, probably I overlooked that, having no idea, which one's offer the most convincing solutions. The Phonitor's crossfeed? the Hugo's? The standard or extended versions of Jan Meier or some of the countless plugins? All I listened to do sound different.

tony's picture

I've heard a few that didn't impress.

I expect to re-create a Salon Listing Room experience.

They don't

I'm happy enough without the Circuit.

I am impressed with the Phonitor and the SPL stuff but not enough to replace my already superb Schiit Asgard2.

So, why bother?

It seems a $1,000/$2,000 solution to a problem that doesn't quite exist.

Tony in Michigan

hanshopf's picture

Right, seems to be a compromise at the moment, but listening without crossfeed to my ears is even more of a compromise. That's why I am having these questions about different characteristics of the available implementations (being digital and very affordable or analogue and more expensive). Best, Eric

tony's picture

You might have to buy one and let it settle into your system for a good bit of time.

But which one?

There are $20,000 to $30,000 dollars worth of devices out there.

If Schiit decides to offer one, I'll buy it.

Schiit stuff is Ebay ready if it doesn't move my needle.

Tony in Michigan

Rillion's picture

Hi,
I've just posted a rather lengthy comparison of the crossfeeds (both hardware and software) that I've tried in the Forums under this thread:

http://www.innerfidelity.com/content/crossfeed

I have never tried any of the pricey ones like the Phonitor or Smyth Realiser.

Tyll Hertsens's picture
Well, I like your idea of comparing cross feeds, but it would be pretty tough gathering them all up to compare. More likely to comment on them separately. Here's one I did recently, and this from a while ago. John Grandberg wrote about this head tracker.

EQ correction is a bit tough for me. Ihave to review headphone in their stock form; EQing them is something I essentially never do. I also think the right way to approach EQing is from the measurements. When the on-line measurement tool gets made, one of the features will be to produce estimated EQ curves for the selected headphones. When that tool is up, I'll write something about that.

The Smyth Realizer is on my radar, but it's quite expensive and been around a long time. Also, it has been reviewed here. Well, sort of, it was a Stereophile article that was moved here when InnerFidelity started.

I think it's worth mentioning that this article was in response to two or three requests from people who wanted to see the info, so while it might not hold much interest for you, they were interested.

hanshopf's picture

Thank you for your kind reply! Frankly I am also wearing glasses, and tried out ones with slim arms and broad arms and wanted to know which ones could add more warmth to my cold HD800's. I ended up with sun glasses, which softened the sound more than some after market cables, adding some dark note. - Ok, I am joking. Forgive me. :)
I had already forgotten your review of this Dynsonics Audio Virtualizer from last month. Probably it's because I missed an evaluation in the context of comparable products on the market which I know like some different crossfeed implementations and therefore had not been able to grasp the relevance of this new product - and forgot about it.
I did not want to sound harsh. In fact I highly appreciate your work, and it's only because I regard your opinion so highly that I sometimes think, there are other topics I'd like to get your evaluation on.
And with regard to EQ I totally understand that you have to review headphones in their natural state. But there are products on the market which offer EQ correction which could be evaluated separately.
But anyway: you have got a vision and do your work with lot's of passion. In the end this is all that counts and what will always bring me back to your page!

tony's picture

This method works beautifully.

Transducers seem like Meat from the Butcher: they have to be seasoned and prepared properly, the higher the quality the better the result.

The measurement graphs are like the combination to a safe, they un-lock the greatness of the headphone.

I recall seeing a big notebook of graphs at one of the early RMAF Seminars ( being passed around ), now I realize how important a treasure that book was.

Tony in Michigan

Jim Tavegia's picture

I did order a pair of AKG K271 mk 2s yesterday and look forward to them being a huge improvement over my 2 pair of Sony 7506s that I've owned for ever it seems.I did order new velour pads for one pair of 7506's. I really like my K701s and came close to buying a pair of K612s, but I knew I needed some better sealed cans so...we'll see tomorrow when they arrive from Sweetwater.com. Came close to buying the Focals Pros, but could not just the extra 4150. Glasses or no glasses, I don't seem to notice much difference, and I often listen with them on and off. Maybe I should be.

Doing much more headphone listening in the last month and really enjoying it.

Reticuli's picture

Unless you're wearing big thick frame arms and closed headphones, I wouldn't stress over it. I think our cheek is more elastic than the dummy head and it's easier in general for us to get a good seal than on the tests. Thanks for the interesting post though, Tyll.

Seth195208's picture

..don't touch the cheek. They only touch the bony part of the head.

Reticuli's picture

Temple, cheek, whatever. Unless Tyll's using felt AND silicone, I doubt it's comparable.

Seth195208's picture

.

Max Minimum's picture

For many headphones I imagine it doesn't matter too much. But the bass is just killed on my hp50 and significantly subdued with my pm3. I have thin-framed glasses. It's bad enough that I'm looking into somehow replacing the arms with some kind of strap on one pair of glasses that I'd just use at home.

xnor's picture

What about sunglasses?

;)

Tyll Hertsens's picture
They darken the response. :P

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