My Freq Response measurements : UM2, E2C, AT CM5
May 21, 2005 at 2:55 PM Thread Starter Post #1 of 30

blackreplica

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Currently Measured Headphones:
Audio Technica CM-5
Shure E2C
Westone UM2
Sennheiser PC150
Sennheiser HD590
Sennheiser HD650
Beyerdynamic DT770 (80 ohm)


I have loudspeaker measurement software at my disposal and just came to realise what an interesting experiment it would be to measure the frequency response characteristics of the phones that i currently own.

I'm not 100% happy with the measurements, i cant help but feel that measuring earphones are not as simple as measuring loudspeakers, so take these measurements with a pinch of salt. Even slight changes in the way i positioned the phones on my mic caused very severe changes in frequency response measured. I suspect the lower frequency range to be quite inaccurate since low frequency response really depends on getting the right seal, and i did not even come close to that with these measurements (though i did try).

Methodology: I used a calibrated condenser measurement mic connected to a preamp to my laptop for processing. I used MLS software to take the frequency response measurements. all earphone measurements were done with the earphone tubes pressed against the mic, with each channel measured and recorded(left and right measurements for each phone are below). With the Westone UM2, i used the triflange sleeve inverted to cover the tip of my mic, creating a psuedo-seal. I did the same with foam tips for the Shure e2c, and used nothing for the Audio Technica CM7 since its an earbud type phone and creating a seal against the mic(or at least trying to get a seal) was impossible. For open headphones, the mic was located about 1cm away from the speaker, between the ear cups. The same was also done for closed headphones. I have also included an ad-hoc measurement i took of my (crappy) laptop speakers as reference. That measurement was taken about 5mm away from the speaker.

Its quite late now where i am and i just uploaded the measurements so i'll let you guys take a look and rejoin the conversation tomorrow or something. Enjoy!

Westone UM2:
Right Channel:
westoneum2rightchannel6pe.jpg

Left Channel:
westoneum2leftchannel9lf.jpg


Shure E2C:
Right Channel:
shuree2crightchannel1yw.jpg

Left Channel:
shuree2cleftchannel7ij.jpg


Audio Technica CM5
Right Channel:
audiotechnicalcm5rightchannel5.jpg

Left Channel:
audiotechnicalcm5leftchannel6r.jpg


Compaq Presario 1714AP Built-in JBL Pro Speakers
Right Channel:
laptopspeakerrightchannel4wt.jpg

Left Channel:
laptopchannelleftchannel6nh.jpg


New Measurements:
Sennheiser PC150
Right Channel:
sennheiserpc150rightchannel9bn.jpg


Left Channel:
sennheiserpc150leftchannel5rb.jpg


Sennheiser HD590:
Right Channel:
sennheiserhd590rightchannel3ak.jpg


Left Channel:
sennheiserhd590leftchannel5ye.jpg


Sennheiser HD650:
Right Channel:
sennheiserhd650rightchannel9qf.jpg


Left Channel:
sennheiserhd650leftchannel3ht.jpg


Beyerdynamic DT770-80:
Measurement taken when NOT worn,Right Channel:
beyerdynamicdt77080prorightcha.jpg


Measurement taken when NOT worn,Left Channel:
beyerdynamicdt77080proleftchan.jpg


Beyerdynamic DT770-80:
Measurement taken when worn,Right Channel:
beyerdynamicdt77080prorightcha.jpg


Measurement taken when worn,Left Channel:
beyerdynamicdt77080proleftchan.jpg
 
May 21, 2005 at 3:37 PM Post #2 of 30
very cool, even if it's not 100% accurate. It looks like lack of a seal killed the graph of the cm5's.

The um2 and e2c graph looks relatively accurate, though. Does headroom have a graph of the e2c's? You could compare the two graphs if they get that part back up on their site (I couldn't find it). Do the e2c's really have a peak at 4k? Interesting.
 
May 21, 2005 at 3:46 PM Post #3 of 30
Thanks for the encouragement....i wasnt too happy with the graphs when i took the measurements but at least i know i couldnt have made them better.

I am pretty sure the midrange is reasonably accurate though. i took at least 5 measurements for each channel on each phone and the peaks came out virtually identical everytime. Everything from about 100Hz onwards was very consistent, the only trouble was with the low frequency(read: seal-dependent
tongue.gif
) information.

Its kinda interesting to me though, because these measurements, despite not being completely accurate i suspect, actually illustrate some interesting things which are consistent with most user reviews (including my own subjective experiences)

The first thing people talk about with shure is the 'forward midrange' and the peak could explain this. The westones have a less forward midrange(although i still think its quite forward), and much better low end extension. The CM5, probably just like any other earbud, and consistent with my opinions(i have a review i posted in this forum a long time ago), that the thing has very sharp, piercing highs, a very thin midrange, and just about no bass whatsoever, when compared to canalphones.

I've seen some measurements to date of other phones and always notice that peak in the midrange. i wonder why manufacturers do this, it could be some correction which is put in place to offset the way our ears work with earphones in them?

Part of the reason i decided to measure the phones was because i havent been able to find any FR graphs online for any of them. So maybe these measurements will satisfy some curiosities other than my own. If you do come across any, let me know, i would love to crosscheck them to see how accurate the measurements are

Regards
 
May 22, 2005 at 3:01 AM Post #4 of 30
No one else interested in this? Was surprised to see no one else has posted in this thread since i left it last night
lambda.gif
 
May 22, 2005 at 3:23 AM Post #5 of 30
It is interesting. Unfortunately, I think your methodology really isn't suited to canal earphones. However, if you used your existing measurements as a benchmark, it would be interesting to see how these measurements compare to the E5s, E4s and the Etymotic earphones. The new UEs would be nice too...

err, this could get expensive.

Aw, forget it.

It was a neat experiment though!

dotyman
 
May 23, 2005 at 10:17 PM Post #6 of 30
The Shure measurements actually look like how mine sound to me. I thought I had a broken pair when I had to EQ it -6dB at 2.5kHz to sound decent. I would be interested in seeing any other measurements you can produce on other headphones.
 
May 24, 2005 at 12:38 AM Post #7 of 30
measuring them was quite fun
smily_headphones1.gif
unfortunately those are the only phones i have. i do have a sennheiser pc150 multimedia headphone on the way for pc usage though, i'll measure that as soon as i get them!
 
May 31, 2005 at 1:15 AM Post #9 of 30
having made the shift from the cm5s to the e2c's some time back, let me tell you that the difference will blow you away! Trust me, you'll enjoy them plenty!
etysmile.gif
 
Jun 1, 2005 at 5:13 AM Post #10 of 30
I would just like to say i have added the Sennheiser PC150 headphones to the list of measurements. i just recieved them in the mail today and only reluctantly bought them at the request of my brother who is a gaming nut and wanted something with an integrated mic.

A short review of my opinions of these cans:

Pros:
1 - Very good quality mic. i did some recording on my iriver mp3 player and my voice came out surprisingly clear, noise and hiss free. Sounded almost professional in quality. no corners were cut with this mic
2 - Good spacious sound as expected from open style headphones (yes, these phones are open).
3 - Very good high end extension. picks up a lot of detail in the treble. excellent for instrumental/classical type genres of music.
4 - Bass is good for an open phone. Good extension.

Cons:
1 - Difficult to drive through portable players. My iriver H140 was struggling to drive it even at max volume. No trouble with my laptop sound card though.
2 - Not much impact in the bass. Well, what do you expect with open phones right?
3 - Can get a bit harsh and spitty in the treble when playing songs with a lot of different sounds(gets all messy sounding)
4 - No isolation at all

Overall, far surpassed my expectations for the 35USD price tag(from ebay). by no means audiophile stuff, but the good mic coupled with above average sound and the sennheiser house sound make it a worthwhile purchase.

Measurements are in the first post.

I just thought i would mention that i also have a beyer dt770-80 on the way, and i will take more measurements of them and update this page when i can. I also have a friend who owns a Senn HD590 and HD650 and will try to take measurements of those phones and post them here as well if i get the chance. Stay tuned!

Regards
 
Jun 17, 2005 at 2:47 AM Post #11 of 30
Hi everyone,

I have updated the first post to include measurements i have taken of the Sennheiser HD590, HD650, and Beyerdynamic DT770-80 (which is possibly faulty, if it is, it will be replaced, and i will take new measurements)
 
Jun 17, 2005 at 3:10 PM Post #12 of 30
Interesting, particularly the DT770-80 measurements. I've been doing some measurements myself lately (I'll try to post them soon), and the DT770 measurements (while worn) look extremely similar to my MDR-V6 measurements, but with more upper treble in the MDR-V6, as you would expect.

Measuring headphones is really a challenge, as you mentioned in your first post. Open headphones have generally been more difficult than closed for me, and smaller are more diifcult than large ones. Aside from the seal, background noise is always an issue; HVAC noise complicates things for me 30Hz, but I think I'm generally satisfied with the way mine have turned up. Does MLS have any provisions in it for filtering out noise?
 
Jun 18, 2005 at 12:41 AM Post #13 of 30
Yes it does have a gating system that only takes measurements within a short time window, good for loudspeakers, but the issue is that when i measure headphones the mic is so close that early reflections may be a problem, but i'm not sure....i'm still waiting on word about whether my beyers are spoilt or not so its best not to take the beyer measurements seriously until i find out for sure
biggrin.gif


What software do you use to take measurements?
 
Jun 18, 2005 at 1:11 AM Post #14 of 30
Very interesting. Measuring these things is tough. Rightfully some people think these measurements have no value, but I think they can be somewhat useful, maybe.
Interesting to see the difference in the 770 between being worn and not.
Can you do the same for the 650?
 
Jun 18, 2005 at 1:56 AM Post #15 of 30
i probably could, but it would take a long while before i get a chance to meet my friend with the 650s again, i'm having exams ATM...but i'll try to get that measurement up one day
biggrin.gif
 

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