CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS

Lobby => Headphone Measurements => Topic started by: Marvey on December 06, 2011, 03:58:49 AM

Title: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 06, 2011, 03:58:49 AM
Sennheiser HD650 CSD Waterfall Plots. These cans are very clean.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: LFF on December 06, 2011, 04:46:37 AM
That is impressive....
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 06, 2011, 04:49:19 AM
There's a dip in the upper midrange / lower treble. I'm wondering if this accounts for the "veil". I've heard this headphone many times and did note this area is recessed, but I would hardly call this headphone veiled. If the HD650 is veiled, then the LCD2/3 is AM radio.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: rhythmdevils on December 06, 2011, 05:14:44 AM
Recessed upper midrange FTW!!!! 

I bought these for the 3rd time after seeing your CSD on the other site and I like them, they're not offensive but they still sound dull to me.  I don't think I have enough jiggawatts for them.  Either that or I've gotten use to orthospeed
Title: Sennheiser HD650 Frequency Response
Post by: Marvey on December 09, 2011, 06:13:48 PM
Sennheiser HD650 Frequency Response
(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=210;image)
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: rhythmdevils on December 09, 2011, 07:26:23 PM
Do you hear a dip in the upper midrange to that extent?  I don't...
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 09, 2011, 07:55:13 PM
I heard a dip more in the lower treble with these cans. Unlike peaks, dips are very very hard to hear.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: khaos on December 12, 2011, 11:25:00 AM
An interesting experience would be to play with either a parametric EQ or a FIR based EQ until the measured frequency response is near flat, and then report how it sounds, alternatively, one could play around with EQ until it sounds flat an neutral and then measure the FR (that's more or less what LFF did with the Paradox if I'm not wrong).

I think the HD 650, the HD 800 or the LCD-3 should be quiet appropriate for these endeavors since their FR is quite regular to begin with.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: victor25 on March 07, 2013, 07:53:33 AM
I'm interested in how the HD600 will compare to these. Are there any measurements or any proof that there is such a thing as the old and new HD650's? Mine are very old with the black drivers/backs.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: donunus on September 04, 2013, 01:12:38 PM
Random statement here: I have heard an old black driver hd650 with much less upper mids to lower treble vs a silver driver one before but now I have gotten a hold of a silver driver version that sounds more like the old black driver one WTF is up with the hd650 quality control?
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Lumos on September 09, 2013, 09:26:50 AM
Random statement here: I have heard an old black driver hd650 with much less upper mids to lower treble vs a silver driver one before but now I have gotten a hold of a silver driver version that sounds more like the old black driver one WTF is up with the hd650 quality control?

hmm... I have silver driver made in 2012, still I think they lack sparkle and engagement of upper mids. probably this is why I don't like them...(I modded it but still not my cup of tea) is your driver's diaphragm transparent?

New= thicker Duofol material with parts number printed on diaphragm.
Old= thinner, shinier, with a number stamped on to the center of the diaphragm''

more pics: http://www.head-fi.org/t/197776/sennheiser-hd650-appreciation-thread/3990
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: ultrabike on July 17, 2014, 06:55:08 AM
Adding an HD650 measurement redo... Something seems to be wrong with the left channel this time (very easy to hear). It may be a cable contact problem, but not sure.

Frequency Response

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7015;image)

Distortion Right

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7017;image)

Distortion Left

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7019;image)

CSD Right

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7021;image)

CSD Left

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7023;image)
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: anetode on July 17, 2014, 11:45:48 PM
Thanks again for the measurements. I'll investigate the driver mishap later, from the graphs it almost looks like it was knocked out of position.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: fishski13 on July 18, 2014, 03:18:23 AM
don't worry, the Zu Mobis cable will sort it out. 
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: anetode on July 18, 2014, 04:04:14 AM
don't worry, the Zu Mobis cable will sort it out. 

Yeah, I'll just use the stock cable on the opposite site to balance it out  :-Z
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: ultrabike on July 18, 2014, 05:21:38 AM
Did that and that did not work ... worth the try. Looking at the drivers, I think the left one is off center. Will see what I can find out.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on July 18, 2014, 05:47:54 AM
My older black driver, original pads and stock cable HD650:

(http://diyaudioheaven.files.wordpress.com/2013/12/hd650.png?w=614&h=418)

and CSD (left and right superimposed)

(http://diyaudioheaven.files.wordpress.com/2013/12/csd-hd650.png?w=614&h=317)

I listen to it like this:

(http://diyaudioheaven.files.wordpress.com/2014/05/hd650-kameleon.png?w=614&h=369)

Note the dB scale is 5dB/div and is 'stretched' in vertical sense compared to the usual graphs shown here.
Sounds like the measurements show as well.
It's one of the headphones I will never part with.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: ultrabike on July 18, 2014, 06:24:43 AM
The left driver was out of place. I moved it into place and that solved the problem... Measurements on the right driver may also be different from previous ones since that one was also re-positioned.

Frequency Response

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7043;image)

Distortion Right

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7053;image)

Distortion Left

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7055;image)

CSD Right

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7049;image)

CSD Left

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7051;image)
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on July 18, 2014, 08:44:49 AM
I can't do any (relevant) THD measurements as my mic pre-amp is far too noisy which is not important for FR and good enough for CSD above 500Hz.

I like the HD650 mostly because it has about the least amount of distortion of all headphones out there.
In your measurements the HD seems to be below your noise levels as well (maybe the 2nd harmonic is slightly above it).

Perhaps you can make an HD plot without any signals to the headphone and determine your noise floor...
might be a good HD benchmark.


Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: fishski13 on July 18, 2014, 10:51:18 AM
don't worry, the Zu Mobis cable will sort it out. 

Yeah, I'll just use the stock cable on the opposite site to balance it out  :-Z

my comment was an attempt at humor.  live long and prosper.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: ultrabike on July 18, 2014, 05:27:24 PM
I though that was not a bad idea. Could have been that the cable connectors developed an issue...

Perhaps you can make an HD plot without any signals to the headphone and determine your noise floor...
might be a good HD benchmark.

I'll see what I can do SD.

Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: jerg on July 18, 2014, 07:58:54 PM
The left driver was out of place. I moved it into place and that solved the problem... Measurements on the right driver may also be different from previous ones since that one was also re-positioned.

Frequency Response

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7043;image)

Distortion Right

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7053;image)

Distortion Left

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7055;image)

CSD Right

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7049;image)

CSD Left

(http://www.changstar.com/index.php?action=dlattach;topic=40.0;attach=7051;image)

Man that looks glorious, perfectly boring, nothing out of place haha.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: anetode on July 18, 2014, 09:04:14 PM
my comment was an attempt at humor.  live long and prosper.

(http://i.imgur.com/CYDr7GI.jpg)
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: fishski13 on July 19, 2014, 03:47:01 AM
 :)p5  http://www.youtube.com/watch?v=l3P4Fv64T44  (http://www.youtube.com/watch?v=l3P4Fv64T44)
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: lumos on July 19, 2014, 01:17:21 PM
I don't think they sound that linear and clean. Owned them one year... blurry not tight bass and besides warm sound decay of sibilants in vocal like SSS and sh sh was more noticeable in time domain.

Magic mids everyone talks about is only OK I have listened better. Not acceptable for the price

I much prefer Beyer 880 600 ohm over HD650 and 600. However Senns has bigger soundstage. Bayer has better articulated more hi resolution sound 

Generally Sennheiser deserves  :spank: walk the plank2
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: riker1384 on July 29, 2014, 10:09:56 AM
My older black driver, original pads and stock cable HD650:

(http://diyaudioheaven.files.wordpress.com/2013/12/hd650.png?w=614&h=418)

and CSD (left and right superimposed)

(http://diyaudioheaven.files.wordpress.com/2013/12/csd-hd650.png?w=614&h=317)

I listen to it like this:

(http://diyaudioheaven.files.wordpress.com/2014/05/hd650-kameleon.png?w=614&h=369)

Note the dB scale is 5dB/div and is 'stretched' in vertical sense compared to the usual graphs shown here.
Sounds like the measurements show as well.
It's one of the headphones I will never part with.

That's impressive. What EQ filters do you use exactly?
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on August 05, 2014, 10:11:27 AM
It's an analog filter (not an parametric or fixed band equalizer) module dedicated for this specific headphone that is inserted into a portable amp.
I do not sell these amps, just design them and build them for myself.

more info can be found on my website (globe under my avatar) but as it isn't exactly pirate booty (no fancy nor any audiophile stuff in there) and still in its infancy I keep quiet about it.
Look for 'Kameleon'.

I don't use other headphones any more (except for the T50RP and DT1350 with its own modules) and stopped searching for the next (always imperfect) headphone out there.
Doesn't mean I don't enjoy trying out other headphone models (like the A5 Pro recently).
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Deep Funk on August 05, 2014, 10:30:49 AM
It's an analog filter (not an parametric or fixed band equalizer) module dedicated for this specific headphone that is inserted into a portable amp.
I do not sell these amps, just design them and build them for myself.

more info can be found on my website (globe under my avatar) but as it isn't exactly pirate booty (no fancy nor any audiophile stuff in there) and still in its infancy I keep quiet about it.
Look for 'Kameleon'.

I don't use other headphones any more (except for the T50RP and DT1350 with its own modules) and stopped searching for the next (always imperfect) headphone out there.
Doesn't mean I don't enjoy trying out other headphone models (like the A5 Pro recently).


Solderdude's HD650 sounds so good that you really do not want to take it off. When he was measuring the headphones a few weeks back I was amazed by the sound. I am not a Sennheiser guy (except for the HD250 II Linear) and I was hooked.

When a headphone sounds as good as his HD650 you just enjoy the music.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Hands on August 05, 2014, 10:52:20 AM
I don't use other headphones any more...stopped searching for the next (always imperfect) headphone out there.

You, sir, have lost your mind, then! Every headphone is perfect, but in different ways! :P

I'd love to hear how you have this HD650 setup sometime...not sure if that would ever be possible though, haha.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on August 05, 2014, 11:17:09 AM
The amp and filter(s) are very well documented...

It will be available in the USA in the future and is available in small quantities in Europe (as mentioned I am not selling/building them myself, just enjoying it)

And yes... you are correct all headphones are perfect... in being far from perfect !  :)p17
As Deepfunk mentioned I only hear the music on this setup.
To me the source, amp and headphone are out of the equation, only realistic music remains (on well made recordings).

YMMV though and then there is preference as well as crappy recordings which sort-off can make some flawed headphones shine in those other occasions.

Needless to say the HD650 is an excellent headphone with very low distortion and good impulse qualities.
It just needs to be 'motivated' to perform optimally.



Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: semola on September 04, 2014, 09:06:43 AM
Hallo to all.
Please, can someone measure the F.R. and Waterfall of this phone without the stock foam in front of the driver and,if is possible, without the small foam behind the driver?

Semola
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on September 04, 2014, 09:59:02 AM
I made these measurements (FR and waterfall) some time ago.

http://diyaudioheaven.wordpress.com/headphones/measurements/brands-s-se/ (http://diyaudioheaven.wordpress.com/headphones/measurements/brands-s-se/)

Added some info about old and new pads as well.
HD650 is somewhere in the middle of the page.

I use it with stock foam in front and back.
Sennheiser didn't just wing it and the foam appears to be there for a reason.

Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: kothganesh on September 04, 2014, 11:04:26 AM
Solderdude,

IMO, the BH Crack with Speedball is a good motivator for the HD 650. At first listen I thought that the Crack was better for the 800 but I've since changed my opinion in favor of the 650. However I'm not technically competent to explain this.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Hands on September 22, 2014, 11:40:29 PM
Time for my HD650 measurements. Stock for stock, I like these more than the HD600, mostly due to the smoother 1-4KHz response. I did prefer the treble rendition on the HD600 otherwise. I wish they would make a baby. The more laid back upper-mids and treble on the HD650 make the mid-bass hump stand out more, so they sound thicker and woolier. On the upside, the HD650 does have improved THD results. CSDs look clean as always. That stuff below 1-2KHz or so is just inherent to my setup - not gonna get much cleaner from a headphone (my lookback measurements show resonance crap there too for whatever reason). Overall, not bad looking at all. Why would you buy the PM-1 again? (Again, PM-1 will work OK from about anything. HD650 probably won't. But other than that...)

Like on the HD600, I think the raw 1 and 2 measurements match what I hear a bit better than the 3rd and 4th takes. I don't think they sound as dark or veiled as measurements suggest, but they are on the laid-back side for sure.

Oh, and these were stretched out over a bookshelf speaker for a couple days, so the pads are a bit softer and the clamp isn't quite as tight as fresh out of the box.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Hands on September 22, 2014, 11:49:28 PM
Okey dokey, more measurements. First four pics are comparisons against the stock HD600, my damped and stretched/widened HD600, PM-2, and ZMFxVibro - or whatever you want to call it, if you don't like that name.

The other three pics are some basic mod results. First, I have a stock left channel measurement for reference. This is actually the 1st take of the left channel measurements (raw 1 in previous post).

For damping, I used 2 discs of this in the removable cup section and 1 disc with a hole cutout tightly fit around the driver in the back (got the 1/4" thick material): http://www.foambymail.com/CR/solid-charcoal-regular-foam.html (http://www.foambymail.com/CR/solid-charcoal-regular-foam.html)
I also used 1 disc of this material over the 2 thicker discs in the removable cup section: http://www.foambymail.com/CF0-125LF/1-8-inch-charcoal-regular-foam.html (http://www.foambymail.com/CF0-125LF/1-8-inch-charcoal-regular-foam.html)
This is represented with the 2nd pic.

If one wants something more relaxing sounding, use a disc of that same 1/8" material in front of the driver. This does bring back some of the mid-bass hump, but it sounds cleaner than stock.

This pair wasn't widened as much as the HD600 was for these measurements, so you can probably get a stronger treble response if you were to widen them for a lighter fit and clamp. I did so after making these measurements, and they sound quite good. Great, even!
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: jerg on September 23, 2014, 05:02:25 AM
The pattern reminds me of the Orpheus FR lol.

http://www.changstar.com/index.php/topic,382.0.html
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Hands on September 24, 2014, 03:10:30 AM
Interesting...good catch! I will say, after stretching these out over a speaker for a few days (this also softened the pads), widening them even more, and adding some damping, these sound really great. Surprisingly clean and clear sounding, very balanced. If I had to have one headphone out of anything I've tested so far, it would probably be this.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: transparent201 on December 23, 2014, 07:22:12 PM
(http://s23.postimg.org/hbpfnlcor/Headphones.jpg)

Some measurements I'd like to share for dt990 pro(relatively new pads), hd650 and hd595(moderately worn pads), using a radio shack spl meter, a CD on top of the former's mic and "room equalization wizard"(REW).

I did this more so as an experiment trying to capture the relative differences, on the ground that the process is the same for the three sets. I don't know if I'm scientifically correct regarding my goals(if not please explain-ok sound levels are not matched exactly but this is not of paramount importance). I performed three measurements for each set with repositioning just to be sure about the consistency of the results. The above graph shows the best case scenario as there were no significant diffenences except for the bass levels. as you can see data are raw.

At first I was puzzled when I saw how smooth 650's FR is, until I measured the others. These results are in line with personalaudio.ru tests with the exception of the uppermids 6db notch. I wonder how marvin's upper-mids "marianna trench" came out. To be honest Marvin I haven't found any post in here explaining the whole procedure in detail.

As you can see H595 has serious bass roll-off(some of it is due to the spl meter I think) and sound tinny, although flat. On the other hand 990pros suffer from a midrange dip and a very deep notch around 4K. I always considered dt series as lacking in the mids(excessive dullness and distant feeling) and now I think I found the true cause. Again, many internet measurements prove to be perceptually deceiving.
HD 650 sound to me more or less as I measured them. Flat, true to the source, vivid in the mids with somewhat weak extremes. As I have auditioned Audeze LCD-3 recently the most important improvement I recall over the 650's is in the bass sector(extension, clarity, smootheness). Mids just were just different(less pronounced/shouty), not better.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: OJneg on December 23, 2014, 07:47:49 PM
RatShack SPL meter isn't going to give you particularly useful results. Use omni room measurement USB mic at the very least.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: transparent201 on December 23, 2014, 08:06:06 PM
Ok but ratshack remains the same for every set you put on.
To clarify things, I didn't use an ear dummy. That's the main reason you will never see results such as those on serious sites like e.g. innerfidelity. My purpose is to capture relative differences.
Also, i'd like to mention that if I correct my dt990 pros according to marvin's measurements, or even other more "professional" ones, the sound becomes worse than 20 USD sets sometimes. I'm sure you have noticed the ridiculous differences among the so called serious tests.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 23, 2014, 08:35:26 PM
That's the way they measured. You have to realize there were different versions of the HD650 driver. Also, the age of the pads do make a difference.

See HD650 redux (another HD650 set) measurements here: http://www.changstar.com/index.php/topic,469.msg8386.html#msg8386 (http://www.changstar.com/index.php/topic,469.msg8386.html#msg8386)
Done on the exact same measurement rig. No "Marianna" trench.

(http://www.changstar.com/index.php?action=dlattach;topic=469.0;attach=2116;image)

Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: OJneg on December 23, 2014, 08:38:56 PM
My purpose is to capture relative differences.

And your measurements/graphs still fail in that regard. You can use a potato to record headphones and if the results are bad in an "absolute" sense they won't tell you much in the way of relative differences. The fact that the only variable being switched out is the headphone doesn't change this.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: transparent201 on December 23, 2014, 09:05:04 PM
http://realtraps.com/art_microphones.htm
Is "Rat Suck" bad; Yes it is, but not potato bad and definitely not particularly bad for the frequency range of interest(100Hz to ~10.000Hz) and the aforementioned purpose(FR differences).

@Marvey
We had this discussion before. I acknowledge the facts concerning HD650. OTOH, your dt990 pro measurements, which remain almost the same through time(I bought recently another 990pro which sounds almost the same as the one I had years before), indicate huge amounts of treble energy beyond 5Khz(~12db), which if corrected results in a blanketed sound on both of my 990 sets. Also your measurements show some sharp dips(4Khz and 6Khz IIRC) whereas headphoneinfo(professional equipment used) and personalaudio.ru don't reveal any problem. Moreover, personalaudio.ru shows a strong rise in volume from 3Khz upwards, whereas headphoneinfo shows the exact opposite until 6-8Khz(pictures from both sites indicate ear pads in good condition).

The question remains. Which measurement should we trust? Matters become worse when you start comparing relative headphone differences among different sites(let alone HD650).

p.s: I forgot to ask you, if you are using dummy ears.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 23, 2014, 09:19:11 PM
DT990 are bright and bassy to my ears. I'm don't read personalaudio.ru so I cannot say much. Are their measurements smoothed in any way? Sometime smoothing will eliminate dips. Also, sometimes dips arise from interactions between coupler and headphone - wave cancellations. This phenomena is difficult to eliminate and varies among measurement rigs.

As for which to trust: You already know the answer. It's relative differences within the same framework that matter. Comparing measurements taken using different rigs is a really bad idea. As Jude says in his HF profile, different measurement rigs, different results. You can see a picture of my first iteration measurement rig if you click on Jude's profile. I'm now using a damper solid coupler with hair, ear simulators now for my V2 iteration measurements.

Any attempt to correct or compensate the measurements here to another system will result in catastrophic error and disaster. World might possibly end with floods, earthquakes, etc.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: transparent201 on December 23, 2014, 09:54:49 PM
Concerning, personalaudio.ru maybe it's the second(wave cancellations in your rig), because sharp notches manifest themselves even in smoothed diagrams as shallow dips.

Quote (selected)
As for which to trust: You already know the answer. It's relative differences within the same framework that matter.

Let's say that we try to equalize dt 990 pro in order to sound like HD 650 using data only from personalaudio.ru. HD650 sounds almost totally flat(according to personal audio) so we need to make 990 pro sound flat too. We face the problem of having to reduce the treble up to 12 db starting from 4Khz. According to my experience this destroys the sound and the most relevant measurement to my perception is that of headphoneinfo and goldenears.net which show a sharp treble increase only around 10Khz. It's more of a sizzle than harsh sibilance, subjectively.

Now it's better to understand the nature of the problem. The real problem is the relative differences among frequencies of one measurement on a certain rig when compared to other measurements on different rigs.
For example, measurement A on rig A tells as that 4Khz is 4db higher than 2Khz for headphone X whereas measurement B on rig B tells us that 4Khz is 3db lower than 2Khz for the same headphone.

And thanks for the info.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on December 23, 2014, 10:00:33 PM
DT990 (old 600 Ohm) ARE bassy and trebly to my ears and my (yet based on other types of measurements) rig as well.
Of course my measurements too are incorrect in an absolute sense but are useful for me in a relative sense to my other measurements.
They may be useful for others as well though.
Only one person on this planet seems to have an absolute accurate (proprietary) rig but he won't be measuring the DT990 for you.  ;D

(https://diyaudioheaven.files.wordpress.com/2013/12/dt990-600-nieuwe-meting.png?w=614&h=435)

Non-smoothed and somewhat 'corrected' so that a horizontal line would sound 'flat' to my ears.
The test rig only set me back a few bucks so don't complain about inaccuracies please.

The plot basically is very similar (when smoothed) to the personal audio.ru plots.
The (extremely smoothed) plot below is from the mentioned Russian site:
http://personalaudio.ru/raa/otchety/naushniki/beyerdynamic-dt-990-600-ohm/

(http://personalaudio.ru/raa/otchety/naushniki/beyerdynamic-dt-990-600-ohm/Beyerdynamic_DT%20990%20%20600%20ohm_fr_impedance.png)


Since this thread is about the HD650 I'll also post what my rig 'hears' of it..... for reference sake.

(https://diyaudioheaven.files.wordpress.com/2013/12/hd650.png?w=614&h=418)

For what it's worth... IMO you can't EQ the DT990 so it'll sound like an HD650. You may be able to get it closer tonally but they will still sound different.
At least that's my experience (own and EQ'ed both pretty flat). The HD650 is pretty easy to EQ really flat, the DT990 is nigh-on impossible without steep filters.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 23, 2014, 10:03:59 PM
Yes, just need experience to figure it out. Measurements are a guideline, especially with headphones.

In the end, FR is only one aspect of sound. Aspects of brightness, bassy, mids sucked-out, etc. transcend simple FR measurements - which are in the frequency domain and calculated withing finite time windows. This is not how we hear. Distortion also plays a factor.

Bottom line is to train your ears on equipment where measurements can be duplicated and methods are well-known: speakers. Ultimately ears should make final decision if you want to EQ your headphones. Measurements are a tool. They are not intended to be the truth.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: transparent201 on December 23, 2014, 10:24:47 PM
@Solderdude, @marvey
I expressed myself wrong by talking about emulating HD650 sound. Forget about it. I just wanted to point out that by correcting dt990 according to specific measurements(take a look at headphoneinfo which is significantly different in some regards) you get a cloudy-lifeless sound.
This shouldn't be happening, realizing the fact that fidelity is something objective, very specific and measurable(regardless of how humans perceive sounds) and fidelity involves flat FR. Even if we couldn't simulate hd650's sound(which is the most reasonable for certain reasons) there should have been an improvement.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on December 23, 2014, 10:41:42 PM
The FR corrected DT990 (to get nearer to flat) gave me a good (better as in improved SQ) sounding headphone.
It certainly wasn't lifeless/cloudy.
The DT990 Just did not became as good sounding as the easier to EQ HD650.

No digital EQ was used, only gentle purpose made gentle analog EQ.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 23, 2014, 11:03:23 PM
This shouldn't be happening, realizing the fact that fidelity is something objective, very specific and measurable(regardless of how humans perceive sounds) and fidelity involves flat FR. Even if we couldn't simulate hd650's sound(which is the most reasonable for certain reasons) there should have been an improvement.

What specific EQ settings did you use?
Maybe you prefer the dt990 with a bit of brightness?
Maybe the dt990 driver has a tendency toward being bright and correcting it does not yield good results? Like trying to make someone who is gay straight?
Maybe your dt880 measures slightly differently than here? strong possibility here.
Maybe your subjective experience was influenced by the measurements that you took?
Maybe you have no or little idea what you are doing?

I dunno, lots of possibilities.

As an aside: Sorry, fidelity is not measurable. I'm on my my 22nd or 31st speaker project / variation now. I can tell you that fidelity is not measurable. Even if you take the trinity of FR, non-linear distortion, and CSD, that trinity only tells you 50% of what is going on.

Finally, if you want easy numbers lining up and elegant solutions that work out well, I suggest a hobby in pure mathematics below the university level. Otherwise your whining and bitching about stuff not making sense is getting annoying. I simply don't have the answers. Lots of shit doesn't make sense, even with regular ol' speaker measurements, lots of shit doesn't make sense; but you figure it out over time.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: transparent201 on December 23, 2014, 11:29:51 PM
DT 990pro from headphoneinfo
http://content.reviewed.com/products/2836/specs/5331/freq.gif

and

DT 990 edition from the same site:
http://content.reviewed.com/products/22772/specs/5331/freq.jpg

Vastly different sound structure(subjectively piercing treble on the 990 edition, 990 pro-->normal treble with a little sizzle) which marvey's measurements and russian site don't show.
Solderdude is right about 990 600 Ohm. Edition 990s(250 or 600 Ohms) have completely different damping(and pressure) compared to pros and should be sounding differently(and therefore need the severe treble cut).

Again the same question arises. Who shows the true difference between 990 edition and 990 pro. Headphoneinfo or the others. Are measurements trustworthy?

Quote (selected)
Sorry, fidelity is not measurable

Fidelity means sound A is indistinguishable from sound B. And as far as I'm concerned sound is a fluctuation of air pressure. A thing with measurable characteristics regardless of how it is analyzed by humans, animals, aliens etc.

p.s: I will end the off topic on my behalf here.
I will only add that the measurements I posted on the previous page are of practical use since I corrected my 990pro based on hd650 response(essentially flat) and the final result had better mids without harming the rest of the sound.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: OJneg on December 23, 2014, 11:52:50 PM
Fidelity means sound A is indistinguishable from sound B. And as far as I'm concerned sound is a fluctuation of air pressure. A thing with measurable characteristics regardless of how it is analyzed by humans, animals, aliens etc.

Are you 14?
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 24, 2014, 12:23:41 AM

It's OK.

Lots of people don't understand FR graphs come from FFT transforms of the impulse response which is in turn derived from sweep, mini-length, or noise sequences. The fact that FR graphs come out differently based on the gates of the window and edge functions is lost on most. There is a serious misunderstanding that FR graphs actually represent the totality of phenomena when it is fact missing behavior-over-time information.

The way the hair cells in our ears work is similar to a spectrum analyzer but over time. FR graphs wouldn't be a problem if all we heard were steady-state tones. Unfortunately, music or reality phenomenon does not consist of steady-state tones.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on December 24, 2014, 11:22:23 AM
Again the same question arises. Who shows the true difference between 990 edition and 990 pro. Headphoneinfo or the others. Are measurements trustworthy?

Only the site who has done measurements of the 2 different models on the exact same rig can show the DIFFERENCES between the 2 models.

On the question are measurements trustworthy than I would have to say NO.

For instance, have a look at Tyll's raw plots (the grey lines under the 'final' measurement).
They are taken on the same rig but with different positions on the rig.
These different positions, more often than not produce WILDLY varying plots.
Same headphone, same rig... which of the grey lines would you say was accurate in an absolute sense and what correction would you use, OW or Tyll's or another ?
I get similar on my rig and can get VERY different (as in 10dB even) different plots depending on the position of the headphone ON the rig.

Most often I take the one that represents what I hear closest in a position it would have on a real head.

Even this isn't a guarantee, take the large diameter of the pads for instance. They may break seal on some heads, and not of others, hears may do the same (don't have much !)
Then there is 'correction, compensation, HRTF theories' etc.
All of these will produce different absolute results compared to perceived sound.

Having said that ... all measurements out there may give you a pretty good idea of how they sound TONALLY.
All DT990 measurements will show roll-off in the sublows, a peak in the lows, recessed mids and a substantial peak in the highs.
Well not in the plots you mentioned, they stop at 100Hz.
low and treble roll-off, peaks, dips and general tonal aspects all show how the tonal balance is and that's the 'value' of measurements.
They need to be accurate in an absolute sense and to your ears/taste if you want to base EQ on them.

Then there is spread between drivers even of the same MODEL which can be several dB's and shouldn't be understimated.
Resonances that may occur can differ substantially from rig to rig.. Pinna or no pinna, hard surface or soft/porous, flat or headshaped surface even temperature van make a difference in seal when having memory foam in pads.

Too much variables ... but ... if you found a website (or made your own rig) that you trust you should stick to them.
Pirates often can find themselves in plots made by Marv, UB or Hans.
If you feel other plots are more 'correct' to your perception than you just use those and ignore, or take for granted, the plots shown here.

Only when you have made measurements yourself you start to get a feel how difficult it is, even more so in the speaker realm with reflections and resonances etc.

That's called freedom of choice..
I make my own choices, so can every one else.

Here (in Pirate land) plots are viewed as indicative and to give an idea of how it measures compared to other measured plots, not as absolute truth.
No one here has ever claimed absolute accuracy.
Take the plots for what they are ....


Back on topic .... I really like the HD650 ... EQ'ed flat... not in stock form.


Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: transparent201 on December 24, 2014, 11:42:33 AM
On topic
Considering the fact that radio shack spl meters are inaccurate above 2Khz and tend to overestimate SPL, HD 650 frequency response might resemble a flat line with a downward slope above 2Khz when measured on a simple plate as a CD.
The problem with this kind of measurements-I believe-is that they do not take into account the distance between the transducer and a real ear as well as the dispersion characteristics of the former.
I would be glad to have your opinion on this one. Can simple measurements on a plate-without the use of dummy ears-accurately capture the FR differences between different sets? Only their relative differences. Not how their sound is perceived.


Are you 14?
Yes, I am 14 years old. The same age as Dr Sean Olive from Harman. The person who performs experiments on the relationship between FR and subjective sound quality. And like him I never said that FR is the one and only factor to describe sound. However, if you want to achieve fidelity, then it is a parameter you have to get it right.
If you don't believe in fidelity as a set of well defined goals, you must ask yourself what is that you pay for hundreds or thousands of dollars. Technical expertise gained through rigorous scientific work(measurable properties including FR) or blind experimentation which can be performed even by a 14 year old?

ps: Thank for your elaborate response Solderdude.
You are right about variations due to slighlty different positioning on the rig. Although I didn't notice any significant variation in my little experiment. Perhaps it's the limited sensitivity of the spl meter or the lack of a simulated ear.

Quote (selected)
Back on topic .... I really like the HD650 ... EQ'ed flat... not in stock form.
Would you like to share your settings in REW filter settings form?
I mean like this:
Filter  1: ON  PK       Fc    50,0 Hz  Gain -10,0 dB  Q  2,50
Filter  2: ON  Modal    Fc     100H z  Gain   3,0 dB  Q  5,41  T60 target   100 ms
Filter  3: ON  LP       Fc   8.000 Hz
Thank you in advance
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on December 24, 2014, 02:53:41 PM
Considering the fact that radio shack spl meters are inaccurate above 2Khz and tend to overestimate SPL, HD 650 frequency response might resemble a flat line with a downward slope above 2Khz when measured on a simple plate as a CD.
The problem with this kind of measurements-I believe-is that they do not take into account the distance between the transducer and a real ear as well as the dispersion characteristics of the former.
I would be glad to have your opinion on this one. Can simple measurements on a plate-without the use of dummy ears-accurately capture the FR differences between different sets? Only their relative differences. Not how their sound is perceived.

Written below is my personal take on this and NOT proven science !
many may disagree on my views which is O.K.

Radio Shack meters cannot be used for accurately measuring FR, not even in 'C weighing' and 'fast' mode.
The moment you apply a baffle around a microphone tip the FR changes considerably.
The tip of measurement microphones isn't very small in diameter with a large 'stick' behind it for nothing.
Reflections a baffle creates must be avoided when measuring.
You can only use these meters for measuring average SPL in free air.
The CD also reflects sound quite differently than skin.

Once the sounds reach our outer ear what happens inside doesn't matter AND has to be corrected anyway so why use a tube inside to mimic an eardrum.
The ear drum itself 'hears' a completely different sound than what's outside of the ear anyway.
I think what's OUTSIDE of the ear should be 'flat' and not 'speaker like in a room' but others may seek 'speaker like in a room' and detest really flat.
preference.... POV... religion ... whatever rocks your pirateship.
HP drivers pump soundwaves directly into our ear canals and the Pinna/Concha only marginally affects what goes in there.
With speakers the Concha and Pinna have a FAR greater and different effect as the sound comes from another direction all together and thus 'compensation' of HATS need to differ as well.
HOW the soundwaves are affected depends on driver diameter, position and air volume as well as (freq dependent) seal of pads.
I don't think HATS used for evaluating speakers is perfect for measuring headphones either.
Every type of rig has its own + and - assets, no rig is correct in an absolute sense. Some are closer than others.

I have found in experiments that the absence of a Pinna can make a substantial difference in measurements with HP-A yet very little difference with HP-B even when both are over-ear headphones.
No way to tell what is accurate in an absolute sense. One can only guess based on what they hear and 'adjust' the rig accordingly if needed.
Myself I only use a form of 'adapter' when measuring on-ear and don't use a Pinna for several reasons.
I don't like in-ears at all, nor their sound, and think these are nigh on impossible to measure accurately compared to how they are perceiced for a number of reasons, so stay away from that trap.
There SHOULD be a standard for this.


Would you like to share your settings in REW filter settings form?
I mean like this:
Filter  1: ON  PK       Fc    50,0 Hz  Gain -10,0 dB  Q  2,50
Filter  2: ON  Modal    Fc     100H z  Gain   3,0 dB  Q  5,41  T60 target   100 ms
Filter  3: ON  LP       Fc   8.000 Hz
Thank you in advance

Can't do that.... not because I feel it is proprietary or secret or don't want to share but because I don't use any EQ in REW.
I use my own rig (its described here and there) with a WM61A capsule and a home made mic pre-amp with  analog (passive and active) compensation for the mic capsule.
The line signal into my EMU0404 is thus already compensated (and hisses a lot so cannot do distortion tests).
The only referencing I do is my EMU- amplifier (Ember proto) - EMU line loop.

My headphones are all compensated in the analog plane and those are all well documented. I don't like digital EQ.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: AZ on December 24, 2014, 04:03:01 PM
Agree and wouch for everything you say solderdude. Great post!
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Marvey on December 24, 2014, 04:10:52 PM
My observations and views generally jive with Solderdude's

Pinna makes a difference with certain kinds of headphones, but not all. I ended up with a simplified pinna for the purpose of being able to take measurements of supra-aural headphones. Distance on microphone plane of solid-coupler to the headphone driver will make a difference to the bass-treble balance of the resulting measurement. The can be tweaked. I prefer flattish instead of speaker-in-a-room response, hence no "DF" or "FF", unless IEMs, which I feel a little bit of that kind of response.

As for the plate or the baffle, some of its effects have to be considered. The headphones lie on skin and bone, which is essentially a baffle, but with different characteristics from a CD. You can experiment and try lining different materials on top of the CD. Also, correct seal with a baffle is required to get good results on bass. Too much seal overemphasizes bass measurements, hence I implemented hair simulator strips. A free-air or semi-free air measurement provides useful information as well, I think our ears can filter out even the early reflections in the cup - but this method has issues sometimes with seal / pressure to have the correct bass measurement.

Certain measurement techniques work with certain kinds of headphone designs better than others. Eventually, I had to pick one that worked best on the majority for the sake of consistency.

As far as HATs using to measure speakers, that doesn't make any sense unless you are trying to develop complex transfer functions exploring the inner workings of the ear and torso. Speaker measurement is always a mic wand at listening position in the studio or mic wand at 1 or 2 meters out at tweeter level by speaker builders. With a HATS, by the time you are done applying the compensation for pinna, concha, ear canal, it's supposed to be the same as the mic wand.

HATs do have different directivity characteristics than a wand mic(s), and tend thus lend themselves well to stereo recording. In any event a measurement must be taken with a wand mic and compensation must to applied to the HATS.

I don't mind giving hints, but I generally don't talk about or give specifics on my measurement rig(s) or techniques. Several cases where people who have seen my rig have gotten ideas / asked a bunch of questions and started to implement their own measurement systems to sell headphones. I'm sure all of these people could have developed a system themselves, but I don't like making it any easier for them.

Again, I think Dr. Olive is a better source for such discussions. I treat this as a hobby trying to get quick-n-dirty results and crude insights. I don't claim accuracy nor intend for the work here to be in academic papers or journals.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: transparent201 on December 24, 2014, 04:51:49 PM
Very informative posts from both. Thanks again.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Armaegis on December 24, 2014, 11:01:54 PM
I have found in experiments that the absence of a Pinna can make a substantial difference in measurements with HP-A yet very little difference with HP-B even when both are over-ear headphones.
No way to tell what is accurate in an absolute sense. One can only guess based on what they hear and 'adjust' the rig accordingly if needed.

I wonder if there's a correlation to the driver size/wavefront and the interaction with the pinna etc.

Hmm now my brain is pondering how to create a "microphone" that can map a 2d space rather than point.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: thune on December 25, 2014, 02:42:00 AM
Took me way-too-long to get my head around the idea (elaborated above) that if you took 6 various headphones and measured them on all the different measurement rigs, that you don't get a consistent delta between any two rigs -- it is headphone/rig, geometry/wavefront dependent. That is, it's impossible to create a single compensation curve to translate marv->tyll measurements for example, since the delta varies from headphone to headphone and the spread can be quite large.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on December 25, 2014, 08:08:21 AM
That is indeed what I think is the case.

When you take a look at the exact same headphones that have been measured by Marv and Hans (and/or UB) you will see similarities but also differences that can easily exceed a very audible 3dB.
Those differences will also differ from headphone to headphone so a 'standard' conversion between 2 rigs won't be possible unless the rigs are completely the same.

This does put relative differences between a few different headphones on the same rig in a questionable light though as we tend to 'trust' those.
A bit like measuring a speaker in different rooms or at different distances, same speaker, same rig.

It just shows measuring acoustic signals is sooooo much more complicated than an electric signal.
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Moonhead on January 12, 2015, 01:00:56 PM
Not long ago I tested LCD3 non-fazor with Alo MK3 and It sounded ok, except the lack of details and soundstage.

Sometime later I tried HD650 straight out of my iPhone and I'm pretty sure I got better details and soundstage, but I couldn't hear what the bassist where playing like I could with LCD3

If Im right it proves how good value Hd650 are and how expensive Audeze are.

Anyway I used a lot Of different genres on both cans, but I always use this track.

http://m.youtube.com/watch?v=lAF8D0ugyVk
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Golmang on April 13, 2015, 12:02:36 PM
Hey Solderdude, have you given your HD 650 modification a second thought in regarding a smaller release for others?  :)p6
Title: Re: Sennheiser HD650 CSD Waterfall Plots
Post by: Solderdude on April 13, 2015, 08:35:37 PM
The "SeNNator' is actually a small practical joke that originated on another forum and is based on an actual product.
Not manufactured by me, I don't sell anything at all (except headphones I tried and want to get rid of).
But it does exist and could be built by those that are interested once I published how to build one (for HD600's as well by request).

One of the, not really existing, but functional SeNNators is currently enroute to Ringingears that might bring it to meets just for the fun of it when it arrives in time.
It's not a serious attempt to bring something truly unique and doesn't contain any magic nor audiophile parts.
Just some cheap components and LM4562's that try to drive the HD650 it should be connected to.

Those preferring true high end equipment will laugh at it and may even find it just decent or perhaps even rather poor sounding.
Those that feel the HD650 is just a tad too warm and lacks real 'grunt' and does not want to spend top dollar on the next best amp but like balanced sound may prefer the actual product the 'joke' is based on a worthwhile investment as it is cheaper than the HD650 by itself.