Headphone CSD waterfall plots

[purrin]

 
Quote:

purrin, is it safe to generalize that FR curves reflect the responsiveness of the driver, while the waterfall charts reflect the interplay between the driver and its enclosure?

The answer is not necessarily. The enclosure can affect both FR and waterfall. FR spikes correlate highly with waterfall ridges.
 
Here are a couple observations - and you guys are free to come up with your own. I can always test hypotheses by removing the driver from the enclosure and measuring it.
 

• The area below ~2.5k after the initial ~1.5ms on the CSDs do reflect more on the interplay between the driver and the enclosure than the driver itself. One of the reasons is that most small drivers of this size are not going to ring there (except DJ100). Very open phones such as the Sennheiser HD558, HP1000, HD800, and SR80i are going to measure cleaner in that area. Although it should be noted that the SR80i has an obvious 2k ridge from the enclosure if left untreated. Sennheiser is really good in designing their cups. I've really come to appreciate the engineering that's behind their headphones even though I keep poking them at their claims that the HD800 is "neutral".
• Sharp ridges, especially after 2.5k tend to indicate driver ringing regardless of enclosure. Grados are a good example. HF2 seriously rings at 3.5k, 5k, 9k. The SR80i has certain ridges that no modification (Dynamat, felt, cups, etc.) will ever mitigate.
• Finally there is the one caveat which gets to the heart your question. Enclosures can affect driver ringing by extending their decay over time. I suspect that in the more closed phones, there is no place for the energy to dissipate. In fact, the enclosure may even provide a a trampoline effect to keep it going forever, e.g. DJ100.

 

 

[purrin]

Quote:

Either we need to get you a Q701 to measure or Tyll an ESP950, or both.  I'm very curious how those two headphones' measurements compare.
 
Looking forward to seeing how clean the LCD-2 actually is in light of our high expectations of it after the low res plot.

 
If you are really curious, you can see Arnaud's data crunching of K701. The data is from Tyll's existing measurements - not new ones.
 
Tyll's equipment and methodologies are differ significantly from mine, so the results really shouldn't be compared.

 

[tdockweiler]

This is all very interesting..I always felt like the small aluminum cups of the DJ100 were holding back the sound a bit. When you open them up, there is almost no room in there at all. I guess it's time to do some more DJ100 modding. I tried some blu-tak previously, but that seemed to make the mids actually too forward, but seemed to improve the bass for whatever reason. Maybe I'll try some foam or Dynamat and see if I can hear any changes. Now I just need to read up more on all this.
 
I always felt like my open-modded DJ100 sounded better than the closed version, so this all kind of makes sense now.
 
I know this sounds stupid, but I wonder if the stock DJ100 pads can play a small role in how badly these measured. Probably not, but I always felt there was just something wrong with the stock pads that hurt the sound a bit.
 
Another headphone I feel would get similar results is the Kicker HP541. It's a bass monster and the enclosure is even smaller. 50mm driver in such a tiny cup can't be helping the sound any...
 
EDIT: I was thinking that maybe drilling a couple holes and adding some thin dampening material to the cups would really help. All my closed headphones have some sort of vents for air, but these have ZERO. The KRK KNS-6400 (closed) has four on the left and 5 on the right. I've never figured out why there is only 4 on the left near the plug for the cable. I'm sure KRK has a reason for this. Despite all this, I still love how the DJ100 sounds (especially with M50 pads), so I'm all for making it even better. I bet even adding some cheap foam or something would make these measure somewhat better, but hard to say.
 
BTW won't all small, closed and slightly bass heavy headphones suffer some of the same effects that the DJ100 did? Is there a bass heavy headphone that's just as small that measures better? I'm just kind of curious if many other similar closed headphones would measure the same way. I imagine the larger closed headphones such as the DT-770 would measure much better. You don't have measurements for the M50 do you? It'd be interesting to see the insides of that headphone again.
 
At least now I know all my time spent trying to mod the DJ100 wasn't a total waste...maybe.
 
 

 

[Reticuli2]

You'll have to PM me a link, because I have no clue what other site you're talking about.  You mean there are other sites besides head-fi on these interwebs?!!  heh heh.
 
Not sure why I wouldn't be serious.
 
"We at the FBI don't have a sense of humor that we are aware of."

 

[rhythmdevils]

Purrin, I'd love to see the SRH840 and SRH940 compared this way.  My suspicion from patterns I've noticed on head-fi, and backed up by how similar Tyll's measurements are of the two cans except for different FR, is that the 940 is basically an 840 with more treble and less bass.  It would be interesting to see more measurements because it could be a great example of how simple changes in FR affect the perception of every other quality- speed, accuracy, detail, distortion, etc.  From Tyll's measurements, the 840 actually measures better AFAIK, but the 940 is compared to the HD800... 
 
I think it would be interesting anyways. 

 
 
 

 

[Anaxilus]

Quote:

Purrin, I'd love to see the SRH840 and SRH940 compared this way.  My suspicion from patterns I've noticed on head-fi, and backed up by how similar Tyll's measurements are of the two cans except for different FR, is that the 940 is basically an 840 with more treble and less bass.  It would be interesting to see more measurements because it could be a great example of how simple changes in FR affect the perception of every other quality- speed, accuracy, detail, distortion, etc.  From Tyll's measurements, the 840 actually measures better AFAIK, but the 940 is compared to the HD800... 
 
I think it would be interesting anyways. 

Doesn't surprise me.  Glad I unsubscribed to the newer, pricier, brighter, heavier 840 thread.  Watching the vid of the marketing rep describe the 940 sent chills down my spine.  Brrrr......
 

 

[dw1narso]

Good stuffs, Purrin... One of the most useful thread in Head-Fi, I believe...

Would it be possible for you to measure the multi-order Harmonic Distortions plots as well? (such as this driver )

I thought CSD + knowing which order of harmonic distortion is dominant, would make it much easier to "guess" how a driver (or phone in this case) would sound...

 

[purrin]

Quote:

Good stuffs, Purrin... One of the most useful thread in Head-Fi, I believe...

Would it be possible for you to measure the multi-order Harmonic Distortions plots as well? (such as this driver )

I thought CSD + knowing which order of harmonic distortion is dominant, would make it much easier to "guess" how a driver (or phone in this case) would sound...
 

Yeah, Zaph's got some great data for speaker drivers. I think he's using SoundEasy, which seems cheap enough.
 
I'm a little bit more partial to how Mark K. measures non-linear distortion with 3 tones. See bottom three graphs on this link. I like how Mark indicates the 2nd, 3rd, 4th, etc. HD order. You get to see what lights up in the entire spectrum that way. I like to see the bloody details.
 

 

[JamesMcProgger]

this thread is great.
 
Purrin, any plans to add the AKG K601 and K501? Id also like to see some grado with wood cups. I'd send you those if I lived in the use...

 

[purrin]

I've got some Grado SR80i drivers in wood cups, but haven't soldered wires or glued them on yet. I want to take bare driver measurements of those to gain more insights of the effects of the cups.
 
As for specific requests, I'll measure what I can get my hands on. I've just been borrowing stuff from people I know locally.

 

[dw1narso]

Ah... I got what you mean on Mark K graph....

I always thought that only up to 5th order is useful and beyond that would be very low.... but apparently not so... From your link, The PHL1120 at 150Hz 3 tones, show that higher order distortion could still have bad effect too... this driver should not be let to sing lower than 300Hz :rolleyes:

 

[purrin]

Thanks everyone for the compliments. I didn't know if anyone would really care for these measurements, but I thought I would throw them out anyways. I really wanted to do these a year or two ago, but my priorities back then were on little kids who couldn't walk and talk yet.
 
/rant on
 
So this is what really pushed me over the edge and made me get off my ass:
 

 ME I just heard the <current FOTY> 'phones and thought it was a tizzy in a small spot over <prior FOTY> 'phones. FANBOY Are you sure? I think you are wrong. Fanboy posts the ubiquitous HeadRoom FR graph, which of course "objectively" shows that I am wrong.

 
I get irked at how some people use the HeadRoom FR graphs - as if they were some kind of absolute master authority. They are indeed authoritative (Tyll's gone to great lengths to explain his methodology). But they are only one data point, and only one type of measurement (of three at a minimum which I feel are required to give us a good picture.)
 
/rant off
 
dw1narso's suggestion on measuring non-linear distortion was awesome and a breath of fresh air for me. Finally, someone who gets it!
 
Yes folks, IMO it's actually possible to get a pretty good picture of how something will sound with these three measurements: frequency response, waterfall plots, and non-linear (includes harmonic) distortion. Give any experienced speaker builder those three measurements and the size of the driver, and he will be able to tell you something about how it sounds, even its cone stiffness, surround material, and motor design, etc.
 
My sincere wish that these posts would be educational and informative are coming to fruition, and this makes me happy. I think it's about time that someone else provided data like this, and I hope others will take this on in the future. The more data points the better.
 
 
---------------------------------------------------
 
ANSWERS TO POST 94:
 
#1 HD800
#2 ESP950
#3 HP1000
 

• Which one is the 'stat? #2 Faster decay than the dynamics. The spurious little blue bumps I believe are a characteristic of 'stats I suspect.
• Which one has the most open enclosure? #1 Examine the areas after 1ms and below 2.5k to see the effect of the enclosures. The HD800 enclosure is the most open of them. The HP1000, despite being a Grado, is actually not as open as you would think. There is a big metal button in the way. 
• Which one may have a little bit of hardness or glare? #1 There is a red / orange splotch at 5k that continues on for another 1/2ms after the rest of the spectrum after 7k starts to fall.
• Which one has the most restrictive enclosure? #2 (#3 is close) The ESP950 enclosure with its plastic grill with tiny perforated holes is not very open at all.
• Which one has a lot of stored energy in the treble? #1 To a certain extent #3 has it, but #1 has the treble from 5k to 20k all lit up in red.
• Which one is still one of the fastest dynamics despite being produced in the 80s? #3 I'm amazed how good this headphone still is.

 

[Anaxilus]

Quote:

I've got some Grado SR80i drivers in wood cups, but haven't soldered wires or glued them on yet. I want to take bare driver measurements of those to gain more insights of the effects of the cups.
 
As for specific requests, I'll measure what I can get my hands on. I've just been borrowing stuff from people I know locally.

Ah that's right.  Let's measure your bare sr80 drivers against my bare sr225 drivers and settle that thread for once and all.
 

 

[arnaud]

Reticuli2, here are the CSDs I processed from Tyll's data. Moving forward, he may be posting all the results on Inner Fidelity website. As mentioned by Purrin, we're still working our way through his data acquisition process to make sure the CSD graphs are meaningful.
 
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Looking forward to seeing how clean the LCD-2 actually is in light of our high expectations of it after the low res plot.

 


 
 
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[size=10pt]Anyone got the other big boy, the T1, to send to him? [/size]

 


 
 
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Either we need to get you a Q701 to measure or Tyll an ESP950, or both.  I'm very curious how those two headphones' measurements compare.

 

 

[dw1narso]

dw1narso's suggestion on measuring non-linear distortion...

Glad that I could give input... I really hope that I could learn a lot from this thread... I'm barely understand audio physics and electronics...