Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › Headphone CSD waterfall plots
New Posts  All Forums:Forum Nav:

Headphone CSD waterfall plots - Page 61

post #901 of 937
Quote:
Originally Posted by ultrabike View Post

Very nice work stv014. Have you considered using valarrays? IME they are faster and have certain arithmetic features that make them more appealing than vectors in certain situations. It's much easier to dynamically grow vectors though.

 

One easy way to improve performance would be to replace my FFT code with the Ooura FFT library, which is also used in SoX, for example. It is about 1.5 times faster. Also, in the resample utility (which is currently about 1.8 times slower than the sox "rate" effect at similar settings), there are some possible changes for additional speedup: the FIR lowpass filter for integer power of two resample ratios could take advantage of the fact that there are zero samples in the input (upsample), or samples of the output will be discarded (downsample). Additionally, the interpolation could use a pre-calculated lookup table for simple rational resample ratios, rather than calculating the sinc function and window directly, as long as the memory requirement of the table is reasonably small.

post #902 of 937

That sounds kool. For FFTs I usually go for FFTW libraries. Dunno how they compare to the Ooura library though.

post #903 of 937

FFTW is even faster, but is more difficult to replace the original code with, and it also has a GPL license.


Edited by stv014 - 3/22/13 at 7:30am
post #904 of 937

Sorry to bump this thread for such an old headphone.  Are there any CSD plots for the JVC DX1000?

post #905 of 937
Quote:
Originally Posted by preproman View Post

Sorry to bump this thread for such an old headphone.  Are there any CSD plots for the JVC DX1000?


Haven't seen any yet, but here is the FR...

post #906 of 937

http://www.geocities.jp/ryumatsuba/hp-dx1000.html

 

Though I've heard grumblings about the reliability of the measurements on that site. Check out some of their other measurements to get a feel.

post #907 of 937

Thanks guys

 

beerchug.gif

post #908 of 937

(Yamaha HP-50S, modded.)

 

Worth keeping in mind that in the '70s Yamaha handed these out for free with their line of electronic organs. The phones' main contribution as stated on the box was to enable one to play the organ at night without being a nuisance to others.


Edited by vid - 4/8/13 at 5:25pm
post #909 of 937

I am not sure if this has already been discussed, but it looks like AKG significantly improved on their K550 with the newer K551 - the latter seems to have a more neutral frequency response and a much faster decay. Here are the measurements for K550 and here's K551. The newer model measures so well according to that site, that I am really tempted to buy myself a pair.

post #910 of 937
Quote:
Originally Posted by Pianist View Post

I am not sure if this has already been discussed, but it looks like AKG significantly improved on their K550 with the newer K551 - the latter seems to have a more neutral frequency response and a much faster decay. Here are the measurements for K550 and here's K551. The newer model measures so well according to that site, that I am really tempted to buy myself a pair.

 

Looks like they improved on it a bit, and at the same time it looks like it rings in the treble much the same as before. (Though not to say I don't appreciate AKG putting actual effort into an xx1 model rather than just renaming the old one as before.)

 

Mind you, I don't know why Golden Ears use massive 1/3 octave smoothing on their CSD.


Edited by vid - 4/8/13 at 5:25pm
post #911 of 937
Quote:
Originally Posted by vid View Post

 

Looks like they improved on it a bit, and at the same time it looks like it rings in the treble much the same as before. (Though not to say I don't appreciate AKG putting actual effort into an xx1 model rather than just renaming the old one as before.)

 

Mind you, I don't know why Golden Ears use massive 1/3 octave smoothing on their CSD. Below is how the HP-50 measurement I just did would look like with 1/3 octave smoothing.

 

 

Not very useful, eh.

I think we can all guess why. Reduced smoothing shows a lot more information, likely a bit too much (for them).

post #912 of 937
Thread Starter 

1/3 octave resolution is about as much we can make out with music. The application of 1/3 octave smoothing is appropriate for frequency response graphs - and for practical application of GED or PEQ.

 

For CSDs where the intent is to locate resonances (seen as ridges), I prefer to use no smoothing or maybe at most 1/9 octave. I feel it's important to see the nature of the ridges without smoothing because there is a difference in how they correspond to what we hear. Also, as you have demonstrated, some of the minor resonances tend to disappear into thin air.


Edited by purrin - 3/27/13 at 1:09pm
post #913 of 937

Maybe I don't know how to interpret the graphs properly, but K551 frequency response and csd look better to me than those of HD800 from the same website. Of course, HD800 has a better driver...

post #914 of 937

 

 

More Unipolar fun. Raw graph, so the ~3 kHz peak doesn't belong. The others do, unfortunately.

 

The other channel rings a lot less thanks to modding, but this channel seems to resist.


Edited by vid - 4/8/13 at 5:25pm
post #915 of 937

AKG K 260 as a Philips rebadge. Posted a measurement of this in 2d six months back, though I think it's worth seeing in 3d HD.


Edited by vid - 4/8/13 at 5:24pm
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphones (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › Headphone CSD waterfall plots