CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS

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Author Topic: Different Stuff  (Read 8063 times)

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arnaud

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Re: Different Stuff
« Reply #30 on: August 26, 2012, 08:14:24 AM »
Sure captain!

Let me give it a shot tonight with say, the 009 (it'd be nice to explain the 300Hz SW response...). I'll check how much the raw impulse response deviates from minimum phase at the same time since this has been puzzling me for a while (what a strange hobby indeed)...
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electropop

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Re: Different Stuff
« Reply #31 on: August 30, 2012, 02:58:22 PM »
Hoy! What do the D'x' values in harmonic distortion measurements represent exactly? Steps in fed signal as in different orders?
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Marvey

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Re: Different Stuff
« Reply #32 on: August 30, 2012, 03:02:25 PM »
D2 = 2nd harmonic
D3 = 3rd harmonic
D4 = 4th harmonic
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electropop

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Re: Different Stuff
« Reply #33 on: August 30, 2012, 06:18:21 PM »
... Thanks :)

Without sounding more stupid, where I can read more into this?

I understand this kind of measurement: http://www.head-fi.org/t/595683/fostex-th900-impressions-discussion-thread/1350#post_8550368

How do the harmonics compare to this?

Since the whole frequency range is covered, does it mean that you use four different signals to excite the driver?

Edit: Nevermind. Found this thread: http://www.changstar.com/index.php/topic,370.0.html

Thanks!
« Last Edit: August 30, 2012, 08:55:30 PM by electropop »
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arnaud

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Re: Different Stuff
« Reply #34 on: September 07, 2012, 03:44:23 PM »
Edit: updated links

So, I went through with the idea to remove the measuring head/torso effect from all of Tyll's data (i.e. not just the FRF magnitude but also impulse and square wave responses) using minimum phase inverse filter of the Diffuse Field and Independent of Direction HRTFs.

It seems it went somewhere after all... From what I can see, the SR009 seems to have been designed to follow DF target curves. Furthermore, once you remove the head effect from the impulse and square wave responses, you end up with much more reasonable looking results. For instance, the overshoot in the 300Hz SW response is no longer present after equalizing out DF response curve of the measuring head...

And now some pictures, because we like pretty pictures on this site  :)p1 :)p1 :)p1:








« Last Edit: September 08, 2012, 12:16:07 AM by arnaud »
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Marvey

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Re: Different Stuff
« Reply #35 on: September 07, 2012, 04:15:05 PM »
I like it.
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ujamerstand

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Re: Different Stuff
« Reply #36 on: September 07, 2012, 05:42:17 PM »
YES. This is exactly what I've been waiting for. Did you construct the inverse filters from Tyll's Diffuse Field Equalization Curve and ID Field Equalization Curve?
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ultrabike

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Re: Different Stuff
« Reply #37 on: September 07, 2012, 05:51:04 PM »
Very nice!
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gurubhai

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Re: Different Stuff
« Reply #38 on: September 07, 2012, 05:56:48 PM »
Great stuff, Arnaud!
Would love to see graphs of more headphones if possible.
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Tyll Hertsens

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Re: Different Stuff
« Reply #39 on: September 07, 2012, 09:11:24 PM »
Great stuff Arnaud.

I'm wondering if we could work backwards to get a better HRTF compensation.  For example, let's just assume the HD800 is perfect. Then use it's raw data to create an HRTF. Then have a look at it's square waves to see how clean they are.  Thank run a, let's say, LCD3 through that HRTF and see how it comes out. 

Maybe it's possible to take three or four headphones we think are very, very good; make an average of their raw FR; then create an HRTF from that. I don't know...I'd really like to have something better than the stock ID or DF HRTF, but I really don't know how to get there.
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Cheers,

Tyll (like on the floor only spelled different)
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