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Re: Test report MBP built-in audio device
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Re: Test report MBP built-in audio device

Mikael Hakman wrote:
Brian,
..
The very first chart in my report at http://www.dkab.net/Realtek HDA report.pdf shows you Impulse Response for the actual device. It is entitled Single Pulse Response because this name is easier to understand for people I presume will read that report. The name Impulse Response is used in signal processing. In even more mathematically oriented papers it is often called Transfer Function.

It is correct that for an ideal linear time-invariant system, its Transfer Function tells you all, in mathematical sense that is. This means that given any kind of input and system's transfer function, you can compute system's response (output). This is done by convolution of input and transfer function.

..

I do not disclose all the details because I don't want to. You'll see some of the details in the forthcoming proper paper if you read that kind of press that is. You won't see all the details until there is valid patent in place.


Perhaps you can at least say what the patent is for - some device that eliminates (linearizes?) the, um, distortion, caused by DC and anti-alias filters attached to a codec when fed a signal with short-term aliasing (i.e. with an onset discontinuity)? Or a codec chip that doesn't need them? Either would be remarkable, and should generate a considerable income stream. If only one could do the same for loudspeakers.

Where will you be submitting your paper? I have access to the AES Journal, and also any IEEE publication (via an academic gateway). Anything else I should look out for?

In the meantime, perhaps you would consider copying your original post to comp.dsp, where you will be able to discuss impulse responses, LTI (or not) systems, transfer functions and convolution without compromise. Many industrially-employed dsp professionals are on that list (to say nothing of those who have also authored primary books on dsp), so they fully understand the need for less than full disclosure. They are the sorts of folk who would likely be the peers who would review your paper. I think they may nevertheless be surprised to hear that the Impulse Response is also known as the Transfer Function, and may need some mathematical clarification.

Richard Dobson



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References: 


 >Re: Test report MBP built-in audio device (From: Brian Davies <email@hidden>)


 >Re: Test report MBP built-in audio device (From: "Mikael Hakman" <email@hidden>)


 >Re: Test report MBP built-in audio device (From: "James Chandler Jr" <email@hidden>)


 >Re: Test report MBP built-in audio device (From: "Mikael Hakman" <email@hidden>)


 >Re: Test report MBP built-in audio device (From: Brian Willoughby <email@hidden>)


 >Re: Test report MBP built-in audio device (From: "Mikael Hakman" <email@hidden>)























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