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#18011 - 20/09/2000 14:20 Re: EQ Question/Feature Enhancement [Re: eternalsun]
rob
carpal tunnel

Registered: 21/05/1999
Posts: 5335
Loc: Cambridge UK
The parametric EQ is an audiophile function, and right now it performs as advertised. I would be nervous about advertising a 20 band EQ which in fact is only an approximation of the expected function - audiophile types are very scathing about that sort of thing.

Anyway, it's a lot of mathematics and work for something with rather limited commercial and functional gain. I don't think we'll be pulling John away from RDS for this one.

Rob



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#18012 - 20/09/2000 14:28 Re: EQ Question/Feature Enhancement [Re: eternalsun]
tanstaafl.
carpal tunnel

Registered: 08/07/1999
Posts: 5549
Loc: Ajijic, Mexico
you'd then have to install the empeg upside down and that would be unacceptable.

Unacceptable? No, it would be great! We would have the volume control on the left where it should be, and the problem some of us have with not being able to read the first few letters of the info display would be solved as well.

I think you're on to something here, Calvin!

tanstaafl.



"There Ain't No Such Thing As A Free Lunch"
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"There Ain't No Such Thing As A Free Lunch"

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#18013 - 20/09/2000 14:51 Re: EQ Question/Feature Enhancement [Re: rob]
eternalsun
Pooh-Bah

Registered: 09/09/1999
Posts: 1721
Loc: San Jose, CA
I agree, but I just had to point out that it is possible. The math will kill you though.

Calvin


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#18014 - 20/09/2000 14:52 Re: EQ Question/Feature Enhancement [Re: tanstaafl.]
Jazzwire
addict

Registered: 09/06/1999
Posts: 483
Loc: Guernsey
Don't forget there is a kernel switch to flip the display upside down... =)

Jazz
(List 112, Mk2 12 gig #40. Mk1 4 gig #30. Mk3 1.6 16v)
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Jazz (List 112, Mk2 42 gig #40. Mk1 4 gig #30. Mk3 1.6 16v)

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#18015 - 20/09/2000 15:28 Re: EQ Question/Feature Enhancement [Re: Jazzwire]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
Don't forget there is a kernel switch to flip the display upside down... =)

Definitely the result of OEM work creeping into the Empeg-Car's source code. Interesting.

___________
Tony Fabris
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Tony Fabris

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#18016 - 20/09/2000 17:28 Re: EQ Question/Feature Enhancement [Re: eternalsun]
n6mod
enthusiast

Registered: 27/09/1999
Posts: 200
Loc: Berkeley, CA
The real problem with rotating the DSP 90 degrees is that it will start sending imaginary numbers to the DAC.



-Zandr
Mk.I #150
Mk.II #39
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-Zandr
Mk.IIa #010101243 currently getting a 500GB SSD. More spares in the shed.

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#18017 - 21/09/2000 03:58 Re: EQ Question/Feature Enhancement [Re: eternalsun]
bonzi
pooh-bah

Registered: 13/09/1999
Posts: 2401
Loc: Croatia
I agree, but I just had to point out that it is possible. The math will kill you though.

Well, I survived it (and forgotten - it was 15 years ago)... Let's see, it's 15 degrees of freedom nonlinear fit with just 20 data points. Doable, but slow and requiring good initial guess for parameters.

However, plotting the resulting curve with known frequencies (centroids), Q's (deviations) and gains (amplitudes) should be straightforward, so it should not be too difficult to show approximate shape of the envelope.

All this, of course, assuming we are talking about Gaussians added/substracted to constant response curve (or at least something else easily describable analytically). Needless to say, knowing nothing about DSPs, I don't have a foggiest idea whether they really produce something like this, or something much wildler.

BTW, didn't we already discuss this (graphical feedback was one of my wishes), and somebody said that not enough documentation on DSP algorithms is there to model response function with any accuracy?

Cheers!

Dragi "Bonzi" Raos
Zagreb, Croatia
Q#5196, MkII#80000376, 18GB green
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Dragi "Bonzi" Raos Q#5196 MkII #080000376, 18GB green MkIIa #040103247, 60GB blue

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#18018 - 21/09/2000 14:04 Re: EQ Question/Feature Enhancement [Re: n6mod]
eternalsun
Pooh-Bah

Registered: 09/09/1999
Posts: 1721
Loc: San Jose, CA
You're right, and with all the imaginary numbers coming out, it would kill the CPU to convert them back to reals since the CPU is only operating in integer mode. ;)

Calvin


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