Amplitude Sweep?, the equation for generating amplitude sweep |
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Amplitude Sweep?, the equation for generating amplitude sweep |
 Mar 19 2012, 07:45
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#1
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Group: Members Posts: 17 Joined: 2-December 11 From: bangalore Member No.: 95532  |
hello guys,
I am trying to generate Amplitude Sweep Signal, at a given constant frequency with the following equation CODE X(n) = 10^{(start_amp + Delta.k.t)/20} * Sin(2.pi.f .t) * (1<<24) but i am not getting exact Amplitude sweep signal, can any one know whats wrong with above formula.... If there exist a better way of generating Amplitude sweep signal with a specific formula, please explain Thanks in Advance.... |
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Mar 19 2012, 21:26
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#2
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 Group: Members Posts: 581 Joined: 17-August 09 Member No.: 72373 |
Looks like you're on the right track. What are you using for start_amp, Delta and k? What's going wrong?
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Mar 20 2012, 05:28
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#3
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Group: Members Posts: 17 Joined: 2-December 11 From: bangalore Member No.: 95532 |
QUOTE (Notat @ Mar 20 2012, 01:56)  Looks like you're on the right track. What are you using for start_amp, Delta and k? What's going wrong? According to the test stream start_amp = -120 stop_amp = 0 duration of sweep = 30 sec Delta.k = (stop_amp - start_amp)/duration of sweep = 120/30 = 4 sampling rate = 48000 and yes bro, i am almost there, but my problem is up-to 2 digits of decimal part the amplitude values are matching with reference and after that they are differing and some( 2 or 3) values in decimal part are entirely differing. Any thoughts ? This post has been edited by ksr: Mar 20 2012, 05:49 |
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Mar 20 2012, 14:40
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#4
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 Group: Members Posts: 3221 Joined: 29-October 08 From: USA, 48236 Member No.: 61311 |
QUOTE (ksr @ Mar 19 2012, 02:45) hello guys, I am trying to generate Amplitude Sweep Signal, at a given constant frequency with the following equation CODE X(n) = 10^{(start_amp + Delta.k.t)/20} * Sin(2.pi.f .t) * (1<<24) but i am not getting exact Amplitude sweep signal, can any one know whats wrong with above formula.... If there exist a better way of generating Amplitude sweep signal with a specific formula, please explain Thanks in Advance.... You might be expecting too much. The highest amplitude sample points on the waveform of a sweep naturally jump up and down because the sampling frequency does not always line up with the frequency of the generated wave at most points. |
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Mar 21 2012, 05:06
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#5
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Group: Members Posts: 17 Joined: 2-December 11 From: bangalore Member No.: 95532 |
QUOTE (Arnold B. Krueger @ Mar 20 2012, 19:10) QUOTE (ksr @ Mar 19 2012, 02:45) hello guys, I am trying to generate Amplitude Sweep Signal, at a given constant frequency with the following equation CODE X(n) = 10^{(start_amp + Delta.k.t)/20} * Sin(2.pi.f .t) * (1<<24) but i am not getting exact Amplitude sweep signal, can any one know whats wrong with above formula.... If there exist a better way of generating Amplitude sweep signal with a specific formula, please explain Thanks in Advance.... You might be expecting too much. The highest amplitude sample points on the waveform of a sweep naturally jump up and down because the sampling frequency does not always line up with the frequency of the generated wave at most points. Thanks bro...can you explain in detail the above concept ???? |
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Lo-Fi Version | Time is now: 20th June 2013 - 06:45 |
