Sound - Сообщения
#1 Опубликовано: 10.04.2018 11:40:58
I think I need a program loop to get the graph to show up correctly. Suggestions?
Quick Sound Loss.smz (132 КиБ) скачан 63 раз(а).
Quick Sound Loss.smz (132 КиБ) скачан 63 раз(а).
#2 Опубликовано: 10.04.2018 11:56:29
WroteI think I need a program loop to get the graph to show up correctly.Suggestions?
"Why does log10 look different ?"
because you have two different formulas, thus two different results
#3 Опубликовано: 10.04.2018 12:39:19
Jean,
The second equation is off/not evaluated. Graphically log to base x and log10 display differently. Question is about graph though
The second equation is off/not evaluated. Graphically log to base x and log10 display differently. Question is about graph though
#4 Опубликовано: 10.04.2018 14:31:49
Strict math seems correct to me; let's compare the values for different directivity factors at ssame distance.
we have:
to simplify things we can get rid of the absolute value; in your example all numbers are above 1, plus logarithms' arguments are <= 8 in numerator and >= 12 in denominator (4*pi*distance_greater_than_1), thus:
at same distance, log10(f(x)) is the same for every directivity factor Q
Lw(Q,1.5) loses -3dB when you double Q, but at the same time the absolute value term adds +3B -> so why values are so close (and functions overlapped in the plot)
In fact, if you go further, you can do the same for Lw:
and decimal shown in the workshet are only because different decimal places shown in the results
we have:
log(a/b)=log(a)-log(b)
|10*log10(a/b)| = 10*(log10(b)-log10(a)) = 10*(log10(f(x))-log10(Q)) = 10*log10(f(x))-10*log10(Q)
10*log10(f(x))-10*log10(Q) = const-10*log10(Q)
10*log10(2)=3, 10*log10(4)=6, 10*log10(8)=9 (approx)
Lp(Q,x)=Lw(Q,1.5)-|10*log10(a/b)|=Lw(Q,1.5)-const+10*log10(Q)
In fact, if you go further, you can do the same for Lw:
Lw(Q,dist) = Ltot+|10*log10(Q/f(dist))| = Ltot+10*log10(f(dist))-10*log10(Q) = const2-10*log10(Q)
Lp(Q,x) = Lw(Q,1.5)-const1+10*log10(Q) = const2-10*log10(Q)-const1+10*log10(Q) = const2-const1 = constant
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#5 Опубликовано: 10.04.2018 14:50:48
What might be wrong...
You have sound pressure measured by the vendor -> You have to calculate the power level for the distance and directivity condition of the vendor
Then you have the sound power level of your source... it's a constant! Use this value to estimate the sound power at various distances for various directivity conditions!

Quick Sound Loss - rev.1.sm (134 КиБ) скачан 58 раз(а).
You have sound pressure measured by the vendor -> You have to calculate the power level for the distance and directivity condition of the vendor
Then you have the sound power level of your source... it's a constant! Use this value to estimate the sound power at various distances for various directivity conditions!
Quick Sound Loss - rev.1.sm (134 КиБ) скачан 58 раз(а).
If you like my plugins please consider to support the program buying a license; for personal contributions to me: paypal.me/dcprojects
#6 Опубликовано: 10.04.2018 15:19:57
Davide,
I did the same thing, where I assumed directivity is b=2 on Lw. I'll just document that and move on as the rest of the math appears to work out
I did the same thing, where I assumed directivity is b=2 on Lw. I'll just document that and move on as the rest of the math appears to work out
#7 Опубликовано: 10.04.2018 16:42:50
WroteJean,
The second equation is off/not evaluated.Graphically log to base x and log10 display differently.Question is about graph though
Few more things you can do as real project.
Line style "splines" is a bit smoother in the low region.
Quick Sound Loss - rev.2.sm (134 КиБ) скачан 53 раз(а).
#8 Опубликовано: 10.04.2018 17:41:23
Funny ...
OK, here I am as I had done most of the items that Davide and Jean added. Now I would like to add a "dot" or a vertical line where the dB.final is. Please use this sheet
Quick Sound Loss.smz (135 КиБ) скачан 57 раз(а).
Jean, I did not see where you used a spline
All should I be using "cinterp" to place the "dot?
OK, here I am as I had done most of the items that Davide and Jean added. Now I would like to add a "dot" or a vertical line where the dB.final is. Please use this sheet
Quick Sound Loss.smz (135 КиБ) скачан 57 раз(а).
Jean, I did not see where you used a spline
All should I be using "cinterp" to place the "dot?
#9 Опубликовано: 10.04.2018 19:30:35
#10 Опубликовано: 10.04.2018 19:43:06
WroteJean, I did not see where you used a spline
All should I be using "cinterp" to place the "dot?
1. spline is for line style ... line/spline.
2. what that gyzma #,#,#,,,does in maths ?
3. X_Y plot does not support " in your plot suggestion
4. X_Y is for final/final/final ... project
once done, if you rework something above=> it will freak the plot
X_Y plot has slightly pregnant memory. Doctored in red .
Quick Sound Loss (3).sm (140 КиБ) скачан 63 раз(а).
#11 Опубликовано: 10.04.2018 20:45:59
#12 Опубликовано: 10.04.2018 21:18:04
#13 Опубликовано: 10.04.2018 22:38:04
#14 Опубликовано: 11.04.2018 09:58:39
WroteFew more things you can do as real project.
Thanks Elsid,
Nice project, saved for myself, you can have it as is.
Jean
Inst_dB Sound.sm (142 КиБ) скачан 53 раз(а).
#15 Опубликовано: 13.04.2018 02:23:09
Well, Here we go again ...
I found a quirk. Depending on values dB initial values, neither solve nor FindRoot is functional. I was plugging in values by hand without seeing an issue. I tried a "higher" dB set of values (86 vs 75) for equipment and the calculation *zap*
Quick Sound Loss.smz (168 КиБ) скачан 55 раз(а).
Also, the X-Y plot legend information *ZAP*
I found a quirk. Depending on values dB initial values, neither solve nor FindRoot is functional. I was plugging in values by hand without seeing an issue. I tried a "higher" dB set of values (86 vs 75) for equipment and the calculation *zap*
Quick Sound Loss.smz (168 КиБ) скачан 55 раз(а).
Also, the X-Y plot legend information *ZAP*
#16 Опубликовано: 13.04.2018 08:55:34
WroteWell, Here we go again ...
I found a quirk.Depending on values dB initial values, neither solve nor FindRoot is functional.I was plugging in values by hand without seeing an issue.I tried a "higher" dB set of values (86 vs 75) for equipment and the calculation *zap*
That one was Doctored and you don't use the Doctored version.
Explained before, if above X_Y something is Doctored, zap.
Quick Sound Loss (4) Doctored 20180413.sm (167 КиБ) скачан 56 раз(а).
#17 Опубликовано: 13.04.2018 10:33:23
Found the issue(s). See revamped file. Still having issues in that X-Y plot Labels for the legend *zap*Quick Sound Loss.smz (142 КиБ) скачан 92 раз(а).
Edit: Two bugs
There is additional documentation and function definition updates. Sanity check the graph x scale (adjusted for feet since I'm in the US). Should be good now
Edit: Two bugs
- X-Y Plot. If functions crash, *Zap* to the legend titles. All other titles OK. Legend is empty due to laziness after last 5 crashes
- solve(4) did not like trying to cancel units in the denominator of the final function (#dist). As I was adding units to x:0-100 FT and dividing the units meters in the function, the function crashed in the solve block (Just the function, with all values plugged in except for x = vector, so it's a solve(4) issue).
There is additional documentation and function definition updates. Sanity check the graph x scale (adjusted for feet since I'm in the US). Should be good now
#18 Опубликовано: 13.04.2018 11:38:07
WroteFound the issue.I'll post revamp file.Still having issues in that X-Y plot Labels for the legend *zap*
Clik on "list", edit "series name".
#19 Опубликовано: 25.01.2021 20:16:25
Revisiting this old calc with SMath newer features and some function definitions.
Sound Loss (Quick).sm (476 КиБ) скачан 38 раз(а).
Thanks for the help.
- No longer works if I redefine the logarithmic sum with vectorize
- I cannot get the "heat capacity function" to work for ploting
Sound Loss (Quick).sm (476 КиБ) скачан 38 раз(а).
Thanks for the help.
#20 Опубликовано: 25.01.2021 21:34:45
Hi. Some notes, but I'm not sure if this solve all of the issues:
1. Use count inside rangeindividual, but not outside. You use it in f(x, b ), and guess that could be problematic.
2. After that, you divide x by 'm in f and x by feet in rangeindividual, choose only one.
3. Maybe here don't affect, but if rangeindividual have not f(#,#) as parameter, define f before rangeindividual, you know, just in case.

Best regards.
Alvaro.
1. Use count inside rangeindividual, but not outside. You use it in f(x, b ), and guess that could be problematic.
2. After that, you divide x by 'm in f and x by feet in rangeindividual, choose only one.
3. Maybe here don't affect, but if rangeindividual have not f(#,#) as parameter, define f before rangeindividual, you know, just in case.
Best regards.
Alvaro.
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ElSid 25.01.2021 21:53:00
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