posted
I have a idea about the wave forms that have accured on three competitors vechicls all running the same amps,steve , dave ,and james .
Ok here it goes they all run Plnaet Audio amps(which i still think have all the power)and in testing that i have done myself i have seen some waves on o-scopes which would explain this.
These amps have alot of adjustable pots and one of them is the q-factor of the band width, you can go from a narrow to a full band width for the freq. when at a narrow band width the amps will not only purduce more power but also cause some things to play different(i am not saying cheating so dont get that wrong).The people running the amps not only are top notch guys but have a love for the sport.i makes me feel good to have designed both ss 1-2 cars that are the loudest cars but also the group of people they are,(craig you need to stop all you stuff and relax because you will get what you want soon).Dave didnt have a problem in 2nd he has always done the woofer blow since sacramento when he and i both smoked our subs and i pleased the crowd.The crowd never gets to see stuff like that so i showed Dave and he has done it since.
Posts: 228 | From: Your distant future | Registered: Aug 2000
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posted
Hmmm.... so if you boost one frequency, and play another, weird things happen, sounds interesting. I'd love to see what would happen if you boosted say 82 Hz and played 41 Hz, would it show up red? Interesting thoughts.
-------------------- Team Shedluv Team Sweep Team Kicker Team JBL
posted
When you will clip an amp, you will have more than just the frequency you put in. Hm, it´s difficult for me to explain it in english, but u will have nearly ALL frequencies, like pink / white noise...
So its possible to get a wave over 80hz... But then the filter in TermLab is active.
Maybe some "bad waves" can have an influence to the db #´s. When somebody work with it, it´s ok for me. But TermLab saves the waveforms, so u can say, I have XXX dB´s with a correct sine wave. (Better in my opinion)
Üüüühh!!! Michael
-------------------- www.sqpl.de I´m a Kraut,and I want it loud! Üüüühh!!!
quote:Originally posted by Shedluv: Hmmm.... so if you boost one frequency, and play another, weird things happen, sounds interesting. I'd love to see what would happen if you boosted say 82 Hz and played 41 Hz, would it show up red? Interesting thoughts.
I doubt it. First off, playing straight sine waves, term lab doesnt red flag until 85 hz anyways (did some testing of my own). Also, the test tracks on Db jams are purely sinusoidal, meaning that there is no 82 hz frequency component in a 41 hz note.
-------------------- Nate Scholten Team Sounds And Motion SS 1-2 3rd place 2004 finals -THE BUILD- ~Our Drinking Team Has A Stereo Problem~
posted
Term-LAB uses a "detector" and not a filter. In dB Drag Racing mode, the frequency resolution is around 4 Hz. Therefore, when 80 Hz is selected as the detection frequency, the unit will "red flag" somewhere around 82 Hz.
Term-LAB identifies the 4 Hz wide "bin" that has the most energy. If this bin occurs above 80 Hz, then the red flag detector is activated. Think of it like this... In dB Drag Racing mode, imagine a spectrum analyzer where each bar is only 4 Hz wide (as opposed to an octave or 1/3 octave). Term-LAB looks at these "bars" (bins) and identifies which one is "tallest". This is the frequency that Term-LAB uses for high-frequency detection.
As Oki said, when clipping occurs, there can be a large number of harmonics. Harmonics are multiples of the fundamental frequency being played. For example, if you play a 60 Hz tone and you clip your amps, frequency components (typically "odd-order" harmonics) will appear at 180 (3x), 300 (5x), and so on. Each of these harmonics will have a lower amplitude (they won't be as loud) than the original fundamental frequency of 60 Hz.
Term-Lab calculates the RMS sum of ALL bins (bars) below 2500 Hz in dB Drag Racing mode. This is because harmonics are a naturally occurring part of music and should be included when calculating SPL. The loudest (fundamental) frequency being measured must be below 80 Hz or the high frequency detector will be activated.
Pretty cool, huh?
-------------------- "Keep it Loud and Make me Proud!"
quote:Originally posted by BEYOND AUDIO: Very well said Wayne
So technically could the upper harmonics somehow be affecting the results even thoguh the lower harmonics of say 60Hz are louder????
Harmonics do contribute to the overall score, but the contribution is very, very low because the harmonics are typically at least 10 dB "down" from the fundemental. I wouldn't expect you to see more than 0.1 dB or so added to your score because of harmonics.
-------------------- "Keep it Loud and Make me Proud!"
posted
All I know is yes we run the Planet amps, and they are flat out awesome. We used the q-band deal, and narrowed smack on 60 hz, and thats what we played, so? What is it you are trying to say, we B confused.
-------------------- James Borel We are the Noise. We took on the Beast with a 168.5. Team Planet, Home of the Big Bang. 2000 DBRA World Finals Extreme 9+ 5-10k 5th place winner. 2001 DBRA World Finals Extreme 13+ 7th place winner. Highest score to date, 170.9. Posts: 1148 | From: BEREA, KY,USA | Registered: Apr 2000
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posted
Yo Tom u can take credit for helpin me build my $hit ........But you cant manage to get ahold of me??????????? wtf? lol.....anyhow...You got my #.......
P.S. Seen any strokers lately??
-------------------- Team Soundworks 2001 World Record Holders SS 1-2 164.5 db
Posts: 108 | From: Florence, OR US | Registered: May 2001
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quote:Originally posted by DaveGoss: Yo Tom u can take credit for helpin me build my $hit ........But you cant manage to get ahold of me??????????? wtf? lol.....anyhow...You got my #.......
P.S. Seen any strokers lately??
i hear he got so bloody rich off selling the finals losing port, that he bought his own dam island somewhere in the south pacific.
but dave, i hear he has his own website. i think it is www.lying-pos.com
might try him there
Posts: 38 | From: down south | Registered: May 2001
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Harmonics do contribute to the overall score, but the contribution is very, very low because the harmonics are typically at least 10 dB "down" from the fundemental. I wouldn't expect you to see more than 0.1 dB or so added to your score because of harmonics.
Wayne, in recent years when harmonics was used more frequently with the high notes. I have seen vehicles gain up to 10db with a high note compared to a frequency under 80hz. I am wondering if this clipped harmonic signal would have effect the meter in any way.
There is a vehicle that I can not add to the Planet Audio clipped signal, is Danny Britians 170+'s with Crossfire amplifiers.
The only other thing that has come to question is that these mics are more sensitive then mics in the past, maybe after being hammered with 160+db over and over again they began to come apart. I could beleive this since we did have mics that needed resodered back together.
***Team Nutz***Team Force*** 2006 DB Drag Overall Death Match Champions 2006 Db Drag World Finals 2nd Place 2005 Db Drag Street Max Death Match Champions 2005 Db Drag World Finals 3rd Place 2001 Db Drag World Finals 3rd Place 2000 Db Drag World Finals 3rd Place 2000 IASCA Idbl World Finals 3rd Place
Posts: 846 | From: Pittsburgh, PA | Registered: May 2000
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quote:Originally posted by Wayne Harris: Term-LAB identifies the 4 Hz wide "bin" that has the most energy. If this bin occurs above 80 Hz, then the red flag detector is activated. Think of it like this... In dB Drag Racing mode, imagine a spectrum analyzer where each bar is only 4 Hz wide (as opposed to an octave or 1/3 octave). Term-LAB looks at these "bars" (bins) and identifies which one is "tallest". This is the frequency that Term-LAB uses for high-frequency detection.
As Oki said, when clipping occurs, there can be a large number of harmonics. Harmonics are multiples of the fundamental frequency being played. For example, if you play a 60 Hz tone and you clip your amps, frequency components (typically "odd-order" harmonics) will appear at 180 (3x), 300 (5x), and so on. Each of these harmonics will have a lower amplitude (they won't be as loud) than the original fundamental frequency of 60 Hz.
Term-Lab calculates the RMS sum of ALL bins (bars) below 2500 Hz in dB Drag Racing mode. This is because harmonics are a naturally occurring part of music and should be included when calculating SPL. The loudest (fundamental) frequency being measured must be below 80 Hz or the high frequency detector will be activated.
Pretty cool, huh?
So it uses FFT right.? Problem is if each bar or bin is about the same you would gain 3 db if a 2nd bar is just right below the first in amplitude. Then if two more almost the same then and additional 3 db more and so on. I believe the spl part of the of the program should consist in a fixed number of the highest bars only. say between 1 to 3 bars. these would prevent you from calculate the SPL till after the run though so I suggest 1 bar reads only.
-------------------- My 45's want fit in that slot!
Posts: 1147 | From: Rowlett, TX, USA | Registered: Jun 2000
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So it uses FFT right.? Problem is if each bar or bin is about the same you would gain 3 db if a 2nd bar is just right below the first in amplitude. Then if two more almost the same then and additional 3 db more and so on. I believe the spl part of the of the program should consist in a fixed number of the highest bars only. say between 1 to 3 bars. these would prevent you from calculate the SPL till after the run though so I suggest 1 bar reads only.
Not correct. RMS value of 512 bars (1024 samples). Very technical. Sorry I can't go in to more detail.
-------------------- "Keep it Loud and Make me Proud!"
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