While searching for design information on classD amp, I came across this information hosted on national.com.
Audio Fundamentals Course 5 - All About Class D Audio Amplifiers
In the link they have given equation for solve the values for L & C for the given RL.
I have put them on mathcad sheet. There if found discrepancy in results.
The equation they have mentioned for finding L & C don't get the same frequency when verified using the mentioned equation.
wondering whats going wrong.
Attached the pdf of mathcad results.
Audio Fundamentals Course 5 - All About Class D Audio Amplifiers
In the link they have given equation for solve the values for L & C for the given RL.
I have put them on mathcad sheet. There if found discrepancy in results.
The equation they have mentioned for finding L & C don't get the same frequency when verified using the mentioned equation.
wondering whats going wrong.
Attached the pdf of mathcad results.
thanks JinGeo,
I tried as you said, I could equations matches. now the Q changes to 1. where as it was 0.8 prior. which generates hump. ( i simulated it using the values.)
on the national site they say Q should be 0.707.
I tried as you said, I could equations matches. now the Q changes to 1. where as it was 0.8 prior. which generates hump. ( i simulated it using the values.)
on the national site they say Q should be 0.707.
I am still seeing lot of confusion. 🙁
got another site ,http://www.eetimes.com/design/audio-design/4015847/Understanding-output-filters-for-Class-D-amplifiers
THe equation seems ok here. even with Q calcualtions.
But the simulation of graph do not agree with this. it shows small bump. so the Q must be more than 0.707
got another site ,http://www.eetimes.com/design/audio-design/4015847/Understanding-output-filters-for-Class-D-amplifiers
THe equation seems ok here. even with Q calcualtions.
But the simulation of graph do not agree with this. it shows small bump. so the Q must be more than 0.707
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Let me ask you a question.
Most driver impedance curves rise pretty much in the higher audible frequency areas.
Why is this not considred in those formulas???
Most driver impedance curves rise pretty much in the higher audible frequency areas.
Why is this not considred in those formulas???
Sound check, I agree with you.
Each speaker must have zobal network connected to each driver. and so calculated. Speaker Zobel / Impedance Equalization Network Circuit Calculator
Each speaker must have zobal network connected to each driver. and so calculated. Speaker Zobel / Impedance Equalization Network Circuit Calculator
Most of the Class-D output stages come with Zobels on the output.
These obviously won't be "One Size Fits All" configurations.
I'm wondering how you'd match that Zobel with a complex impedance ( multi ways + crossover )
How exact does it has to be?
These obviously won't be "One Size Fits All" configurations.
I'm wondering how you'd match that Zobel with a complex impedance ( multi ways + crossover )
How exact does it has to be?
...probably it requires a Zobel in front of each driver, similar as it's done with Tube amps
...best would be to run active setups with perfect amp/driver alignment
and no crossover in between
...then. What's actually in for us if we'd put that much effort into such a project?? Do we really gain that much?
...best would be to run active setups with perfect amp/driver alignment
and no crossover in between
...then. What's actually in for us if we'd put that much effort into such a project?? Do we really gain that much?
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