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|24th March 2011, 10:50 AM||#51|
Join Date: Dec 2004
Ok, PCBs arrived.
- LM317/337 are swapped. Their 2 and 3 pins should be switched prior to mounting. What a silly mistake
- PSU input is buried in PS caps - pretty hard to get there after you put all the components.
- Not enough space for regulator heatsinks (i knew it). Could be fixed by squeezing the regulators inwards (there is enough space for this).
- Mounting holes require tiny screws (standart M3 screw but with small (conical) head).
s3t.it> Active crossover: AXO3
|5th April 2011, 10:34 PM||#52|
Join Date: Dec 2004
Little bit of updates to software:
Control points are draggable, and the graph is recalculated in real time while you drag the point. You get smooth frequency response manipulation.
Q for notches is changed by right-click-dragging of notch control point.
- Added phase plot to frequency response graph - looks better now. It's color is yet to be changed to something less aggressive than red.
In the future i'll add biquad parameters generator, so you could use this program for DSPs too.
Adding enclosure/port simulator would be nice, as well as baffle (edge-like).
Frequency response import is a must.
Last edited by s3tup; 5th April 2011 at 10:43 PM.
|5th October 2011, 03:27 PM||#53|
Join Date: Dec 2004
I have resurrected the filter designer project, with some updates from last week:
- Now i am able to plot frequency/phase responses of digital biquads
- I have made a GUI for chaining filter blocks into signal paths:
Implemented FFT (FFTW3-based) with various window functions and smoothing (currently works with WAV files and built-in noise generators):
- White/pink noise generators.
- WAVe file read
- No sound input/output
- No biquads calculator from actual transfer functions - probably, i'll need to do the math myself/grab it from books/internet.
- No solid synched envirement
1. Take analog transfer functions (filters)
2. Chain them in the blocks-designer
3. Modify their parameters with control points on the graph
4. Generate digital biquad coefficients for the actual transfer functions
5. Apply the biquads/signal path to some DSP software core (in the program, or external plugin for foobar)
6. Play white noise/impulse/whatsoever thru these digital filters, and measure response of resulting speaker+filter combination with microphone
7. Display the measured response on the graph, where you have control points from step 3.
8. Repeat it.
The idea behind this is to keep everything "realtime", i.e. when you move the control point, it changes biquad coefficients, and the playing music passes thru these coefficients - and you hear what you are doing in real time (as well as measure it with built-in functions generator/FFT).
When you settle on particular filter configuration, you "build" it for following targets:
- Analog board from this thread (or any other)
- TAS3108 DSP board (to be designed)
- Software Foobar 2000 plugin (to be designed) (maybe winamp too)
- Other platforms - as biquads list (or any other way, need to reverse-engineer the particular applications).
All this i'd like to put in Microsoft Visual Studio-styled environment (MDI).
Kinda WYSIWYG editor for filters
Wavelets, CSD et cetera would be nice, but the features listed abowe should be implemented first.
- Frequency response import.
- "Box" control point, for modelling speaker boxes
- "Real Bafflestep" control point for baffle diffraction simulation (where could i find the math equations/theory for this?)
Last edited by s3tup; 5th October 2011 at 03:34 PM.
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