2024-11-01 11:16 AM
Hello everyone.
Regarding an amplifier with two TDA7294 in bridge configuration, looking at the diagram, on IC 1 at pin 3, there is a high pass filter formed by the 0.56uF capacitor C1 and the 22K Ohm resistor. The cutoff frequency is 12,91 Hz.
I would like to get closer to 0 Hz by increasing the capacitance of C1 to 22uF (cutoff frequency is 0,32 Hz).
If you see IC 2, at pin 3 there is another filter formed by C2 (0.56uF) and the 22K resistor.
For symmetry with the first IC, should I also increase the capacitance of C2 to 22uF in your opinion?
Or leave it at 0.56uF?
I thank you very much in advance for your kind reply.
Cheers,
Enrico
2024-11-09 11:34 PM - edited 2024-11-09 11:35 PM
No , Enrico, i am no musician.
I just was building audio stuff 40 years ago, that time also some big expo-horn constructions for disco and live PA .
Later then was my focus on power amp design for many years, also at university , on every free time reading all the JAES stuff .
Later then more Hi-End ....and then industrial electronics.
About the La Scala II : (i dont have them) but from (private) reviews :
What's missing: Real deep bass.
So dont think, you will improve anything, by lowering the input filter cutoff (-1dB / 20Hz , with the 0,56uF /22k).
see La Scala response (typical for a horn speaker):
So at 30 or 20 Hz this speaker producing no sound pressure and its totally waste of energy, to give more subsonic sound to these speakers.
IF you want to gain the bass, add some gain in the 60..120Hz range; THIS you will hear and it will make the speaker sounding more "big" and fat/impressive.
With a horn speaker , giving more subsonics to the speaker, you will in best case (!) change nothing on the sound, usually it will sound more bad or "thin" .