kulamario wrote:
I know this MX50 amplifier because I have this set myself
and he really does not have much bass
In this amplifier the top is more exposed and the bottom is not too much
Generally, this amplifier is not the best design
I don't have the schematic, but it's hard to believe there is anything in power amp circuit that limit the low frequency. They usually are flat frequency response within the audio frequency.
I have been designing power amps for a few years, I just discover how critical the grounding is. The same amp I designed got so much better bottom by improving the grounding and lower the isolation resistor as described in the article. If you build your amp, you might want to check that also. Take a look starting at page 7 of this article:
http://hifisonix.com/wordpress/wp-content/uploads/2018/07/Amplifier-PCB-Design-Guidlines-for-Minimizing-Hum-1-1.pdfPeople usually think grounding is just to eliminate hum, but there's a lot more to it. The article talk about ground loop emitting EMI that couple to the other part of the circuit, I feel it's more than that. Ground current cause slight potential change on the ground even if you have ground plane on the pcb or using big wires. I have been working on this very thing for the last two months, the improvement of the bottom is staggering without changing any other part of the circuit EXCEPT the HRB ( hum break resistor) from 22ohm to 1ohm. This resistor is very effective to reduce hum, BUT it will cause the bottom to be very weak.
I don't want to get into detail as I am still experimenting and looking at the theory, but this is where I am at.
Yes, MX50 is a cheap circuit, don't expect too much, but from my experience, there should be room for improvement without spending a lot of money.