UCD amp Bass lose

[Dzony988]

Hi guys

I have one problem that I don know to explain..

I have homemade UCD D class amp with IR2110 and LM311, both chanels is the same.. One transformer and PSU for both chanles, same GND on outputs....

First I thought that half bridge has low bass and when I connect in full bridge bass is great.. Then I realise that half bridge is not a problem, because when I connect first group of speakers (2 x 15" 8R in parallel) on first chanel bass is also great, but when I connect second group of speakers (same like first group) on second chanel, bass is very low on both chanels.. Bass simply disappear on both chanles..

When I disconnect any gropu of speakres from any chanel, bass returns on other chanel who is still connected and playing the music..

Wher is the problem? Is this normal for half bridge amps or what?
Thanks

 

[JonSnell Electronic]

Are the speakers in or out of phase?

 

[Dzony988]

All speakers are in phase..

 

[Dzony988]

Everything is ok when I revers phase on on grup of speakres...

huh, this is creazy 😀

 

[stewin]

what about your power supply capacitor bank? are the caps o.k?

 

[phase_accurate]

Do you have symmetrical inputs and did you maybe cross the input wires of one channel ? Did you even do that for achieving the full-bridge topology ?

What happens to you is defitely an inverted pahse case.

Regards

Charles