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Your frequency response is dropping above only 6.5kHz.
Maybe your simulator software does not know how poor is a 52 years old 741 opamp and how low will be the output power from your amplifier.
10W into 4 ohms is 2.25A peak. The weak opamp and minimum spec'd transistors might produce only 150mA peak which is only 0.045W.
You need a half-decent modern audio opamp and power darlingtons or Sziklai pair transistors.
Here is your frequency response simulation spread out vertically so we can see its level dropping above 6.5kHz:
looks like you have plenty of phase margin, reduce your compensation cap size... a schematic would help, but it does look like overkill on the compensation cap.
and you don't have to go from DC to daylight on the AC sweep... 10hz-1Mhz is enough it will get you better scaling on both axes also, kep the phase margin scale in the picture too, it is important.