[quote author="Family Hoof"]but if you have power sag because of small cap value the first thing to suffer is low frequencies (bass) because (assuming full-bandwidth program material) they are usually loudest and thus require most power. Am I making any sense here?[/quote]
Yes, but the argument is a fallacy.
The low frequencies are present in highest proportion (size) so they trigger the clipping as the power rails sag, but if you are sweeping a tone at a constant amplitude, there is absolutely NO difference in amplitude across the band, therefore ALL frequencies trigger it when they are present in the same amplitudes.
There is NO LF extension due to PS caps. Misunderstood by many.
Consider DC like in car audio. There's no 120Hz (or 100Hz in Europe) recharge pulse... it's all pure DC and resistive. Now... how does a cap assist beyond acting like a bit of a flywheel? At equal amplitude, whether DC, 100Hz or 120HZ recharging, ALL frequencies are equal.
Keith