Axiom engineered a low power mode but it is not of the minimum power design I described in my last post. The trigger on the Axiom subs shuts down the amp - not the linear power supply. This means the huge transformer's primary winding draws power in stand-by not unlike your phone's charger.
Axiom has said this stand-by draw is about 10W - and this spec goes back to v2 product. I can't explain why you're measuring 20W.
Regarding the stand-by design, my sense is it grew organically at Axiom rather than someone sitting down and thinking it through logically from first principles. And when Andrew designed the v4, he likely didn't realize the implications of the existing design or ignored it because he was focusing on making the DSP subs sealed and more robust from a warranty perspective. He also re-worked all the ported subs in a big way. It's possible given the goals he had of making the subs sound better and be more robust, the trigger slipped through the cracks.
P.S. Yours may be drawing more because the capacitors are old and have higher ESR (i.e. they are leaky).
Last edited by Mojo; 09/05/22 01:42 PM.
