Negative Reviews

[maxijazz]

I don't know where I read it but I do remember reading somewhere what @Jean-Marie is saying, just turning SAM on at 0% turns on phase correction. Increasing the percentage setting increases bass extension. I have never seen anything from Devialet about how they increase bass extension but my feeling is that it is by boosting the lower frequencies because the only way to make bass (or any frequency) which is either inaudible or only faintly audible is by boosting output at those frequencies.

I have no way of measuring the phase response of my speakers with and without SAM to try and confirm my original comment and Jean Marie's confirmation but I did think of one measurement I could perform. I use a PS Audio P12 power conditioner which has a display screen which can report a number of performance measures, one of which is the total power output from the P12 on a moment to moment basis. With SAM on at 0%, it showed the P12 was delivering 81 to 82 W of power to my system for the track I was playing at the time. I turned SAM off and the power output dropped to 71-72 W of power, a 10 W reduction. Turning SAM back on increased power output back to the original 81 to 82W of power. Since no other changes occurred apart from turning SAM on and off I think we can safely assume that just having SAM on at 0% resulted in my amp using 10W of power more than it does with SAM off. I don't think that the amp would require an additional 10W just to provide bass correction during this test given that my volume setting was -21 dB so I was listening at quite moderate levels and there was no need for the amp to actually apply volume correction.  When I've made some previous tests using the P12's info display I've noticed that the system draws somewhere around 35-40 W or so of power with the amp off so the amp draws around 30 W of power with music playing and SAM off, and around 40 W of power with SAM on at 0% so having SAM on at the level I was listening at actually increases the amp's power draw by around 33%. That's a big increase in power draw for just applying speaker protection and that suggests that something more than just speaker protection is occurring with SAM at 0%.

This test doesn't prove that phase correction is being applied with SAM at 0%, only actual phase measurements of the speaker's output at 0% would do that, but I do think the above results give very strong grounds for believing that whatever SAM is doing at 0 % involves more than simply providing speaker protection and phase correction is the only other candidate we have to explain what else might be going on.

 You explanation makes sense.
I am too wondering how increasing of extension is implemented while we rise SAM's "percents". Maybe that is just adding power to lower frequencies (= equalisation) as you mentioned.