Sam

[Sailor4W]

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Secondly, if SAM can kick in some room nodes, so why doing it altogether? I know one has to try, but to me the concept seems to be too much influenced by the speaker‘s environment.

Thirdly, I am asking myself how room EQing interferes, or is influenced, by SAM. Most rooms need some EQing in the range between 100-200 Hz, and, remembering Devialet‘s statement, that’s where SAM kicks in.…

Why use SAM if it can kick in some room modes? Well, not using SAM will kick in the same modes but probably not as severely. It's not SAM that's activating the room modes, it's frequencies that are present in the music on the recording. In addition, SAM is not intended to correct room behaviour, it's intended to correct a problem with speaker behaviour at low frequencies. That correction may cause an issue for room modes in one room but it also won't cause an issue in a lot of other rooms and, if it does cause an issue then you have some control over the resulting problem by adjusting the setting of the SAM level downwards or even removing the SAM profile from your configurator file. SAM is definitely beneficial for many people and correcting speaker phase behaviour at low frequencies is beneficial in theory. It's a good option to have, even if you personally don't like the result. I liked SAM with the speakers I had when I got my Devialet and then some time later I upgraded my speakers. I don't like what it does in my room with my new speakers so I don't use SAM with them. 

As to room EQ, if SAM exacerbates a room mode you'll need a bit more EQ correction for the boosted peaks occurring at the listening position and the amount of EQ correction you will need will be dependent on the size of the boost SAM provides so it is going to depend to a degree on your SAM setting. When it comes to the dips at the listening position caused by a mode exacerbated by SAM there's probably nothing you can do. You can't correct a modal dip by boosting the level at that frequency because the dip will just swallow the boost, the dip exists because you have a null pressure zone in that area of the room. You can reduce peaks  but you can't correct dips with EQ. If you've got a dip with SAM, you will also have a dip without SAM. The only way to deal with dips is probably to move the listening position out or the area where the dip is located but that may move it into an area where you have a dip from another modal frequency. 

Basically, SAM doesn't cause any room problems but it can make an existing problem worse. If y ou get a room modal problem with SAM, the problem already existed but perhaps not serverely enough for you to notice it. The way to fix room modal problems exacerbated by SAM is the same way you fix room modal problems normally but if you don't want to address the modal problems directly then lowering the SAM level will reduce the severaty of the exacerbation and removing SAM from your profile will leave you with just the original room problems you always had.

Thanks for the explanations! Kicking in room modes was maybe imprecisely described, exacerbating is the appropriate expression!

My experience with SAM was mixed. As I said, it also depends on the recording. With some albums, I hear no effect at all with SAM, with others, particularly with recent recordings, SAM all of a sudden boosts low frequencies, even though it's set only to 20%. Might just as well be the effect of a room mode that is not so perceptible in the absence of SAM.

Good to know that SAM can be combined with EQing!