05-Dec-2019, 14:21
I have measured the frequency response / SPL curves for my system with REW, and plotted the differences with various SAM % settings. In broad terms, SAM boosts the SPL's for the frequencies below the point at which the speaker's bass response would otherwise theoretically "roll off" in a neutral room or anechoic chamber. I could plot the curve using REW and see the SPL's for the bass end of the curve pick up progressively for SAM 10%, SAM 20%, SAM 30% and so on.
In my case, the room provides a degree of bass reinforcement at the lower frequencies, so SAM and the room work together to "boost" bass. Hence why reducing the SAM % can be very desirable for many. As an example, you would not really want the room naturally boosting bass by +15dB at a particular frequency and then have SAM adding another +15dB on top.
Of course, SAM will behave differently for every room / speaker combination, so it easy to imagine that things might go a little wrong in some cases, with SAM boosting frequencies that happen to coincide with room modes.
In my case, the room provides a degree of bass reinforcement at the lower frequencies, so SAM and the room work together to "boost" bass. Hence why reducing the SAM % can be very desirable for many. As an example, you would not really want the room naturally boosting bass by +15dB at a particular frequency and then have SAM adding another +15dB on top.
Of course, SAM will behave differently for every room / speaker combination, so it easy to imagine that things might go a little wrong in some cases, with SAM boosting frequencies that happen to coincide with room modes.
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