22-Dec-2023, 04:25
(This post was last modified: 22-Dec-2023, 04:29 by daniel.avasilichioaei.)
Besides the 3 things mentioned in the previous post, SAM does two more things, one desired from the design (which is positive or negative, depending on many factors) and one undesirable (which is negative).
The desired design is that it progressively reduces frequencies below 30 Hz, which Devialet considered insignificant for music. If I remember correctly, frequencies below 20 Hz are strongly reduced, and below 15 Hz are cut completely. You can test this with audio files with pure and fixed sinusoidal frequencies.
The undesirable by design is that for pure and fixed sinusoidal frequencies in the range of 20-35 Hz, the SAM software "enters into resonance" (I haven't found a more suitable term).
Even at low volumes and at SAM % far from 100%, the bass amplification gets out of control, it is done in an exaggerated way and the protection of the speaker from the SAM is automatically triggered. This happens significantly and visibly only at frequencies of 20-35 Hz (it does not happen either below or above this range).
The SAM % at which this happens depends on the volume and the type of speaker. For example, in my system it happens at SAM 33% in one set of speakers and at SAM 66% in another set of speakers (this at the same volume).
I asked Devialet about this bug and the answer was that SAM was designed for music, not for sinusoids with fixed frequencies. Obviously, I immediately asked myself the question "And if a song contains 1-2 seconds of such a sound?..."
There is something else very important about SAM: if you watch the YouTube video about how the SAM profile is generated, you will easily notice that there are many things that can go wrong. One of the most important is the speaker used by Devialet for measurements: it may not have been burnin (sometimes they use speakers they find at dealers).
There are also the manual decisions / settings made for generating the SAM profile.
For example, I suspected such a situation in the case of a set of speakers of mine and Devialet provided me with an "adjusted" SAM profile (different from the one in the configurator).
In theory, SAM is something very good and intelligent. However, in practice the result depends on luck and many other variables.
After all my experience and all the tests I done, I think the most recommended option is to call Devialet to your home and measure YOUR speakers (Devialet offers this service), AFTER you have burnin the speakers.
The desired design is that it progressively reduces frequencies below 30 Hz, which Devialet considered insignificant for music. If I remember correctly, frequencies below 20 Hz are strongly reduced, and below 15 Hz are cut completely. You can test this with audio files with pure and fixed sinusoidal frequencies.
The undesirable by design is that for pure and fixed sinusoidal frequencies in the range of 20-35 Hz, the SAM software "enters into resonance" (I haven't found a more suitable term).
Even at low volumes and at SAM % far from 100%, the bass amplification gets out of control, it is done in an exaggerated way and the protection of the speaker from the SAM is automatically triggered. This happens significantly and visibly only at frequencies of 20-35 Hz (it does not happen either below or above this range).
The SAM % at which this happens depends on the volume and the type of speaker. For example, in my system it happens at SAM 33% in one set of speakers and at SAM 66% in another set of speakers (this at the same volume).
I asked Devialet about this bug and the answer was that SAM was designed for music, not for sinusoids with fixed frequencies. Obviously, I immediately asked myself the question "And if a song contains 1-2 seconds of such a sound?..."
There is something else very important about SAM: if you watch the YouTube video about how the SAM profile is generated, you will easily notice that there are many things that can go wrong. One of the most important is the speaker used by Devialet for measurements: it may not have been burnin (sometimes they use speakers they find at dealers).
There are also the manual decisions / settings made for generating the SAM profile.
For example, I suspected such a situation in the case of a set of speakers of mine and Devialet provided me with an "adjusted" SAM profile (different from the one in the configurator).
In theory, SAM is something very good and intelligent. However, in practice the result depends on luck and many other variables.
After all my experience and all the tests I done, I think the most recommended option is to call Devialet to your home and measure YOUR speakers (Devialet offers this service), AFTER you have burnin the speakers.
