Another point of clarification from a newbie in the Devialet world. I am very familiar with room correction and use it extensively in my systems. I have a Tact 2.2XP and Tact 2150XDM room correction systems, which can sometimes do an amazing job of making a speaker fit a difficult acoustic. They can sometimes also fix problems with the speaker itself. I recently got a pair of Proac Response 3.5s, a highly regarded speaker from the 1990s-2000s. One speaker was perfectly working, the other had some strange issues with the two 7" dual midrange/woofer cones. The defective speaker produced a response curve about 15 dB below the normally working speaker in the midrange, but matched the working unit in the treble and bass. Anyway, after room correction, the two speakers sounded exactly the same. You could not tell them apart on mono material (like BBC World Service broadcasts).
So, digital room correction is well understood, works very well in many cases, and has a solid foundation in acoustics and signal processing. Feed the speaker an impulse, compute its frequency response, and correct it to any desired response (the Tact allows modifying the response on a PC, which runs all the computations).
Now, what does SAM do? Devialet has a web page "explaining" what SAM does for the B&W 800 Diamond, a speaker that I own, except it explains nothing. It shows two curves, which look like time domain curves, one somehow is corrected to follow the actual signal more closely than the other uncorrected curve. Also, the same page says the frequency response of the B&W 800 Diamond is extended to 16 Hz, which is well below the manufacturer's specification. This is a bit worrying as well, and you have to wonder if this is a safe thing to do (after all, B&W designed the speaker and chose the bass extension cutoff based on the ability of the speaker to achieve a certain bass frequency safely).
http://en.devialet.com/speakers/bowers-w...00-diamond
What they claim is the following: "SAM processes in real-time the musical signal, ensuring that the sound pressure reproduced by the speaker matches exactly the one recorded by the microphone."
It sounds like SAM is correcting for the speaker's response, but without actually measuring the speaker in my listening room, it is hard to see how this can be done at all. Presumably the correction signal is computed in Devaliet's listening room, which may have completely different acoustics. The whole thing is quite mysterious, and another reason for concern from a prospective buyer.
So, digital room correction is well understood, works very well in many cases, and has a solid foundation in acoustics and signal processing. Feed the speaker an impulse, compute its frequency response, and correct it to any desired response (the Tact allows modifying the response on a PC, which runs all the computations).
Now, what does SAM do? Devialet has a web page "explaining" what SAM does for the B&W 800 Diamond, a speaker that I own, except it explains nothing. It shows two curves, which look like time domain curves, one somehow is corrected to follow the actual signal more closely than the other uncorrected curve. Also, the same page says the frequency response of the B&W 800 Diamond is extended to 16 Hz, which is well below the manufacturer's specification. This is a bit worrying as well, and you have to wonder if this is a safe thing to do (after all, B&W designed the speaker and chose the bass extension cutoff based on the ability of the speaker to achieve a certain bass frequency safely).
http://en.devialet.com/speakers/bowers-w...00-diamond
What they claim is the following: "SAM processes in real-time the musical signal, ensuring that the sound pressure reproduced by the speaker matches exactly the one recorded by the microphone."
It sounds like SAM is correcting for the speaker's response, but without actually measuring the speaker in my listening room, it is hard to see how this can be done at all. Presumably the correction signal is computed in Devaliet's listening room, which may have completely different acoustics. The whole thing is quite mysterious, and another reason for concern from a prospective buyer.
