07-Dec-2020, 21:11
@Confused ,
I should have responded to your earlier post by now but the weekend got in the way and I've been thinking, probably thinking too much because I don't know enough about what's going on to hope for much result that will convince anyone, but I have come up with something.
So far we have 3 sets of results, 2 with REW and one with XYZ Room Analyser. I don't know how much the difference in software makes so I'll just say what I see from the 2 REW results.
@jvoki 's result shows frequency response with SAM On at 0% dropping from around 25 Hz but also stronger below 25 Hz with SAM at 50 and 100% than with SAM off. Looking at Devialet's info for SAM with the Magico S7 it shows extension to 26 Hz with SAM off and to 17 Hz with SAM on but doesn't say what the SAM setting is. In some ways jvoki's result matches what Devialet are saying. The increasing gain with higher levels of SAM starts at around 50 Hz and increases as frequency drops. The gain really starts about an octave above where the divergence between SAM On and OFF starts.
Your results with the Blades are actually similar to jvoki's in some ways. Devialet give an extension of 24.6 Hz without SAM and 14.4 with SAM. Your results with SAM Off and at 0% start diverging more at around 24 Hz and your boost with SAM at 100 % starts a bit above 50 Hz, a little more than an octave above where the divergence between SAM Off and at 0% starts. In both your case and jvoki's, the divergence between SAM Off and at 0% starts at around the frequency Devialet give for your speakers without SAM. What's really different between your result and jvoki's is what happens below the frequency where SAM Off and at 0% starts to occur.
That leads me to wonder whether the difference is due to the nature of the phase error being corrected at that frequency. In other words, I think the result both of you got is probably in line with Devialet's published claims about your speakers, pretty minimal as the information for Devialet's claims is given that it just gives us 2 frequencies, no description of what is going on at the before frequency when SAM is switched on, and no plots which show actual frequency response.
@Delija reports that measurements with SAM off and SAM on for his Dyns is the same and from your results and jvoki's that what I would expect to see down to the claimed extension frequency without SAM. Below that what your results and jvoki's show is that the amount of divergence differs with different speakers and Delija reports no difference with his which is closer to your result than to jvoki's.
All 3 of you have presented your results with plots with different scales and overall frequency ranges which makes comparing the actual results tricky but when I really started analysing them, I ended up thinking that they may not be all that different to each other for the reasons given above.
I think we'd all like to see a lot more information from Devialet to tell us what's going on.
I should have responded to your earlier post by now but the weekend got in the way and I've been thinking, probably thinking too much because I don't know enough about what's going on to hope for much result that will convince anyone, but I have come up with something.
So far we have 3 sets of results, 2 with REW and one with XYZ Room Analyser. I don't know how much the difference in software makes so I'll just say what I see from the 2 REW results.
@jvoki 's result shows frequency response with SAM On at 0% dropping from around 25 Hz but also stronger below 25 Hz with SAM at 50 and 100% than with SAM off. Looking at Devialet's info for SAM with the Magico S7 it shows extension to 26 Hz with SAM off and to 17 Hz with SAM on but doesn't say what the SAM setting is. In some ways jvoki's result matches what Devialet are saying. The increasing gain with higher levels of SAM starts at around 50 Hz and increases as frequency drops. The gain really starts about an octave above where the divergence between SAM On and OFF starts.
Your results with the Blades are actually similar to jvoki's in some ways. Devialet give an extension of 24.6 Hz without SAM and 14.4 with SAM. Your results with SAM Off and at 0% start diverging more at around 24 Hz and your boost with SAM at 100 % starts a bit above 50 Hz, a little more than an octave above where the divergence between SAM Off and at 0% starts. In both your case and jvoki's, the divergence between SAM Off and at 0% starts at around the frequency Devialet give for your speakers without SAM. What's really different between your result and jvoki's is what happens below the frequency where SAM Off and at 0% starts to occur.
That leads me to wonder whether the difference is due to the nature of the phase error being corrected at that frequency. In other words, I think the result both of you got is probably in line with Devialet's published claims about your speakers, pretty minimal as the information for Devialet's claims is given that it just gives us 2 frequencies, no description of what is going on at the before frequency when SAM is switched on, and no plots which show actual frequency response.
@Delija reports that measurements with SAM off and SAM on for his Dyns is the same and from your results and jvoki's that what I would expect to see down to the claimed extension frequency without SAM. Below that what your results and jvoki's show is that the amount of divergence differs with different speakers and Delija reports no difference with his which is closer to your result than to jvoki's.
All 3 of you have presented your results with plots with different scales and overall frequency ranges which makes comparing the actual results tricky but when I really started analysing them, I ended up thinking that they may not be all that different to each other for the reasons given above.
I think we'd all like to see a lot more information from Devialet to tell us what's going on.
Roon Nucleus+, Devilalet Expert 140 Pro CI, Focal Sopra 2, PS Audio P12, Keces P8 LPS, Uptone Audio EtherREGEN with optical fibre link to my router, Shunyata Alpha NR and Sigma NR power cables, Shunyata Sigma ethernet cables, Shunyata Alpha V2 speaker cables, Grand Prix Audio Monaco rack, RealTRAPS acoustic treatment.
Brisbane, Qld, Australia
