I have a couple of queries.
I've got a disc with lots of system checks on it, one being a phase check. A voice speaks firstly in phase, then out. In phase the voice is central in the sound stage, out of phase the voice is at the edges of the sound stage. When I use the Devialet to adjust the output to be in phase or out, there is no difference made to the out of phase voice from the CD. Why is this?
Secondly, I can play low frequency sound waves from the CD. If I play a 21Hz sound wave with SAM off, I can just about hear the tone. With SAM on at 100%, the loudness of the sound is increased, but the sound pulses at a non regular interval. This also happens at 23Hz, 24Hz and all the way up to 30Hz when the pulsing ceases and there is no difference in the loudness of the tone with SAM on or off. Is this irregular pulsing effect a sign that SAM is cutting the signal to "save" my speakers? If I reduce the ammount of SAM to 30%, the pulsing goes away. Also, when SAM is on at 100%, there is a "breathy" overtone to the sound waves up to 30Hz.
I am leaving SAM off now as it doesn't seem to be making any noticeable difference to the sound.
Any thoughts?
The phase control inverts the phase of both channels. The phase check CD is there to make sure you have connected up your speakers correctly, so it only inverts the phase of one of the channels.
Some people believe that absolute phase makes a difference, so may well use the phase control on those discs they think were recorded with phase reversed. I do not
My main speakers do not have a SAM profile so I am guessing here but maybe the loudness level you are trying to achieve with SAM on is causing one of the protection strategies to come into play???
I half suspected the phase answer, thanks for putting it into words for me, Frank.
Changing the volume had no effect on the pulsing though...
(26-Sep-2015, 17:19)Axel Wrote: [ -> ]I half suspected the phase answer, thanks for putting it into words for me, Frank.
Changing the volume had no effect on the pulsing though...
Are you running 8.1.3 / SAM V2? I have a test tone CD, and I'll try this tomorrow on my system and report back.
(26-Sep-2015, 18:06)Confused Wrote: [ -> ] (26-Sep-2015, 17:19)Axel Wrote: [ -> ]I half suspected the phase answer, thanks for putting it into words for me, Frank.
Changing the volume had no effect on the pulsing though...
Are you running 8.1.3 / SAM V2? I have a test tone CD, and I'll try this tomorrow on my system and report back.
Yes Confucious, 8.1.3/V2. Thanks, I'll look forward to your findings.
(26-Sep-2015, 17:00)f1eng Wrote: [ -> ]The phase control inverts the phase of both channels. The phase check CD is there to make sure you have connected up your speakers correctly, so it only inverts the phase of one of the channels.
Some people believe that absolute phase makes a difference, so may well use the phase control on those discs they think were recorded with phase reversed. I do not
My main speakers do not have a SAM profile so I am guessing here but maybe the loudness level you are trying to achieve with SAM on is causing one of the protection strategies to come into play???
Sorry, i was wrong. The problem goes away under -26 Hz, but I usually listen louder than this so SAM protection is cutting in too early for me.
I tried the 21Hz test tone this morning. In fact, today was a good day to try this because for other reasons I was planning to switch from 7.1.3 SAM V1 back to 8.1.3 SAM V2, I will report on this further in the SAM V2 thread.
Anyway, when I first tried the 21Hz tone on SAM V1, it ran at a constant tone, but would occasionally, and randomly, produce a very strange effect where the tone ceased to be smooth and the volume peaked upwards and then maybe dropped slightly / momentarily. Very hard to describe, but not a smooth tone. With SAM off, smooth a bass tone, but lower volume, as you might expect. Now here is a curious thing, when trying the SAM on / off routine, I accidentally turned the amps off by hitting the wrong button. After the amps restarted, I could run the 21Hz tone with either SAM on or off and every was exactly as it should be, smooth constant bass with SAM 100%, the only real issue was things in my room vibrating a bit! Why turning the amp on and off made this difference is a mystery. My theory? Maybe there is some kind of protection system built into the amps that may in part react to temperatures, so may have responded to the amps being off momentarily. This is perhaps a bad theory, as prior to these tests I had being playing music a very modest levels, so the amps would not have been that hot anyway. OK, so I haven't really got a clue! It may just remain one of those Devialet mysteries.
Reverting back to SAM to 8.1.3 SAM V2, the 21Hz tone ran perfectly with SAM 100%, SAM off or whatever, it just worked as it should. I also tried 18Hz, this too worked fine, but made me feel slightly unwell.
Reading back through @Axel's post re the 21Hz test, what I experienced with the SAM 1 test may possibly be similar to as described by Axel. A curious one this.
This is all very curious. I have a ticket logged with Devialet at the moment about occasional 'thumps' with a few tracks with full SAM which they do seem to be looking into quite vigorously. The strange thing is that these thumps can be much reduced after a reboot of the unit. I wonder if there's a connection?
They did re-profile (or regenerate the SAM config data from the v1 profile perhaps?) my speakers, but it seemed to make it worse.
(27-Sep-2015, 12:22)Confused Wrote: [ -> ]I tried the 21Hz test tone this morning. In fact, today was a good day to try this because for other reasons I was planning to switch from 7.1.3 SAM V1 back to 8.1.3 SAM V2, I will report on this further in the SAM V2 thread.
Anyway, when I first tried the 21Hz tone on SAM V1, it ran at a constant tone, but would occasionally, and randomly, produce a very strange effect where the tone ceased to be smooth and the volume peaked upwards and then maybe dropped slightly / momentarily. Very hard to describe, but not a smooth tone. With SAM off, smooth a bass tone, but lower volume, as you might expect. Now here is a curious thing, when trying the SAM on / off routine, I accidentally turned the amps off by hitting the wrong button. After the amps restarted, I could run the 21Hz tone with either SAM on or off and every was exactly as it should be, smooth constant bass with SAM 100%, the only real issue was things in my room vibrating a bit! Why turning the amp on and off made this difference is a mystery. My theory? Maybe there is some kind of protection system built into the amps that may in part react to temperatures, so may have responded to the amps being off momentarily. This is perhaps a bad theory, as prior to these tests I had being playing music a very modest levels, so the amps would not have been that hot anyway. OK, so I haven't really got a clue! It may just remain one of those Devialet mysteries.
Reverting back to SAM to 8.1.3 SAM V2, the 21Hz tone ran perfectly with SAM 100%, SAM off or whatever, it just worked as it should. I also tried 18Hz, this too worked fine, but made me feel slightly unwell.
Reading back through @Axel's post re the 21Hz test, what I experienced with the SAM 1 test may possibly be similar to as described by Axel. A curious one this.
I think that we are experiencing the same anomaly, but because we have different systems, the cause is going to be hard to pin down exactly. Next time I've had the amp on for a while, I'll try the reset procedure.
Thanks for sharing your experience. :0)
Axel, mindful of your experience and Rufus' words above, I too will try this periodically. It seems more than a coincidence that Rufus can clear his issue by shutting down / re-starting the amp, and I too could not reproduce the issue after a shut down. One to keep an eye on! (or an ear on, at least)