To SAM or not to SAM and DRC - Printable Version +- Devialet Chat (https://devialetchat.com) +-- Forum: Devialet Chat (https://devialetchat.com/Forum-Devialet-Chat) +--- Forum: Tweaker's Corner (https://devialetchat.com/Forum-Tweaker-s-Corner) +--- Thread: To SAM or not to SAM and DRC (/Thread-To-SAM-or-not-to-SAM-and-DRC) |
RE: To SAM or not to SAM and DRC - Soniclife - 23-Nov-2016 (23-Nov-2016, 17:39)yabaVR Wrote: The most difficult thing in this test is the transparency of your system chain...I know, I know, everybody in this forum would claim his system for being very transparent . "I've made up my mind, don't confuse me with the facts." There is no point proposing a subjective test if your going to reject the samples that don't agree with your theory. There are so many reasons for why different people and systems could produce very different results here. Of the top of my head hear are a few. 1) The different transform functions of the different SAM profiles may act, or not on the relevant frequencies. 2) In general the smaller the speaker the larger the group delay that would need fixing, so it might be critical to have SAM on for small speakers, but off for large speakers. Same goes for the response equalisation. 3) 2 way vs 3 way, depending on the crossover frequency some SAM profiles might need to, but won't from my understanding of how the measurements are done, take account of the output from the midrange unit if shallow slopes are used in the crossover. 4) Doppler effect of moving small drive units a large amount more than originally designed might impact midrange performance. 5) How SAM'able a speaker is. I've been curious why some speakers cannot be SAM'ed, but other similar designs can, e.g. Fact 8 (can) vs Fact 12 (cannot, they have tried and failed more than once apparently), makes me wonder if there is a sliding scale of how well SAM works, with some just qualifying and others ideal. 6) Multiple bass units vs one, I'm guessing multiples are harder to correct than single ones, they must be harder to measure. I expect anyone who has studied sound, or loudspeaker design will have many more, and this is before we get to such standard hifi reasons as peoples rooms, the recordings used and personal preference. I'm amazed it works at all. RE: To SAM or not to SAM and DRC - ogs - 23-Nov-2016 (23-Nov-2016, 21:13)yabaVR Wrote:(23-Nov-2016, 14:44)ogs Wrote: Hi gui I think I know what you mean. I'll test as soon as my amp is back from Paris. Like Hifi_swlon I have compromises in speaker placement and depend on RC. RE: To SAM or not to SAM and DRC - Soniclife - 23-Nov-2016 (23-Nov-2016, 21:35)Hifi_swlon Wrote: SAM does very little here. Yes it makes the facts go deeper, but i always feel it comes with a narrowing of soundstage, and in my average shared use lounge this extra bass doesn't really sound right anyway. I also sense a slight 'softening' of the sound with SAM. FWIW, and in your case this really isn't worth anything, when I had Fact 8s on home dem one of the things I struggled with is that there was no way I would want them without SAM, and I wasn't sure about buying a speaker that only worked with SAM, but with SAM I was very close to wanting them. SAM added deep extension, really filling in the bottom end, and that brought a much larger acoustic with it, but it didn't do anything for the higher up edginess I ultimately decided I didn't like. Rooms are a pain, if only I liked headphones. RE: To SAM or not to SAM and DRC - yabaVR - 24-Nov-2016 (23-Nov-2016, 22:24)Soniclife Wrote:(23-Nov-2016, 17:39)yabaVR Wrote: The most difficult thing in this test is the transparency of your system chain...I know, I know, everybody in this forum would claim his system for being very transparent . My comment wasn't meant to offend and I'm not rejecting any samples but wanted to give an explanation for those not hearing large differences or no differences at all, hence the smilies . For the rest of your post you're absolutely right. One can not estimate on all influences that belong to the sensed effects. gui RE: To SAM or not to SAM and DRC - baconbrain - 24-Nov-2016 I had also propagated the merits of SAM after purchasing my 250. To me, it just sounded better. After investing in additional DRC equipment and listening to the significant change in results, I also began to question the value of SAM again. If SAM is truely doing everything that it is marketed to do, why the significant difference in SQ after additional DRC? For me, it ultimately links back to the acoustics of the listening room. I am quite sure that the room Devialet used when setting up SAM for my speakers was no where close to my living room ... RE: To SAM or not to SAM and DRC - yabaVR - 24-Nov-2016 (23-Nov-2016, 21:21)Jean-Marie Wrote: ... Good point Jean-Marie and somehow it made 'klick' in my head this morning. I may got it wrong inasmuch as looking ONLY on single sound objects. Thinking more over it you are right that a phase shift is a phase shift for ALL sound objects in the end. But there is this last point standing. That's the SAM test from above. The difference/effect in SAM On/Off can clearly be recognized. There has to be a conclusion to this effect for me. If I think of SAM doing it right in theory but to accomplish its task it has to use digital filters. SAM compensates for phase and volume flaws of the speakers BUT has to use filters that itself have phase shifts involved on the freq they are used on (6dB/90°, 12dB/180°, 18dB/270°, 24dB/0°). Even 24dB (no phase shift?) needs processing time, so there is a time dependency here? As I'm no engineer on this task now it would be nice to have Devialet engineer on hand and have some enlightment. It's all patented anyway. He could make detailed comments. Ok, dream on... But may this be the point? SAM compensates for the big flaws of a speaker but can not prevent smaller flaws (phase shifts) to appear in the music signal hence its function parameters? gui RE: To SAM or not to SAM and DRC - yabaVR - 24-Nov-2016 (24-Nov-2016, 09:12)baconbrain Wrote: I had also propagated the merits of SAM after purchasing my 250. To me, it just sounded better. I don't have the link on hand but Devialet showed in a vid how they meassure a speaker with SAM. The mic is very close to the speaker and it only meassures the direct sound coming from the speaker. Reflections of the room won't get meassured as they say. Conclusion for me is that SAM does only compensate for the speaker parameters not the room parameters. That's why you achieve further improvements with DRC. gui RE: To SAM or not to SAM and DRC - Hifi_swlon - 24-Nov-2016 I didn't think they measured with a mic at all? I thought it was impedance etc and driver excursions measured by laser? They also measure a single speaker driver per model, and rely on all speakers ever made performing 100% identically. How realistic that is I'm not sure. For those who place a lot of weight on speaker cables, jumpers and connectors making significant differences, I'm not sure how these things are taken into account either. RE: To SAM or not to SAM and DRC - yabaVR - 24-Nov-2016 (24-Nov-2016, 12:09)Hifi_swlon Wrote: I didn't think they measured with a mic at all? I thought it was impedance etc and driver excursions measured by laser? Yeah, sorry...you're absolutely right. No mic was involved in SAM meassurement. gui RE: To SAM or not to SAM and DRC - Hifi_swlon - 24-Nov-2016 (24-Nov-2016, 12:42)yabaVR Wrote:(24-Nov-2016, 12:09)Hifi_swlon Wrote: I didn't think they measured with a mic at all? I thought it was impedance etc and driver excursions measured by laser? No apology needed! But definitely none of the room creeping into measurements (for whoever was worried about that), well, unless the whole room was vibrating, or containing an as yet undiscovered black hole perhaps. |