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SME

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Everything posted by SME

  1. SME

    MicroWrecker build thread

    Each cabinet has two subs in dual-opposed configuration, and I have two cabinets.
  2. SME

    MicroWrecker build thread

    Wow! Those are a lot bigger than my D.O. 21" subs (800mm x 700m x 600mm). Now I want to know how big the MegaWrecker is. 😵
  3. Dedicated subs for each Atmos output channel? That's pretty ambitious! I can't recall, but I thought Atmos heights were specified to be limited bandwidth? Assuming they were, I also don't recall if the bass management was supposed to be done by the playback processor, the authoring tools, or by the mixers themselves.
  4. SME

    MicroWrecker build thread

    ^ I almost wrote something very close to that. I used Festool equipment to build my speakers and subs, and its reliance on metric was a big plus for me to invest in it. I hate fractional inches and all the inane conversions of the Imperial system with a passion. While we're putting the Imperial system of unit to rest, can we also abolish Daylight Savings Time? It is a pointless bi-annual exercise that literally kills people, but it seems that the U.S. isn't the only country unable to wean itself away from this vestigial ritual. I must admit though that all this sounds like a lot of whining in light of current events in the UK, and I dare say things are looking a bit shaky in a number of other countries too.
  5. SME

    MicroWrecker build thread

    I doubt those kinds of errors in dimensions would have made much of a difference, but anyway units matter. :)
  6. No BEQ applied for any titles in that post, and I gave my subjective impressions. It seemed to me that many of the smaller effects in JW had decent ULF including some in the single digits. I presume the larger effects are more strongly filtered (which is consistent with my experience), and these effects dominate the appearance of the PvA. If this is indeed the case for JW, then BEQ is likely to give mixed results rather than across-the-board improvement. Whether there is an improvement on-net may be a matter of opinion and may depend on the playback system too. For example, the biggest effects may get the right amount of ULF, but the smaller effects might end up with too much ULF. A lot of people may be OK with that. I prefer to prioritize correctness above 20-30 Hz before worrying about ULF at all, because IMO the higher frequency stuff is a lot more important. (This is a key point I probably didn't emphasize enough in some of my recent posts in which I criticized BEQ in which the same EQ is applied to all the channels to make the channel-sum PvA data look prettier.) I should also clarify that I experience ULF on my system a bit different than I think a lot of people do. Even though my subs have plenty of output and I'm on a suspended floor, the floor doesn't actually move or vibrate much at all. I rarely get wobbles, and usually only with long duration content at specific frequencies that resonate with my floor (there's a scene in "Star Trek" that I know of). However, I definitely notice a difference with and without ULF, and I experience it as much or more in the tactile domain. Basically, I get a lot of chest and body cavity sensations with my bass in general, and the ULF affects those sensations in ways I detail in the next paragraph. First, I need to point out that even if a soundtrack is filtered, one can still "hear" and "feel" the ULF content that was part of the original sound design in many cases. That's because such content almost always occurs in conjunction with higher harmonics and/or amplitude modulation, which clues the brain into the missing fundamental. Of course the filter still adversely affects the *quality* of the sound and tactile sensation. For movies that are obnoxiously humped, you often get a kind of droning in the 20-40 Hz range (depending on where the hump is) that undulates at the lower (missing) fundamental frequencies. For example, a helicopter filtered this way might deliver a kind of sloppy "woob-woob-woob-woob" sound and sensation, beating at 7-11 Hz (or whatever), even though the content at the actual fundamental frequency has been filtered away. Without the filter however the sound and sensation are much tighter and more firm. It's more of a "thD----------thD----------thD----------thD---------thD---------", where the dashes emphasize the dead space between pulses and the capital 'D' emphasizes that there's still lots of weight, even though it's very tight. The filtered version may seem heavier, but the unfiltered version is much more natural and realistic. In general, the lowest frequency undulations in a soundtrack seem much more articulate and *palpable* without a filter. Of course the experience may be very different on a system that struggles to accurately recreate the non-ULF frequencies, which is most of them. For at least some people, the 7-11 Hz beating of the helicopter rotor may be completely missing without high SPL reproduction of the actual 7-11 Hz component, in which case I would expect people to prefer the ULF boost despite potential harm done to the rest of the spectrum. As such, I kind of gave up arguing my concerns about the quality of the BEQs posted on AVSForum (as opposed to those done by @maxmercy and posted here on DB) because I realize those BEQs probably *do* improve things for a lot of people, especially those with TTs/MAs that may otherwise be idling. For me personally, I (believe I) have extremely high accuracy across the spectrum (bottom to top), and I definitely notice degradation to the non-ULF bass frequencies. Indeed on a good soundtrack, I don't really hear "bass" isolated from the rest of the spectrum, unless it's specifically called for in the score or in the scene (such as when sound systems are depicted in cars or clubs). What I hear are synergistic full-band sounds, some of which induce physical sensations that can be quite strong and sometimes intricate. The bass is just part of the sound and sensation. Significant degradation anywhere in the spectrum ruins that synergy, so I do what I can to preserve it. Spinning "chopper" blades may indeed have a fundamental at 7 Hz, but the "chop" has a very broad spectrum with content all the way into the treble. The sound of a sine wave of 7 Hz is a very smooth undulation, one that requires obscenely high SPL (or a vibrating floor) to perceive. However, that's nothing like the "chop" of a helicopter blade which is a much tighter, more abrupt sound and sensation. The 7 Hz part is probably the least important part of the spectrum from a perceptual standpoint.
  7. SME

    The Bass EQ for Movies Thread

    I watched it again recently after another house curve improvement and loved it even more. I also played the race scene at the beginning as a demo (full "-5" MV with house curve, so peaks > 120 dB) for some family including my step mother who wasn't an audio enthusiast in the least. I think I changed her mind. Edit: Among our conversations was her complaint that action movies (which she likes to see "big") in movie theaters are just way too loud a lot of the time. I explained that, even though the mixers work on dub-stages calibrated using the same flawed standard as cinemas, the dub stages still usually sound way better than cinemas. So what sounds too loud in a cinema was probably just "really exciting" for the mixers. I think the demo cemented that understanding quite well.
  8. I'm way behind on the MI series so probably won't see this one for at least a year or something. I am getting caught up on a lot of other recent movies. Here are some recent watches and mini-reviews, in no particular order: '"Maze Runner 2" (Atmos): boomy 40 Hz effects but extremely dynamic soundtrack with very crisp, tight gunfire that really pings the chest; played at or near MV "0" "Maze Runner 3 (Atmos ?)": hump / filter at ~25-30 Hz is very obvious among the rather relentless and monotonous bass; relatively disappointing ending; played at more typical MV "-5" "Avengers" (7.1): uninspired sound design (especially in the surrounds and bass); dynamics not completely massacred like in "Black Panther" but still thoroughly screwed up; big effects lack impact and come across as harsh; I'm playing this at MV "0" and there's nothing there but a lot of wasted headroom; way over-hyped/over-rated movie, especially the ending "Solo" (7.1): played at or near MV "0"; very heavy on treble and treble effects, many of which are surprisingly dynamic; limited use of bass with some repetitive 28-30 Hz drone; ignoring the bass, I really like this track for its life-like treble and absolutely loved the movie, which was underrated IMO "Jurassic World" (7.1): mostly entertaining movie with some nice bass; I thought it was filtered and was expecting 30 Hz boom, but a lot of the smaller effects were very palpable; played at MV "-4"; like many movies, I wish it had more mid range "Dawn of the Planet of the Apes" (Atmos): decent movie with fairly unremarkable (and mostly filtered / boomy, IIRC) bass; excellent use of Atmos/surrounds for ambiance; loud with bad clipping; played at MV "-6" and then backed down to ~"-9" after my ears got tired "Incredibles 2" (7.1): hump at 30 Hz which seemed to rob the presentation of a lot of slam/impact; decent macro-dynamics (for recent Disney), but otherwise unremarkable; I wanted to like this movie more: it starts out exploring a theme based on contemporary social issues but the ending doesn't provide a satisfying resolution to those issues, which makes the film come across as exploitive in hindsight; I don't think it will age well like the original did FWIW, my opinions are very mixed as far as recent Disney/Lucasfilm/Marvel soundtracks goes. I think some of the soundtracks are very good, some are mediocre, and others are crap. The one thing that's consistent about these tracks is a lack of consistency. Reference playback level is typically higher than other films, except when it isn't (e.g. GOTG 2). Re-EQ application seems to be inconsistent, with some films getting it and others not. Some films with higher reference level use the extra headroom for very nice micro-dynamic sound; others have aggressive limiting, leaving most of the headroom wasted. Overall, I think the Star Wars and Pixar films have faired better than the Marvel films, especially the most recent ones. Maybe it's a sign that Marvel as a franchise is running out of gas?
  9. SME

    Ricci's Skhorn Subwoofer & Files

    At least get a friend to take a picture of your face when you push those things for the first time. At 25 Hz, you're doing better than the vast majority of cinemas and almost all pro sound systems in existence. Going lower will definitely make a big difference with *some* movies (maybe 1 in 3 action/scifi) and a subtle difference with many of the others. Because of room gain, you don't necessarily need a lot of output at the "tuning frequency" of a horn if it's below ~30 Hz. A lot depends on what the room is doing. Mine ramps up like crazy to 20 Hz. IIRC, I theoretically can do near 130 dB sine waves with my subs and without using a huge amount of power) A pair of MicroWreckers at 20 Hz full tilt probably could destroy my home. I guess you'll find out what you get with them in your room.
  10. SME

    Ricci's Skhorn Subwoofer & Files

    My point is that the Skhorn offers most of the same benefits as other sub horns, regardless of whether the Skhorn is technically a horn or not: The driver is relatively concealed, which helps filter unwanted driver distortion and noise. The expanding slot for the front provides acoustic loading at the upper end of its bandwidth. The vent/box resonance provides acoustic loading at the lower end. By "larger effective area" I think you are referring to directivity/dispersion control. The Skhorn doesn't provide much dispersion/directivity control, but most sub bass horns don't either because the waves are so long. What's probably relevant to you about the Skhorn is not that it isn't a true horn but that it that doesn't extend as low as you'd like for home theater content without plugging vents, which makes compression more likely. The Skhorn does look cleaner in the mid bass than the tapped horns do, so for music integration, I'd expect the Skhorn to typically give better results, but a lot depends on room, placement, setup, etc. I think you chose the MWs because you wanted as much extension as you could get while sticking with a horn, which may be more difficult (but certainly not impossible) to integrate with the mains. If money and floor space were not an issue, I'd suggest you maybe go with a Skhorn together with some sealed or vented subs dedicated to the bottom end. You could just leave them turned off when listening to music if you wanted an "all horn" system. Or maybe keep things simple and build a M.A.U.L.
  11. SME

    Ricci's Skhorn Subwoofer & Files

    I would call the SKhorn a horn hybrid as it does behave like a horn in the upper end of its bandwidth and like a vented cabinet in the lower end. But really, I think obsessing about terminology misses out on the important nuances. When you use the term "force multiplication", I think you are describing the increase in efficiency that occurs as a result of an increase in acoustic impedance of the air adjacent to the driver. Put another way, the air near the driver is under more pressure than it normally would be without the "horn loading". Truth be told, there are many ways to accomplish this acoustic loading. One simple example that arises with subs in small rooms is placement of subs in or near a corner. The corner placement actually increases the acoustic impedance of the air, loading the driver like a horn would. Another way to increase acoustic loading is by placing multiple drivers next to one another. These strategies can be combined. For example, subs may be stacked in a corner in a floor to ceiling array, leading to an effective infinite line source and excellent acoustic loading. These do exactly the same things that horns do, and if one is flexible in one's thinking, one can see how such arrangements *are horns* for all practical purposes. This makes me think of "waveguide theory", which basically provides a new set of mathematical tools to analyze and understand horns. But at the time, horn speakers had a bad rep in audiophile circles for having screechy treble, so the people promoting the theory and speakers based around them insisted on calling their horns "waveguides", probably because the term was both less likely to sound offensive and more likely to sound sexy and innovative. BTW, I hold waveguide theory in high regard and believe it has contributed to far superior horn designs, but I think it's still silly to call a "horn" a "waveguide" just because it was optimized using the better theory.
  12. SME

    Ricci's Skhorn Subwoofer & Files

    Can you design it so I don't need to buy any separate speakers or PAs? I want to be able to run them full-range. Edit: I think I could live with the end result if it at least got up to 20 kHz. That should make it easier for you, see.
  13. I'm not the least bit surprised that the resulting mono tracks look very similar, even for cases in which the results sound totally different. In fact, I would expect this to occur especially when people are using your app to create the BEQs visually as opposed to doing it completely blindly and by-ear.
  14. I agree with you in part, but I think the differences can be greater than you'd think. A lot will depend on the particular mix and also the particular playback system and possibly some subjective preference. In TLJ, the failure to recover ULF from the surrounds is a sin of omission, which is relatively minor. Yes, it does mean that a spaceship might lose its weightiness as it pans from the front, overhead and to the rear, but at least the sound is not worse than what you started with. I picked the surrounds in my example because the difference is quite dramatic on paper and is one that we could all agree would be very audible with those discrete surround effects. However the front LRC channels are another story. Even though they roll-off at a similar point, their shapes are still quite different from LFE. So an EQ solution that is optimized to the mono sum average (which is dominated by LFE), could introduce new humps or bumps into the front LRC that weren't there before. Here's where we *can disagree* about what's audible and what's not. Though arguing from personal experience, even quite small bumps can be audibly degrading. Much depends on shape and bandwidth of the feature, in addition to the level, and also ... Audibility of differences will depend on the playback system. Systems with substantial bass problems may not reveal degrading resonances as readily. (That's not a virtue as such systems also fail to reveal a lot of content.) For example, a BEQ filter applied to front LRC that increases ULF while adding a slight bump around 55 Hz may have a pronounced boom around that area in general, but on a system with a severe boomy room mode at 45 Hz, the problem at 55 Hz may be hardly noticed. The BEQ might be an unqualified improvement on this flawed system, but on a system with very clean bass response, the 55 Hz bump may be much more obvious and degrading. If you had to choose between full ULF extension and balanced response between the deep bass, mid-bass, and upper bass, which would you choose? Personally, I'll take the balanced response over the ULF extension any day. IMO, the ULF is the least important frequency range. I believe the notion that "[global] BEQ that gives 80-90% of the improvement" is overly optimistic, but I am also inclined to judge the soundtrack for what it will sound like on a revealing system vs. an "average" one. So practically speaking, a global BEQ may be an improvement for most people who choose to use it, even if it does degrade other aspects of the bass somewhat. And I do understand that most people who have EQ capability at all can only use it on the sub output. I agree many filtered tracks can be improved to an extent with a global BEQ and that it's worth doing even if an independent channels BEQ would sound better. But I'm skeptical that a global BEQ will always be better than nothing at all. Focusing only on ULF, a BEQed track will always seem to be an improvement, but if one considers the sound as a whole, BEQ that introduces new bass resonances in some of the channels could end up sounding worse than nothing at all. Again, a lot is going to depend on the playback system. When doing these BEQs (whether global or channel-independent), it's very important to listen to the results on a system that is as accurate and revealing as possible. (This is probably my biggest gripe with the AVSForum thread where it appears BEQs are being developed using all eyes and no ears.)
  15. Again I disagree, and I think you're missing something key here. For any effect that is mixed exclusively to the surround channels and that contains sub bass , the difference between an independent-channels BEQ and all-channels BEQ is whether or not it's filtered at 60-80 Hz. The all-channels BEQ does boost the low end of the surround channels, but nowhere enough to keep it from rolling off rapidly below 60-80 Hz. I don't think we disagree over whether "filtered at 60-80 Hz" is subtle or not. To repeat myself, the only real open question is how much of the bass within the sounds mixed to the surround channels was copied to the LFE channel. To answer that question requires comparing the tracks side-by-side to see what the mixers did. To repeat what I wrote above, the total shelf gain recommended by @maxmercy for TLJ was +48 dB and not +60 dB. The +60 dB for GotG which also recovers meaningful content. Either way, any attenuation of say 60 dB by a filter should not be enough to force the relevant content into the quantization noise floor unless the tracks are getting down-sampled to less than 24-bits (i.e. 16-bits, -96 dBFS quantization noise floor) somewhere between where the attenuating filters were applied in production and where the BEQ filters are applied on playback. I believe DTS HD and Dolby TrueHD are always 24-bit. The rest of the production chain was almost certainly using at least 24-bit precision (probably 32-bit or 64-bit float in the DAWs). Realize that 24-bit has a quantization noise floor of -144 dBFS. It's actually quite impressive that I can get away with the +60 dB boost for GotG being that the signal inputs to my processor are analog (unbalanced actually). The ULF noise floor of my unbalanced analog connections must be in the neighborhood of -100 dBFS. This is incorrect because it is outdated, on two accounts. The situation changed with immersive formats. First, as I explained in my above posts, Atmos for cinemas (and probably other immersive formats) introduced support for bass management to be used for surround and overhead channels with dedicated "surround subwoofers", preferably located at the sides or rear of the room. The Dolby specs *require* every screen, surround, and overhead channel to extend to 40 Hz, using bass management as necessary to meet this goal. I don't know how many dub stages use 40 Hz vs. 30 Hz subs for surrounds, being that the front channels are still run without subs (usually extending to 40 Hz on their own). Second, cinema Atmos is not compatible with the home Atmos. This means that *all* Atmos BD and UHD releases are dedicated home mixes or masters. This work is done in small rooms that mimic home theaters, and I expect all of them use bass management for the overheads and surrounds (and probably fronts too). The Atmos home format (or rather the equipment that implements it) does not support separate surround subs, so bass managed bass all goes to the one SUB channel, which will almost certainly extend to 30 Hz or below. Also keep in mind that sound design is a separate step from the mixing. Most sound design is being done in small room studios where capabilities (for better or worse) are very different from the dub stage. Some sound designers might even work using sealed subs and small enough rooms to get significant ULF. But even if they can't hear the ULF on the track, it's not fair to say that it wasn't part of the sound design. Whether the ULF was part of a recorded or synthesized effect, it originated as part of the design process. The only question is whether the designers/mixers/directors are able to hear what they've done.
  16. I assume the after is with the @maxmercy BEQ applied? Either way, I strongly disagree that the fact that the surrounds have lower average levels means their shape is not audibly important. Average level depends on short-term level, duration, and frequency of effects. Most action happens up front and in the center, so it's no surprise that the surrounds have much lower average levels than the fronts. Yes. However, without additional information we can't tell how the LFE channel was used. There's no guarantee that content that's mixed to one or more front/surround channels gets sent to LFE too. Many strategies are possible, and you can't really tell what was done by looking at either of the PvA curves. *Of course* there are distinct effects in the surrounds! Any sound that gets mixed to the surrounds that has bass will be affected by the filters applied to that channel during production and the BEQ filters applied during playback. Unless most of that bass was copied to or sent to the LFE channel, an independent channels BEQ will recover ULF in the surrounds that an all-channels BEQ can't. The result won't be subtle for the discrete surround (and overhead) effects with sub bass, especially given the ~60 Hz filter! I do agree that the post BEQ surround channel averages look odd, particularly below 30 Hz. Why do all the surround channel curves converge to one curve below there? I would not expect that to happen. The shape of the curves and lack of finer details is also unusual. It looks like it could be garbage. Maybe insufficient precision somewhere? Are you applying the 1st order high pass at 10 Hz? And is it working correctly?
  17. How would you define "extremely large"? It's a bit hard to tell from your pictures, but it looks like the green curve for least one surround channel levels out at around -72 dB (average) below 20 Hz. To get this content to about the same level as the stuff at 100 Hz (-33 dB) requires up to +39 dB of shelf. Here's the total shelf gain for each channel for the @maxmercy BEQ correction: LFE: +20 dB LCR: +18 dB SURR: +48 dB (!) Note that these also use 1st order high pass filters (f0=3.0 Hz for LCR+LFE and f0=10.0 Hz for SURR) to remove DC noise in the track. I'm pretty sure this BEQ has it covered. Is +48 dB really an extreme boost? I don't think so. One of my other favorite BEQs, which I just watched the other day is for Guardians of the Galaxy: LFE: +40.5 dB LCR: +20 dB SURR: +60 dB (!!) As a point of note: my processor is connected to the upstream via analog, so I do have to worry about the effect of boost on the analog noise floor. With the GotG BEQ applied and no sound playing, I get periodic spurts of noise that are enough to register on my Motu 16A display ("-48 dBFS") and to light up the "signal present" lights on my amp. That's probably only ~1W actually going to the subs, so no worry there. However unfortunately, even at that extremely low level the ULF output is enough to cause one of my living room windows to make ticking noises. GRR!!! Ignoring that though, the above GotG BEQ delivers very excellent sound.
  18. By "levels", are you referring to relative level of each channel in the PvA data? If so, I disagree with your argument, at least in general. A lot depends on how the mixers created the LFE channel content. For TLJ, It could be that that the bass under 60 Hz in the surround channels just gets thrown out rather than being sent to LFE. If that's the case, then a global BEQ will likely have little to no effect on the surrounds because the ULF boost will be well below the 60 Hz roll-off. To figure this out, I guess one would have to compare the tracks, looking for some place where an effect with bass plays on the surrounds only and then checking if any of that missing bottom end found its way into LFE. I'm curious if @maxmercy has any insight here. How much evidence is there of mixers splitting content between surrounds and LFE using HPF/LPF pairs? I'd bet there are many different strategies used for managing LFE and that for a great many cases, a separate-channels BEQ will be much better.
  19. SME

    Othorn - HT capable?

    Nice ideas here. I hope that XO processor works out for you. Definitely experiment with different settings. Measure and compare if you can and have the patience. Unless you're using real weak amps on the mid/high horns, you might seriously consider adjusting the passive circuit to attenuate things more. I don't know if that would be feasible in your case, but it could make a huge difference with regard to noise while also improving safety from faults (both for the drivers and your ears). Even if you listen real loud, I seriously doubt you need sensitivity that high. It may be fun to brag about, but practically speaking it's a nuisance with regard to noise and possible safety concerns in the event of a fault. My speakers have horns covering content above 850 Hz+ that are 108 dB sensitivity without passive electronics. I have a passive circuit to cut them by 6-10 dB over most their range and I've cut the output gains for them on my DSP an additional 6 dB, meaning that I probably hit like 50W peak before clipping in the DSP, most of which is sunk into the resistors of my passive circuit. My DSP interface has peak and average indicators for each channel so I can literally watch my headroom. I listen to plenty of stuff plenty loud, and it's rare for the peak level to exceed -10 dBFS. Only with a handful of cases do I see peaks up near the top. One example of some demanding treble (at least for my horns) is the hand-held phaser shoot-out in "Star Trek" (2009) when playing at a MV in which I probably hit peaks > 125 dB SPL (with help from the subs) in other scenes. Of course, with the kind of subs you're building, you may listen to stuff way louder than I do. But seriously, those kinds of levels are not going to be good for your hearing in the long-term. I can play a good dynamic multi-channel concert video at something like "+3 dB" vs. reference level (and a generous house curve on the bass), and it sounds wonderful without even a hint of strain! The sound is so clean, detailed, expansive, and powerful. And then after 5 minutes it stops and my ears will be slightly ringing and after a couple hours, my hearing will still be altered. That's hearing damage territory, and for me, that's *enough* headroom.
  20. I should be able to see that one soon and will give my feedback. I do hope it's not as bad as "Black Panther", which as I said sounded more compressed than analog TV to me. BP had a $200 million budget, and given that "sound is half the movie", there is no excuse for this. At this point, I don't really have a problem with studios pulling dynamics back a bit for home mixes. The mid-range emphasis that results when a cinema or dub-stage is calibrated to the X-curve target makes the sound smaller and whimpier. For a long time, I assumed that mixers compensated for the lack of bass and treble using EQ boost, but I was mostly wrong about that. I say "mostly" because I think some EQ does find its way in to a lot of tracks, but it's much less than would be needed to reverse the effect of the X-curve calibration. So even after EQ tweaks, the sound in the cinema is still lacking in bass and treble and seems small and whimpy. The mixers compensate another way: using the faders. The consequence is a mix with exaggerated macro-dynamics because the mixers are pushing up the levels of the big effects for more pop. There's a huge difference, however, between pulling dynamics back a bit for a more authentic "cinema-like" experience at home and crushing the mix to the dynamic range of a typical Internet pod cast. Also, I could be wrong but it sounds like BP just got shoved through an algorithm without any scene-by-scene consideration at all. I don't have a problem with automation being used as part of the process, but at the least there should be people going through the mix and making tweaks for different scenes. It took a lot of fader twiddling to get the cinema mix the way it was. It's ridiculous to assume that a simple algorithm can reverse all of that. The sad thing about all this is that most consumers don't complain. The industry thinks that means that it doesn't matter, but it does even if consumer don't complain. Most consumers don't notice the lack of dynamics. They don't notice the lack of emotional impact and lack of connection with the actors. They don't notice that the overall movie experience is less inspiring or that their motivation to purchase media in the future is diminished. And when the sales start to drop, will the industry recognize that quality matters even when the consumer isn't aware of it? Or will they just blame the loss of sales on pirates?
  21. FWIW, I liked TLJ as a film a lot more after the second watch. It's definitely flawed, but what SW film isn't? Yes! Because the channel architecture includes the LFE channel for extra bass headroom, any film mixer that wants to use LFE in the mix must effectively use some kind of bass management when creating it. Microphones and synthesizers don't tend to spit out separate LFE tracks, and I doubt the sound designers deliver content with separate LFE either. Even if they did, it wouldn't allow optimal budgeting of headroom in the mix, so basically it comes down to the mixer to figure out how to distribute the sub bass between the different channels of the mix. I'm sure many different strategies are employed including the wacky filtering schemes seen in TLJ and many other movies. I wouldn't be surprised if a lot of the bass that appears to have been filtered from the surrounds was simply re-routed to LFE instead. This is probably why almost every one of the BEQs developed by @maxmercy uses quite different filters on each channel, and why I believe this approach is usually necessary for good BEQ sound quality. Even then, it's probably not possible to fix everything. The bass management on the production side may be applying very different filters to sound that is redirected from each mains channel to LFE. For example with TLJ, it's possible that the 40-60 Hz part of the LFE channel contains a lot more bass that goes with sounds in the surround channels than screen channels, but below 40 Hz, it's a more even mix of screens and surrounds. So any adjustments made to LFE could have different effects on the surrounds vs. the mains. Lastly, we need to remind ourselves that bass management on playback systems has a lot of problems too. Probably very few systems out there have neutral sounding bass for sounds on all 7.1+ channels of a soundtrack because of sub crossover phase issues. The more savvy home theater people know to optimize sub delay for best sub crossover response, which makes a *huge* difference, but this is only possible on one channel (i.e. the center channel for movie optimization) or some weighted sum (i.e. left+right for music optimization). How many people here or anywhere have good response in the sub XO region on their surround and overhead channels? Yes, those channels do get used for bass, and they get used a lot more now because immersive formats for the cinema specify bass management for the surrounds. I personally have the capability to optimize bass management completely and separately for each mains channel and for LFE, which is itself optimized to blend best with simultaneous content in the center channel. IMO, this should be a minimum requirement for a "high performance" home theate, but it's not possible to do this with any standard home theater processors I know of (without spending 6 figures $ at least). I doubt very many "Atmos at home" production systems have that capability, which means they aren't hearing the bass right on their own soundtracks. (Sadly, I wouldn't be surprised if many of these don't even have the sub distance optimized for best center channel response.) At least Atmos in the cinema specifies that surround and overhead channels be bass managed to separate "surround subs" located closer to the back of the room, which probably helps a lot, but Atmos for home is still essentially a 7.1+ format.
  22. SME

    Ricci's Skhorn Subwoofer & Files

    While within their limits, amps are essentially voltage control devices, so the loads in parallel won't interact via an electrical path. There may still be mechanical interactions from shared air space or external proximity/boundary/acoustic loading effects but from an electrical standpoint, the two drivers don't "see" each other. In a series configuration however, it is possible for power to be transferred between the drivers unless they're exactly the same. Any electrical or mechanical differences between the two drivers may cause energy to flow between the two, which can complicate their behavior compared to systems with all drivers in parallel. It's also possible that this interaction could couple with another interaction (say acoustic or mechanical interaction due to proximity or shared air space) in a way that leads to a feedback loop that causes unstable behavior. In reality, the differences involved are probably too small for this to be a problem most of the time. However, I believe there are always opportunities for exceptions. Some manufacturers may be more consistent than others with regard to parameters that matter. Loading drivers into a tuned enclosure (especially one with higher pressures like a horn) could amplify certain problems. Running the drivers harder where non-linearity becomes a big factor is probably likely to accentuate such problems too. But this is all really just theoretical speculation. I have no idea if any of these effects are really strong enough to cause serious problems.
  23. Other movies watched recent: "Ghost in the Shell": I liked it a lot, and it had some cool mid-bass glitch effects and a very interesting score. The bass was OK otherwise, filtered in the 20s but not too aggressively. "Jumnaji": Worst bass I've heard in a while. It had some ULF, but it had a severe 30 Hz hump and almost no mid-bass. It was loud and boomy and had absolutely no punch or clarity and almost no tactile at all. For all the attention given to ULF, I think good mid-bass is more important. Without enough mid-bass in the track, the low stuff just sounds terrible. (Edit) "Ready: Player One" with BEQ: Bass movie of the year for me. Possibly my new favorite bass movie ever. Excellent full-bandwidth sound design. Very tactile throughout. You are *there*. I kind of miss the discussion here where we gave our subjective impressions of these tracks. Maybe all of that happens at AVSForum these days?
  24. So I watched "Black Panther" finally. I played the BD 7.1 at "-1" (!), and my Denon did not indicate any dialnorm compensation was applied. I have to agree that this soundtrack has serious deficiencies caused by excessive and/or mis-configured dynamics processing. It was bad. It seemed worse than the dynamics of old analog TV. Not only were macro-dynamics largely eliminated but the compressor attack seemed to act immediately and aggressively on transiently loud sounds such as gun shots. IMO, the consequences were wide and substantially degrading to the viewing experience. The experience was passive and uninvolving. The on-screen action and actors seemed trivial and insignificant. It wasn't just special effects that were harm but also the score, dialog, ambiance, etc. The scoring involving live acoustic instruments (vs. the pop / hip-hop style music) sounded completely unnatural and irritating to listen to because of the pumping effects. In one scene, dialog alternated between a few key characters and a large crowd, both of which were rendered equally loud but of course this made the crowd sound very whimpy, and the aggressive compression really muddied their voices together. It really broke the immersion. The acting seemed quite forced throughout the movie, but I could also tell that the dialog completely lacked the dynamics which may play a big part in conveying passion and emotion. The weird thing is that even if this aggressive compression was done on purpose, perhaps to optimize for hand-held devices in high noise environments, the level of the track was extremely low. I basically had to turn things up to cinema reference level to get sound that still wasn't that loud. That's a huge amount of gain as far as hand-helds go. On most if not all such devices, this track would be difficult to hear even with the volume at max. Oddly enough though, it had some decent bass in a few places, particularly in some of the quieter scenes where there wasn't as much mid/high frequency content to compete against. The tonal balance was actually quite nice, and I experienced a surprising amount of ULF with rather strong tactile effect. A lot of ULF just makes the windows rattle and maybe shakes the floor a bit, but this was felt quite strongly in the chest area. I believe the presence of higher harmonic frequencies with good balance all the way up essential for this sensation. The ULF itself makes the least contribution to the sensation but helps fill it out and make it more real and present. It's just too bad that the good bass was totally missing from a lot of transient effects. Anyway, I have a hard time believing that the problems with this soundtrack were intentional. It's certainly possible that people misjudged the quality of the track because they were too tired or something. Or maybe people were just rushed. Maybe mistakes were made that were to difficult to correct. Still, this is bad enough that I think it'd be reasonable to ask for a correction and recall. I didn't buy this film, and have no interest in doing so after what I experienced. Still, I hope this isn't an example of Disney's future. I thought some of the Pixar films like "Coco", "Inside Out", and "Finding Dory" were fine as far as dynamics were concerned. They might have been pulled back a bit compared to typical cinema tracks, but I kind of expect that with kids movies. And anyway they still were *way more dynamic* than "Black Panther". Edit: Just to clarify with my opinions regard to discussion in some of the recent posts: I thought "Black Panther" and "The Last Jedi" were kind of at opposite ends of sound quality and performance. TLJ had very nice dynamics, it just needs high master volume to get things nice and loud. BP is about the same average loudness as TLJ was (7.1 at least) but had practically no dynamics at all, for which there's no real cure. BP really looks like a QC error as does the Thor:Ragnorok Atmos track which apparent has severe compression but only for the first half. I hope it's just these two, but I guess I'll find out how Avengers 3 is.
  25. SME

    Ricci's Skhorn Subwoofer & Files

    Do you have any real world examples of this kind of positive feedback loop occurring, causing unexpected bottoming or failure due to uneven power dissipation? Or maybe just really bad sound? I'm skeptical, but I'm also paranoid. I'm also a bit paranoid about having multiple drivers share the same air space. I opted for a solid barrier between air spaces within my dual-opposed sealed subs. You might want to consider that too if these kinds of interactions between drivers are really a problem for you.
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