Jump to content


Popular Content

Showing content with the highest reputation since 04/23/2018 in Posts

  1. 2 points
    I think "How to Train Your Dragon" should be near the top of the list for ULF as well, and it's also a pretty good movie if you like family / animation. Some would argue it's tilted toward the bottom a bit too much. The movie is full of ULF, but one noteworthy scene is maybe 1/3 of the way through in a large hall with a lot of thunder and a big door slam. That door really gets the air moving and is very noticeable because it is an isolated effect. Another animated movie with great overall bass and plenty of ULF is "9". It has many good effects. Among my favorites are the scene about 1/4 of the way through which bombs being dropped and huge mecha stomping around. A good one-off effect is the firing of the artillery near the end. The Dolby Atmos trailers I'm familiar with don't have a lot of ULF, but there are a few minor moments. In "Amaze", the "thundering bass" scene has some 14 Hz. I think it also has some 16 Hz at the very end. IIRC the leaf demo also has some 16 Hz at the end but nothing else. The "Horizon" demo has a few moments with moderate ULF, but it's completely inconsistent. The "Unfold" demo actually has good extension but isn't especially loud. Unfortunately, the trend with newer movies seems to be more filtering. A handful of us are able to work around this issue by re-EQing the soundtrack before bass management. Other than "Hacksaw Ridge", another recent Atmos mix that has ULF is "Wonder Woman". Even though most of the content is above 20 Hz, there's enough below 20 Hz to matter and the bass overall is top notch IMO.
  2. 2 points
    The Incredible Hulk is still the track I compare all others to. A close second is the Star Trek reboot, War of the Worlds, and all of the 5-Star films on the first page of the thread. For lots of 20Hz and below energy, Battle:LA is hard to beat as well. JSS
  3. 1 point
    This doesn't solve the phase match problem. If one uses a textbook electrical LR4, then the phase shift of the high pass and low pass filter will be identical vs. frequency. However, unless the speaker and sub(s) are ruler flat throughout the crossover region and co-located, they likely won't be phase-matched to begin with. The THX crossover was developed assuming the mains were sealed and had a natural Qtc=0.707 (Butterworth) 2nd roll-off. Two cascaded 2nd-order Butterworths makes an LR4, so the THX crossover applied a single 2nd order Butterworth to the mains and a full LR4 LPF to the subs. Provided that the subs didn't roll-off anywhere within the crossover region, that the mains behaved precisely as specified, and that they were co-located such that room effects applied to each equally, the result was ideal. In reality of course, "bass management" is a stinking mess. The whole point of it was that one could put the subs somewhere better for sub bass, but often the "better" locations are not so good for integrating with mains, especially where multi-listener is a priority. And of course, very few mains are sealed with perfect Qtc 0.707 and Fb 80 Hz. Any significant deviations from there substantially influence the phase response in the critical crossover region. Most mains these days are ported and tuned well below 80 Hz, so they have only slight phase shift at that point. They would do better with a full LR4 HPF, but few AVRs / processors seem to offer more than one XO type. My Denon AVR has the THX 2nd order 0.707 HPF baked in, which totally destroys the bass-managed mid-bass response with any speakers I've owned. The LFE response may measure picture perfect, but the mid-bass response of the other channels looks like trash. Also, how many subs are actually flat through the XO? Most of the beefier drivers are already dropping off from inductance effects. Sad to say, home theater "technology" is still stuck in the 90s in many respects. Great sound pretty much requires extensive customization, as I've learned over the years, and the affordable options for doing so leave a lot to be desired.
  4. 1 point
    Thanks for the offer, but it'll be some time before I'm ready to do serious testing on other systems, at which point I'll need to be present to listen to the results myself. Of course, if I move to Europe or something, it could happen sooner. A flat in-room response will probably not give the best sound. At the very least, you'll probably want 5-6 dB of bass boost centered around 80-160 Hz. You may also want a more gradual slope (i.e. 1 dB/octave) a ways above and below that point. Feel free to experiment, of course. I'm not aware of any online samples from Floyd Toole's book, but if you are curious, I highly recommend buying it. In my opinion, it's the best book on the subject of sound reproduction, particularly for small room systems. A lot of stuff in there seemed counter-intuitive to me when I first read about it, but my experience over time as led me to change my mind and conclude it was correct.
  5. 1 point
    Those look interesting. I'll definitely read them when I get the chance. The first article I opened (most popular) is dated 1998. Surprise surprise. This is hardly a "new" problem. The latest edition of Floyd Toole's Sound Reproduction book also has an entire chapter dedicated to discussing cinema sound where he remarks about the 2 kHz knee among other issues. Toole is consulting with an industry group that has recently been studying the problem with the aim of eventually establishing new SMPTE standards to address the problems with the X-curve. Toole's and Harman's recommendation seems to be to calibrate smoothed in-room response to a target that looks more like the Harman curve was is optimized (at least in theory) for "anechoic flat" speaker response cinema rooms and listening distances. While I think this approach would lead to an incremental improvement, it's still less than ideal. For starters, when people talk about frequency response, they don't bother to specify *how* the response was smoothed and *what form* was smoothed. These details actually matter a lot as far as the end result is concerned. For starters, one can choose a smoothing kernel which can be a flat-top ("moving average"), which is easiest to implement. Or it might use some kind of curve, for example a gaussian, which provides a smoother looking end result. As for what form, one can smooth the magnitude, the power, log-magnitude (i.e. the dB value), or the complex amplitude (where magnitude and phase are treated together as a composite 2D value). Power smoothing yields results most consistent with RTA and other continuous averaging instruments. Complex smoothing is actually mathematically equivalent to frequency-dependent window (!). FWIW from my testing, REW appears to do log-magnitude smoothing with a kernel that's similar to a gaussian. While it makes the data look prettier, it has a substantial effect on the end product. Furthermore, I have 99.9% confidence in the fact that fitting in-room response to any kind of target (even a room variable target) is suboptimal. Smooth in-room response should never occur in practice where any reflections are present, which means that in the process of EQing in-room response to be smooth, one actually introduces harmful resonances. How ironic! While I am a ways away from definitely solving this problem, I get the feeling I'm further along than anyone else at this point. It sure sounds like it.
  6. 1 point
    You have a point. When I said "unfiltered", I left it vague. The context was ULF, which could be informally taken to be under 20 Hz. Extension under 20 Hz seems to be pretty rare these days, but there is a decent amount of stuff that reaches to 20 Hz or 25 Hz, as you pointed out. Of course studios have no obligation to deliver audio that's flat to DC (or 3 Hz?). Though it's nice when it happens. I wish they'd do it more often, for the tactile transducer users among other reasons. I know a number of cinemas have transducers now. Although they may be mainly of the "shaker" type with poor extension.
  7. 1 point
    You'll be surprised once in a while. Some TV shows do have some good ULF, albeit it can be spotty and inconsistent sometimes, and it's rarely as loud (relative to the dialog) as in movies.
  8. 1 point
    I can agree to your first statements, but I'm confused by what you mean in bold here. Do you mean to say that there are many more unfiltered movies than it appears because many movies are not measured here? Yes, good surround mixing is a big plus too, as well as is overall better tonal balance, which also has a big impact on the perception of both bass and ambiance.
  9. 1 point
    Enjoy! Not much. There will be some, sure but not a note-worthy amount. The point of those demos is to demo Atmos. Hogwash. It only seems like a "trend" because audio enthusiasts started graphing bass when things started to get interesting and the industry has reeled back, for the most part, since. Look at it another way and bass content in film <25hz is the exception rather than the rule. For every "filtered" new movie there is one or more that isn't. Also depends on what bandwidth of movie titles you consume. Fortunately, the trend with newer movies is better surround mixes but we don't talk about that here.
  10. 1 point
    Agreed with @maxmercy list there. Both Dunkirk and Jedi will not be great titles to test <20hz content, imo. They will both have powerful bass but >20hz (which isn't a bad thing). I can think of a handful of "scenes" to test out for true ULF. Entering the Grid - Tron Legacy Elysium - laser templates being cycled through before cutting into Bugattipod Captain America: Winter Solider - vending machine Hurt Locker - M2 .50cal scene Lone Survivor - the whole Chinook sequence Edge of Tomorrow - opening title ULF Dredd - interrogation scene Pulse - server scene (~18hz but sustained, trip dem breakers!) and more
  11. 1 point
    The WW cab is a good data point and just about the Goldilocks size for this driver for HT. Honestly I wouldn't go any bigger for this driver for a vented cab tuned near 18-20Hz. It just doesn't need it. 10-12ft seems about perfect. Any bigger would hit the point of diminishing returns. Don't forget that you'll likely get some lift below 30Hz in room. 3 to 6dB in the 16-20Hz range is a good general guess. 20ft would be great for 2 drivers though.
  12. 1 point
    Reading this (above) makes me happy. SME builds, measures, makes adjustments, attention to details that surely can not make any difference - but it does. Then he - SME - describes the amazing sound, well, what does he know that all the others don't.. And the proof is in hearing and experiencing yourself. As lowerFE did. When you focus on the parts that are important for sound quality, and fix it, you actually get results that matters.
  13. 1 point
    So after reading this thread over the past year and amazed and the technical depth and extreme attention to detail paid to the tuning of this system and going "man I really want to hear this!", I flew and went to check out this system. And boy what an amazing system to listen to! My mind was blown as I was amazed by one thing after the other. All the work put into getting the tonal balance of this speaker correct really paid off big time. The whole system just sounds really "correct", and the more I listen to it the more I'm amazed by it. I brought my Reference Mini's with me as a comparison, and there was a very obvious difference in sound quality. I thought my speakers sounded really great, but it sound noticeably "off" when compared to this system. The speakers had a fantastic amount of detail, and the transients are awesome! It felt like I'm listening to a pair of really good headphones (and few people realize how hard and impressive it is to achieve this), but I also get the enveloping sound that makes speaker listening so pleasurable. It's the best of both worlds. What's even more impressive is the bass. I don't think I've heard bass so tight and full sounding in a room, which is clearly due to the complex integration efforts of multiple subs and individual EQ's to get such flat bass over a large number of seats. The clarity and tightness is seriously impressive. Again, just like a headphone, and that is actually something I've never heard before from a subwoofer. It is straight up the best sounding bass I've heard in a room. Now when you also get the whole body physical sensation from bass, addictive is an understatement. One thing that is unforgettable and blew my mind is how great the speakers sound in the kitchen! I don't think SME has ever mentioned this, but it was indeed one of his goals. It was remarkable hearing a correct tonal balance with almost no treble roll off in a different room! I still can't believe this is achievable. It must be the combination of controlled directivity speakers and properly placed diffusers pulled this amazing magic trick of a feat. I've heard a lot of amazing home theaters, but this is the first time I heard imaging from surrounds. It was trippy to be able to pinpoint the location of the sound going across the rear stage. I really wish we watched an action movie and be able to so accurately track the position of the sound effects. This is even more impressive as I seem to clearly have less ability to hear imaging compared to other people. Speaking about imaging, the speakers reproduced phase manipulated music tracks far more accurately than anything I've heard so far. It must be the room treatments that are preserving the phase accuracy of the speakers. It was like "oh this is where it is supposed to sound!" I was also exposed to the dark secrets of the time domain in room correction. That was a revelation to me to be exposed to so much more information and tools to analyze room acoustics. Now it makes sense why and how the room is mucking up the sound. It's all in the time domain! Now I am able to correlate measurements and subjective judgment of how good (or bad) the room sounds. I have so much to dig and play around with now. Measurements really can tell you about how good something sounds if you look at the right things and how to interpret it properly. Thank you SME and his wife for being such amazingly gracious hosts. That was one hell of a weekend! Oh, and did I make it clear enough that your system sounds good?
  14. 1 point
    Heheh. Yeah, I know what you mean. I believe you when you say it is better. Just poking fun a lil at your post. You're a very smart guy and knowledgeable but it almost seemed like nothing short of perfection wasn't good enough. Do don't that to yourself. You'll never be happy.... but, it sounds like you are so ignore me. Sometimes the constant "improving" can have a detrimental effect on the enjoyment of the HT room. I had to learn to love it even with the warts and all!
  15. 1 point
    Speaking of disappointing, Underworld: Blood Wars and Resident Evil The Final Chapter are also filtered. A letdown after the franchises' previous offerings.
  16. 1 point
    Hacksaw Ridge is the real deal. Tremendous surround work with tremendous bass. The polar opposite to flat, one-dimensional LF. Surely amongst the very finest, most realistic soundtracks I've ever experienced in my home. And the movie was surprisingly good too. There was something very genuine about the storytelling that seems rare in modern large-scale filmmaking. It really moved me. And the crafting of the violent battle scenes is mind-blowingly (no pun intended...) good.
  17. 1 point
    I watched Rogue One tonight, so I can add subjective opinions to the numbers... This is definitely a 30Hz humpfest, and most big low end effects have a distinctive 'tone' to them as a result. It's so apparent that it becomes distracting at times. For instance (and this is a spoiler if you're one of the holdouts that still haven't seen this one), when the Death Star destroys Jeddha City, there are a few big shots of the planet's surface lifting up and shattering due to the shock wave. It's visually impressive. Those shots also call for some incredibly deep, room shaking bass. Now, the bass that is there is loud, and it does pressurize the room, but you can definitely feel that the lowest octave or so isn't quite there, and the 27-36Hz frequencies have been boosted so much that it almost sounds like a sine wave has been put into the effect. It reminded me a bit of Interstellar in a way. Whatever clipping is present is masked withing the louder effects, so for the most part it isn't noticeable (on my less than ideal system anyway). Some explosions do have that 'crunch' to them that usually indicates that they are clipped, but it is brief and the soundtrack is well balanced in terms of volume spikes so at no point does it get fatiguing. Overall this soundtrack is a bit of a disappointment. The bass is much more one dimensional and generic than in The Force Awakens. Even the brief Force rumbles are less interesting. On it's own it might have been okay, but coming after Hacksaw Ridge it's a big letdown.
  18. 1 point
    The reason HR's sound design is so good is that there are no two explosions that sound exactly alike. Many have different fundamental freqs and almost all have a single peak or multiple peaks somewhere in the 15-100Hz range (the most impactful hits have very broad 18-80Hz 'peaks'), with or without content to <5Hz. Makes for a widely varied, explosive soundscape. JSS
  19. 1 point
    I think we should have a data-bass bake-off for the best cake. Please send all entries to me and I will make a definitive and concrete supposition of who will win this bake-off and therefore have the theoretical absolute best cake on the internets.
  20. 1 point
    Let's start with the single channel measurements as they were done first. 8 OHM Single Channel Results The SP2-12000 SpeakerPower was up first at 8ohms. The burst tests were done first followed by the long term sine wave test. Nothing notable to report. The SP2-12000 had no issues even when driven several dB into clipping. The fans didn't even turn on. The K20 followed also at 8ohms again nothing to report here. The amp chugged along. The single channel 8 ohm burst data is represented in the chart below. The K20 is set as the baseline measurement in the blue column and it's results are set at "0". The SP2-12000 result is shown in dBW relative to that recorded by the K20. A positive number indicates higher output a negative number equals less. Again this is the recorded acoustic output of a group of heavy duty speakers when driven with both amplifiers. We can see that during this test the K20 recorded about 1.6dB higher output on average. No long term comparison data. The reason will be explained below. 4 OHM Single Channel Results The K20 went first at 4 ohms. The burst tests were done first followed by the long term sine wave test. The burst tests went as expected. No issues. However when running the sine wave test which starts way down near 2Hz, the K20 muted the outputs. The output level had to be dropped way down by 7-9dB to get it to complete the sweep without muting the output during the beginning of the sweep in the extreme low frequencies. I had never encountered this behavior before so I tried the other channel with the same result. I even tried the other K20 I have and it repeated the same. I started moving the start frequency of the sweep up to see if this would help and once the sweep started closer to 20Hz the K20 would complete the sweep at full output without protecting. The SP2-12000 however, after running through its burst testing, had no issues with the full sine wave sweep even when driven several dB into clipping as before. Since the K20 wouldn't complete the full sweep in this setup unless the bandwidth was restricted or the level was reduced some 6dB or more below the SP2-12000 capability I saw no point in presenting the long term data comparison for this test. The SP2-12000 clearly won that portion of the test. The burst testing is presented below in the same manner as previously outlined. The K20 is the baseline "0" result and the SP2-12000 output is shown referenced to that baseline. Similar to the 8ohm single channel results the K20 has about 1.9dB greater output on average with the 4ohm burst tests. 2 OHM Single Channel Results The SP2-12000 went first at 2 ohms. The burst tests were done first followed by the long term sine wave test. The burst tests went as expected. The only thing that cropped up was that I was able to get the SP2-12000 to mute briefly with the 10Hz burst with it driven WAY into clipping while trying to get every last 0.1dB. Otherwise it was uneventful and backing off a little bit removed that issue. The long term test was also not an issue for the SP2-12000 after backing off the signal a bit from the burst testing. The clip lights were still illuminated for nearly the entire sweep. I knew that the K20 would likely repeat the issue from the 4 ohm long term sweep test at 2 ohms, so the SP2-12000 would win the long term single channel portion with ease. This was the case. The K20 did not like being asked for full power in the extreme low frequencies with one channel driven. It muted the outputs unless the level was greatly reduced or unless the bandwidth below 20Hz was skipped. The issue even started to show up in the 2 ohm burst testing. The K20 would mute at the 10 through 16Hz bands if pushed too hard. At 10 and 12.5Hz the output prior to muting was down some 8 to 10dB from the SP2-12000's recorded results. At 16Hz the K20 kind of got its act together and was around 3dB low from what it would have been. The SP2-12000 produced notably more output at that band as well. At 20Hz and above the K20 finally started doing its thing and averaged about 1.3dB higher output. Ok so at this point a couple of things are clear. On a single channel versus single channel basis the K20 can burst higher numbers short term but the SP2-12000 kicks its ass with longer term or higher duty cycle signals at very low frequencies and lower impedance loads. The limited K20 output and aversion to extreme low frequency information is why the long term data is not compared for the single channel tests. It's a clear cut result. At this point I sent some of this information to Brian and asked his opinion on some things since he is a certified amplifier guru and I'm more like the guy who stayed at the Holiday Inn Express last night when it comes to amplifiers. I know a little about thery and design but I don't kid myself when comparing my limited understanding to someone who does it for a living. This will be covered in the next post.
  21. 1 point
    Attached here is an example of the wiring plate used and also an example impedance of one of the drivers in a sealed cab of about the same airspace with the coils in series. Obviously the impedance of the cabs shifted somewhat with heat and high displacement of the drivers but this is the baseline. The use of so many drivers should have kept the amount of heat buildup in the coils from being excessive and causing notable compression or parameter shifting. Regardless both amplifiers were driven into the same loading so should have experienced the same things or close enough for the rough general nature of this type of testing. By looking at the impedance we can get a rough guideline of the areas that required the highest current from the amps and which areas were near the peak and required more voltage.
  22. 1 point
    When using the Oppo with Hdmi out to a reciever I guess you would want the reciever do do the decoding. So set the Oppo to passthrough/bitstream and it will not touch the audio stream, and won't cause any issues with clipping etc. However, having a BDP which costs a shitload of money with very nice analogue audio outputs and using HDMI bitstream seems like a waste of money to me. If one doesn't care much of the build quality and such of the Oppo which I'm guessing is top notch... This is why it is so sad with this clipping issue, it has very high quality analogue outputs which are rendered almost useless as soon as bass redirection is activated, very sad indeed... Virtually any BDP should handle HDMI bitstream correctly as it is not supposed to do anything with the audio other than simply passing it in encoded form out the HDMI port down to the next device downstream for decoding there...
  23. 1 point
    Looks like a Marantz I have here delivers 4.0Vrms clean on pre outputs. When sub out trim level is set to -12dB, it will handle a all-channel 0dBFS signal up to 0dB MV. The only situation that can make it clip is if there are low-frequency square-wave signals on any of the channels that gets summed and filtered. The filtering will change the waveform so that the peak value increases, up to +3dB. How this is handled internally I don't know, it actually did not cross my mind to check when I verified this. If it clips digitally I really don't see a disaster anyway, as the clipping then will only preserve what was originally there from the soundtrack. You can forget everything about nice sound, accurate sound, in fact, sound quality at all, when such waveforms are placed on a soundtrack, so it does not really matter. If more headroom is needed, for the square waves, you will have to lower the ref level to somewhere below 0dB MV. The 4.0Vrms limit is not a practical problem, as any subwoofer system should be able to get max output with 4.0Vrms or less. As long as it is possible to reduce output level using trim or MV to preserve the waveform and prevent distrorion and clipping, you only need enough voltage to ensure the subwoofer amplifiers can be driver to clipping. --------------- And thanks again for starting this thread, really an eye-opener and very valuable information for anyone looking for a new pre/pro or avr.
  24. 1 point
    Star Wars:Revenge of the Sith Level - 2 Stars (106.31dB composite) Extension - 4 Stars (14Hz) Dynamics - 5 Stars (27.59dB) Execution - 3 Stars - A total mail-in in level and overall sound. The lightsabers in Episode II really have heft. In this film, not so much. Oh, and any film can have incredible 'dynamics' if it is nearly 3 hours long with long stretches of terrible dialogue. Overall - 3.5 Stars Recommendation - Rent. JSS
  25. 1 point
    And finally one worth posting about. How to Train Your Dragon: Level - 4 Stars (112.3dB composite) Extension - 5 Stars (2Hz) Dynamics - 5 Stars (31.35dB) Execution - 5 Stars - What FOH and Bosso said. Overall - 4.75 Stars - Add some effects above 60Hz with some weight and you rival WotW. Recommendation - Buy, just like the above folks said. Terrific soundtrack, great film. Yes, that graph is correct. The signal asks your speakers to play back a 2Hz tone at 117.8dB at one point. JSS