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Kvalsvoll last won the day on December 8 2017

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  1. The Bass EQ for Movies Thread

    I don't know the Nanoavr products, but checking the mindsp web pages it seems the HD can do the job. Since it is digital in-out on hdmi, it will not have any negative impact on sound quality, part from the user setting up bad eq points. But check that you can actually use it, I believe it does not process TrueHD or DTS. We usually do BEQ by applying eq on the sound track in the movie file directly, which means it can be played back just like any other movie. But this requires equipment and knowledge do do it. If your bass-system has a dsp with parametric eq, you can use this to accomplish much - if not most - of the improvements. If the system has presets, you can program one or two presets with ulf bass boost, and select the most suitable one for the movie you want to watch. A simple approach, much more user-friendly. This will work very good on movies that requires modest bass eq, such as Oblivion, The later Star-Wars.
  2. The case againts subwoofers

    Don't read articles like this. The information presented is plain wrong and misleading. Some statements from the article: "music rarely has extremely deep, under-50Hz bass": Wrong. Most music has essential information below 50hz, and some music has content in the sub range below 20hz. In the 2-ch article I presented spectrograms taken from various music samples, which shows there is lots of low frequency information in various types of music. " most speakers with 5-inch (127mm) or larger woofers can muster 50Hz bass": No, a 5" driver can not even reproduce 200hz properly, if a realistic sound presentation is the goal. " Achieving the perfect blend isn't always possible -- subwoofer crossover tweaking isn't an exact science": Actually the integration part is science, and a manageable set of rules solves it. But you need the equipment and the knowledge to do it properly. If the sound does not improve after adding a subwoofer/bass-system, you did not do it right.
  3. X-curve compensation re-EQ

    This is not true. Acoustics determines the ratio between early direct sound and later reflected sound. The ratio between early direct sound and early reflected energy defines clarity. This is the case both for reproduction and when speaking in a room, and there are established standards for this. Those standards makes is possible to predict intelligibility in class rooms and auditoriums, and adjust acoustics according to intended use to make the rooms perform well. In REW there is now a Clarity graph, which shows the performance of the measured system in regards of those parameters: "Clarity C50 The early to late energy ratio in dB, using sound energy in the first 50 ms as the 'early' part. C50 is most often used as an indicator of speech clarity." The soundtrack is of course a crucial part here, but acoustics determine how well this soundtrack is reproduced, and with several sounds going on simultaneously it will be more difficult to discern the different parts of the sound when there are more and louder late energy because this late energy will then mask parts of the transient sounds in the early arrival sound.
  4. X-curve compensation re-EQ

    Too much information, but i appreciate your dedication to elaborate and explain your thoughts, and I did read it all. I have selected a small subset from your post to comment on, realizing we can not cover all aspects of sound reproduction in a few posts in this thread. Distortion and masking: Distortion components at higher frequencies are not masked by low frequency content, unless this content also has higher frequency harmonics sufficiently loud in level. Masking occurs around the fundamental tone, and when the difference in frequency is large enough there will be no masking at all. For low harmonics the masking is high, so that for 2. h the detection level is around 2%. For higher harmonics, or any other content at much higher frequency, the detection level approaches the audibility limit for a tone at that higher frequency, as if the low freq tone was not present at all. I know this because i have preformed a controlled experiment just for the purpose of investigating detection level and masking for harmonic distortion. Dialogue: Yes, some dialogue can be more difficult to understand, and whether you experience intelligibility to be sufficient or lacking will always be a subjective evaluation. And some systems will be better and some worse. The typical home system with a center speaker close to the floor and a table between this center and the listening position is not a good starting point. In such a system, it is likely that the frequency response is very compromised through the midrange, and there will be severe early reflections. This causes poor intelligibility. A simple measurement will reveal that freq resp is far from flat, and early decay is poor. On top of that, I suspect that many center speakers have problems with both on-axis frequency response and poor off-axis linearity. In many cases room acoustics is not suitable for sound reproduction because the room is not sufficiently damped, causing problems with overall decay and early reflection level. This is the reason for all those "can't hear the dialogue" comments. The only solution to this is to improve the sound system and room acoustics.
  5. X-curve compensation re-EQ

    The response of the x-curve calibrated system may actually be a lot closer to neutral than the simple frequency response measurement indicates. The tonal balance depends on the direct sound and the decay, so both loudspeaker radiation pattern and room acoustics matter. Since the x-curve was made by comparing a typical cinema speaker with hf horn to a much closer typical "hifi"-speaker, the x-curve correction is supposed to fix exactly that. Though several later studies have shown the flaws of the x-curve calibration, so something obviously got lost somewhere in the process. The small-room-is-louder is another myth originated from making wrong assumptions on why the small room often sounds louder. Room size is not a property of loudness. If the decay is similar, the loudness will be the same. It is all about acoustics and speaker radiation pattern. Distortion is not a tonal issue, but radiation pattern and decay can make distortion more audible. I have at least two movies where I have different sound tracks available, where one sounds bad and the other is much better. Try to compare the first Gravity 5.1 release to the later atmos - the atmos sounds much better. And the mixers may very well be aware of issues with the sound, but for a number of reasons choose to not do anything about it. There was one movie with very bad dialogue, the noise gating was very obvious and caused the dialogue to sound distorted. I showed it to a professional sound engineer, what was his thoughts about this, could it be fixed. Yes, he could have fixed that, he could remove all the audible noise, to make the dialogue sound clean and nice. BUT: It would cost time and money. His suggestion as that there simply was not time available to fix it, since the plug-ins and method required to do it was no secret or unknown mystery to any sound engineer. For most people - even the sound enthusiasts - watching a movie is like climbing a mountain to ski it ONCE. Perfect conditions would be nice, but since you ski it only once, you take what is there, and make the best of it. If it isn't that good, you don't climb it once more to see if it got better. And you certainly can live with parts of the run being in bad condition, if other parts are excellent. We watch the movie ONCE, and if the sound was excellent, it is a plus, but if there was one scene where the dialogue sounded distorted and noisy, it doesn't destroy the film.
  6. X-curve compensation re-EQ

    Continuing from my last post, some general thoughts. The problem with eq on playback is that there is access only to eq everything in one channel. This means that eq on the center to fix dialogue issues, such as cutting the hf, will also affect other sound effects, and that may not be desirable. Some movies sound better. But it is the odd one with the strange sound that we notice. And it gets worse with louder playback level. It is quite clear that many movies are not suitable for 0dB master for a pleasant and natural sound - especially dialogue gets way too loud. So, why not just turn it down? Turning the master down destroys dynamics and impact. At -10dB you have lost 10dB dynamics, and the experience of low frequency sound effects are compromised, tactile experience across the whole frequency range is lost. Tonal balance on dialogue is one thing. I believe distortion and noise caused by pushing the dialogue level too loud is even worse, and this is impossible to fix. You can hear this on many movies - voices are too loud, they sound hard and harsh, you can easily hear the noise when the dialogue is gated. On a decent system dialogue is easily heard and intelligible at -30dB master, on any movie. On most movies the dialogue gets louder than natural at levels beyond -10dB. If the full dynamic range was utilized, the sound would be much more pleasant and at the same time would have much more impact and realism. When the overall level is reduced, the contrast will be larger, so that transients will be perceived as more powerful, and it is not necessary to clip everything. It would sound much better.
  7. The Bass EQ for Movies Thread

    BEQ for Valerian and the city of a thousand planets: LFE: sfm 19Hz Q=2.2 gain=+10dB LCR: sfm 22Hz Q=2.2 gain=+16dB The LCR drops off a cliff at around 45-50Hz, and trying to repair this to get it flat will only give unpredictable results, the filter suggested will only partially recover some bass below and slightly reduce the 50Hz bump. LFE turned out quite well. There is not much bass in this movie (from looking at the signals), but this filter recovers just enough to improve the experience from something that has no low end into a quite balanced, full-range sound with much more impact. The experienced difference is huge.
  8. X-curve compensation re-EQ

    @SME, I tried the upper-bass/low-mid cut eq on the center now while checking the BEQ, and it worked well for this movie. BooOOomy voices are gone. I have noticed the problem before, but never thinking that this is a result of the calibration on typical monitoring systems, and that it is possible to do something about it. Could also be due to artistic choice to get fuller voices. There is no real dsp in the chain on LCR/surround in this system, but the processor allows for simple manual graphic eq. Easy to implement a crude eq on the center, to improve dialog. The problem with eq on the finished product is that everything gets the same eq, and that may not be the best solution. Doing this for the center only, fixes most of the dialog, while keeping the balance as-is on other sound effects in the other channels. Easy to see the obvious flaw - dialog in L-R and panning will be wrong. Since this will be a compromise regardless how you do it, the center only can be a simple and quick improvement on some movies.
  9. X-curve compensation re-EQ

    Just checked some new movies, to verify they will play, and always curious about the sound. In one they got the low freqs right, amazing how the very last octave has so huge effect on the overall experience. But since I rarely watch movies these days, the "movie-sound" dialogue is apparent once they start talking - it booms, and the upper freq range has a very strange tonal character. So re-eq for the rest, doing not only the bass-eq, certainly makes sense. The problem is to know the eq profile. Doing this properly, for each movie, is just too much work just to watch a movie. But is it possible to do it right, so that voices have a natural tonal balance, without the excessive boom and strange nasality? Perhaps my speakers are wrong? Vocal in music does not sound like this, and a typical well-made documentary usually sounds very good. So it is definitely possible, and the problem is how the sound is made in the movies. The best solution would be if the movies were properly made - no low bass cut to adapt to bass studio and cinema speaker systems, and tonal balance that sounds natural on a reasonably flat system. The next best would be if they could provide a eq profile with the movie, so that it is possible to apply the necessary re-eq with reasonable effort.
  10. Bulding the Room2 listening room

    At moderate loudness levels, capacity will not be a factor. But when you turn it up, there may be very significant differences between something that overloads and the one with headroom to spare. I don't have any cd-speakers here now, but I do have 2 systems where one has the F1 with limited hf capacity in the horn-loaded ribbons, the other has the F2 with horn-load large AMT. The AMT wins, and the difference is obvious when you have the opportunity to compare instantly - same music, same volume, very different resolution and easy in the upper octaves. Something like Jøkleba with the quite loud trumpet really brings those differences - at +6dB, the F1 struggles, while the F2 sound exactly the same regardless of volume. And there may be compression on transients long before it starts to sound really bad. I believe this affects realism. The peak transient level can be very high. I measured this once, on music, and if I remember correctly the transient level was around -6dB at high frequencies, while the rms level in the same frequency range was in the -20dB range. Radiation pattern differences are also very important. A directive horn will throw more sound energy towards the back of the room, while the typical dome will spread the sound more closer to the speaker. This causes significant differences in how the total sound appears at the listening position. In the decay plot they can look quite similar, though the horn will tend to fall off sharper in early decay, and have more late decay.
  11. Bulding the Room2 listening room

    I try to tell they have to find out for themselves. Listen and experience. It all starts with curiosity and an open mind, if they don't want to learn and are not ready to accept that their current beliefs can be wrong, it is hopeless and a waste of time.
  12. Bulding the Room2 listening room

    I think they certainly would hear a difference, but I also think they would fail to tell which is which. The room would also be a major factor here - the horn system would interact different with the room, creating a different sound-stage. And what is a horn speaker - could be anything from something with a hf horn and trad low frequency drivers, or a large system with horn all over. And horns can have very different radiation patterns.
  13. Bulding the Room2 listening room

    Just to continue.. But horns are actually back in fashion - among some people. Not only for home theater, but for dedicated 2-channel. Those systems are typically diy, with large horns, often front-loaded bass horns with directivity control from around 100hz and up. Some of them are now trying SEOS horns. We also have commercial horn speakers, like Avantgarde. Still, it seems like there are two sorts of people - those who like horns, and those who do not.
  14. Bulding the Room2 listening room

    I have never been a dealer or manufacturer of audio equipment, the professional side of this is new with the company Kvålsvoll Design. But I was one of the last people to convert from vinyl, I have had speakers of very different types, though all of them have been designed and built by me. In the mid-80ies I was part working in a local audio shop, so I have quite good experience with commercially available speakers too. But back then, it was not common to find 400 liter ported cabinets loaded with 15-inch woofers with high Bl, in any shop. This was also the time when the Apogees came, and that was something that actually did sound different and on some parameters quite an improvement. If you look in the designs section on my we page, there is a short note about the planar speakers I made late 80ies, with some pictures from a newspaper article. Those could never play loud, but they had some qualities that I suspect my current design never will be able to match. Trying to explain this (about the electronics) to the typical hard-core audiophile is pointless, you will never break through. For those who are not that much emotionally connected to the tech side there is hope, if you get them in to the room to listen. Most of this is actually quite simple. If you hear a difference in a dac, but this difference disappear if you do not know what you listen to, the only logical explanation is that this experienced difference is created in your brain, and has nothing to do with sound. For rational people capable of some very simple logical reasoning, this is possible to understand. But all electronics must be good enough. This does not necessarily cost much money, and as an electronics designer this is obvious to me, the parts to make an amplifier circuit does not cost a lot of money, and there are no mysterious phenomena unknown to science, that strangely only affect audio signals. The cheap amplifier in Room2 has more power, less noise, inaudible distortion - as long as you don't push the output stage beyond limits. Sound quality improve because the noise that was audible on the audiophile preamp is now gone, and there is more power available before clipping. This goes well only because the F2 speakers have decent efficiency, they are true 8 ohm - not "8 ohm dipping down to 3 ohm - and they are placed in a small room. But adding a couple of decent output stages does not need to cost so much either, like I had to in the Moderate Cinema, because the F1s kept on killing the Marantz unsufficiently dimensioned output stages. When we get into functionality, the new cheap amp kills the old on all aspects. I have already mentioned the dsp functionality for delay and crossover to the bass system. Then we have the built-in dac - no need for a separate box, and it has hdmi input for best possible connection to the computer. and then there is the calibrated master volume. No need for this on music, some will say. I say I love it, I always know how loud I have my volume turned up, on any system, because they are all calibrated to the same level. Not to mention when you want to measure something - you always know the volume is correct and repeatable. Then we have the speakers and the room. Not so easy. But solving and leaving those other issues that proved insignificant, at least leave all our time and resources and effort available to improve and solve what matters. And they say "high-end is dying".. Yes, I certainly hope so, to be replaced by good sound instead.
  15. Bulding the Room2 listening room

    This is how it looks up front in Room2 now. Had the photographer visiting some days ago, to take photos of the new subwoofers, and we snapped this picture. It is interesting to notice what is in the media console - rather, what is not. There are only two things left - an amplifier, and the retired cd-player. The cd-player is connected, but never used. This is what has been removed: - Preamplifier - Exotic class-A output stage (25W, lots of heat, no global feedback yet still distortion below noise floor, exotic output devices, single stage input and voltage gain). - A NAS with separate dedicated wireless router. - SOTA CD-player can also be considered removed, as it is never used. This is a picture of todays dilemma in state-of-the-art audio. The very nice, expensive items of yesterday is rendered obsolete. The new configuration destroys the traditional old-style hifi-setup on all parameters except for two - price and looks. It is not very expensive, and it does not look very expensive and sophisticated. The sound is much better, convenience of operation is much better, it takes up a lot less space, it has functionality such as dsp in the amplifier that makes it possible to integrate the bass-system properly. The current system consist of a laptop computer connected to the local network streaming from the server or the net, a cheap amplifier with dsp, dsp amplifiers for the bass system. This system is guaranteed sonically transparent up to the terminals on the main speakers.