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Showing content with the highest reputation on 02/28/2018 in all areas

  1. 1 point
    I agree with much of what you say. I've thought about this for a while. Frequency response of subwoofers should have an output rating attached with it to keep things honest. Otherwise you get things like tiny 10" powered subs claiming 14Hz extension and other nonsense like you mentioned. For subwoofers I would like to specify a "useful" range and not worry too much about +/-3dB or whatever. What I do worry about is how much output a subwoofer is capable of. In my opinion this must be attached to the FR rating. These days almost anything can be equalized flat to very low frequencies. Who cares if it gets flat down to 14Hz if it can only produce 75dB? The way this would be kept honest is by attaching a detailed output rating to the lowest useful extension claimed. Too much detail is overload, but not enough allows specsmanship, or gaming the system. Balancing the 2 is tricky. The output rating itself has to have all the details necessary to make it comparable and honest. It must note whether the output is calculated or measured, microphone distance, whether it is a peak reading and whether the environment is full, half, quarter-space, etc. Distortion such as via Don Keele's tone bursts would be nice, but not required. Also absolutely necessary is the frequency used for the output rating. This is what I would like to see used. It keeps things as simple as possible, but provides the necessary detail for some sort of quick comparison. The attached measurements are from the dual opposed 24" sealed cube with 21Ipal's and a SP1-6000 amp as an example. There is a raw FR and the distortion limited and maximum output bursts. I'm using this one as an extreme example since it is sealed and has ridiculous upper bass output which skews the raw FR by a huge margin. Clearly no one would run this system sans EQ. Almost any bass system these days will employ EQ for response shaping. Certainly any active / turn key sub system for sale. It would be quite easy to make this response shape flattish to an arbitrary low frequency. Say 20-150Hz +/-3dB for example. Let's call that the FR rating and assume that was done. There will be a limit to how loud the sub can be pushed before it starts to limit the low frequency output and the response shape is no longer maintained. In this case the all out max burst of the sub was measured at 113.7dB at 20hz. I'd like to see the output rounded to the nearest 0.5dB so as not to get into splitting data points of less than 0.5dB between units, so let's call it 113.5dB. I'd call this "minimum output" or something like that. Many subs will also define a useful frequency range which is a bit looser (sometimes +-10dB) and beyond the tighter FR spec. This being a rather high output sealed sub we could reasonably call the useful lower FR limit as 10Hz. Let's call the "useful FR" 10-150Hz. That being the case we should also specify the max output at 10Hz since it is claimed to be useful. That would be 102.2dB all out with no THD limit. Rounded down to 102dB. A maximum in band output would also be useful. as we all know it's much easier to make something really loud at 150Hz than at 15Hz. Personally I think all subwoofers should be rated at 63Hz or lower for maximum output. 63Hz is a legitimate bass frequency which will avoid cheating and using peaks in output up above 80Hz (or even an octave higher) for a "sub". If the sub has peak output at a lower frequency great, however the DB the measurements show that to be a very rare sub indeed. 63Hz is also high enough in frequency that any cab calling itself a "sub" should be able to hit it in bandwidth with power. In the case of this sub we would use the 63Hz burst which measured an even 130dB. The ratings for this sub would look like this. Frequency Response: 20-150Hz +/-3dB / Half-space / 2m (assuming after DSP of course) Minimum output with rated Frequency Response: 113.5dB SPL@20Hz / Half-space / 2m / Measured Useful Frequency Range: 10-150Hz Useful Low Frequency Output: 102dB SPL@10Hz / Half-space / 2m / Measured Maximum Output: 130dB SPL@63Hz / Half-space / 2m / Measured
  2. 1 point
    When I first heard about it, I thought wave-field synthesis (WFS) sounded like a really cool concept. I'm a lot more skeptical now. Part of the problem is that a system of immense complexity (and expense!) appears to be required to achieve a high quality realization of WFS. Second, it's not clear that its really solving the right problem. In its ideal realization, WFS can synthesize a complete, spatially consistent (or spatially-dependent, if so desired) sound field within a listening space. This is basically the Holy Grail of audio. If an entire sound field can be reproduced in the space perfectly, then the reproduction is absolutely true and correct. In reality though, WFS cannot be realized ideally with any practical configuration of existing components. As a consequence, there will be errors in the reproduction. On paper those errors may be fairly minimal, especially compared to the gross distortions to the sound field induced by the effect of acoustic boundaries in a "normal" system involving speakers playing in a room. However, it turns out that people are very well adapted to listening to sources reproduced in rooms with complicated acoustic effects; whereas, they may not be that well adapted to listening to the errors that arise from WFS. From some reading, it would seem these errors have been minimized enough for the strengths of the technology to be fully appreciated. That is encouraging, and I'd certainly like to hear a setup some day. I'm sure it has its benefits and its applications. Though I can't help but wonder how much better the tech could be if wasn't so obsessively focused on creating a perfect / anechoic sound-field replica and instead took advantage of the acoustics of the space its in to achieve a smoother, even if less "correct" sound. Edit: I forgot to add that I'm in the early planning stages of trying to build my own arrays consisting of many independently-controlled elements, to be used as surround and/or Atmos speakers that provide far more even seat-to-seat coverage than conventional speakers could achieve. I'm not sure if the approach I plan will look like WFS or not, but I have rather different objectives in mind, so who knows?
  3. 1 point
    NEW playlist: The Demo Tracks - Advanced: Moving into more advanced territory, with music that requires more both from you as a listener and your sound system. https://tidal.com/playlist/4337c9a0-0405-48db-94ac-7dfd5fe6e46c # Title Artist Album Time 1 Poppkorn Jøkleba Jøkleba! / Nu Jøk? 3:20 2 Shopenhauer Jøkleba Jøkleba! / Nu Jøk? 3:47 3 All Through the Night Emancipator Safe In the Steep Cliffs 4:33 4 Rattlesnakes Emancipator Safe In the Steep Cliffs 4:10 5 Kleine Dreigroschenmusik (Arr. for Chamber Ensemble) - VII. Cannon Song: Charleston-Tempo Chicago Pro Musica Medinah Sessions 2:20 6 Shamanimal (Live at Satellit Café) Hadouk Trio Utopies 7:10 7 The Golden Striker The Modern Jazz Quartet No Sun In Venice 3:41 8 Vals (En Vivo) Puente Celeste En Vivo en Cafe Vinilo 3:56 9 Buey (En Vivo) Puente Celeste En Vivo en Cafe Vinilo 7:58 10 Taquito Militar La Segunda Será Una Noche 3:35 11 La Roca La Segunda Será Una Noche 5:06 12 Ascent Lyle Mays Lyle Mays 6:59 13 Flowmotion Vestbo Trio Flowmotion 4:19 14 I Love Paris (Live) The Hot Sardines Live At Joe's Pub 5:17 15 Rainfall Daniel Herskedal Slow Eastbound Train 3:37 16 There Are Three Things You Cannot Hide Love Smoke and a Man Riding on a Camel Daniel Herskedal The Roc 5:01 17 Pink Froid Infected Mushroom Converting Vegetarians II 7:40 18 We the Dub Yore Salmonella Dub Dub for Straights (1993 Sessions) 3:44 19 Dirt Bikes And Street Vendors The Flashbulb Soundtrack to a Vacant Life 1:55 20 Swollen Trees The Flashbulb Soundtrack to a Vacant Life 2:28 21 Rose Hierarchy The Flashbulb Nothing Is Real
  4. 1 point
    Tidal playlist "The Demo Tracks Part 1": Description Assorted demo tracks, put together from the collection built while listening to Tidal in the Kvålsvoll Design Room2. This is the "popular" list - music which is easy to like. Some of these tracks are often played in showrooms and exhibitions. This is not a selection of productions with exceptional technical qualities, rather examples of diversity and variation both musically and in sound style. Some have obvious flaws - if your sound system is good, it will still present the music. Tracks on playlist 1 How It Feels (Album Version) Sophie Zelmani 2 Ticket To The World Ayo 3 Cocaine Eric Clapton 4 Tin Pan Alley (AKA Roughest Place in Town) Stevie Ray Vaughan & Double Trouble 5 Summertime (Alternate Take) Janis Joplin 6 Trampled Underfoot Vanessa Fernandez 7 When the Levee Breaks Vanessa Fernandez 8 Here I Am Now Steve Gadd 9 Be Brave My Brightest Diamond 10 Train Song Holly Cole 11 Little Things India.Arie 12 Us and Them Anne Bisson 13 I Miss My Love Anne Bisson 14 Island On An Endless Plane The Flashbulb 15 Four Women Malia 16 As Time Goes By Viktoria Tolstoy 17 Get Lucky Daft Punk 18 Royals Lorde 19 Goodbye Yellow Brick Road (Live in Atlanta) Sara Bareilles 20 September in Montreal Anne Bisson 21 Stay Yello 22 Everything I Need (Album Version) Keb'Mo' 23 Le vent souffle encore Vincent Bélanger, Anne Bisson
  5. 1 point
    Just wanted to mention a side-effect of having a true full-range system, something the typical data-bass reader can relate to; You sit down in the carefully located listening chair, put on some quite ordinary music - jazz with vocal, acoustic instruments, perhaps some classical with a small string quartet ensemble. Sounds nice, the ears warm up a little, and you increase the volume slightly, usually end up keeping it at 0dB. Then - suddenly, out of nowhere, this string quartet makes the whole world kind of shift as a very powerful pulse of ulf noise makes your heart stop. You don't really hear it, you feel the air blast and the movement . Like in a well-done action movie - except that in the movie, it is expected, appropriate and part of what makes the experience better - and you are don't get scared. It is obvious that not only movie production studios lack low frequency reproduction capability, music studios have the same limitations, and they don't need it either for the string quartet. Except when someone stomps the floor, or touches the microphone housing, and a microphone picks up this and creates an earthquake on the sound track. If the recording is processed full-range, and no one checks for sub-20hz noise using a spectrum analyzer, this will go unnoticed. Until I play it on my system. At 0dB. Lots of recordings have ulf noise that is audible, and some have these occasional potential heart-attack inducing monster transients.
  6. 0 points
    Tonight listening to music fairly loud, hitting the peak limiters in the iNuke 3000 DSP, suddenly I had red rings of death. I did have a saved preset file, and also some screen shots of the DSP settings. The amp made 6 years before it failed.