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mojave

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Everything posted by mojave

  1. I've built several AE PB18H+ sealed about the size of your desired ported sub size, but the larger woofer size helps out.
  2. Kvalsvoll is right and the Clarity score is only based on reflections as defined by ISO 3382. A Clarity score is based off the room impulse response (RIR). On the RIR the direct sound is set to be relative time zero so it is not factored in the equation. The Clarity score takes the RIR and divides it at a certain time point. The energy before the divider (early reflections) is summed and the energy after the divider (late reflections) is summed. It then does an early to late energy ratio expressed in dB. I use SMAART and get a C10, C35, C50, and C80 score for each octave and 1/3rd octave band and an overall score. C50 is used to score a performance space for speech and C80 is used to score a performance space for orchestral music. However, the lower Clarity figures are helpful for small room acoustics. Gerald Marshall provided a "Poor, Fair, Good" chart in his 1996 AES article called An Analysis Procedure for Room Acoustics and Sound Amplification Systems Based on the Early-to-Late Sound Energy Ratio. He used a weighted average octave band score with 15% for 500 Hz, 25% for 1kHz, 35% for 2kHz, and 25% for 4Khz. My preference for speakers are those that avoid a crossover in any of these bands. My JTR 215RT's have a crossover at 350 Hz and 6500 kHz.
  3. Here is another article about Wonder Woman: Sound Wonder Woman
  4. AES paper 1886 is an "Evaluation of the SMPTE X-curve Based on a Survey of Re-recording Mixers." Here is an article on the sound design goals of Wonder Woman: http://postperspective.com/sound-wonder-womans-superpower/
  5. You have to add the horn path length to the distance of the sub from the main listening position in addition to other delay caused by the LPF or DSP.
  6. The Yamaha CX-A5100 will do a little over 24 dBu (13 VRMS) on its subwoofer output. However, its bass management will clip the signal on worse case real content unless the subwoofer trim is set to -7 dB and master volume control isn't above 0 dB. I've checked 3 Marantz 7702 MKII's in the past two weeks and they all clip when using bass management unless the master volume control was at -3 dB and the subwoofer trim was at -7 dB. With the master volume control at 0 dB and the trim at -10 dB, they still clipped. I tested with How to Train Your Dragon and White House Down. I don't really like Marantz or Denon processors because they are limited to 20 ms of delay. You can't integrate a horn subwoofer properly, use them in large home theater, or add additional external subwoofer DSP (depending on latency of the DSP). Yamaha allows for 72 ms of delay. I am a Denon and Yamaha dealer.
  7. I probably threw you off with the low price. You need to be thinking in the category of speakers that includes the Stenheim Reference Statement or Genesis Prime.
  8. I got to hear a pair of these at their debut at JTR Speakers' 10th Anniversary party. I told Jeff that these might be my favorite of all of his subs. When I was at the 10th Anniversary Party, Jeff showed me a motorcycle engine he was working on. The goal is to produce as much power as possible while staying within the the rules for the class you are racing. Ever since Jeff helped design the original Lab 12 driver, he has been working on producing subwoofer motors with high motor strength and incredible efficiency. This often means not using "modest parts," but using the best available. There is a subwoofer that sells for $30,000+ that sources its voice coil from the same place as JTR. Jeff does further engineering to the voice coil to maximize the power from his amplifier. Jeff said this on another forum, "We spent 1 1/2 years developing and optimizing the Captivator 118 driver. The decision to use the pro audio style surround was made because it maximized the cone area and minimized moving mass while having enough travel. Using to a large, half roll surround would have reduced efficiency (higher mass, less cone area). The cone is custom, well damped and very strong. The motor is the largest and heaviest that Eminence had ever built so we had to go though several processes of getting it approved, including negotiations, drop testing, and manufacturing engineers working out the assembly process. The reason we went though all of this is was to produce the highest efficiency with the highest excursion. The 1/2" thick steel top plate gives us 33% thicker magnetic gap than most of our competitors (commonly using 0.375") which increases motor strength and efficiency. We double stacked 120oz magnets because their larger diameter increases flux in the gap which increased motor strength and efficiency. The 120oz magnets are 1" thick so the pair of them is 2" thick for 2" of clearance between the bottom of the top plate and the back plate which gives us more clearance for increased travel over most of our competitors (using two 0.75" thick magnets plus 0.25" bumped back plate for 1.75"). We went through everything and spared nothing to make the Captivator 118 the best it can be."
  9. mojave

    B&C 21DS115

    Sound Quality = (BL2/Res) / (LE/Res) 1 Acoustic Elegance, TD18H+-4A Apollo 2 Acoustic Elegance, TD15M-4A Apollo 3 Rockford Fosgate, T3S2-19 4 Aurasound, NS18-994-A 5 B&C Speakers, 21-IPAL 6 BMS, 18N862 8ohm 7 B&C Speakers, 21SW152-4 8 18Sound, 21LW1400 9 JBL, 2242HPL 10 Faital, 18HP1060 11 MTX Audio, 9515-44 12 Dayton Audio, UM18-22 13 B&C Speakers, 21DS115-4 14 Dayton Audio, RS-18HO 15 TC Sounds, Pro 5100 16 TC Sounds, LMS-Ultra 5400 17 FocusWorks Audio, GUJ21V1 18 TC Sounds, LMS-5400 19 FocusWorks Audio, GUJ18V1
  10. JRiver does equal loudness contour, limiting, has a multi-band limiter for bass and supports VST plugins. Voxengo makes multi-channel VST plugins and provides compressors, a bass harmonic synthesizer, and many other VST plugins. They all have 64-bit processing so work well in JRiver's 64-bit DSP engine.
  11. B Bag End still sells their Active Bass Trap although I haven't seen it reviewed in years.
  12. If you take 5 db off across the board for CEA-2010 Max Burst, then the S1 would have the following advantage over the FW18: 10 Hz: +0.9 dB 12.5 Hz: +0.7 dB 16 Hz: +2.1 dB 20 Hz: +3.7 dB 25 Hz: +3.5 dB 31.5 Hz: +2.3 dB 40 Hz: +1.9 dB 50 Hz: +1.5 dB 63 Hz: +0.2 dB 80 Hz: -0.7 dB 100 Hz: -0.9 dB
  13. LMS Ultra 5400's are currently $750 at Parts Express.
  14. Yes, I use "normalize by album." Any album with its tracks played back sequentially only uses a single fixed amount for the entire album. This preserves track to track volume levels as intended by the artist.
  15. All my music is analyzed according to R128 volume leveling standards. In order to play the quietest song (Felix Hell - Organ Sensation - Guilmant: Sonata No. 1 in D minor: II. Pastorale) the same volume as the loudest song (Godsmack - Faceless) requires a 33.9 dB adjustment in volume. With 24-bit recordings, stereo tracks can easily have their average levels down 30+ dB from peak. The capability of your equipment and how high you turn it up determines the peak volume, not the encoded levels. Playing 20-30 dB above theatrical reference just means the song was encoded that much quieter to give room for dynamic peaks.
  16. Beast, it looks like you have a bag of Scotts Super Stuff Builder! It works great for DIY builds.
  17. Thanks. I guess I should have watched the video before commenting. I've enjoyed the Soundworks Collection stuff in the past.
  18. Since this was mixed for Dolby Atmos, it maybe followed the the Dolby Atmos specifications for speakers/subs:
  19. The Redbox Escape Plan that I got yesterday only had an DD 5.1 soundtrack. I'd like to use this statement for a discussion on dynamics. The Levels and Dynamic Range criteria used here for scoring seem counter to the actual dynamics available in a movie. The Dynamic Range term used for scoring is actually a measure of the crest factor. Bob Katz, in his Mastering Audio book, and others use "dynamic range" to refer to the difference between the loudest and softest portions in a movie. As is pointed out in articles, dynamic range is used interchangeably for either crest factor or loudness differences. When most comment about dynamics in a movie, though, they are referring to loudness differences. Level The higher this number, the less actual average loudness range a movie will have. This is because the total average loudness is so high. FOH made a post at AVS a few weeks ago that pertains: Dynamic Range If you think about dynamics as the softest to the loudest portion of a soundtrack, most LFE tracks have silence and can peak at 115 dB. Even with the difference between the quietest and loudest actual sound there can a loudness range of 105 dB when combining all channels. A Spectrum Lab waterfall chart will show this loudness range. Comparing the crest factor of two movies tells you nothing about these changes in loudness, how often they occur, and the impact they have on the listener. For example, there was recently this dialog about Elysium in the AVS Master List of Bass thread: Carp: Watched Elysium tonight. There was some nice low bass in it, but as others have mentioned the lack of dynamics ruined it. Defsoundz: I agree on Elysium. For the nature of the movie, you'd expect a much more lively and dynamic soundtrack. Nube: Elysium has measured 5 star dynamics. While not the absolute best dynamics, this is pretty great for an action film that's heavy in the ELF region. Carp: When I said dynamics I wasn't just talking about the bass, it just seemed like everything was in a 10 db range or something. Very often in action movies huge volume swings will make me jump, not even close with this movie. Cowboys: I agree. I posted a while back that this movie did not impress me. GPBurns: probably one the weakest big budget sci-fi mixes in recent history in regards to scene dynamics Nube: When we measure dynamics, we measure the entire track, not just bass. Elysium had over 28dB dynamics, and it really shows in many of the action sequences. I'm not gonna continue to try to change your opinions about this, but Elysium had better dynamics than TIH, WOTW, etc. You can see that there was a complete disconnect here with crest factor and loudness range getting mixed up. Here are some comments by Dennis Erkstine on movie dynamics (few year old):
  20. If you playback on a computer, then it is easy to just select an external subtitle file for a movie. This movie is different in that it was shot twice - once in English and once in Norwegian. The Norwegian version is 119 minutes and the English version is 96 minutes. You would need the English subtitle file for the 119 minute version. Two Versions of 'Kon-Tiki' in Two Different Languages
  21. You decode the audio first off a ripped Blu-ray. You can keep it as the original 6 or 8 channels or can combine all channels into a mono wav file. It can be done using something like EAC3to or JRiver Media Center. Once setup, you can can even pull the audio out of clips in just a few seconds. It takes about 30 minutes to rip the movie, 10-15 minutes to convert audio to wav file, and 2 minutes to run the entire movie through Spectrum Lab. Once the movie is ripped you can also convert the entire movie or any playback range. I posted a guide at AVS in The New Master List of Bass in Movies with Frequency Charts thread: http://www.avsforum.com/t/1333462/the-new-master-list-of-bass-in-movies-with-frequency-charts/8800_100#post_23468771
  22. Yes, I am desertdome at AVS and mojave on other forums. I PM'd you the answer, but I'll post it here, too. When downmixing 5.1 or 7.1 you have to use different levels (as noted in the tutorial). This is because JRiver uses different levels when downmixing the two formats. When downmixing, for 5.1 to 1.0 the level reduction is -1.76 for LFE and -11.76 for all other channels. For 7.1 to 1.0 the level reduction is -2.30 for LFE and -12.30 for all other channels. In order for their to be equal reduction of -10.2 dB for LFE and -20.2 dB for all other channels, the following additional attenuation needs to be added using the Parametric Equalizer: 5.1: -8.44 dB 7.1: -7.90 dB Both the downmix algorithm and the appropriate PEQ attenuation combine to produce -10.2 dB for LFE and -20.2 for all other channels for both 5.1 and 7.1. This gives one the apples to apples comparison. It makes sure that under a worse case scenario, 7.1 coherent channels at maximum levels, that there will never be clipping caused by downmixing.
  23. maxmercy has mentioned that it may soon be possible to create waterfall charts directly from the file. Now one can analyze the exact content on the disc in just seconds with no soundcard involved! maxmercy has been very involved in this process and has confirmed that the procedure creates a mono wave file of all channels mixed together with the proper levels. The mono wave file can then be analyzed in Spectrum Lab. JRiver Media Center recently added a feature called "Convert Video to Audio" that was primarily intended for converting a Blu-ray concert into individual FLAC files (or other format) for playback without video or for syncing with a handheld device. This feature also enables one to instantly convert the audio from a portion of a movie into a mono wav file that can be read by Spectrum Lab. I have created a Tutorial at AVSforum in The New Master List of BASS in Movies with Frequency Charts thread.
  24. I watched the RedBox Blu-ray and it only had a DTS-HDMA 5.1 audio track. About a month ago I rewatched Sky Captain and the World of Tomorrow. It has some very nice bass and is listed as a 5 star movie at AVS. It might be worth adding to the queue.
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