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mojave last won the day on October 13 2017

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  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.
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