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Showing most liked content since 03/28/2012 in all areas

  1. 8 points
    Final quarter of 2017 update. JTR Speakers Captivator 212Pro results have just been posted. KRK Systems 12S2 subwoofer testing is done. Should be posted next. WW Speakers / Mark Seaton designed X21 cabinet loaded with B&C 21DS115-4 driver testing is done. Will be posted ASAP as well. This was tested with both vents open and with a vent plugged and with both the Powersoft K20 and an Inuke 3000DSP. That's 4 full measurement sets. We're killing a lot birds with one stone on this one. We have some information on the Inuke 3000DSP amp driving a real load. We have the 21DS115-4 driver itself, which a lot of people are interested in and lastly we have the X21 vented cabinet which is available off the shelf to fit a variety of pro 21's. I tell you the cab is built solid and of course Mark designed it well. It is not cheap but it certainly offers an easy button option. Next up is a set of 3 subwoofers from one of the commercial vendors. I'm not totally sure these will be public on the site since the MFG reserves the right to decide whether the results are public or private. I believe they will be though as so far their behavior appears to be well designed. And...After that...I have a couple of cabs from a pro audio company that will be on deck. Not sure these will be public yet either but I suspect so. I'm trying to get this all tested and posted by the end of the year. That's the goal. I have more DIY type driver tests sitting in the wings too.
  2. 6 points
    Kong: Skull Island (Dolby ATMOS) Level - 4 Stars (111.38dB composite) Extension - 5 Stars (1Hz) Dynamics - 5 Stars (28.84dB) Execution - TBD Overall - TBD Notes - This film delivers bass in spades, especially in the shake-and-move-stuff wheelhouse range of 12-25Hz. Clipping analysis shows flat tops in nearly every channel, Center is most egregious, but all the clipping appears to have rounded edges as if some sort of limiting was put in place like Pixels, so not completely objectionable, like Tron:Legacy clipping was. LFE channel clips with sharp corners, but low-pass filtering will smooth them out. Better movie than anticipated, but it almost always seems that way when you expect nothing from a film. Good surround use, good soundtrack. BEQ should make this a structure-endangerer. JSS
  3. 6 points
    I just attached the plans to the first post for anyone that wants them. I've had 3 or 4 other people request these plans over in Europe. Hopefully there will be some more documented builds coming up.
  4. 4 points
    I've mentioned it a few times before. A pair of JBL 4675C's. The 2226H drivers out of the double 15" (4508A) bottoms I sold off and replaced with AE TD15M-4 drivers with the Apollo upgrade. They are wired in series. The big 2360A "butt" lenses still have the 2446H CD's on them. Those sit on top of the MAUL's. It is a tri-amplified stereo system run from a Peavey mixer into a DCX2496 which provides processing and routing to the amps. The current amps are a 20 year old Mackie M1400i on the 2446H drivers (Run from about 600Hz up.), a Crest 8002 powers the TD15M's which run about 80-600Hz roughly and a single SP2-12000 currently has a MAUL on each channel running <80Hz. There's no surround sound and I never replaced the old projector after it died a few years back so there is no video right now either. It's just a mammoth stereo or PA as needed. It's nothing special but does the job. Eventually I planned to swap out the 2446H's for some BMS coax's or something Be and probably change the lenses too. Now I'm having thoughts of doing something different for the mids and highs entirely. Try to roll my own Synergy's or other design? Not sure what yet. I'll probably upgrade the amps first. Eventually I'll put my K20's one on each Maul and move to SP's at the house so I won't have to deal with fan noise at home anymore. I want to get a newer amp for the CD's. Only class AB or H for those though. I still don't think class D is quite as good for HF. I might just go with an A500. The power requirements on the CD's is almost nothing even at ear splitting levels. The room is in an old rundown, warehouse / factory, in a ghetto part of town. Myself and the other musicians I work with, have been renting there for 8 years or maybe more. The whole building just about is rented out to musicians, artists or people needing storage. The outdoor test spot is right out the backdoor. The room itself is a shotgun shaped space about 18ft x 15ft x 36ft. Roughly 10,000cu ft. I'm guesstimating and could be off some, since I've never actually measured it. Walls are double carpet hung over sheetmetal and studs with main building supports in there too. Flimsy and leaky as hell but the carpet hanging from the walls and the directivity of the horns actually keeps the space relatively dead. Every surface in the room except for the garage style door and the ceiling are covered in carpet. The room is over the basement level, but the floors are 4 to 5 inch thick cement type material over timbers, so it will shake some, but not easily like a suspended floor in a house. It takes a bit more energy. Ceiling is the same deal. Back wall is a brick interior wall with carpet over it. The back ground noise level is high usually of course. There are no placement options really as the room is jam packed with equipment of all sorts. It is not ideal and there are all sorts of acoustic and structural issues that color the sound. For one my drums usually sit directly in front of one side of the stack. Thankfully the horns are 8 or 9 ft off the floor well over top of them and the bass just goes around, so most of the sound ends up in the right place regardless. None of that matters really because that's not what it's about in there anyway.
  5. 3 points
    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?
  6. 3 points
    Crowsons and even speakers should be fine, like SME said, the LFE channel will have a lowpass that smooths out the corners. I really only found sharp corners objectionable on a few films. Tron:Legacy and Star Trek:Into Deafness were the two that are the worst standouts. But many films clip. Many times it is not objectionable. For instance, both Iron Man and Iron Man 2 clip a lot whenever the repulsors are firing, but I never found it problematic, as the closest thing to repulsors are jet engines, which clip our ears. But when you clip a violin, or something that is very familiar, it just sounds wrong. Star Trek 2009, for all its accolades, clips the warp booms (WTF are they 'supposed' to sound like?). But they still sound great. At the same time, the film clips hardly anything else. JSS
  7. 3 points
    Or, there may not be that much research done on this at all. If the subject has little interest outside audio/hifi - because audio research has always had a tendency to focus on technical properties that may not be very relevant, and less on hearing perception mechanisms. I did a test to find audibility limits for distortion not long ago. Look at these numbers. 440hz: 60dB 2h -34dB 2% 3h -50dB 0.32% 4h -50dB 0.32% 5h -53dB 0.22% 6h -50dB 0.32% 8h -58dB 0.13% 70dB 2h -34dB 2% 3h -50dB 0.32% 4h -54dB 0.2% 5h -65dB 0.056% 6h -64dB 0.063% 8h -72dB 0.025% 80dB 2h -34dB 2% 3h -34dB 2% 4h -43dB 0.71% 5h -65dB 0.056% 6h -72dB 0.025% 8h -76dB 0.016% This data suggests that the presence of a 80dB tone does not reduce hearing threshold when the frequency of the other low-level signal is sufficiently far away in frequency. Because you can see that detection level for higher order harmonics is lower in percentage as the volume increases, and if you plot this data into a frequency response chart, you can see that the detection level remains constant at threshold of hearing around 0dB, with a masking around the fundamental tone. The masking follows the level of the fundamental tone, but far away the detection level remains the same, regardless of fundamental tone loudness. The 80dB fundamental does not reduce hearing threshold, it only masks around the tone. Then we understand 2 things: - Dynamic range is at least 80dB for 80dB sound - Louder means more detail and more revealing to faults in the audio chain So, why did I not test for even louder fundamentals, say up to 120dB? That data could be interesting to have. When I did the test, it was for a different purpose, and 60 to 80dB was sufficient. Louder presents some challenges - more difficult to ensure that the only distortion present is what is being tested for, and listening to tones louder than 80dB up into the midrange is actually so loud it is quite unpleasant.
  8. 3 points
    That may be true, but that 140dB range does not apply for short time spans, because the ear has a built-in compressor that adjusts sensitivity according to exposed sound pressure level. If a very loud 140dB peak occurs, the sensitivity is immediately reduced, so that sound at very low spl can not be heard until the ears recalibrate, and that takes some time. Purpose of this mechanism can be to protect hearing, and also is the mechanism that actually makes it possible to have such a wide dynamic range. How large is the actual dynamic range, at a given moment, for a given spl exposure? Perhaps someone knows, I am sure there has been lots of research conducted on this. This relationship has attack time, hold delay, depends on peak vs rms level. This has consequences. We see that hearing is not a time-invariant system, because the output (what we hear) depends on what happened before in time.
  9. 3 points
    Right...That's what I mean. If you preserve incredibly high dynamic range with digital media that means your average level is going to be very low volume/signal strength, requiring much more gain to get the average sounds to a typical playback level. I wish there were more recordings like that. Just turn up the volume and the problem is solved. But the problem is, if you attempt to play a regular heavily compressed song after, it will blow your head off and make the dynamic recording sound weak in comparison. That's exactly how the loudness war started. Get the average level as high as possible. Louder=better or more noticeable. I'd like to see groups make 2 mixes. The squashed "radio" track and a much lower average volume mix with more dynamics. I see this issue as separate from your speaker system being capable of producing huge short term output. I consider that a reasonable goal that improves sound quality on a number of fronts.
  10. 3 points
    Gjallarhorn 2 plans. GH 2 print.pdf GH 2 print.DXF
  11. 3 points
    Othorn files. OTHORN print AUTOCAD 2000.DXF OTHORN DXF scale print.pdf
  12. 3 points
    Back from the dead... I finally have the last 4 drivers for the second cab and have been slowly installing them. I should hopefully have the 2nd one ready to plug in late tonight. I am not looking forward to moving everything out and putting these back in the corners. I have to pull the first one back out of the corner, pull the hatches and a couple drivers and rewire it the same as the second too. Lift with the legs...
  13. 2 points
    Just made all of the good stuff for this visible. Please discuss here.
  14. 2 points
  15. 2 points
  16. 2 points
    Thanks for the links and for the tips. Unfortunately, the majority of posted images were Photobucketed, as you say. I did look at a few images. Because most of the measurements were of the "Edge of Tomorrow" opener, which is a very different kind of signal, I decided to look at the vibration vs. time data instead. I can post a screen-shot of that measurement it if people want me to, but I think it's rather boring. It looks quite a bit like pink noise. Recall that the test sample is pink noise which is filtered fairly steeply at the top between 40-50 Hz and played at around 97 dBZ RMS, according to my mic, which is not calibrated below 5 Hz. It looks like my RMS vibration values came out to roughly 0.0055 in the X and Y axes and 0.025 in the Z axis. With a little math, I can extrapolate this to the higher levels that would likely present with peak effects, say 15-20 dB hotter, which is a factor between roughly 5 and 10 for a "level quantity" like acceleration. So with pink noise at a more spirited level, I could maybe push over 0.25g on the *really hot* effects. I believe that on something like a PvA, the pink noise response should rise toward the bottom by about 3 dB/octave, which is not unusual for some of the stuff that's bottom heavier. Comparing these extrapolated results to what I see in the thread, it seems I'm coming out on the low end of the results. Unfortunately, very few people are measuring or reporting SPL along with their vibration response, so it's hard to tell just how hot people are running things on that end Furthermore, The "Edge of Tomorrow" opener is not a very useful test signal, and it's most of what I could find on the early pages. While each fundamental frequency in the sequence hits a different part of the deep bass / ULF spectrum, the overall coverage of the spectrum is extremely narrow. I'm thinking that tomorrow I will try measuring a slow sine sweep. Unfortunately, without getting at the raw data and analyzing it, I won't get the kind of noise rejection that sine sweep impulse response measurements benefit from. I could always buy the app and whatnot, but if I'm going to spend money, I'd rather do it right. For now it's not a priority. I'm not especially bothered by the fact that my readings appear to be low. I see a lot of enthusiasm in the thread about gains made by doing stuff like mis-aligning the timing of the subs and compromising frequency response. And of course, there's the interest paid to (alleged) differences between ported and sealed subs. But I have to ask: Is this what we really want? Is tactile response so important that aspects of performance related to frequency response should be compromised? This is an especially important question when one considers that a lot of these responses may be quite ugly and full or resonances. Mine sure is in the low teens. This makes for a pretty lo-fi experience, all things considered. Another thing is that, to the extent the floor is shaking, it's likely the walls are shaking too. That can add a lot of unwanted noise to the bass experience and really kill the immersion. That's something that I believe improved with my multi-seat EQ optimization, and I wouldn't be surprised if my EQ optimization reduced my couch vibrations too. Is that really a bad thing? I happen to really how it sounds, and I can clearly hear ULF well into the low teens when it's above hearing threshold levels. I also love the very tight transient response and "bottomless" quality of the sound on un-ftilered tracks. And if the level is up there, I feel plenty of tactile sensation. It's just rather different from couch shake. On another note, I definitely think I experienced more shaking with the old Hsu subs, which were ported and tuned to 18 Hz or so. However, I noticed this even more at higher frequencies, like 25-50 Hz, above which the near-ish field MBMs took over. I seriously doubt that the fact that they were ported had anything to do with the higher frequency sensations. My strongest suspicious is that this shaking was caused by mechanical vibrations of the cabinet. The D.O. configuration eliminated those and thus "cleaned up" a whole lot of floor vibration. It took some time to get used to less shaking, and I did opt to boost the subs a bit more than before. But I'm OK with the change. To me, having a more vibrationally inert presentation is more accurate and realistic. In other news, I can add "The Incredible Hulk" to the list of movies that I *cannot* play at my preferred listening level with my system as it is calibrated. The university scene played just fine, and was actually a lot of fun. The cop car smash scene did not work out so well. The big hit at the end (when there's practically nothing left of the car) is enough to light up the orange clip lights, at only "-9" on the MV. My preferred level would be more like "-5". For all the effort I went through to get as much ULF as possible out of this system, it's still not enough for these most demanding scenes. When I upgrade the amp power source to 240V, I should get another 3 dB of headroom, but I doubt it will be very useful, being that the drivers are probably close to their clean max excursion. What disappointed me more is that I honestly can't say whether I the perceived low end of that content. Was that effect at 8 Hz? If it was there, it was very subtle. Maybe if I paid attention, I could feel my hair move or something. This is something I'll want to double blind test later along with ULF on more transient sounds. It may be that this content just isn't hot enough to perceive without the help of floor/couch motion, and clearly, I have very little of that below 11 Hz. This would then imply that the content under 10 Hz is of no interest in an *accurate* presentation. The only way you'll know it's there is if the floor or furniture is vibrating to it or if the subs are distorting enough to enhance the phantom fundamental. In a studio with concrete floors and no motion actuators, it may not be perceived at all. This does make me seriously consider Crowson's. If the goal is to make the couch shake, I'd rather use the right tool for the job. Although, this kind of upgrade will be a fair ways off. Unfortunately, I'd need another Motu unit for more output channels. And then I have to worry about my racks getting cramped with an extra amp or two. My sofa is a 5 piece sectional, which is rather inconvenient, not to mention expensive. If I used Crowsons, I think I would low pass them at around 20 Hz. As for the subs, I guess it all depends on how I feel after double blind testing. I have a lot of options there. I can EQ things less aggressively down low. I can use less boost below some frequency. I can also try to implement some kind of frequency-selective limiting, though this gets tricky with ULF if I want to avoid unnecessary phase shift. Another option I might consider is a bit more of a ramp in the ULF, which I can probably get away with if I ramp down or high pass below 10 Hz. There are still a lot of possibilities to explore.
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