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Showing content with the highest reputation since 09/13/2019 in Posts

  1. 3 points
    I see it's been about two years since my last update. My hardware configuration hasn't really changed in that time. I still have all the drivers I was going to use to build new MBMs, but I'm now not even sure I need them. Building them is a very low priority, and the amp I bought to power them is likely to get used to power my "demo" speaker system instead. OTOH, the DSP configuration has been modified heavily. In other threads here, I've hinted about my discovery of a novel method for optimizing low frequencies. I've made substantial progress on this and also on optimizing high frequencies, which seemed to benefit from more attention after I'd managed to drastically reduce the muddying effect of low frequency problems. Lately, my attention has returned to low frequencies, this time dealing with sensitivity to physical /environmental changes such as the precise location of MBMs and absorber panels vs. where they were when I measured. Just this week, I finally implemented the first algorithmically optimized low frequency configuration. I expected some improvement below 40 Hz, but was amazed by how much the increase in precision provided by computer vs. hand optimization improved the sound from the mid-range on down to the very bottom. I watched some of the scenes from "Ready: Player One" using the @maxmercy BEQ. It's hard to describe the experience. Despite pushing into the 120s dB, the bass never trampled the mids and highs, which came through clearly even on the weightiest of sound effects, yet the bass itself contributed intense physicality to some of the sounds. The slam was impressive, not just because it was there but because it was *everywhere* and in a wide variety of different flavors rather than being a one-note-ish thump as is often the case with PA systems. I also didn't notice any house shaking at all, but I don't know if this will be the case with other movies. As a kind of ironic conclusion to this thread, I figured out that I didn't need 4 MBMs with independent DSP to get "perfect bass response" at all my seats, yet the title seems to be a reasonable description of what I experience now with my optimized configuration. What I mean is that the bass almost feels like it's coming from inside my own body, and this sensation follows me around the room, even when I'm well outside the "calibrated" listening area. This is similar to experiences I've had with superb quality bass systems outdoors, but I'm experiencing this indoors throughout a room that's not especially large nor heavily outfitted with absorption. The low frequency sound in general seems to be completely untainted by the room, and the acoustics of the recordings (whether natural or synthetic) come through with remarkable clarity. Unlike those outdoor systems, I am able to take full advantage of room gain and hit high SPL down to much lower frequencies. Part of the reason I became so quiet about my recent work on my system is that I am seriously thinking about seeking commercial application for my technology. My confidence in this regard has been growing over the last year or so. I'm now fairly confident (i.e. > 50% chance) that I will go into business, in some form or another, with this technology. I haven't worked out the details yet, but I have some ideas. I'm likely to start small with custom / bespoke installs. These could be for ultra high-end home theater or perhaps for mixing / mastering rooms. These early jobs could fund further research into adapting my methods (or developing new ones, where necessary) for cars as well as potentially larger rooms (cinemas?) and outdoor environments. Admittedly, I'm shying away from doing any kind of consumer product because I don't know if I will be able to make my tech work reliably under those circumstances. I don't know if I can really make it "idiot proof" enough, but I can potentially research that too. So with that said, I'll try not to self-advertise too much in these threads. Thus far, I haven't really meant to. I'm just passionate about this subject and am having a very hard time "keeping this great sound to myself". Maybe I should just record my system and post it on YouTube? () Seriously though, from a marketing standpoint I've already lost. Just about everything positive I'd like to claim about my own sound has already been claimed repeatedly for other products that, IMO, don't live up to the hype. So perhaps my best approach is just not to *say* anything and let my systems "speak" for me. That probably means starting small and growing very slowly, which isn't necessarily bad.
  2. 2 points
    Finished a Skram a couple of weeks ago and I love the sound. My wife even commented on how smooth it sounded. Completely outran my tops. I originally put a driver from zxpc in it since the LaVoce was out of stock. Pretty ugly. Anyway got the LaVoce in and this is what I measured quick and dirty. No reference as to SPL - I used the USB OmniMic but I was running a signal flat from computer to mixer to xover. I think I lowpassed it at 200hz; high pass was off. Actually, not sure where I lowpassed it... somewhere above 100 hz. Also, I'm between jobs and would love to sell this to someone. Guess I should post it in the for sale section.
  3. 2 points
    So by request, the comparison of DVD vs BD LOTR Extended Edition. I remember graphing them a few years ago, but with the LF content thread request, I dug a little deeper. Here is the comparo between DVD and BD Fellowship of the Ring: The DVD has the green Peak and red Avg graph, the BluRay the cyan Peak and the green Avg graph. Stats for the DVD mix: DC offset -0.000046 Min level -0.663155 Max level 0.593566 Pk lev dB -3.57 RMS lev dB -32.86 RMS Pk dB -10.99 RMS Tr dB -119.97 Crest factor 29.15 Flat factor 0.00 Pk count 2 Bit-depth 24/24 Num samples 657M Length s 13686.741 Scale max 1.000000 Window s 0.125 The DVD clips in 12 locations across all 7 channels, mainly in the Right Surround channel. Stats for the BD mix: DC offset -0.000048 Min level -0.629489 Max level 0.594391 Pk lev dB -4.02 RMS lev dB -33.07 RMS Pk dB -11.22 RMS Tr dB -234.33 Crest factor 28.36 Flat factor 0.00 Pk count 2 Bit-depth 24/24 Num samples 657M Length s 13697.685 Scale max 1.000000 Window s 0.125 The BD clips in only 2 locations across all 7 channels. The tracks differ only about 1/2dB all around, including only 1/4dB difference in dynamics. They appear to be very similar, likely the same track save for some minor differences when putting the whole thing together. Given SME's prior remarks, and the BD's lack of clipping, I think the BD is the track to get since it is lossless and may contain more HF content compression may take away. Looking at every channel's PvA, it is quite obvious why this track is held in high regard for LF content. ALL the LCRS channels extend to nearly 5Hz. This track may be amenable to BEQ. The Two Towers and Return of the King as I have time. JSS
  4. 2 points
    Here is the requested comparison, I included the 5 most prominent drivers for this cab. It already looks like a small mess, which is why I didn't include more.
  5. 2 points
    Prelim BEQ for Fellowship: Lots of under 3Hz noise, hence the extra highpass down low, now I just need the time to screen it properly. These are long films. JSS
  6. 1 point
    Thanks for the good advices! I´ll be back with some testing results of the materials and maybe we try some cooling systems (not sure yet)
  7. 1 point
    Mines are almost ready as well, just have to put one more varnish coat, put the driver (21DS115-4) in and measure them ! Will post everything there as soon as I'll have the time to setup everything and when the weather will get better here.
  8. 1 point
    So, Im finally going to start building my SKrams.... my new room is finished and getting all the sub stuff buttoned up. I have all the pieces CNC'd. Is there a good order to put it together?
  9. 1 point
    I've mixed shows where the PA with only vocals on it could hardly keep up with the dumkit in the room. I'm talking 120dbA here, room for 150 people. No acoustic treatment, often not even half full. Hardcore drummers with a Snare drum forged on Mt. Doom. I don't mind a little stage bleed in mid-sized venues, as it usually just results in a 1-4khz boost in the cymbal range. That's what we can bring cympads for if it gets out of hand, but at some point it's just too much. It's all about optimizing the sound at the FOH and you have to find the right balance. And if you have issues playing a little less loud (ofc I wouldn't expect anyone to reduce his Metal drumming to conversation volume) you just need to practice more. I've been playing the drums in an Orchestra for 15 years now, that's where you really learn to control your dynamics. On the other side I'm also playing live shows with my Deathcore band and mix engineers often wonder why I'm playing so quietly heh. The 100dbA I was talking about was during the songs with 3s average. Long term average over an entire show (Swiss, Z7, 1200 guests, huge venue) was 95dbA. It was a Punk show, so pretty low crest factor stuff. I was told to stay under 100dbA long term average and was a little intimidated by the main guy telling me that he'd turn the PA off if I exceeded that. He turned out to be a really nice guy thou and told me a story where some guy started a show with 10 minutes of 120dbA average and he just shut the entire thing down. Some people really seem to lose their mind on the mixing desk. A friend recently had problems with loudness measurements at an outdoor event, where he saw the volume exceeding 120db periodically in the logs and they just couldn't figure out what happened. After some investigation it turned out to be freight trains passing by. Great choice of mic placement
  10. 1 point
    I often hear sound guys talk of too much stage volume from the band members especially drummers, but it's not as simple as just play quieter like it would seem to be. It can fundamentally affect the entire feel of the composition for the drummer, the entire band and even the audience since the group now has less energy, especially in the smaller intimate venues where this type of problem usually occurs. Basically you are asking the drummer to tone it down, and not put nearly as much energy and dynamics into the performance as usual. Usually there's a reason these drummers play like this. I'm one BTW...Usually drummers that are really loud are used to playing with little to no PA reinforcement (perhaps just kick if even that) and having to provide the beat with acoustic drums only while competing against amplified instruments. If you think about it there is probably no other instrument that you would literally ask the person to alter their usual playing style and performance in such a big way. I guess you could go to an all electric kit with triggers but that carries a host of other trade offs. In the smaller clubs or bars with live musicians the "PA" often isn't really needed a whole lot for overall volume, but mostly for vocals, samples and other instruments which need a boost in volume. In large clubs and especially arenas there is often enough distance and dispersion to work around loud players and the PA does a whole lot more work in these situations. Anyway that's a subject I'm very familiar with.
  11. 1 point
    120db was unweighted or dbC. You wouldn't enjoy a concert at 120dbA. When I mix shows outdoors or indoors in a venue with a capacity of say 500 and up I like to keep the dbA average at 100, because that's where it 'excites' you but it still doesn't hurt. That also happens to be the European standard and limit/goal for Rock concerts usually. When observing the db meter I noticed that some crowds (cheering of 1000 people and more) easily exceeded 100dbA. When mixing shows in smaller clubs you'll notice that the un-mic'd drumkit already exceeds 100dbA and you're left hoping for the drummer to accept your request for playing quieter or you can't really mix. Legally, you'd have to end the gig halfway through, because the band was 'using up' their loudness units too quickly. I've got two smaller shows in Austria next month, I'll have a look what dbZ I'm usually reaching, but my guess it that it's gonna be around 115db-120db while the kick drum is playing.
  12. 1 point
    Return of the King Extended Edition DVD vs BD: Very similar again, with the BD having slightly better dynamics and more clipping noted on the DVD version. DVD Stats: DC offset -0.000001 Min level -0.541110 Max level 0.589154 Pk lev dB -4.60 RMS lev dB -35.16 RMS Pk dB -10.58 RMS Tr dB -190.65 Crest factor 33.76 Flat factor 0.00 Pk count 2 Bit-depth 24/24 Num samples 758M Length s 15794.069 Scale max 1.000000 Window s 0.125 BD Stats: DC offset -0.000000 Min level -0.630937 Max level 0.592822 Pk lev dB -4.00 RMS lev dB -34.94 RMS Pk dB -10.14 RMS Tr dB -468.38 Crest factor 35.23 Flat factor 0.00 Pk count 2 Bit-depth 24/24 Num samples 758M Length s 15797.877 Scale max 1.000000 Window s 0.125 Crest Factors listed on all the stats are simple ratios of RMS vs peak amplitude, they are not in dB. This film has even more full bandwidth LCRS than the previous two films, with significant infrasonics in the back center channel (DVD and BD), and little roll-off in the LCRS save for under 10Hz. Basically, the DVD and BD presentations of these films are essentially the same. No tampering or shelving like we saw in 'Master and Commander'. JSS
  13. 1 point
    The Two Towers Extended Edition DVD vs BD: Again, virtually identical graphs. Clipping in this film is more prominent, especially in the LCR channels, both on DVD and BD, with more clipping in the DVD version. Stats for DVD: DC offset -0.000001 Min level -0.461359 Max level 0.464815 Pk lev dB -6.65 RMS lev dB -37.72 RMS Pk dB -14.70 RMS Tr dB -1.#J Crest factor 35.74 Flat factor 0.00 Pk count 2 Bit-depth 23/24 Num samples 678M Length s 14125.920 Scale max 1.000000 Window s 0.125 Stats for BD: DC offset -0.000000 Min level -0.521735 Max level 0.440078 Pk lev dB -5.65 RMS lev dB -37.58 RMS Pk dB -14.72 RMS Tr dB -143.65 Crest factor 39.49 Flat factor 0.00 Pk count 2 Bit-depth 24/24 Num samples 678M Length s 14131.499 Scale max 1.000000 Window s 0.125 Similar stats with slightly more dynamics on BD, but essentially the same track. This film had some strange filters applied to the LFE channel, and full bandwidth LCR channels, extending even deeper than FOTR. It is BEQ-able, with a possible pre-post: JSS
  14. 1 point
    Btw I posted the Skhorn driver comparison to the Skhorn thread. Skram should be similar (in terms of differences between drivers). Noteworthy is that the cheaper drivers all offer the same headroom, the Eminence more bottom end headroom and the IPAL more overall headroom. IPAL is above the Eminence at all frequencies, the difference ranged from a fraction of a db to like 3db around 80Hz iirc. I also just ordered two more 21DS115, but I won't be building Skrams, or I could post some measurements. I'm currently more interested in my own design, which models just to my liking (Skram is too big).
  15. 1 point
    I'll reply a bit more later but let me say that when modeling for maximum output, otherwise known as "Bench Racing", there are a number of limitations about simulations that should be kept in mind. 1.) Sims are usually greatly simplified and usually lack a variety of effects that occur in the real world like non linearity in the drivers BL, suspension, thermal effects in the voice coil, port and other air flow related losses, etc. All of these cause compression of the output. 2.) Sims are only as good as the data input. 3.) Amplifiers are not constant power devices, they are constant voltage. Speaker impedance varies with frequency. 4.) System output is usually limited by a number of different factors. Driver excursion, amplifier voltage, amplifier current and the resulting amplifier power are the main limitations. Which limitation kicks in first depends on the frequency range. There are also other factors such as vent compression, PR excursion limitations and thermal compression or power handling of the driver to consider. Horn Response allows a good approximation of max output based on entry of a number of these parameters. This is what Peniku was showing in his simulations. Limiting by wattage isn't really the best way to go about it. 5.) Power handling and xmax ratings are not all created equal. 6.) Eq can modify the driver excursion profile and which frequencies run the amplifier or driver into the limits first.
  16. 1 point
    Godzilla: KOTM has an improvement: It gains some needed heft and slam, but the film overall is lacking. Will post BEQ correction later. JSS
  17. 1 point
    Notes and free-air specs for these gigantic 24" drivers have been posted under the driver page. These weigh in at a back straining 115lbs and are capable of 4" peak to peak. Beef it's what's for dinner
  18. 1 point
    I'll see how much information I can sweep up, but I can tell you that a fixed HPF is present on almost every mic-pre nowadays and it is very often being used. When it comes to plugins, you almost always see Waves plugins being used. I could also imagine that removing ULF could be a part of de-noising. That is typically done in iZotope RX, which I own but have not used yet, so I can't tell if that is happening there. What I think is most likely is that the HPFs are baked into the SFX files directly, which also explains why you sometimes see a graph that looks like several different low shelves were cascaded (the result of stacking effects with different HPF points). I should go through some of my sample packs and see if these come with a HPF in place right from the store.
  19. 1 point
    But why neuter the sound below 25 Hz unnecessarily? If a system can’t play that low, it’s just like systems that can’t play to 20,000 Hz, no big deal. But once they start putting these canned filters in the bass, they’re negatively affecting the soundtrack for no good reason. I wonder how many would cry if they started rolling off the top end at 18,000 Hz. Oh well, I was about to write, I wish I knew how to get through to these soundtrack engineers and then I thought about them having a trade group or society. Does anyone know what group the soundtrack engineers might be members of?
  20. 1 point
    Ahhhh. I think you're right. Unfortunately according to the SI website that may be the case for these drivers, which is a shame. I wonder how many were sold at the sale price last holiday season. Perhaps it'll be a small batch as requested type of deal. I need to get my ass in gear and figure out what type of cabs I'm going to build to test these. I still have the giant sealed cab from the original HS-24 testing. I'm tempted to see if I can somehow cram 2 or 3, 6" aero-ports in that cab without too much trouble.
  21. 1 point
    Ports are complete, PL max is curing, and 4 out of 6 pieces of wood are glued together, I had a good friend and AES fellow come by and help out.
  22. 1 point
    While fooling around with some 18" pro drivers I found that if you wanted them to play down to 30Hz (F3, not F10), the cab required would be so big that it could also fit a 21. Since most 21" drivers cost just a tad (maybe 10%) more than their 18" equivalent, going with 18" doesn't make much sense imo. If the cab is too deep for you, you could trade some depth for height. That would extend the horn section, but you might run into issues with the port length. Maybe make it very tall and compensate for the shorter port with added back chamber volume. If it's tall enough, the horn section could also be a single segment, or well, a big segment and the small segment which opens to the front.
  23. 1 point
    @Droogne It would lower the rear chamber volume and then the bass reflex tuning would go up. If others can confirm. You'll not reach 30hz if you reduce the depth, maybe 35hz with 70cm but with 60cm, you're losing a lot. You can edit the hornresp sim to see what you're gonna lose exactly.
  24. 1 point
    DXF files uploaded to the first post...
  25. 1 point
    Wow! Great job! Fantastic attention to detail. Can’t wait to see the final result.
  26. 1 point
    This is a shot of the inside of the elbow before the other lengths were added. A few coats of Duratex with sanding in between make the surface fairly smooth.
  27. 1 point
    For whatever reason I cannot get the DXF to attach here even though I had no problem with the Othorn, GH, Skhorn, etc... You can pm me your email address and I'll email it to you.
  28. 1 point
    Avengers: Endgame (Dolby ATMOS 7.1 channel bed) Level: 4 Stars (110.9dB composite) Extension: 3 Stars (16Hz) Dynamics: 5 Stars (29.44dB) Execution: TBD Overall: TBD Notes: the DTS 7.1 track is not as dynamic as the ATMOS track. JSS
  29. 1 point
    Huh??? What makes you say that "all of the amps limit"? Speakers are not purely resistive loads. The average impedance is far higher than the nominal and even so 3000 watts or so of true average power into a speaker is a TON of power. You can clearly see trends in the sub compression during the sweeps well before the loudest sweep. There are only a few cases where the amplifier limits during the sweep. Most of them are extremely high power multiple driver cabs (MAUL, Skhorn) or systems with an impedance too low for the bridged K20 ( 1 ohm or 2ohm nominal load,( RF-19, dual 21IPal, SP4 18D1)) or where the SP1-6000 has not enough power. Even in those cases ONLY the loudest sweep runs into amp limitations. In those few cases what is the alternative amplifier that will provide an increase in headroom over a bridged K20 or a SP1-6000? In what case would MORE amplifier than this be put on a single cabinet? The speakers are tested with both a very long duration signal and also very short duration burst signals. The data is there to make judgments on how the cabs respond to both and what will happen with normal signals that are in between. The long term output sweeps do not show heating of the voice coil only. They also show the effects of suspension changes and loss of excursion linearity beyond Xmax as well. There may also be some amplifier limiting in the loudest sweep for passive cabs. All of these things are shown in those graphs. If you want to see the effect of thermal effects only look at the repeat lower SPL sweep taken after the build up to the maximum sweep level. This is the one that shows how much shifting and heating has occurred in the driver with the amplifier and excursion related changes removed.
  30. 1 point
    The output power of a K20 vs an X4 K20: 145 V RMS for less than a second at 2.05 ohms both channels driven Then it limits to 58 V then it goes down to 52. This means 10.5 kw per channel for long bursts 1680 watts for 4-10 seconds 1350 watts per channel for almost a minute then thermal protection. Similar output is offered at 2.5 ohms , 70 V RMS for 4-10 seconds. This time constant depends on the internal temperature. The X4 can do 2950 W for 2 seconds at 4 ohms, then 1600 watts per channel at 4 ohms for 20 seconds single channel. 2*2650 w for 0.8 seconds then 950 watts per channel at 4 ohms for 12 seconds 2 channels driven After 20 respectively 12 seconds, the amp shuts down the output, going into protection. There is also a review of the X4 on Production Partner showing interesting result with all channels driven at the same time with the same signal. Ipal module is pretty small. Maximum output power is 4500 watt for 0.3 seconds then it will reduce to 2500 watts for 3 seconds then it limits to 700 watts continuous for 35 seconds then down to 400 watts for long term. K3 at 2.3 ohm load will deliver 3150W per channel for less than 0.4 seconds both channels driven, will then go down to 1450 for a second then slowly down to 500 watts a channel in 1.5 seconds. Why I receive this thread? Because now Powersoft launched a new model, X4L , a forced bridged X8 amp, that has 4 channels with 300 Vpeak and 140Apeak. If 2 X4 channels can deliver that sustained power and program power, then I believe the new X4L will surpass the K20 if asymmetrical loading is used. The idea is that a series loaded 2*21Ipal loaded Skhorn presents a pretty high minimum impedance for a K20 so mostly the output is voltage limited in normal use. Bridging the amp would be too much for the long safe run and very expensive. With this new model, voltage will not be a problem anymore, the maximum average output power is high enough for using 8 21 Ipal on 4 channels and. It can be almost 3 dB louder on peak output than with the K20 but with awesome processing and three phase ready.
  31. 1 point
    Hey I resemble that remark!
  32. 1 point
    The idea behind this build is to learn. I started my company to sell subs, because here in this part of Europe, there is a very deep lack of powerful high quality bass Mostly I wanted to see people's reactions, the power density, the extension, to see if the weight and dimensions are a big problem. They are now installed in a basement where we got them by hand. I wanted to see about the power compression, port noises, chuffing, I have learned how and why to install protection grilles, handles, wheels, I wanted to see if I can improve their performance in any way without any other compromise except cost and complexity. I wanted to learn about braces, hatches, accessibility. These gave me a good insight on all of these These subs will be loaded with 21ID and Ipal modules and will permanently stay in rent in a small club where people love good sound. Based on what I learned, I'll continue my other designs and after all 4 designs will be ready and I'll have a stock of 4 of each, I'll publish the specs, measurements, graphs , technical details , pictures and videos and I'll start selling those.
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