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  1. 7 points
    So close. Loading drivers and doing the wiring today
  2. 6 points
    Ok... report after 3 full days of Skram use. Josh, thank you for this amazing design! I am simply blown away that this kind of performance can be had through diy designs, you are doing the music world a huge service with your knowledge and plans! I do feel I need to apologize if I created any doubt in my previous posts about the low frequency output of these things.... a stack of 4 center clustered with all the mouths centered to each other create just a crazy amount of output, they blur your vision and make your voice change haha! After the feedback from earlier discussions I added some parametric eq to flatten the the raw response (thanks SME) and they really seemed to respond well to that. They still retained the incredible kick and midbass impact while also having literal giggle inducing deep gobs of sub bass output. They are just so incredibly clean and powerful no matter what you put into them, just stunning really. Following some recommendations in another thread I had my limiters set as per the recommendations for 45 volts / 500 watts during bass music acts and lowered it to about 35 volts or 300 watts during our techno and psytrance acts. I never needed to run them up to these limits, they provided tons of output to easily keep up with my sh-46's. The combination of the skrams and danleys is just amazing, I couldn't be happier. I didn't take any videos myself as I was running my ass off all weekend, but a friend shared this iphone video with me. Ben Rama from Techgnosis records playing some super minimal atmospheric tech trance. If you listen with headphones you can get a sense of how powerful and clean the dynamics of the skrams are. Kick drums and bass feel immense, and clean clean clean. Video taken at about 150 feet from our visuals booth. And a pic of the set up https://i.imgur.com/IGh2BDp.jpg
  3. 5 points
  4. 4 points
    It's hard to believe, but I've finished my subwoofer - global pandemic be damned. It seems like it took forever, but at some point you just have to stop. Painting the box the way I did greatly increased the time it took. Leaving it square & painting it with truck bed liner would've saved me weeks. No matter now. Here's the finished box. Just so someone will know I painted the bottom the same way... here's the bottom. Because I have a dual 2 ohm voice coil driver, I wired it in series. I ran one wire to connect the negative of one coil & the positive of the other voice coil. Then the internal wire was split with the positive to one coil & the negative to the other. My concern over getting the driver positioned correctly so I could get the screws through the holes in the baffle was unnecessary. With only a slight bit of adjustment the screws lined up & the driver was tightened into place. Sliding the ports in & attaching them with 4 screws was even easier. Voila! I couldn't let a comparison with my former 100 watt 12" Polk sub be overlooked. I took a picture of my entertainment center with the Polk sub in place. Now with my new SI SQL15 sub with a 1100 watt Crown amp - with & without speaker grill: It sounds absolutely wonderful, but I don't have a microphone I can use to give you any kind of performance data. I'll get to that soon. But I want to thank all the people who helped me get through this process - especially @dgage who helped me set up a visit with Nick at Stereo Integrity along with other good advice. Everyone was so gracious to this old man that I can hardly express the extent of my gratitude The picture of my MDF was taken on Jan 21. On June 5 I hooked it up & listened to it for the first time. Worth every minute.
  5. 3 points
    I will try to explain as best I can here. Shorting rings don't act mechanically, at least not directly. They magnetically interact with the voice coil to reduce and/or linearize inductance through the driver's stroke. The voice coil is a natural inductor. Inductors store and release energy via the magnetic field in their proximity. For a straight wire with pure resistance, the current responds in perfect lock-step to changes in voltage. If an inductor is subject to a sudden increase in voltage, however, some time and energy are required for the current to "spin up" the magnetic field. At that point, if the voltage is suddenly cut to zero then the current flow continues for some time while the magnetic field "spins down" and releases stored energy. Hence, rapid fluctuations in voltage tend to be smoothed out in current, e.g. high frequencies are reduced. This is a major cause of high frequency loss and sometimes "humping" in a speaker driver's response. At the same time, the inductance itself is likely to vary, not just with frequency but with changes in instantaneous current and/or driver stroke. This is *non-linear* behavior, which causes distortion, including inter-modulation distortion, which may be particularly undesirable. Though the linear aspects can also be degrading if not precisely corrected with EQ. The response "humping" alters the spectral balance and likely imparts a non-neutral characteristic sound. A shorting ring is made from a material that is both magnetically and electrically active. The magnetic field generated by the current induces current flow within the ring. The ring "shorts" this current to the rest of the driver assembly, allowing some of the energy in the magnetic field to be transferred to the shorting ring and dissipated as heat instead of stored. If designed correctly, this effectively reduces the inductance of the coil), and depending on the position of the rings vs. the voice coil, may also keep inductance from fluctuating as much throughout the stroke. The relationship between inductance and damping is via the electrical impedance. Impedance is essentially a 2-dimensional quantity which can be described in terms of a pair of parameters: either *magnitude* and *phase angle* or *real* (resistive) and *imaginary* (reactive). Inter-conversion is possible via basic trigonometry; see the "Complex plane". Damping is a property of the resistive / dissipative (non-energy storing) component of impedance. Pure inductance and capacitance both contribute only to the reactive (energy storing) component of impedance. Speakers using a composite electrical circuit that has effective resistances, inductances, and capacitance contributed by several different factors including the mechanical and acoustic properties of the system. So needless to say, inductance and "damping factor" both contribute to the system behavior in a way that's not simple to describe. To answer your last question: No. I mean, if the resistance of your speaker wire is high enough be a problem in the absence of shorting rings, then shorting rings probably won't fix that problem.
  6. 3 points
    The CKRAM is a compact, single 21" subwoofer, that is designed to be flexible enough to suit a variety of applications, but is primarily intended for sound reinforcement or Pro use. Dimensions: (24" / 610mm) Width x (30" / 762mm) Height x (28" / 711mm) Depth Drivers: Most of the good pro audio 21" drivers will work well in this cab. The Lavoce SAN214.50 is a good budget option. The Eminence NSW6021-6 is what the CKRAM was designed with during modeling. It or the B&C 21Ipal are top tier options. Other drivers that should work well include 18 Sound 21NLW9601, 21ID, B&C 21SW152, 21DS115, etc... Design: The CKRAM is a hybrid 6th order design in some ways similar to the SKHORN and SKRAM designs but notably different in others. The CKRAM has a multi-port back section which allows for adjustment of the port tuning to suite the application. The front section is in effect an extremely short, symmetric, horn/slot/small vented chamber. The front assembly is intended to be removable and the CKRAM can also be operated in a standard vented alignment. Vent Tunings: Note that the CKRAM can be operated in 6th order or standard vented operation. In either case the vent tunings remain the same. All vents open = 30Hz 3 vents open = 25Hz 2 vents open = 21Hz 1 vent open = 15Hz Horn Response Models: These should be close. The inputs for each vent configuration are included. The match is quite close to a much more detailed Akabak model. Use the semi inductance specs for the driver you are simulating! NSW6021-6 semi inductance This is the Akabak script if anyone wants to dive that deep. ckcomplx.aks
  7. 3 points
    It's my dad's and my shop, yes. The biggest benefit is that my recording studio and my equipment storage area are in the same building. Plus everything is well isolated (acoustically) so that I can work way past midnight without anybody caring. The CNC was the latest addition to the shop last summer and it has easily been the most used machine in the room ever since 😊 It may look spacious, but it really isn't. There are machines everywhere!
  8. 3 points
    Hi Everyone, I have taken @dsl1 files from page 15, edited them to test the fitment of everything on my laser scaled for 5mm and 3mm thick birch ply. I have made a few minor adjustments so far and created a good assembly test setup 6.5" wide, 10" tall and 9" deep. I have ordered the handles, T-nuts and Duratex from Parts-Express. I have to say I really like the updated design that eliminates all of the multiple bracing pieces in the original design files and combines them into larger single pieces for faster assembly. I plan on changing some of the joints on my files so that the edges interlock when I do go to V-Carve and CNC cut the full size design. I also plan on adding a piece that covers all of the front ports for storage so no critters get in and make a mess. Once my scaled files are done for the 3mm and 5mm birch I will share the illustrator and dxf files so anyone can make a mini box if they would like to as well. I like physically handling the box at this scale, it helps me visualize the assembly and work through any kinks.
  9. 3 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
  10. 3 points
    Hope everything is good with you Luke. Good luck with the sale.
  11. 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.
  12. 3 points
  13. 3 points
    Na, they are in our studio with the big Danleys. Had about a dozen friends over last night for a listening party with the new Tool Album. Holy shit! I am continually blown away with these Skram subs. Danny Carey's drums sounded so immense! kick drums right in the soul haha! In all seriousness we collectively agreed that none of us have ever heard kick drums sound this good out of a soundsystem. Made for a super memorable night, fuck going to concerts lol!
  14. 3 points
    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
  15. 3 points
    Wow! What complete and utter rubbish. I'm not going to question the author's reputation as a mixer, which may or may not be well deserved, but most of what's written there is embarrassingly wrong. It's hardly unique to the author. He's just perpetuating myths that are widespread throughout that community. These myths come about because people are trying to relate their subjective experiences with sound to objective principles, without sufficiently understanding the latter. One of the worst issues I see are that he blames "muddy sound" on rooms being too small for the wavelengths. That's only true in a very ironic and roundabout way. It ignores the fact that mud is at least as serious of a problem for frequencies in the 100-500 Hz range, whose wavelengths are also long enough such that the speaker/monitor interacts with nearby large boundaries from walls and in particular the mixing consoles (!!) in widespread use. The picture even illustrates what appear to be a bunch of narrow EQ cuts, which while much less offensive than equivalent boosts, nevertheless are likely degrade the sound quality of the tracks substantially to the extent that they reflect problems in the monitoring system vs. the actual soundtrack. Worst of all is where he suggests using a sub-harmonic synthesis plug-in to "boost [the sub frequencies]" *as an alternative* to installing a subwoofer into the monitoring system. This is completely confusing the critical distinction between *adding more bass to the monitor system* and *adding more bass to the soundtrack*, which I would expect any competent mixer to understand and appreciate. Yet, this confusion also is not unique to this author and seems to be widespread among mixers. And because the mixers running these plugins can't hear what they are actually doing, this is actually a "worst of both worlds" solution. To emphasize the wrongness there's this sentence at the end: And what exactly do plug-ins, used to alter the soundtrack, have to do with whether *your monitoring system* has a subwoofer? Nuff said. Now with that criticism out of the way I want to point out that I don't think the author is incompetent nor is he trying to deceive people intentionally. He is correct that the mid-range is the most important part of the spectrum, even for "bass" instruments and "bass" music genres. He is writing based on real lived experience of how systems with subwoofers sound and what it's like to work with them. The reality is that good sub integration, with or without "auto EQ" tools, is quite difficult and is beyond the skill of many mixers such as himself. For many such people, monitoring with *no* subs may be better than monitoring with *bad* subs. It's hard enough to deal with the issues in the 100-500 Hz range that are common to every studio using "near-field" monitors and/or a large mixing console. Throwing a sub into the mix is likely to only make things worse. I also agree with his implication that soundtracks often have too much sub boost in them. This is very common for movies which (surprise surprise) are mixed under bass deficient conditions, but it's also becoming quite common with music releases. I get the feeling that excessive sub boost on soundtracks may be the major reason for him to write the article, yet his advice is essentially the opposite of what's likely to help. At the same time, I feel sorry for him and many others like him because it's clear to me that he has probably never heard a good small-room bass system in his life, despite his professional pedigree. They just assume that bass cannot be reproduced in small rooms like it is in large rooms or outdoors because they haven't heard it done before. Perhaps if they knew what was actually possible, they would have a quite different opinion.
  16. 3 points
    Correct, we just glue with PL Premium 3X and then clamp for 24 hours. Wood glues, when used correctly, are stronger than the actual wood. I’ve tested this by gluing two parts together at a right-angle and then swinging the wood against a tree, the wood broke but the joint did not. We tested the 8X and did not like it as much though I think cost had a lot to do with it since we have to worry about cost in a production instance that DIYers don’t have to worry about. But I’m willing to pay more for better performance, but we liked the PL 3X better. Here is a video showing the construction of our Mariana 18S subwoofer. We put it together and use 2 ratchet straps to go around the sides and then 8 parallel clamps for front to back. Like I said, we let the glue dry for 24 hours and the enclosure is solid. The corners are 2” mdf corners, everything else is 18mm Baltic Birch plywood.
  17. 3 points
    It’s not how I will normally deploy them... but figured they should hang and and get to know each other https://imgur.com/gallery/r5UkOor
  18. 2 points
    Small update from my side: I was very eager on posting results here but the blown amp has demotivated me to the part that I went on to finish other projects first. So now I have a vacuum hold down on my CNC. And about the broken amp, the replacement power input board arrived and it blew up as well. Means the PSU is broken, which will run me about 300$ probably. Good thing is that I've watched a movie with one of the spare amps I had in the store and the clip lights didn't even light up once. I didn't change the settings and volume matched everything properly. Means I can now run the quieter amp (fan noise) with much lower idle power draw without any performance penalties. The spare amp does like 2000W total, which is fine with the SKHorn as efficient bass maker and the BOSS platform as efficient TR maker. Now that I think back about the times that I had the bridged clone amp on the SKHorn and this bridged amp on the TR I realize how overkill it was. I watch my movies at -10MV with the EQ at +15db at 20Hz. No dynamic EQ. Will post the first test results some time next week I guess, I will add different frequency tests when I have the time to do those.
  19. 2 points
    @kipman725 Interesting concept, I guess you're going into a similar direction as what current high power PFC amps are doing? I like the trend of new amps to come with a universal power supply. The new Powersoft amps work with any input voltage from 70-270V iirc, single bi and triple phase. Fully equipped with PFC, relatively high efficiency and the option to set a breaker in the dsp. As I see it, only increasing efficiency and stored energy will allow for more output with high crest factor content. And yea on the amp, it was my main HT amp. I swapped it for one of my spare amps and lost ~8db headroom. The SKHorn is efficient in the upper register and room gain of my small room helps with the lower end of the spectrum, so the single sub I'm running will probable be fine. Gramps is currently investigating the remains of the amp to check for bad parts. I'll swap out the entire broke board and see if I get it running again. If that doesn't do it I'll see what if would cost to swap the entire PSU. I suspect the mains relais to be the point of failure, which would be an easy fix. @klipsch I've read about it blowing up. notnyt is actually the guy who sold me the Pmillet Soundcard Interface, which I'm using for my tests 🙂 @Ricci I had it on a C16 breaker, which tripped after 14s. When I hooked it up for 32A230V it blew up... The clone muted its output (DC protection) a few ms into the 1Ohm test. Maximum it did was 3.5KW for half a cycle. It also muted the output when I set my test frequency to 10khz instead of 1khz accidentally. I do all tests with a 1khz sine wave. "If the amp can do 10 cycles at 1khz it can do 1 cycle at 100Hz" is my logic, so the 1khz test allowed for a 1ms "resolution". I will publish the results as seen below. The graph below is the first I've finished. @SME I evaluated the results of the Sanway amp and noticed that the 2Ohm power sustained for 260ms, not 80. 260ms is very nice imo. Idk what it would look like with both channels driven, since I couldn't test that anymore. The graph stops at 13.3s, because the breaker tripped. I won't test the amp again on a 32A circuit, even if I get it working again. I tried to do all tests at a total duration of 2 minutes, but out of the 4 amps I tested this way one was fine, one started smoking, one started smelling and the clone blew up. What would you guys suggest? Is 2 minutes too long? Not useful info anyways? Not all amps have superior safety mechanisms built in like maybe a Powersoft amp does... I had a look at Martin Garrix's "Animals", which is a pretty bass intensive song. The longest duration of more or less uninterrupted bass was 28 seconds with a pretty low crest factor. Even most heavy bass dubstep songs have something that resembles a chorus and quieter sections in between, so I think a 30s sine wave test should cover most of it. I'm not in the situation yet where I can afford to blow up half of my amps because I want to test them at their absolute limits. I'm hoping to have a write up on my testing methodology posted after the weekend and maybe some final results already.
  20. 2 points
    The Loadbank While a bucket might've been the easiest solution, I wanted something rack mounted (for easy storage) that at least somewhat resembled something store-bought. I figured I could fit everything into 3 rack spaces, so I bought a 3U case from Amazon. As with everything I do, I first made a 3D model in Inventor. That always proved to leave very little room for errors. This is the front plate I made: After I was happy with the design, I generated some G-Code with Inventor HSM and made the front plate on my cnc router. I used a 2mm end mill to cut the holes. I have since bought a 3mm end mill specifically for sheet metal, which is much better suited for the task obviously, but the results were decent nontheless. For the hardware I used regular Neutrik connectors, heavy duty (30A) switches and busbars for easy wiring. I glued the busbars to the front plate. The heavy gauge wires were a pain to solder with my tiny soldering iron... I have 12 heating elements with the blue cap on the back and 4 without (went out of stock). The elements without the cap have a slightly lower impedance (~0.4 Ohm less). I cut a hole into the rear case wall and made a mounting bracket for the heating elements with some acrylic. The plan was to screw the elements into the acrylic (has been tested with scrap pieces before) but that didn't work out and I didn't want to try myself out on thread milling just yet. I used my favourite stepped drill bit to make the holes a little larger and glued in the elements that wouldn't fit with silicone. Everything else came together nicely. A quick sanity-check revealed that everything works as intended, which was a small surprise to me because I did all the wiring from the back of my head without a wiring diagram. With the current setup I can do 4x8, 4x4, 2x2 and 1x1. And of course various useless impedance combinations. The device is quite heavy fully assembled. I haven't weighed it yet, but it's probably around 40lbs. And it's sturdy. This is what the back looks like now: At first I thought I could get away with air cooling, but after one of those elements almost exploded into my face after plugging it into the wall in free air, I decided to go with a basic water bin. I still have lots of spare acrylic, which came in handy here. I trimmed the edges with a flush trim bit and even made a roundover. I never planned on doing any experiments with hot-forming or welding. The glue I used basically welds plastics anyways. The container was made to slide into the case. You basically fill it up with water (to the point I marked to avoid overflow) and put the loadbank over it. The loadbank then rests on the container, with the heating elements being surrounded by at least an inch of water at all sides. The case has enough room to accomodate the container as well. Without water preferably when stowing it... That about wraps up my build, which I'm pretty satisfied with. I tested one amp already and it worked like a charm. The banana sockets are connections for my Pmillet Soundcard Interface (or basically any oscilloscope). The font I used for the text on the front plate is called Elixia!
  21. 2 points
    Finally! Measurements coming soon. If the weather is on my side.
  22. 2 points
    Just a quick update. I have attached the front baffle, so all of the construction is over. Here's a pic of the completed box with the grill frame attached by magnets. It was at this point that serious sanding began. I decided to take the edge off of the sharp edges of the corners. I used a sanding block to "blunt" those edges. After a lot of work I had barely changed the shape of the corners. I knew after I used a router once that I would not be able to use a router indoors - the blizzard of dust would ruin my house. I realized that using a round-over bit once the box was built was out of the question. My wife & I are not able to pick up the box & take it to the carport to mitigate the dust in my house - remember, I'm 69 & my wife is 70. I have no idea how much this box weighs, but I guess it's easily over 125 lbs. I had never used a plane while working with MDF (hell, I've never sanded this much either), but I decided to give it a try - starting on the bottom of the sub in order to "hide" any screw-ups. I liked the early results so I continued to the rest of the box. I'm pretty happy with the results so far. Some more sanding to go before I start applying oil-based primer. I took the sub off of the saw horses because I need to roll it around to work on the various sides. Taking it off the saw horses was an exercise of "controlled fall." No damage to the sub, the room, and most importantly, no damage to me.
  23. 2 points
  24. 2 points
    I don't know much about particle velocity, except the basic fact that it causes compression at some point, and neither have I run compression sweeps of my cabs yet (waiting for better weather), but while looking at your hornresp parameters, I noticed that you haven't added the driver and front "chamber" volume anywhere. Normally you'd be using the driver's front air volume plus the small section with the thickness of the plywood you're using (was about 11000cc VTC with the IPALs iirc), but as to @Ricci's suggestion and my own comparisons with my finished cab, adding the driver's cross sectional area to S2 in horn resp results in a sim much closer to the real thing. For the 21" drivers you can add about 350cm² to S2 (driver+wood when back mounting).
  25. 2 points
    They are addicting! 2 is a nice start but 4 has a nice symmetry to it. 6 makes a good stacking height for your tops but is an odd number for amp channels.... better just make it 8 haha!
  26. 2 points
    Well, I finally got mine built! Lol took a while but life got in the way. I'm also just staring to do my fiber optic ceiling, so multiple things at once!. I should have the subs up and running next week. Drivers are DS115. Just getting duratex. Will be my nearfield subs lol.
  27. 2 points
    Installed behind screen. Hope to have them powered up this week. Unfortunately will have no time run any voltage to them this weekend 😫
  28. 2 points
    Hi Everyone, I have been following Data-Bass and the other forums for many years while building an art car. This year was its first year to the Playa after 4 years of work, a divorce, a child being born, etc etc. I teach illustrator, CNC Plasma, CNC Router, Laser and NFPA 160 Flame effects at a local makers space here in Truckee CA. I own a Boss Laser HP3655 Stainless Steel cutting 150Watt CO2 laser that I am using to make the art car with and helping other artists with their projects as well. This project is a labor of love and not for profit. http://www.instagram.com/jackalotus https://www.instagram.com/p/B2qSE1zhUI5/ https://www.instagram.com/p/B2ISZPCBKgp/ I currently have in mind building my own cabinets using two 21SW152's I currently own. I have been working on ported box designs for quite some time, but keep drooling over Ricci's awesome work on various forums going back to I think 2010. I plan on building tops with help from a Electrical engineer friend who works at Meyers Sound. I have a stack of Baltic Birch sitting here in my garage waiting for the right design to build around my 21SW152's and I think I have decided to throw my ported designs in the waste basket and go with the SKRAM design of Ricci's that everyone here is building. I plan on placing 2 of these boxes under the head of the PlayaPachederm. My Question is... Is anyone willing to share/sell an Autodesk file or VCARVE file? Also wondering how i can donate to all the hard work Ricci put in for us? Need anything laser cut out of stainless let me know
  29. 2 points
    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
  30. 2 points
    I doubt it. Psytrance needs a lot of power and control in the kick and midbass range and the skrams deliver it without breaking a sweat. Mind you the sh46’s pack a wallop themselves, matched up with the skrams its a potent combination. I’ve been in front of enough f1 and turbosound systems that really excel at reproducing psytrance transients and my system doesn’t leave me wanting at all. These Danleys continually blow me a away, I have no doubt Tom borrowed tech from recovered alien space craft 😂. I have a stack of 6 reconditioned Martin Audio b115 front loaded horn kick bins as well, next summer I’ll give them a go between the Danleys and Skrams just to see what happens
  31. 2 points
    Set up pic from our Halloween cabaret last night. Experimented with a 100hz crossover and found it to be the most impactful and cleanest config I’ve tried yet. Techno and psytrance all night, sounded incredible. https://imgur.com/gallery/qrU6jyD https://imgur.com/a/dacbWrI
  32. 2 points
    Droogne I've done square ports before and they work well. The ideal is round and heavily flared or shaped which I've also done where it makes sense. Have you read the available AES and other papers on ports? There are many. Compression and chuffing noise do not necessarily correlate. There are also papers which point to some possible advantages with multiple smaller vents despite the increased skin effect. In the case of the Skhorn and Skram variable tuning is an integral part of the design that I considered fundamental. That is why they have many smaller vents instead of a larger single. Also it is structurally very strong. When considering them as individual smaller vents they are not too far from square. Its all about the tradeoffs. I think you may be overestimating the effect a change to the shape may have on compression. A single square or even round vent the area of one of the Skhorn vents isn't going to gain much. They will still overload and compress. The area is not enough to cope with the demand once the sub is pushed at tuning. This is true of almost every sub tuned under 20Hz. In the Skhorn's native tuning with all vents open with 3X the vent area this isn't really an issue as the testing showed. At the end of the day it's all about vent area in my opinion.
  33. 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.
  34. 2 points
    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
  35. 2 points
    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
  36. 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.
  37. 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
  38. 2 points
    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.
  39. 2 points
    Let's see if this is enough to win the day today. It is a whole lot of win... Apparently it is
  40. 2 points
    Butterworth 24db filters at 80hz. Crest prolite 7.5 on the Danley sh-46 and powersoft k10 2 skrams per channel 2 ohms load
  41. 2 points
    You could inject a low amplitude sine below a the audible band (~10Hz) before the power amps (IE in your DSP). Then use a sound card on a computer to measure the driver impedance at this frequency using the pilot tone. It would work best to use 3 sound card channels so you can recover the carrier, current and voltage and use coherent IQ demodulation to recover the signal. Given sufficient integration time you should be able to obtain good results up to almost the full dynamic range of the ADCs.
  42. 2 points
    I'm sorry to hear that. DJ's are notorious for pushing subs as hard as they will go and blowing speakers. This means often pushing the signal DEEP into bass amp clipping and leaving it running like that for hours. What this does is effectively chop the peaks off of the signal and increase the RMS power into the drivers. The drivers are no longer getting "breaks". If the 6K was effectively clipping constantly it possible that the driver received an average power of 1000w or perhaps even more. If that happens at frequencies with little driver excursion it will result in a cooked coil very shortly. I wasn't there and there is no way of knowing what the content was, what spectral makeup, or whether the above is true, but I'd bet that something similar to the above happened. The signals used and the duration are big variables. Despite having an AES power handling of 1700w in no way will the 21DS115-4 handle that amount of power for any significant amount of time. None of the drivers will. A 100% duty cycle signal with that amount of power will destroy the coil in under a minute. Was a limiter in use? The harder and longer that the subs will be played the more tightly set the limiter will need to be. Also the type of music is a big factor. A sub for HT or sporadic music listening in a home can probably get away with no limiter. The content is very dynamic and the amp/sub isn't constantly pushed to its limits. Live sound with rock type music would be another area where the limiter may not need set very hard as it would mostly just be the kick drum peaks with bass guitar or other bass instruments much lower in level. Once you get into electronically generated bass heavy music with lower crest factor and prolonged maximum output use you have to be much more conservative. As an example of how conservative... The 21IPAL driver is rated as a 2500w AES driver with a huge 6" coil, very high efficiency and tons of motor venting etc. In the IPAL amplifier module manual the long term power limiter setting is recommended at 700w maximum for that driver. About 1/4 of the AES rating and that's one of the highest power handling drivers on the market and that's the bleeding edge maximum that they recommend for it. The default setting for it is 400w... Based on that I'd say that starting with a long term average power limit of 400w maximum with a 3 or 4 second attack and release seems a reasonable start for the 21DS115 and it may need adjusted down a bit from there. Your peak limiter can be set much higher with a much faster attack/release. Some limiters are voltage based, some are current, and others power. If yours is voltage based something like 40 volts rms equates to about 400w into 4ohms. Unfortunately the NX Behringers only seem to have a single "peak" voltage limiter which is really not much to work with in this case. The problem is not peaks but sustained power over long periods. Perhaps someone can confirm the available limiting settings on the Behringers. I don't own or use them. The online information is surprisingly vague Limiting is a complex subject and there are so many variables involved. If you are letting others "pilot" your system they will invariably bang it as loud as it can go all night no matter how much rig you bring and how loud it gets, they will find the limits. You will have to plan for worst case scenarios if handing the controls over to others. Basically the same as most companies have to do with their active speakers.
  43. 2 points
    I would say the Othorn sounds considerably different than direct radiators...in a good way! At least compared to the rcf 18's that I owned previous. I have seen it written more than a few times from Othorn users that there is a "sound" to them that people really enjoy, and I can completely agree with that. Perhaps it is due to the driver placement, I cant say for sure. I haven't come across anyone who figured the Othorn was well suited for playback up to 150, I crossed mine around 70 most times and let my tops do most of the kick region. I would have been entirely happy to keep the othorns to be honest. The release of the skram plans happened pretty much right when I was gearing up to build another pair of Othorns. After estimating costs, factoring wood and cnc time in Canadian dollars it cost me roughly 1500 dollars to build 2 othorns and about 1600 dollars to build 4 skrams. With both cabinets built I am happy with changing directions, I think the skrams fit my needs better and will cost less to build more if the time comes. I will likely load the othorns again when I have some spare cash, my living room needs a major stereo upgrade
  44. 2 points
    Yeah..... Spent a good 6 hours or so yesterday in my back yard messing around..... Much love to my neighbors! Played around with a bunch of crossover variables, at the moment I am liking what 75hz-ish with a 24 db butterworth slope is sounding like. My impressions are super positive so far. The Danley and the skram seem to be a good match. The Skram has a really nice tight, clean and impactful sound. I hate using the word but it feels and sounds fast, never sounds muddy or distorted, nice separation between different sounds. I notice that I can feel punch in my body from sounds where I don't expect them to give me a felt impact.... if that makes any sense. The sound is so much cleaner than I am used to coming from front radiating subs, it makes me want to turn the ratio of sub to top up more than I am used to, yet it doesn't sound like the bass is overloading the tops. As for the Danleys, wow! If you haven't every heard them you need to track some down. I would describe the sound as mid forward, every little sound no matter how subtle is right there plain and pure and with unreal clarity and seperation. My buddy that was hanging out with me described it as being able to hear and feel the textures of each sound. Really breathtaking large stereo field, the sound doesn't feel directional from the horns at all, seems to just envelope you from everywhere. We played a bit of everything, metal, rock, folk and a bunch of our favorite electronic tracks, everything sounded amazing and exciting. The mix between the Danley and the Skram seems very fitting, the clean punchy attack of the skrams compliments the Danleys sound nicely. Of note. The skram's have a powerful 30hz grunt to them, very clean and hifi sounding..... but I think the Othorn sounds slightly more exciting with those really low frequencies. The Othorn has some sort of a unique harmonic growl to its 30hz output that is just really sexy. The Skram's are seriously almost there... they are just ever so slightly perhaps a little cleaner so it doesn't sound quite as rowdy as the Othorn does down low. On the other hand the skram up higher is noticeably more impactful and punchy which for most types of music I think is going to serve you better. If you are strictly a bass music lover the Othorn is a pretty amazing beast, If your musical tastes are wider I think the Skram is the way to go. Someone previously mentioned adding kick bins to their system.... you were me a year ago, that's what I figured I needed for the sound I was chasing. I would try the skram first with a nice beefy top cabinet, you may likely agree that kick bins are not needed, the skram's kick plenty. If your stuck on the kickbin idea then maybe the Othorn might be your ticket.
  45. 2 points
    I use PL Premium 3X for my commercial subs and don’t use fasteners for our standard offerings. Not sure what the equivalent that would be on your side of the pond but we’ve tried quite a few types and PL Premium 3X is the one we like the best by far. We used to use Loctite Heavy Duty but we had a couple bad tubes I think so kicked that stuff to the curb. I believe most use true Baltic Birch plywood, which is significantly better than standard plywood (13 void-free plys in 18mm vs inconsistent layering). The true Baltic Birch I get for my business is from Russia/Ukraine and less than $50 USD in bulk for 1520mmx1520mmx18mm sheets. This is definitely the best plywood for building speaker and sub enclosures. You could use MDF but I don’t like it, it’s heavy and won’t hold up if dropped and doesn’t hold screws well.
  46. 2 points
  47. 2 points
    Ok thanks for that, Ill try doing the calibration tonight. Yeah the 46's have a pretty tight pattern, i plan for the time being to run them in landscape config to utilize the 60 deg coverage angle. To realize my goal of a highly power dense system in the least amount of cabinets and size, the 46 seemed to be one of best options I could find. As they are designed to array with more 46's it keeps the door open to expansion down the road. For the time being I am planning to add a second pair of smaller synergy horns to act as fills when I need the extra coverage and to use when I don't need the power of the 46's. Working on a deal now for a pair of sm60f's. I think the 4 subs and 4 synergy horns should give me decent flexibility for both our studio space and our festival stage. Outdoors we deploy in a large geodesic dome, to expand on size this year we are moving the sound and booth tech outside of the dome under an inflatable stage cover that will basically nest up to the arc of the outside of the dome. The dome will cover the dance floor, using shade sails instead of the full cover to provide shade for the daytime. https://jaymichaelt.imgur.com/all/ https://imgur.com/a/67pWeUh Another point is everything needs to fit inside a 8 foot by 12 foot enclosed trailer, sound system, dome, scaffolding camping gear etc. We could barely make it work before, the new system is considerably smaller and approx 400 pounds lighter.
  48. 2 points
    Yup, rookie mistake! I had my prolite 7.5 amp set with the sub crossover setting engaged on the back! Sorry guys. I have run the test over again using my k10, mic measured at 1 meter from the mouth and 2 inches off the ground with a voltage of 1 volt measured at the speaker terminals. It still has the notch that starts at about 149hz.... but it doesn't roll off drastically after 100 hz like it did on the previous measurement. I was in a hurry and forgot to check what my amp gain settings were, ill take a look tomorrow. Anyways, here are pictures of the measured 1 volt at the terminals and the new freq response. https://imgur.com/kWPYnU3 https://imgur.com/GK5D7zt
  49. 2 points
    Ok, 4 Skrams complete. Did some measurements today using REW and a minidsp umik 1. These are loaded with 21sw152 4ohm drivers. I'm still pretty noob to REW so my testing may not be up standards. If there is something else you would like to see measured, or measured in a different way please let me know, wont take me long to set it up again. Measurements were taken in my back yard which is quite large, but there are fences surrounding my back yard. I placed the mic 1 meter from the mouth with the measurement tip about 2 inches off the ground. I ran the tone generator with pink noise and set the output of the sub to about 90 db. In the measurement page I tested the output gain and slightly adjusted it louder until REW told me the gain was ok. Picture 1 shows the settings I have set in the measurement panel. Picture 2 shows a single freq sweep measurement all spl raw no smoothing.
  50. 1 point
    Hey...Welcome to the site. The first info needed will be details help anyone give advice going forward. Budget? Planned use? Live sound / HT / Car audio etc... Size? Restrictions, shape, etc. Weight? Is this an issue? Amplification? Will it be an NU1000 or multiple LG 14000's? What frequency range of coverage is desired?
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