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  1. 9 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. 8 points
    This is the long delayed single driver sub similar in design to the Skhorn. Overall the performance goals and criteria were quite similar. Big surprise there! The Skhorn works so well at what it does that I didn't feel the need to reinvent the sub for this one. This is primarily designed as a professional sound reinforcement or live sound style subwoofer. Big output and clean sound in very big spaces, while covering the typical bass heavy range of music, has always been the primary mission for this sub. Same as it was with the Othorn and Skhorn. It can and I'm sure WILL be employed for other types of situations, but it's a festival or club sub that just happens to be flexible and neutral enough to work in a variety of scenarios. The main differences between the Skram and the Skhorn are as follows. Optimize it more for the cost effective 21's like the 21DS115 and Lavoce SAN214.50 rather than the Ipal drivers like the Skhorn. The Ipal's still work of course, but I relaxed things a bit for the drivers that are a little easier to afford and power. Increased size: Originally I wanted to basically saw the Skhorn in half and slap a top panel on there with modded bracing. It would be a very compact 21" sub, which is great, but the driver would fire directly into an outer panel and even with bracing this is a lot of energy being beamed on axis into a large outside panel. I've never been a fan of high pressure loadings with big drivers that do this. I always want the direct on axis energy from the cone to act on internal panels that are going to keep this energy inside of the cabinet better. This required a rearrangement of the internals. I also added a bit of size while I was at it. I decided to stop at a size that was significantly smaller than the full Skhorn, but not as small as a true half. If this cab is too big or heavy you could always build the true half Skhorn, which would be 24x32x27.71. Increased vent area and slightly increased vented chamber volume. This should help the noise, compression and output near the vent tuning. Increased vent area and length means that the vent pipe resonance is lower in frequency than the Skhorn. I'm, expecting that the response will be less smooth above 150Hz, but that's the tradeoff made for bigger vents. The Skram has 4 vents instead of 3 like on the Skhorn. I decided to add one more for even more tuning options. Tuning with all vents open is basically the same. Being a single driver design, the Skram does not have the dual opposed drivers for mass induced vibration control like in the Skhorn. Other than these changes I would expect that this design behaves and sounds very similar to the Skhorn. I'd expect that the two could be used together without issue. They are more alike than dissimilar. Skram Dimensions: 24"x32"x36" (609.6mm x 812.8mm x 914.4mm) Weight: Cab=115lbs or 52kg projected (Driver will add another 25 to 55lbs (11 to 25kg) depending on the driver. Vent Tuning: All vents open = 29.5Hz / 3 vents open = 25.5Hz / 2 vents open = 20.5Hz / 1 vent open = 14.5Hz Each vent is greater in area than a 6" pipe. All vents open is equivalent in area to 4x 6" ports. All of the usual pro 21's should be a good match. 18Sound 21ID, 21NLW9601 B&C 21DS115, 21SW152, 21Ipal RCF LF21N551 looks decent Lavoce SAN214.50 Eminence NSW6021-6. NOTE about the prints! These are extremely detailed due to being designed in Solidworks and the plans from which my personal cabs would be built. The simplified layout drawing is really all that should be adhered to to build this sub. The bracing and hatch can be simplified to suite your own ideas or the tools available to build the cabs. Just make sure it is solid! Any or all of the hardware can be deleted or substituted or modified to suite your needs. Even outer dimensions can be adjusted within reason. Think of the plans as a chassis guideline that can be modified to taste. You don't have to put all of those holes in your braces or use the handles, a half inch roundover on the cab edges, add a cutout for a plate amp on the hatch, etc... Skram print.pdf skramcutlist12mm.pdf Skramcutlist18mm.pdf DXF files... Back Brace 1^Skram_TI x2.DXF Back Brace 2 ^Skram_TI x 2.DXF Bottom Braces^Skram_TI.DXF Bottom Brace^Skram_TI x 2.DXF Front Brace^Skram_TI x 2.DXF Mid Brace x 4^Skram_TI.DXF Top Brace^Skram_TI.DXF A^Skram_TI.DXF Back^Skram_TI.DXF Bottom^Skram_TI.DXF B^Skram_TI.DXF C^Skram_TI.DXF D^Skram_TI.DXF E^Skram_TI.DXF Front^Skram_TI.DXF Hatch Brace Small^SKHorn.DXF Hatch Brace^SKHorn.DXF Hatch^SKHorn.DXF MirrorSide^Skram_TI.DXF Double - Middle Two.SLDPRT Double - Middle Two.SLDPRT.DXF dxf_filelist.txt Single - Left or Right.DXF Triple.DXF Back^Skram_TI.DXF Bottom^Skram_TI.DXF E^Skram_TI.DXF Side^Skram_TI.DXF Top^Skram_TI.DXF Side_1^Skram_TI.DXF Top^Skram_TI.DXF
  3. 7 points
    Update to powering the RF 19's. The 8 sealed in the HT will now be getting a pair of SP2-12000's. Each 6k module power 2 1ohm T3S1-19 drivers in series in a dual opposed sealed cab. This switch is mostly because the SP amps have less fan noise than the K20's. Also they have slightly better extension below 10Hz. The K20's are going to the band spot to power the MAUL's. Fan noise doesn't matter there. Each MAUL has 4 T3S1-19's wired in series for a 4ohm nominal load and will see a whole bridged K20. Yay headroom... Got power?
  4. 6 points
    Been almost 3 years in the making. Huge undertaking. Just finishing up the last few features but we're closing in!
  5. 5 points
    Agreed...There have always been a lot of hang ups with terminology in audio circles and fixation on defining things by a strict set of rules. In order to be an IB the back volume must equal at least 10X VAS...Waveguide vs horn etc... I consider the Skhorn a hybrid 6th order design. Fun fact...Skhorn is pronounced like the word scorn and I gave it that name because after exploring all the options I could think of attempting to do a horn of some type, I ended up not doing a horn at all. No matter how much I wanted to, and I really wanted to make a horn at first, I simply could not make a horn this size that would perform like this cab. After giving up and scrapping all the horn ideas for a hybrid 6th order BP I called it Skhorn as a middle finger to bass horns in general. Most people think it's called that because it's some kind of horn LOL.
  6. 5 points
    I vote that we let users add graphs, content, build plans, etc. 1 guy can only produce so much content. As far as social media I'll let you guys in on a secret. I've never been active on any form of social media. I don't plan to be either. From what I recall Kyle isn't either. That's why we don't have any of that for DB! Neither one of us wants to deal with it!
  7. 5 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.
  8. 4 points
  9. 4 points
    Some progress shots. We have decided to do a shoot out between the B&C 21SW152, RCF LF21N551 and 18 Sound 21NLW9601. I will share the measurements and results in a couple of weeks.
  10. 4 points
    Finally some pics of the assembly process. The MW's of @lilmike are finished on Wednesday.
  11. 4 points
    Going back to my issue with the drivers in electrical series, I can say there is absolutely no difference between them linked like that or parallel. All my tests and measurements showed me nothing changes, a small voltage difference is present, but only 1-2 V at 60 V sines.
  12. 4 points
    I looked at the sim and it is quite close below 80Hz. This one should have less efficiency and less output above 40Hz on paper. It should have a bit more output near tuning. I'd say the original sims as being the slightly bit louder cab overall for music apps or live sound (kick drum, percussion fundamentals, most of the content being above 40Hz etc.). I've found over the years I like smoother responding wider bandwidth systems vs systems optimized for more sensitivity over a narrower band of operation. This is part of the reason I decided not to do a straight slot. I wanted extra upper bass output and extension well beyond 100Hz as part of the design goal. Often times you'll see guys using subs for 30-70Hz and another set of kick bins for 70-140Hz or whatever. Usually due to sub bins with degraded upper range behavior or just not enough output. I'm not a fan of that approach. I'd much rather have one cab that can handle everything. I think the sim you proposed would be fine. I tried to get the top end as extended as possible on this one. Another reason I didn't choose a large straight slot was to more fully enclose the drivers inside the cab. Most of the time I notice non harmonic mechanical and operational noises before HD gets to be offensive. The acoustic roll off of the slot above 100Hz should help lower HD a bit, but with the driver cone edge only 10" from the end of a large slot with line of sight to the outside world I'd expect there to be more operational noise leakage, though HR doesn't show too much of a difference. I'd like to see that tested actually. Also the drivers would be a little more susceptible to rain or a drink spill, but either arrangement is safer than a direct radiator cab! I didn't go with a push pull driver arrangement due to the minimum clearances needed for the drivers (10.5" driver depth + a large dustcap and +40mm excursion worst case scenario minus some for the baffle thicknesses and depth to the dustcap below the frame plane) and the fact that most high excursion sub drivers make quite a racket from the motor and suspension when pushed hard. Even more of a reason was the uneven loading it would present on the drivers. It would be much more involved and difficult to design the cab to evenly load the drivers with one inverted. Not impossible but it would complicate things. I'd give a rough guess that there would be about a 25-30L difference in the vented air volumes seen by the drivers. Tuning would be slightly different unless compensated for and the throat area would be a concern. I know this has been done in plenty of cabs before but I don't know if I trust it with the kinds of pressures that can be developed inside something like these. I didn't think the potential lowered even order distortion outweighed the concerns with uneven loading and possible mechanical noise from the inverted driver motor. The forces inside these can be pretty ridiculous. The force cancelling works really well on it. It's not like the drivers are 90deg rotated from each other or even 45deg. It's only a 12deg offset and it's a 250+ lb sub. In use the cab has no perceptible rocking from the driver operation. That small amount of offset from exact opposition plus the sheer size and mass just doesn't add up to any real rocking forces fore and aft. Technically I'd guess a perfect driver opposition would measure a bit lower with an accelerometer but in practice it worked like expected and it's a complete non issue. Regular old panel vibration and bracing is a much bigger concern. The Skhorn has been quite good as far as that is concerned when compared with most other large cabs, but this is always a battle on big subs with tons of output. About Edge and directivity. Keep in mind that the math is simplified and goes back to the point source mic placement method. If the radiating points are spread on one sub and focused on another you can never truly get the same mic distance from the two. In practice there is a very large area that one is trying to cover usually inside of a room with boundaries. It's complicated. One sub is more diffuse but that's not necessarily always a bad thing. Edge is a good tool but I don't get too caught up in an apparent half dB advantage here or there. Most of that directivity happens above 80Hz unless the baffle area starts getting truly large. One way I like to think about this is with 2 different philosophies. The first would be maximize the baffle area for the cabinet (think DTS-10 shape or similar) and get as much out in front of the cab with the drivers and design as possible. However at what point does this become impractical? Let's say the cab has a 60x60" baffle and is very shallow and gets some extra forward gain over a very similar design with the same driver which has a baffle of 30x30" but is much deeper. At some point you run into limitations in available depth to use and/or available baffle area. How many 60x60" baffle cabs are going to be able to be arranged? In a lot of cases not too many and eventually you just need more cabs and drivers. You could fit 4 of the 30x30 subs into the same baffle area as the 60x60 that would outperform it. The best case as far as potential output density per baffle area goes is that one entire face of the sub is radiating surface area. That's not going to be the best for directivity control though. You also end up with deeper cabs to get your cab volume. Tradeoffs. Vent area is vent area I'll give you that as an advantage for sure. This is the #1 priority I would have when redesigning the Skhorn. Mostly to work better with the lowered tunings. I try to avoid turns in vents when possible though. The reduced area of the slot for the drivers would increase air velocity over the horn expansion type though. I have some new thoughts on designing vented subs that I haven't gone to far with yet but I'll share once I think it through a bit more. Anyway that's part of the thinking behind not doing the straight slot or push pull drivers originally. It all comes down to tradeoffs and design choices. None of it is black and white it's all grey area and what makes sense for each case.
  13. 4 points
    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.
  14. 4 points
    Here is a RTA of thunder I took with my calibrated-to-4hz Dayton EMM-6 and a TASCAM US-1641 which starts dropping off at 20hz. The mic was inside a window behind the curtain with its windscreen on and SPL is uncalibrated but it clipped my mic just when it hit that peak at 4hz, and I had my mic at 3/4 of gain, so it was a pretty loud peak. The second image is with no smoothing was taken during the RTA. The first has 1/48th octave smoothing and is the total peak. I live far out in the country so there are no sources of infrasound from vehicles or factories except for a very low level 14hz tone from a glass plant about three miles away.
  15. 4 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?
  16. 3 points
    You may have heard...You may not. Eminence is upping their game and coming out with pro woofers that compete directly with the competition. I was able to get some early samples of their 21. So far what I've seen from this woofer is very encouraging. Specs, notes and impedance curve from one of the sample units are posted. Much more info will be coming. https://data-bass.com/#/drivers/5cc9adeb9b899d0004e43084
  17. 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!
  18. 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
  19. 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.
  20. 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
  21. 3 points
    Speakerpower plate fits the hatch cutout nicely.
  22. 3 points
    Getting close, just have to screw/glue it all together...
  23. 3 points
    Finally had an afternoon to cut some stuff.
  24. 3 points
    Just completed the Skhorn and just want to say thanks to @Ricci Never had so much fun firing it up for the first time. Everything in the house shaking and my 10 year old saying his chest "feels weird" Don't have much of a reference to compare to, only had two 15s before this. To say this is a giant leap forward, would be an understatement. Very impressed with the sound sonically, it's pounds, I have the volume at 50% with one bridged side of my inuke nu4. I had to back off or I start breaking my wifes stuff. Can't imagine how it performs with a great amp. Thanks again for making this available!
  25. 3 points
    Ready Player One - Dolby ATMOS (7.1 bed measured) Level - 5 Stars (112.67dB composite) <=NOTE that this is with dialnorm REMOVED=> Extension - 3 Stars (16Hz) Dynamics - 5 Stars (29.53dB Execution - TBD Notes - Clipped but decent soundtrack to accompany terrific visuals. I still do not have overheads, but my surrounds are mounted high and some overhead effects were experienced. Possible BEQ for this one. JSS
  26. 3 points
    I think what db does better than many other sites / forums is that discussion here can be backed by real numbers. Subjectivity, while is fun to discuss and does have value, can't really run unchecked to the existing data. Now, data does not capture everything, and I will admit that there is a certain adoration I hold for some subwoofers that don't even hold a candle to most things in our list and I'm not shy about it. Its fun to discuss everything, big, small, expensive and cheap, don't worry about getting ridiculed.
  27. 3 points
    The lower peak substantially depends on the suspension compliance, which is probably the least accurate T/S parameter given and the most likely to change with break-in as well as temperature and humidity.
  28. 3 points
    This doesn't solve the phase match problem. If one uses a textbook electrical LR4, then the phase shift of the high pass and low pass filter will be identical vs. frequency. However, unless the speaker and sub(s) are ruler flat throughout the crossover region and co-located, they likely won't be phase-matched to begin with. The THX crossover was developed assuming the mains were sealed and had a natural Qtc=0.707 (Butterworth) 2nd roll-off. Two cascaded 2nd-order Butterworths makes an LR4, so the THX crossover applied a single 2nd order Butterworth to the mains and a full LR4 LPF to the subs. Provided that the subs didn't roll-off anywhere within the crossover region, that the mains behaved precisely as specified, and that they were co-located such that room effects applied to each equally, the result was ideal. In reality of course, "bass management" is a stinking mess. The whole point of it was that one could put the subs somewhere better for sub bass, but often the "better" locations are not so good for integrating with mains, especially where multi-listener is a priority. And of course, very few mains are sealed with perfect Qtc 0.707 and Fb 80 Hz. Any significant deviations from there substantially influence the phase response in the critical crossover region. Most mains these days are ported and tuned well below 80 Hz, so they have only slight phase shift at that point. They would do better with a full LR4 HPF, but few AVRs / processors seem to offer more than one XO type. My Denon AVR has the THX 2nd order 0.707 HPF baked in, which totally destroys the bass-managed mid-bass response with any speakers I've owned. The LFE response may measure picture perfect, but the mid-bass response of the other channels looks like trash. Also, how many subs are actually flat through the XO? Most of the beefier drivers are already dropping off from inductance effects. Sad to say, home theater "technology" is still stuck in the 90s in many respects. Great sound pretty much requires extensive customization, as I've learned over the years, and the affordable options for doing so leave a lot to be desired.
  29. 3 points
    Commercial cinemas, when designed, implemented, and maintained properly provide a great low frequency experience, similar to a well done live concert. The caveat is that the experience does not extend much lower than 25-30Hz. Most impact/slam is between 40-100Hz and even higher in frequency. We are freaks here that can monitor and playback the lowest frequencies, that are often taken out of a mix that is CREATED and is meant to be played on a cinema system (25-30Hz vented, high sensitivity subwoofers). While mixing stages have existed in the past that could monitor into the low teens Hz-wise, most cannot monitor below the high-20s. We sometimes are surprised by mixes that do not exclude the content below 30Hz, as those mixes are a significantly different experience in a properly equipped home theatre. Your friends may simply be used to a certain frequency and level of low frequency experience, and call that 'good'. The EQ mixing described is in the Bass EQ for movies thread on this forum. JSS
  30. 3 points
    Very Interesting. While nothing here constitutes definite proof, it does seem reasonable to me that the streaming version is a cinema track mix-down; whereas, the BD version is a re-EQed dedicated home mix. As I've argued before, cinema tracks need quite a bit more low frequency oomph for good impact in an X-curve calibrated cinema. That's because X-curve calibration undoes the natural in-room bass rise exhibited by an anechoic flat speaker due to boundary gain and reverb build-up. Of course a lot of people at home also have systems with less bass output, either because they calibrate to a flat curve (e.g. Audyssey) or because their speakers lack BSC or because they have boundary interference problems. Nevertheless, it appears that recent BD releases with home mixes done at Skywalker Sound Studios have re-EQ to better match systems that perform optimally for music playback. In terms of the graphs, the streaming version looks 5-7 dB hotter through much of the sub region. However, the gap may be much smaller after compensating for loudness differences in the mids and highs. In that case, it may be more accurate to say that the BD version is hotter than the streaming version in the 15-35 Hz region. Certainly the shift of balance toward deep bass could reduce the apparent level of mid-bass, even if the SPL is similar after compensating for loudness difference in the mids and highs. There's a good chance I'll buy the BD version of this film. I may be tempted to try out the streaming version to satisfy my curiosity. I could give my opinion as to whether the streaming version sounds like it is influenced by cinema EQ, for what that's worth. That UHD Atmos tracks often sound louder than BD DTS-MA is a curiosity. Almost all DTS-MA tracks have "0" dialnorm offset, and I don't believe any format supports positive offsets. It's possible that a lot of Atmos "home" tracks are just mixed hotter than the cinema versions, from which the DTS-MA may be derived from. Unfortunately, there are still no formal standards for home mixing and apparently no consistency between studios. For example, I believe (based purely on my subjective evaluation) that Skywalker Sound Studios applies re-EQ to home mixes, whereas most other studios don't. Skywalker Sound also appears to have a dedicated mix room and to use a calibration/mix level that's comparable (in terms of room size differences) to cinemas, i.e. 80-82 dBC @ 500-2kHz. Such mixes are likely to sound quieter, in addition to benefiting from more headroom and cleaner micro-dynamics than cinema mixes. OTOH, it appears that some studios monitor home mixes with calibration as low as (or maybe even lower than) 75 dBC and may still be monitoring near-field in a large room. Such tracks are likely to sound even hotter than cinema tracks and have more potential for clipping and other problems. Also under those conditions, the need for re-EQ is likely to be much less obvious for a number of reasons: (1) tonal imbalances are much less obvious and offensive at lower levels especially excess brightness; (2) lack of boundaries reduces low frequency boundary gain that boosts the bass of flat speakers / mid-field monitors in "small" rooms; and (3) per Floyd Toole, rooms with early reflections are more revealing of tonal balance flaws in a speaker, and I'd argue that this extends to soundtracks as well. From my knowledge, near-field monitoring in a large room is probably the worst environment to monitor a home mix in. Simply monitoring the mix on the dub-stage system, albeit with a Harman-like curve instead of the stupid X-curve, is likely to offer better translation than "near-field". Somehow I need to get the industry people over to my house to listen to and compare mixes.
  31. 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
  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
    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.
  34. 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.
  35. 2 points
  36. 2 points
    21SW152-4 models great in this cab. It's one of the smoother modeling drivers in it. All of the usual pro 21's should be a good match. 18Sound 21ID, 21NLW9601, B&C 21DS115, 21SW152, 21Ipal, RCF LF21N551 looks decent, Lavoce SAN214.50 and the new Eminence NSW6021-6. I'm hoping that it will be smooth up until 150Hz if needed. It should be. Actually I'm hoping it behaves similar to the Skhorn and is relatively smooth up until a bit past 200Hz allowing XO's well in excess of 120Hz if required and a predictable XO transition to the mains. Until I get finished cabs with drivers installed I won't know exactly but it should be close to the sims. As far as sound of the cabs I actually preferred the Skhorn over the Othorn slightly, Skhorn seems a little bit cleaner at high output (lower THD) with a bit more oomph in the 60-120Hz octave, but both are still really good for loud music playback. I'd expect this cab to sound extremely similar to the Skhorn and perhaps a bit better in a Skram pair vs single Skhorn situation. Again I don't have Skram's done yet but that's what I expect. Unfortunately I got rid of my last pair of Othorns a while back so I no longer have those on hand for direct comparison. A lot of people are happy with them though. Output and sensitivity between the 2 cabs isn't a whole lot different overall. Othorn is a larger cab, heavier cab that is 4" deeper, so it likely will have a bit more max output in the 25-35Hz area and a bit more sensitivity over that range too. HIL and all of that. The Skram will likely have a bit more from 35-70Hz or about that. This is with all of the Skram vents open. It is more flexible and can go deeper once the alternate vent tunings are factored in. Top end above 70Hz is a bit of a wash. When I say more output I mean in the neighborhood of a couple of dB or less while using the same drivers. Not huge differences. Once I get to test the real cabs I'll know for sure. I'd say it's more of a lateral move to something a bit different rather than an across the board improvement.
  37. 2 points
    Mr. Ricci, can you design me a ported box for the SI HS-24 with no more than 8 cu.ft. of enclosure volume? And can you tune the port to 12Hz please? You’re the bestest! Thanks Josh. Happy Holidays guys! Thanks for hosting such a magnificent and informative site!
  38. 2 points
  39. 2 points
    Now I have watched half of it, and the impression of the sound is even better than the first brief screenings. ULF is well done, and it sounds much cleaner and less distorted than other movies with clipping and heavy limiter use. I used to believe that a spacecraft that runs out of fuel will just continue at same, constant speed in same direction, but you always learn something new, from watching this movie it is obvious they loose speed and eventually go to a halt.
  40. 2 points
    2018 test season is here! Results and notes for this new JTR sub are viewable now. Enjoy!
  41. 2 points
    Let me see if I got it right: You found a suitable horn (lilmike's F20?), a suitable driver for this horn (pro driver), the size is not an issue, you have cabinet builder ready to make them for you, and you have a friend willing to assist in calibration & setup. Build it. If you go for anything else, you will regret because you will always wonder how those horn would sound. Integration of these horns will be no more problematic than the sub you already have, the worst case scenario is that you achieve a similar result. It can be solved. But first - build the horns. No need to go deep into all potential problems up front. Now I am looking forward to read about how this turned out, how it sounds.
  42. 2 points
    Lead times only about a week atm apparently
  43. 2 points
    When I first heard about it, I thought wave-field synthesis (WFS) sounded like a really cool concept. I'm a lot more skeptical now. Part of the problem is that a system of immense complexity (and expense!) appears to be required to achieve a high quality realization of WFS. Second, it's not clear that its really solving the right problem. In its ideal realization, WFS can synthesize a complete, spatially consistent (or spatially-dependent, if so desired) sound field within a listening space. This is basically the Holy Grail of audio. If an entire sound field can be reproduced in the space perfectly, then the reproduction is absolutely true and correct. In reality though, WFS cannot be realized ideally with any practical configuration of existing components. As a consequence, there will be errors in the reproduction. On paper those errors may be fairly minimal, especially compared to the gross distortions to the sound field induced by the effect of acoustic boundaries in a "normal" system involving speakers playing in a room. However, it turns out that people are very well adapted to listening to sources reproduced in rooms with complicated acoustic effects; whereas, they may not be that well adapted to listening to the errors that arise from WFS. From some reading, it would seem these errors have been minimized enough for the strengths of the technology to be fully appreciated. That is encouraging, and I'd certainly like to hear a setup some day. I'm sure it has its benefits and its applications. Though I can't help but wonder how much better the tech could be if wasn't so obsessively focused on creating a perfect / anechoic sound-field replica and instead took advantage of the acoustics of the space its in to achieve a smoother, even if less "correct" sound. Edit: I forgot to add that I'm in the early planning stages of trying to build my own arrays consisting of many independently-controlled elements, to be used as surround and/or Atmos speakers that provide far more even seat-to-seat coverage than conventional speakers could achieve. I'm not sure if the approach I plan will look like WFS or not, but I have rather different objectives in mind, so who knows?
  44. 2 points
    Making good progress. Might have the site up for preliminary testing by Jan/Feb
  45. 2 points
    Soooo.....you guys (everyone on this forum) needs to purchase Valerian right now. Here are a few screen caps from the first night I tried to watch the movie. I know what you're thinking "now Nick, you said that you 'tried to watch the movie...why did you only try'"? I spent too much time taking screen caps to finish the movie in under 2.5 hours so I had to watch the rest of it the next day. The movie is awesome IMO. I only have a 4.1 system but the use of the rear/surround channels is immense in this movie. It's really really cool the way they heavily used the surround channels. I can only imagine what this movie must sound like in an Atmos setup. Visually the colors and scenes are through the roof. Sound is nuts - PLENTY of low-end throughout the entire movie. But I digress so here are some screen caps from the other night:
  46. 2 points
    The lowend of the Noesis 215RT was carefully designed for a flat response in room. The half space, out door response doesn't give a good indication of the in room response. The Noesis 215RT was very difficult to design because of the horn's directivity transition to the direct radiating woofers and then the spatial and room gain. The attached measurement is a Noesis 215RT, 1ft from the front wall and 3ft from the side wall, in a large, open basement, on a concrete floor.
  47. 2 points
    Reading this (above) makes me happy. SME builds, measures, makes adjustments, attention to details that surely can not make any difference - but it does. Then he - SME - describes the amazing sound, well, what does he know that all the others don't.. And the proof is in hearing and experiencing yourself. As lowerFE did. When you focus on the parts that are important for sound quality, and fix it, you actually get results that matters.
  48. 2 points
    Just made all of the good stuff for this visible. Please discuss here.
  49. 2 points
    Well it's his problem when he has his mixers crank effects up so far that they become compressed, honky, clipped messes (DKR, Interstellar) with heavily filtered LFE's.
  50. 2 points
    Thanks Mike. I must've gave everyone reading information overload. The sims with some of those drivers listed above look quite good to my eye. Vent compression at war volume is my main concern with it. Now I just need to get one built. I'm working on that 8hz horn Scott wants but for some reason I just can't get it to work while still fitting through a doorway. I don't understand what's going on. Might have to try my new, experimental, patent pending, rotary, quadratic, bi-phase, 10th order, sub-harmonic re-accumulator cabinet to get it to work right.
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