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  1. 2 points
    Hope everything is good with you Luke. Good luck with the sale.
  2. 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.
  3. 1 point
    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
  4. 1 point
    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
  5. 1 point
    I've been messing with a more compact single 21" version more similar in size to the half Skhorn that was originally planned. It won't be drastically smaller but I'm hoping to chop a few inches off here and there without losing too much performance.
  6. 1 point
    Here is what the response for the sealed SHS-24 in 300L (10.5 cu ft) would be and the excursion profile at 126.5 volts, which is the maximum for the SP1-6000. Specs are based off of what I measured from my D2's but scaled for D1's so the impedance is correct. Semi inductance specs are used. Basically this is a 28" cube. As you can see this looks nothing like winisd. I'd suggest learning HornResponse if you are serious about designing speakers. I wouldn't worry about the excursion passing 50mm below 4Hz. No driver is linear with power out to that level and content that low in freq is very unlikely to ever be full power. Also the Torpedo amps have a 3Hz 1st order high pass anyway, which most amps do.
  7. 1 point
  8. 1 point
    Here are a few comparisons. This is still using the big 850L enclosure but cutting down the vent length and area and tuning to 10Hz. Light grey line is your original plan. Once you add room gain to this that peak at port tune is going to be WAY too hot. It'll have to be addressed with the HPF and EQ to cut it back anyway or anything that hits that narrow frequency range is going to be heavily boosted relative to everything else. Also this is just an absolutely huge cabinet. Outer volume will probably be approaching 40 cu ft on your original plan. This is similar to what I will probably go with. 425L tuned to 10Hz with multiple vents for different higher tuning options. This is literally half the size of your original plan. Still a very big sub but quite a bit more manageable by 2 people. Yes it gives up some output below 20Hz but relative to the huge size disadvantage it's not that much. This is with the 10Hz tuning. This would work a lot better with typical room gain, but still might require a bit of a cut at 10Hz. This is the same 425L cab with 2X the vents from the 10Hz sim which would raise the tuning to around 14.5Hz. As you can see this compares very well with your original plan that is 2X the size, which is indicated by the light grey line. Sealed is the easiest option. Anything from 200L to 400L per driver should work. Bigger allows the driver to use more excursion with less power. Even at 400L the SHS-24 should be safe from bottoming with an SP1-6000 but it would be getting close. 300L is probably a good intermediary. I'd not recommend something as small as 3cu ft (85L) Even the full output from an SP1-6000 would not push the driver to 20mm excursion. Heat would be a very real enemy in a cab that small.
  9. 1 point
    My sealed HS-24 based subs are flat in-room to 7 Hz at reference. 7 Hz has been measured in over a dozen rooms at this point and one room was flat to 6 Hz as the sub was corner-loaded with 2 exterior walls. So there is something to be said for Josh’s recommendation of a simple sealed enclosure for these subs. Yes you lose some 25+ Hz output compared to the efficiency of ported but below 20-25Hz, the sealed should have more output isn’t a Linkwitz Transfrom. Multiple subs would be needed to make up for the porting efficiency but that would be worthwhile for more even bass response anyway.
  10. 1 point
    I've been thinking about this myself. The SHS-24 is a tough driver to tune really low and port well. It moves a ton of air but it doesn't really call for a very big enclosure for a smooth response. Big air spaces cause a large peak at the port tuning. It's difficult to get enough power on it to effectively use the excursion also. It really depends on your goals and how much you are willing to compromise. The cab you've specified is about 850L with a vent area of about 871cm and a vent length of 169cm. Tuning is around 12.2Hz. Personally I would not use a vent that long. It puts the vent resonance down below 100Hz. My limit on port length I generally set at 40" or 102cm which puts vent resonance at about 150Hz and a half octave above the typical sub LPF. It will greatly decrease your port area though. If you want to increase driver excursion, tuning lower helps but again this either increases vent length or decreases area. If it were me and I was willing to go that big I'd go ahead and tune the cab to almost 10Hz by cutting the vent size way back to a length of 102cm / 40" and drop the area to roughly 363cm which would be equivalent to two 6" Aeroports. You will lose some output from 12-20Hz but it's not as much as you would think. Only a few dB. Airspeed gets really high at 10Hz but should be decent at maximum output above 12Hz. You gain extra extension and output below the original tune, the vent resonance gets pushed up to about 150Hz and the overall size of the system is reduced by about 13%. Don't forget that in a typical home listening environment room gain kicks in and by the 10-14Hz range it is not uncommon to have 10dB of gain. You will likely have to cut back the peak at tune and the low end in general or it could sound overwhelmingly bottom heavy. HR modeling with specs measured from my SHS-24's including complex inductance shows about an 8dB peak at port tuning. Add in roughly 10dB of room gain and you can see where this frequency bandwidth is likely going to need some EQ. Also content at maximum level down below 14Hz is really rare. I don't think you will be running a pair of these at full output at those frequencies very often. It will do things to your home and furnishings. I know from experience. What I'm saying here is I don't feel like all of the extra sacrifices that are caused by making the ports such a large area and length, are worth it for a few dB more output that is unlikely to be called on much, both from an output standpoint and a frequency bandwidth standpoint. Even with greatly reduced port area it should be more than enough for any sane playback level you'll be using in your home. I'm probably going with a 425L ported cab with half the vent area of what is proposed above. The size of the system will also be half of the above though. It's easy to see why most people go sealed or IB with the 24's. Simply put it in a 26" cube and it'll perform very well. No worrying about vent tunings, port velocity, resonances and it's a fraction of the total size.
  11. 1 point
    Seems to work when the port is linear. InBox is the compensated SPL inside a bass reflex cabinet which has dimensions that should result in valid data <80Hz. HornResp is the simulation of this sub. Room compensated was generated by measuring a known subwoofer in the same physical location as the DUT. This known subwoofer is a sealed box and has previously been measured using close mic spliced with time gated measurements. You can see that the response shape for the in box measurement matches that of the compensated response. This box differs a bit from the Hornresp simulation in that there exists a cavity into which the port and driver fire which may increase SPL outside the low bass. Next stage I guess is to make a microphone that can cope with those savage in box pressures!
  12. 1 point
    I thought you were doing a really nice build but that 85 degree port is unacceptable and you probably need to start over. Just kidding. I think it looks great. Great job and you should be very happy.
  13. 1 point
    Not much of an update, since I haven't had a chance to work on this box or it's mate, but here's a few more pictures. There was a small error in the angle of the slices cut with a homemade large miter box and a handsaw, which were edge sanded before gluing, which resulted in a greater than 90 degree angle. The bottom and top of the enclosure need bracing, which will be tied into the front and back, and a few side to side braces will be installed around the driver beside the port before gluing up the last side.
  14. 1 point
    My "Like" is for this part of your post. Incompetent is definitely the wrong word and wrong concept, really. Cinema mixers are generally very competent because if they aren't, they don't get new contracts. But competence really refers to the ability to fulfill a particular job function, which isn't really saying that they know everything to know about the craft. In fact, there is probably a lot about this craft that is as yet unknown and a lot that is "known" that's actually just wrong. The issue I have with some of the recent Marvel releases is dynamics crushed to the point that it's less dynamic than an old analog TV program and doing so in a way that breaks a lot of the artistic integrity of the presentation. It's one thing if a particular scene isn't as BIG as it would have been without dynamics reduction, but another entirely when the dialog in a heated argument gets quieter just because more than one person is talking at once. Or using peak limiting in a way that snuffs transient sounds out of existence. For the most part though, I think mixers (and the other sound people) do a decent job considering the ridiculous time pressure they endure and the complexity of these soundtracks. And this is especially true given the spectral balance problems resulting form X-curve calibration. It's just tragic that this quirk affects the creation of the art in the ways it does. If they had neutral systems and the cinemas were neutral too, I think it would have a huge positive impact on the quality of the overall art. It'd definitely bring us closer to the performers, for better or worse. Exactly. There's no way the DTS and Atmos tracks were each created from scratch. One is likely derivative of the other or at least derived from a similar original. So the fact that one has this noise and the other doens't is puzzling. I know you can apply de-noising to a complete mix, but I doubt anyone does that unless they are trying to restore and re-master old content or something. Maybe that's it, and I just need to think more flexibly. I think @maxmercy sees ULF noise (or really "DC noise", under 3-5 Hz) quite a bit in movie soundtracks, more often in older tracks. However keep in mind that this noise isn't really a problem except when doing BEQ because the BEQ boosts the noise along with the desired content. At least some of the time, the "noise" may simply be due to tracks with the DC noise not being filtered any more steeply than the tracks with desired ULF content. Curiously though, some soundtracks have this noise all over and others don't have it at all. It's totally hit-or-miss. ==================== As a separate response to this overall discussion, I would caution people not to read too much into the PvA data when trying to understand why different soundtracks sound different. Certainly differences in spectral balance are possible, and seemingly minor spectral balance differences (like 1 dB) can actually have a major impact on the perceived sound. Perception is very relative in terms of what's happening at different frequencies, and you can't really see what is happening, spectrally, with the individual effects by looking at the PvA. Keep in mind too that dynamics processing might be quite different between tracks, which likely explains why the PvAs are not exactly consistent in the fine details. Yes, both tracks (and the cinema track too, if it's different) are likely seeing plenty of dynamics processing, which can affect how the sound is perceived. Also, literal dynamics is only one parameter that affects perceived dynamics. Spectral balance affects (e.g. momentary shifts in broad spectral balance and "saturation" effects) can give very different impressions of dynamics even with the SPL pegged to the same number. And the consequences of these differences may all be expressed different on different systems. So the situation is way more complicated than can be depicted with a PvA or even spectrograms, though sometimes these tools reveal interesting things. They are useful tools, but they can only explain so much.
  15. 1 point
    I think it's really insulting and dismissive to automatically claim that the engineers that work on these releases are incompetent. I'm not saying that there aren't incompetent people in audio, as there most certainly are. But in many cases these guys are doing the job that was given to them. Look, as much as we might want to think otherwise, people with capable home theaters are NOT the vast majority of the buying public. HTIB and sound bars in a noisy living room rule the market. So they squash the heck out of the dynamics so those people don't complain about having to constantly adjust the volume. People with capable home theaters can't compete with those numbers, and to be brutally realistic we shouldn't have any expectation that they will. Right or wrong that's just the way it works. Don't misunderstand, I wish things were different too. I wish they didn't filter sub 20Hz material just so they can overcrank the midbass (looking at you Blade Runner 2049). But we have to be realistic at some point. Complain about the quality of the soundtrack all you want, but don't assume that it's automatically because of incompetent engineers.
  16. 1 point
    Everybody"s input has been very helpful to me. To get an additional viewpoint, my long-awaited (not really a "long" wait) visit to Stereo Integrity happened last week. Nick met me in the parking lot & called me over to the back of his Jetta. He lifted up the hatch & showed me his new 15" SQL-15 he had mounted into a remarkably small box he bought for $20 for on Amazon. He had a 1000w amp driving the sub. He also had one of his mid-range woofers & tweeters on each door (he's now discontinued those speakers). He cranked up the volume & actually played some pipe organ music for me first. It was impressive. The vibrations from the extremely deep bass hit me hard in the chest (& everywhere else). Nick said one note was 16Hz. I believed him. It was very deep & loud. My poor wife was in the back seat & during the demo she told me her hair was blowing from the air being moved by the sub. It's not a big surprise. The Xmax on this driver is 28.4mm. That's not 38mm Xmax like his HST-15 mkII, but it's pretty damn good. Air was being moved - a lot of air. Anyway... after a long & enjoyable demo ( including every type of music) & me quizzing Nick about every bass topic I could think of, we began to say "Good-bye" - but even that took a few minutes. He's just a really nice guy. In addition, he was incredibly patient & knowledgable. Of course, I left knowing I would buy one of those babies. They won't be ready to ship until late December, but I'm in no hurry. Now I need more specific advice. I've decided to build a ported sub with ST's 15" SQL-15 driver. Nick recommended 1000w for the amplifier & I'm considering a Crown XLS 1002 with 1100w @ 4 ohms bridged. From SI's website: Ported = 3.75 ft^3 tuned to 29 Hz. I have a Mac & no easy access to a PC, so my access to speaker design software is limited. I found a limited web-based subwoofer design program, but I'd appreciate any feedback on the sketch I'm u ploading. I like the idea of a "pipe" port, but I have an open mind. How many braces should I add inside? All suggestions are welcome.
  17. 1 point
    Avengers:Endgame BEQ (Dolby ATMOS 7.1 Channel Bed) I finally got a chance to screen it with the BEQ, and it is a substantial improvement. Correction: LFE Channel 1. Gain -7dB 2. Low Shelf 17Hz, Slope=1, +6dB 3. Low Shelf 18Hz, Slope=1, +6dB 4. Low Shelf 19Hz, Slope=1, +6dB LCRS Channels 1. Gain -7dB 2. Low Shelf 25Hz, Slope=1.25, +5dB (3 filters for +15dB total) 3. Low Shelf 50Hz, Slope=0.5, +1dB 4. PEQ 30Hz, Q=2.87, +6dB JSS
  18. 1 point
    5 Sheets of 18mm and 1 Sheet of 12mm was enough for TWO Skrams cnc'ed. Sheet 1 - 18mm: Sheet 2 - 18mm: Sheet 3 - 18mm: Enough driver panels for 6 subs... Sheet 4 - 12mm:
  19. 1 point
    Speculation is it might have been the not enough glue on the joint at the former.
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