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Showing content with the highest reputation since 07/29/2020 in all areas

  1. Blowing out the cobwebs today
    6 points
  2. Hi everyone! I'm new to this forum, after beeng very active on different forums here in Norway. Over the years I've built and restored about 200 different cabinets for speakers in my small workshop, and my latest one is the Skhorn. I've also built six Othorns, but these Skhorns are among the largest cabinets I have done. I built three, two for a customer and one for myself. All the parts are cnc'd out of 18 and12mm BB at a friends workshop. I think the build was relative easy compared to the Othorn. I'm going to use the Ipal driver, and will start testing tomorrow with a Crown Itech 6000 am
    5 points
  3. No offense to RF as they do have some sharp guys but the whole, driver optimized for sealed / vented / BP and don't use it in another alignment, is for the most part antiquated thinking from back before modern signal processing. There are drivers that are better suited to some jobs than others make no mistake, but this is not one of those. Usually the reason you will hear that drivers are not suited for sealed is the qts is too low (IOW too efficient) and without EQ it will be bass shy because the top end gains sensitivity quickly and overpowers the low end without EQ. In this case RF is assum
    4 points
  4. 2 of each. Osborn Point out in the Cascades (Washington). Getting out there on the forest service roads is a bit of a challenge, especially with a ton of gear, but the vantage is amazing and you can make as much noise as you like way up there. 21DS115-4 in the Skrams. Keystones are loaded with some spare OEM ceramic, stamped basket 18s from a friend at a local, well known audio manufacturer. They're no B&Cs but they sim nicely and have stood up to some abuse that is frankly well past the specs I was given for them. They've got a good motor and great excursion capability.
    3 points
  5. We finally "finished" our two skrams, at least so far, that we could fire them up for the first time, last weekend. Together with our self designd Top (AMT + double 12" in CB, also just "finished") this was one of the most stunningly setups I´ve ever heard. The skrams made the perfect underline for the Tops, wich were designed to produce the cleanest sound possible. It´s absolutely crazy what output just 2 Skeams have, while the Ipals arent´t even moving. Looking forward to build 2 more of them (but the next will be made of the good old BB and be Paintet with duratex. No fanc
    3 points
  6. Some carpentry sins have been committed due to time constraints and lack of both quality tools and experience, but nothing I don't expect PL and Bondo to hide. It's an intimidating build to do by hand, mostly due to the bracing, but I wanted to do it "right" and I expect the cabinet is going to be stiff as hell. Got some 21DS115-4s on deck and if all goes well they'll be at full flex at an event last weekend in June.
    3 points
  7. I finished a 6Ch amp build made from two Hypex FA123 yesterday. It's a lab amp for speaker testing, so it has all connections on the front. It's not the prettiest and already has a bunch of scratches, but hey, at least it's got cable management..!
    3 points
  8. I don't know if you saw my skram built on page 26 or so, I built 2 of them, made of popplar plywood with a carbon-epoxy layer around to make it stiffer. Then we made the front out of 25mm transparent acryl glass, just to loose the weight savings due to the 10kg (just a wild gues, I forgott the real numbers) of those fronts haha. We didn't put them on a weighting scale yet, but without the heavy front, they would be ridiculously light! So light that we will make a base filled with sand to make sure they dont move more than the drivers do. We also didn't fire them up, but that will happen s
    3 points
  9. Ok. I had a look in HR. It had been awhile. I'd recommend a 3rd order BW at 24Hz or a 4th order LR HPF at 21Hz. This is for operation with all vents open. 4th order LPF adjusted to taste for blending with the mains. Somewhere between 50-120Hz. 70-100Hz is probably what would work for most. The response looks quite good with just the high and low pass added. This is the response with the 21SW152-4. Most of the other recommended drivers are going to be close to this as well. If you want to take it a bit further You can add a single band of PEQ at about
    3 points
  10. Hey guys. While not as rigorous as the excellent testing in this thread I put together a little vid doing some light testing and listening comparisons between the chinese CVR branded 3002 amplifier up against a Powersoft K-10. Might be a good option for people looking for some decent performance at a good price point. Maybe you will find it interesting. Ill have this set up for a couple more days so if you're quick and send me a request for ideas for further testing I can try to accommodate
    3 points
  11. Had my next party on Sunday on the beach with my 2x skrams and 2x Martin W3 tops running from an inverter in my Prius from 2pm till nearly 2am, averaged around 1000w into the whole system (including the CDJs and amps and a few LED lights) and used about 5L of fuel in the car. Around 150 people at the peak of the dancefloor, everyone seemed to love it! Definitely need to build 2 more of these things and upgrade to the proper drivers for even better sensitivity to keep up with the tops
    3 points
  12. Gig report- very impressed. I didn't have time to do proper measurements/EQ with a mic so I fiddled around in hornrep ahead of time to get a phase match with the keystones. Landed on delaying the Keystones 5.8ms with a phase invert. Based on the rich sound, coverage, and amp levels vs output, I think that must have been reasonably close. We had some issues maintaining voltage with the cable runs and generator capacity, and I was quite conservative running the NX6000 into them since I haven't set up proper limiting, but it was more than enough to prove these cabs are quite capable. Got the same
    2 points
  13. Thank you guy's for the awesome inputs, my apologies for the late reply. Much appreciated for side by side comparison of the ipal and nsw Ricci. Although the NSW offers the best bang for the buck, I might try an external series ipal setup, albeit with some thick ass wires. 6 is kinda pushing it for that amp, even with the 152s...specially if I want the damping factor to remain high Been keeping this box on the dl but it's basically similar to the th18 but slightly modified for 21'' woofers, code named the hornicator, I haven't done any measurements on it yet but it sounds hella goo
    2 points
  14. My recommended driver for these is the Eminence NSW6021-6.
    2 points
  15. Finally got time to spraypaint my one remaining SKhorn today. I used Warnex paint and an inexpensive HVLP spray gun. After to layers it lookes pretty ok I guess. Tomorrow I will turn it over and finish the cabinet. After this and finishing the build, I will also glue some acoustic foam in the back chambers, as Ricci suggested.
    2 points
  16. The B&Cs aren't too much more for the actual driver in AUD, its the shipping that's the killer, I can buy a whole extra Dayton for less than the price of shipping for 4x 21s of any kind that I've found so far. Whereas that store seems to already have Australian stock of the Daytons and shipping is basically free. @chrapladm me and a friend in Melbourne are planning to get 2 each and hoping to spend around $7-800 or less per driver including shipping. He's just finished his first cab, followed the plan a lot more closely than my first 2 so will be good to compare!
    2 points
  17. Moving up and down stairs to roundover, sand, fill any tear out, sand and paint was a bit of a chore, requiring assistance of a hand cart, ratchet straps and a strong volunteer. Also, the number of good weather days were limited, coupled with working away from home a lot meant that I could not spend as much time working on these as I would have liked at a time. Second one is partially assembled.
    2 points
  18. I've noticed something very interesting I wouldn't have believed was true when experimenting with my Hypex amps yesterday. These amps needed to be "broken in" with a high level signal or they'll run at unusually high distortion. Sounds like snake oil to me, but heres what I've seen from the data: General info: -Sweep of the audio interface max 0.005% THD 100Hz-24khz (sweep went to 48khz) -THD somehow off rising to 1% at 20Hz (has been RMA'd once, guess it's still slightly damaged) -THD numbers in the following paragraph are mostly constant through the frequency range, so I'm picki
    2 points
  19. Hey Josh. Curious if you would be willing to make a recommendation for high and low pass filters with recommended slopes your Skram design. It’s been a while since I’ve had mine out with the pandemic and all, but I’m planning a day at our studio tomorrow to get everything plugged in and spend some timing tuning and tweaking. Planning to get the measurement mic out and spend some time dialing in the system so I don’t get rusty haha. I’ve been happy with the setting I’ve been running which I don’t remember off hand but I’ve got some different amps on hand so willing to try some new things. Anoth
    2 points
  20. As far as testing goes. There is nothing happening right now and for the immediate future. I've had to turn away a bunch of companies and projects since this time last year and I'm still sitting on a whole summers worth of testing from well previous to that. I'm not planning to be done completely, but after 10 years my priorities and other life goals have shifted and I can't find the hundreds of hours to put into testing, and publishing every year, like I once did.
    2 points
  21. SME answered well. It's complicated. With almost any driver the performance starts to degrade as it is pushed to higher excursion. This really cannot be answered with a single number like xmax that mfg's try to use. The 21Ipal will go to about 30mm one way if not a bit more if you REALLY hammer on it but it does not sound good by then. It gets cleaner at 20mm one way, and again much cleaner at 10mm one way than 20mm.
    2 points
  22. after 4.5 months of preperation and four 12h days for assembly, we finished our second skram, the first one world wide with an acryl glass front? We didnt measure the weight yet, but although the front has about 12kg, it feels a lot lighter than our prototype made of birch, as we used popplar instead. It also feels rock solid due to the carbon-epox enhancement on all surfaces and edges, but the measurements will show if the light material has any disadvantages...
    2 points
  23. Yes---for some definition of "significantly". If you look in B&C's docs, they may describe their methodology for XVAR. Someone else's definition of "Xmax" may yield a different number. The measurements on DataBass don't give a specific number but simply show how compression and distortion increase as the driver is pushed toward its mechanical limits. Realize also that actual distortion depends on more than just excursion. Certain aspects of the cabinet design can suppress or amplify the effects of distortion in the motor.
    2 points
  24. Probably decent, the Lab 12 has great mms and BL for its size giving it a low Q so it would work well in a horn. I don't see any reason this couldn't.
    1 point
  25. Excellent work. The response looks very good. No surprises.
    1 point
  26. And here's some measurements (with UMIC1 and REW): Red: All six ports open Green: Two ports plugged Blue: Four ports plugged No EQ was applied here.
    1 point
  27. Do 4 skrams instead
    1 point
  28. I didnt think there was too big of a worry with 91db sensitivity speakers as opposed to 99db or above. Ala horns and active setups.
    1 point
  29. FYI Maglito...Frame OD on this is 21". It'll be tough getting it into 22.5" height with feet. Not impossible though. I believe my home cabs are about 22.5 x 22.5 on the driver baffle but they do not have feet. The driver was tested in about 4.5ft sealed after driver displacement and bracing. Test cab was 23x23x20". At home I have them sealed in roughly the same amount of volume per driver. They work great. Bring the EQ and the POWER. Adjust to taste. One thing to be aware of is with a moving assembly that weighs 1Kg these can shake the hell out of a small enclosure at war volu
    1 point
  30. Bravo! Very well executed.
    1 point
  31. BB holds screws better as well. In general I avoid MDF or HDF when possible, especially on larger cab sizes. For things like small monitors and car subs it isn't a bad choice to save some money.
    1 point
  32. No, but not because of the different impedances. The biggest issue is that the high frequency section is a lot more efficient than the low frequency section and needs attenuation to play at the right level. Another issue is that you really need a high low pass filter for the mid or else it will make a mess of your upper mid response. And you probably want to cross closer to 1500 Hz. More generally to get good sound quality you really need a crossover that's custom designed for the combination of drivers, which for your case is actually 3 different drivers. In your first post, you said
    1 point
  33. I will agree to pretty much everywhere here. BB is nice for things that get big, even if you don't move it much. When you do need to move it (and you will) you won't regret the BB.
    1 point
  34. Welcome @RCAguy ! Frequency response specs for a sub, even if done "honestly", often don't tell you much about its real capabilities. A DSP (including the one built-in to most powered subs) can re-shape the frequency response, and a lot of commercial subs rely on DSP bass boost to achieve their specs. Of course EQ can't compensate for the physical limitations of the driver and available amp power, but in practice it is often very beneficial to design a sub whose innate response starts rolling off much higher than its intended bandwidth and then compensate for this as needed using DSP/EQ.
    1 point
  35. A nice video on the topic by Bennett Prescott, B&C US sales manager:
    1 point
  36. Perhaps those are Aussie dollars which are 1 : 0.76 USD (currently). Even still! @h3idrun: Tthat driver should do pretty well. Dayton also has a new 21" with similar motor and price, albeit 8 ohm vs. 4 ohm impedance. I don't see it listed at your store, but you might contact them and ask if they are planning to stock it soon: https://www.parts-express.com/Dayton-Audio-PSS555-8-21-Pro-Subwoofer-with-4.5-Voice-Coil-8-Ohm-295-050
    1 point
  37. I'm in Adelaide. I have a pair of 21SW152's sitting on a shelf still waiting for me to build my Skrams. As long as you dont mind the long wait for shipping times there are better options that PE. But if you want it asap then PE is probably your best option.
    1 point
  38. Before adding a subwoofer, if you add baffle size with foldable / detachable wings and top / bottom panels you will increase forward directivity which is useful. Of course, this comes with the caveat that it will make the monitors heavier, not to mention easier to tip over if the wind whips up. This moves the baffle step frequency lower, and may require a bit of tailoring with eq. Wings could be made from dollar store / craft store foam poster boards or 1" xps foam board, assuming you do some rudimentary bracing. Considering you are using a car for transport and are short on space a pair
    1 point
  39. Hey @h3idrun looks like you got decent results. You could try power compression (see testing methods on this site) testing to see how close your actually getting to a 21" (Sweeps increasing in level until your getting 3dB compression). The umik-1 tops out around 120dB so if you will probably need to move it back a few meters to reduce the level. I like the idea of running the Prius as a generator. I have a 6 channel DSP amp box running off a 16S lithium battery I built for portable stuff.
    1 point
  40. RCA, yikes. Graph's looking good! I'd suggest placing a Butterworth 4th order high pass at ~30-35Hz for driver protection and maybe taming that hump down there as well. From the looks of it, you're probably running an acoustic crossover of 120HZ or higher because of that hump at the top. You can use REW to EQ the graph (PEQ like 98Hz -10db Q4 or so), which will clean that up if you add that point to your dsp.
    1 point
  41. Discussion of JBL's most powerful differential drive woofer should go here. This is an oldie but a goody. It's an expensive bugger like most of the woofers I test these days but it is still a cut above most of the 18" units on the market. I always wanted to test one of these just to see how good it is. I don't expect many people to go out and buy these for a project at those prices but it is still a common driver to see in the industry in a lot of JBL's top Pro subs. I figure giving it a run through here should help give insight into the capabilities of the various JBL subs using the 22
    1 point
  42. Last I talked to Josh, sounded like he would be game for my idea, if only this covid thing would go away already.... maybe one day hopefully. I suggested to fly him and his gear up here, we have a suitable area to test, and for the cost of sending him a couple things we could do, well everything we can manage to have prepped 🤪.
    1 point
  43. I'm not entirely sure what it would be for the SI 24's. The cone holds a lot of volume but the surround is huge and protrudes a lot unlike the pro drivers. Also the frame is really thick on these and it'll be front mounted which moves the whole assembly forward quite a bit. It may actually be less than a back mounted 21" pro. This is probably a good generic guess. AVH...300-350cm2 for each driver should be added to S2. This is used rather than Atc/Vtc. It has a better track record, in my offset designs at least. Also the AE drivers have extremely low inductance. I doubt the complex
    1 point
  44. Btw, here is a comparison of a sim I did with the approach mentioned above, in a cab similar to yours, but with only one driver plus a vented back chamber. The real (half space) measurement is the wavy line. The purple line is the Hornresp export (scaled quarter space; not much different from the og half space export) and the cyan-green line, which is closest to the measurement, is the Hornresp export plus baffle gain exported from Edge. The baffle gain was scaled to half space (twice the baffle area). These were not gain-matched, but voltage matched, so the final simulation is prett
    1 point
  45. To my knowledge, the throat chamber is the volume in front of the membrane until it enters the actual horn/slot section, not the entire horn section itself. Think filling up the driver with water with the membrane facing up. For a back-mounted 21" driver that's about 350cm² is cross section, which I add to S2 (Ricci's trick). I guess it's similar for the front-mounted (I guess?) HS24. This is what my inputs look like:
    1 point
  46. This is from the MK1 HS-24 so I'm sure the MKIII has had some tweaks made. In the absence of the complex inductance data for the MKIII I'd suggest using these specs. It'll be closer than not modeling semi-inductance as it's pronounced in these Plug these into HR by double clicking on the LE box. It is activated once the label turns green. Measured Complex Inductance Parameters Re' 3.572 Ω Leb 0.951 mH Le 14.868 mH Rss
    1 point
  47. I've decided to order one of the cvr d-3002's to see whats up with them. I don't have the equipment to bench test but I can do some a/b listening tests vs my K10. Ill report back
    1 point
  48. 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:
    1 point
  49. 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!
    1 point
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