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Showing content with the highest reputation since 05/13/2020 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. 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 othe
    4 points
  5. 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
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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 f
    3 points
  11. My recommended driver for these is the Eminence NSW6021-6.
    2 points
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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
  21. I did. The old 7560's which I believe were the same as the Crown M600 and a couple of other re-badges. It's been a long time but it was something like 1500w burst into 4 ohm and 1000w for a very long time and would do it at 20Hz. Doesn't seem like much these days. These aren't really amplifiers intended for "music" signals. These are industrial grade equipment for labs, measurements, running motors, MRI's, etc. HEAVY loads. They do audio just fine but are WAY overkill for bumping some music. Kinda like taking a Mack tri-axle dump truck to pick up 100lbs of mulch. I love how they rate the
    2 points
  22. 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
    2 points
  23. Thought I should update this thread as I went ahead and built a pair of VBSS subs to live with my Danleys. The hype is real, these are fantastic sounding subs considering their inexpensive cost to build. They wont crack the stucco on my ceiling like the Skrams did, but for listening to music at moderately loud listening levels I couldn't have wished for a better outcome. Thanks for the help everyone, the project was a success! And I didn't blow a bunch of money I didn't need to spend in these strange times. Aesthetically I think they make for a great match with the Danley's as well.
    2 points
  24. The 1kv to ground sounds very weird as even if the heatsink was live on purpose you wouldn't expect 1kV to be generated anywhere in the amp. Mix of output transistors is a very bad idea as they won't share current effectively. On the plus side this is making me very certain I don't want one of these amps in my life
    2 points
  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. 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
    1 point
  28. Do 4 skrams instead
    1 point
  29. Finally got everything up and running. 8 pa460s (2 boxes - each has 4 pa460 in a 2x2 dual opposed sealed box). 6 HT18s sealed up front from 0-60hz. 8 PA460s sealed from 10 to 110hz 2 Nsw6021 skrams 31 to 110hz Bass uniformity across all 7 seats improved a bit. If I were starting from scratch, I'd do 16 pa460s sealed and 4 Nsw6021 skrams. Crazy how these pa460s can only be 70ish bucks shipped with bulk pricing and 15% coupon discount. Integration all done via a 10x10 minidsp.
    1 point
  30. 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
  31. The article listed on that page: http://www.filmaker.com/papers/RM-WhtPpr_Subwoofer Camp.pdf Brings up something that few do, except MonteKay: http://www.mfk-projects.com/Home_Theatre/theatre_woofer.html It is a very important point. Due to the way our ears 'hear', a near infrasonic sound must be played back more cleanly than a midrange sound in order not to have upper harmonics 'color' it due to equal loudness curves. I did several experiments with my first decently low distortion subwoofer system and it is enlightening seeing total harmonic distortions of just above
    1 point
  32. 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
  33. I wouldn't go for a lightweight plywood like that for a design like this. Think of the cabinet like a musical instrument, the stiffness and density of the cabinet will contribute to the sound in many ways. If the cabinet can vibrate and resonate with the driver movement it will color the sound coming from it and you may not be happy with the outcome. If you can't do baltic birch you could get away with mdf as it quite solid and dense, its pretty heavy though.
    1 point
  34. A nice video on the topic by Bennett Prescott, B&C US sales manager:
    1 point
  35. No stress, I can dig through it again. I did play around again a bit over the last week and I think to my ears at least I still like 100 to 110 hz crossover for most music styles. If I drop it down to 80-90 I think it sounds a bit better for stricktly bass music, but for house and techno, rock etc I prefer it a bit higher. Then again its harder hearing it proper indoors. Depending on our pandemic situation when summer rolls around I'm pretty keen on heading out to crown land for a number of days just to work on tuning.
    1 point
  36. Great pic of the sunset. Looks like a good time!
    1 point
  37. Hey guys, I built 2 of these monsters on Boxing Day last year (seemed appropriate) for a New Years party out in the Australian bush, its almost that time of year again and I plan do do 2 more this season so I thought it would be fitting to come back here and thank you for the excellent plans and a year of happy bassing! I didn't (and still don't) have the money for some nice big PA 18"s nor the amps to run them so I am using 4x cheap 10" car audio drivers per box that i had laying around (Memphis SR10 to be precise) and I am blown away by the smooth low end output compared to any other p
    1 point
  38. 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
  39. When going with the larger angle (60°) I‘d move the drivers as close together as possible, simply for the space efficiency. In that case, you could basically reduce S1 to like 500 and also substract 1000qcm from the other cross sections. Ftc and Atc are left empty in my case because that section is integrated into S2. You can try to shape the rear, similar to what Ricci did in the Othorn, but I don‘t think it‘s gonna have any real impact with the 60° angle and after moving the drivers close together. It‘s a bit annoying to manufacture those parts for sure. For the AE drivers you‘d
    1 point
  40. 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
  41. I'm actually heading to our local makerspace woodshop this weekend to cut up panels for another 4 of these. I gave a couple of my music nerdy friends a demo and they immediately asked me to build pairs for them. For less than 1k Canadian you can build a pair with a berry nu3k included in the price. Unreal value for the dollar.
    1 point
  42. Interesting. I wonder how fine-grained the IPAL system is here? Does it adjust EQ in real-time or just gain? If it adjusts EQ, how tight is it? Do the sound characteristics noticeably wander through a live performance? It's not too hard to monitor DC resistance and adjust gain in real-time, but that may not be good enough. I expect that thermal changes manifest over seconds to minutes or hours. If we assume all of the thermal effect is to raise the coil DC resistance, then the nature of the non-linearity is such that we can understand things in terms of linear response that change
    1 point
  43. KMT LC1300 Frequency response: Vmax(RMS): 70,4V Idle power draw: 0W (current readout was 0,0A) Efficiency into 8R: 83% Efficiency into 4R: 78% Efficiency into 2R: 69% Highest observed amperage readout: 13,5A (@232V) DC protection relais kicks in below 20Hz (only above a certain volume threshold about 10db near max output). It mutes the output for half a second. Fans only spin up when both channels are under load, amp started smelling 2 minutes into the 2R test. Single Channel 1x8Ω - 507W @1khz 1x4Ω - 842W @1khz 1x2Ω - 130
    1 point
  44. t.amp TSA4-300 Frequency response: Vmax(RMS): 66,9V Idle power draw: 95W Efficiency: 80% at around 500W output, gradually drops to 60% at 4KW output. Highest observed amperage readout: 17A (@230V) Mains connection is a C14, which is rated at 10A. Resettable fuse triggered during 4x8 and 4x4 tests. Long term power output tapers down to about half the numbers seen here. Amp goes into protect after about 90s during any 4 Ohm test. 4x4 triggers the fuse after 15 seconds. Fans are temperature controlled and have 2 speeds. Soft limiter is quick and relia
    1 point
  45. Finally! Measurements coming soon. If the weather is on my side.
    1 point
  46. 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
  47. 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 s
    1 point
  48. Don't read articles like this. The information presented is plain wrong and misleading. Some statements from the article: "music rarely has extremely deep, under-50Hz bass": Wrong. Most music has essential information below 50hz, and some music has content in the sub range below 20hz. In the 2-ch article I presented spectrograms taken from various music samples, which shows there is lots of low frequency information in various types of music. " most speakers with 5-inch (127mm) or larger woofers can muster 50Hz bass": No, a 5" driver can not even reproduce 200hz prope
    1 point
  49. The article largely misses the point and is mostly audiophool drivel. The article it links to is substantially worse: https://pitchfork.com/features/oped/9667-drop-the-bass-a-case-against-subwoofers/ The question of whether a subwoofer is needed really depends on the system design. If the speakers and amps are adequate for reproducing the lowest frequencies and the room placement is not problematic, then music can be enjoyed without subs just fine. For that matter, movies can be enjoyed without subs being that most AVRs will redirect LFE to the mains, especially using beef
    1 point
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