Jump to content

Leaderboard


Popular Content

Showing content with the highest reputation since 03/10/2019 in all areas

  1. 6 points
    Been almost 3 years in the making. Huge undertaking. Just finishing up the last few features but we're closing in!
  2. 5 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
  3. 4 points
    I don't see myself doing many TH or FLH's in the future. FLH makes more sense for systems without size restrictions, looking to extract maximum from a single driver and those without the need to go very deep. I might employ it for 80-300Hz range or so in the future but it's doubtful I'd do a subwoofer. 30Hz extension is bare minimum for something I consider a "sub". FLH's can be bested in the lower register by smaller more output dense alignments. They can sound very good. TH's I've found that the limited bandwidth and limitations imposed by path length needs and folding options cause them to be difficult to design well. More importantly the harmonic resonances in the response are audible and can cause major issues with harmonic distortion and ringing. In order to keep this up out of the sub bandwidth, well damped and above the low pass filter it's difficult to get extension much lower than the Othorn IMHO. TH's are best with extension to the 30-40Hz range IMHO. When done right they can sound killer as well, but the driver is more exposed usually so they have a bit more operational noise than FLH's. Better driver cooling though. The hybrid BP's I've been doing can be smaller than TH's, much smaller than FLH's and can almost match the TH's output. They are still somewhat tricky to design well and package but easier than a TH and easier to build. The response can be made to lack the upper end response issues more easily. The driver is buried in the cab so mechanical and operational noises are diminished, which is a big deal to me, but the air exchange and cooling is a lot better than a FLH. They are a bit more tolerant of a wider range of drivers as well. The sound is definitely clean and visceral when done right. In summary I have heard excellent examples of all 3 sub types. I'm a big fan of burying the drivers in the cabinet. Reducing the direct operational noise of the drivers especially when operating at high excursion / high output scenarios makes a large difference to me. The tradeoff is it may be difficult to tell just how hard the driver is being worked.
  4. 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.
  5. 3 points
    Get it Kyle! I spent all fall / winter getting all of the old data ported over and cleaning up some of the old text and pics. What a mountain of work that was. Kyle has been plugging away on the software / web design side of things, which is no small amount of work either. I've added a few previously unreleased things and there is going to be some new stuff added for official launch. We will have a new look and a few improvements. The home stretch should be coming up soon. I'm pulling driver specs in the garage right now...
  6. 3 points
  7. 3 points
    There's no question that the BEQs posted to AVSForum cover a wide range of content, which also includes films that IMO didn't need them to begin with. I have a few reasons for being less than enthusiastic about them. For one, headroom requirements are a total unknown, and many appear very aggressive and likely to overload my system. For another, I strongly believe "first, do no harm" as far as the soundtrack is concerned. Ideally, filters of any kind should only be used when they are fundamentally part of the sound. The point of the BEQ, IMO, is to precisely reverse the degrading filters in place, which is not at all the same as making the PvA look perfectly smooth down to 5 Hz. Along these lines, the AVSForum BEQs appear to be to have been EQed quite aggressively for a straighter/smoother, and I strongly suspect that this has degrading consequences. People forget that the PvA data is aggregated and often reflects the contribution of many different effects which may only appear smooth "on average". So trying to make it look perfectly smooth, especially using peaking filters, is likely to screw up the sound. Related to this is the fact that the BEQs are usually made based on a sum of channels PvA, and many mixes have very different PvAs for each channel. I think only a couple BEQs posted here specify the same filters on all channels. The issue with doing this is that it won't really "correct" anything at all. Every channel will be wrong in a different way. Each is likely to come with new resonances that weren't on the soundtrack before. I don't want new resonances. The main reason I like BEQ is because it gets rid of the annoying resonance at the filter cut-off. The experience with a truly neutral bass spectrum is simply marvelous. Transient response is impeccable, and the bass delivered is simultaneously tight and firm. It moves the listener. Any resonances spoil that magic to a great extent. I also appreciate that @maxmercy does a kind of quality check and doesn't post BEQs that didn't improve anything. Very often the sound design just isn't good enough or consistent enough to make it worth it. Often the problem may be inconsistent use of filters in the sound design itself rather than anything to do with how the film is mixed. Related to this, it's possible for a mix to use dynamic filtering that respond to available headroom. Such a mix might be full-band for lower level sounds but cut off at 30 Hz for louder sounds. I suspect this may have been done in Jurassic World but don't know.
  8. 1 point
    I'm experimenting with not just matching/optimizing via a fixed distance delay, but using IIR all-pass filters to mate the group delay of different driver alignments. For reference, I have four sealed subs (4 cubic footish) and two ported (12 cubic footish, ~16 hz tune) in the theater and thought this might be interesting. I started in winisd and played with all-pass parameters on the sealed sim until the system group delay matched with the ported sim. It's possible to get very close with just guess/checking (though it would be nice to write an algorithm to solve for this, particularly for active crossover design of multi-way speakers). I then put those biquad coefficients into a minidsp and ran before/after REW sweeps of the subs separately and together in-room. Theory matched practice pretty closely. The trouble is that, while the phase plots in REW when measured at the seat look fairly close (and much tighter than without the all-pass), when I turn on all subs and run a sweep, the frequency response is markedly worse (bumpy with deep funky null). I'm wondering if part of the problem is much of the phase shaping happens say <30 hz, and there it's more about room modes than first-arrival. Alternately, I've got one sealed sub near-field right up against the seat with the rest dispersed around the room at roughly 10-15 feet distance, and that might be further confusing things. As it is, everything sums ok, but I've always thought it could be better.
  9. 1 point
    Big brother Skhorn is lonely. Will be joined soon with its triplet half brothers Already started cutting the outside panels and drawing the outlines. Josh, would these 3 drivers work in the Skram? B&C 21SW115, 18SW115, 18NW100 These are what I have on hand right now but will get more 21DS115 later if I have some tax refund.
  10. 1 point
    Coil overhang is 14.63mm. Xmax including 1/3rd of the gap is 21mm. It does that easily. Spiders are mirrored and large enough to maintain linearity. Big shorting ring, etc...Very similar to 21Ipal gap and coil specs. 1mm longer gap and just 0.3mm longer coil wind. For comparison the coil overhang on a RCF 551 is 10.5mm and a 1/3rd gap xmax spec of 16.5mm. The DS115 is 11mm overhang and 15.67mm including 1/3rd of the gap. I think you may have had a different issue with your drivers. That's not what mine sound like. What I've been seeing is a higher pitched "ticking". Could be the video recording quality though. I'll see if I can get something to upload.
  11. 1 point
    Ok so about the ticking noise...I have a plethora of 21's in house from 4 different mfgs. Its not just the Ipals. One of the Lavoce 21's exhibits it and the other does not. And one of the Eminence 21's exhibits it and the other doesn't. It isnt audible in the sealed cab unless I put my ear right up to it. I dont think this is related to the spider gluing. It is present even with less than a few mm excursion. I almost wonder if it is the shorting action of the inductance rings even though that seems really far fetched but it does sound like a small spark jumping a gap. Really odd that Ive seen the same thing from 3 different major mfg's from 2 different continents on drivers with similar motor designs. That many unglued spiders out of such a small sample of drivers from multiple big name mfgs just doesn't seem possible.
  12. 1 point
    Well I added some info and screenshots at least. I don't have real cabs or test data yet but it will happen this summer. Based on the results from my last couple of designs I've got a high confidence of what these are going to behave like.
  13. 1 point
    Sorry guys I meant to make this topic hidden. Kinda jumped the gun a bit. Thought I would have the files ready but Ice been too busy to wrap them up the last couple of days. Hoping to get to it before the week is out.
  14. 1 point
    @Ricci help this poor guy out.
  15. 1 point
  16. 1 point
    That makes sense. I just placed an order for the HTM-10's - a bit more cone area, and a step up without going bananas in terms of size. I'll report back in a few weeks once I've got them assembled and dialed in.
  17. 1 point
    Once you are restricted to a certain cabinet size the only options for "more" are drivers with higher efficiency, more excursion, higher power handling, and more powerful amplifiers. Notice the trend there? All of those things increase the cost. It gets expensive quickly and you quickly reach a point of diminishing returns for ever higher performance. A few of us go down this path but most just make room for bigger or more cabs. The suggestion for stronger more efficient mains is on point. You might be surprised how much it seems to improve your bass range too. Even though it may not be putting out the real bass frequencies it can make things like kick drum and bass guitar seem to be a lot fuller. There's a LOT of content in the 80-200Hz range including upper harmonics from the bass range and that's where small woofers start to struggle.
  18. 1 point
    Bolserst is a long time contributing member over at DIYAudio forums. He has developed this spreadsheet that will take an impedance measurement and calculate the complex inductance of a driver. David McBean the author of HornResponse has added the capability to simulate using this data into HR. This is a much more accurate way to simulate and design speakers and subs. In short if you are designing bass systems using modern, high power, long throw drivers and you are not accounting for complex inductance in your modeling; The models are probably not representative of what you would be building. Previously you would need to purchase costly software in order to derive and simulate using these parameters, or figure out a way to roll your own way. The spreadsheet imports a text file of an impedance measurement and calculates the complex inductance specs. Additionally if you have an added mass or Vas (Known air volume) impedance measurement you can also import it and the spreadsheet will calculate all driver parameters needed for modeling. A driver file can then be exported for use in HR. Semi-Le_Calc_V2.zip
  19. 1 point
    I'll add a second to Ricci's post. I typically measure big drivers at about a watt applied, so 2V for a 4R driver, 2.83V for an 8R driver. My DATS and WT2 aren't quite enough for the big drivers, the Clio Pocket does OK though. The Clio manual recommends the lowest drive level that yields a clean signal. The headphone out on the UCA202 is almost enough power, but the crosstalk killed it as a contender, Pity, it was widely available and only $30. I haven't tried the headphone outs on the other Behringer USB interfaces I have. Maybe one of these days... When I need an amp, I use an old single-channel amp I got from a buddy now, it is an old TOA. Overkill for the low level stuff and it weighs WAY too much to move around, but it was free and does the job. Be sure to use a good meter and watch voltages when using an amp, it's way too easy to send more signal than the sound card can handle. Back to back Zener diodes and/or voltage dividers are a good idea. Yeah - my last post was ambitious... It has been damn near 6 months and I still haven't had the time to pull final specs and design final boxes. Worse yet, I am rapidly working my way through my stash of plywood building other projects.
  20. 1 point
    So I finally watched "John Wick". Wow! Excellent bass soundtrack and a fairly decent movie too. My wife likes it enough to buy it, so I'll have it handy for demoing. I have to agree that the shootout at the club scene is superb. It's not what I expected. It's fairly long and rather relaxed in pace rather than an all-out massacre. I love the scene in the bathroom in which the bass from the music in the main room leaks through. I thought the sound in there was very realistic and believable. The bassline in the music has a pretty strong fundamental traversing the 20-30s Hz range. Of course there're plenty of gun shots, and lots of very physical bass from them. The gun shots in the movie had a lot of weight but I did not notice ringing. They were very tight. Some heavier effects in the movie did ring a bit in the low 20s, but it was mild and not unreasonable for what was being depicted. All bass effects in the movie had ample amounts of mid and upper bass. This was not a 30 Hz boomer. Would more ULF have added something to the movie? Maybe, a little. But for the most part, it sounded good without it.
  21. 1 point
    Hey boss that’s not a problem it’ll work in that cab pm me your mail i’l Send you something
  22. 1 point
    All speakers have inherent differences in power handling vs frequency. Its assumed that any serious outfit would work out limiting or amplifier matching depending on content/ use, amps and drivers for their individual case. It depends quite a bit on all of these factors. I can say that with my pair I've beat on them hard and haven't had any issues but I'm not banging off the clip / limiter for 12hrs with extremely compressed content either. YMMV. If you have the ability to do true long term power averaging I'd set it to somewhere between 500-1500w depending on drivers to be truly safe but that is a absolutely huge amount of average power with typical music crest factor. Way more than it seems. If you are matching the amp rating to the recommended driver AES power rating range and not exeeding it or running consistently into the limiter it shouldn't be a concern. Running a 9kw rated k20 channel for all it is capable of into a single 21ipal loaded Skhorn with a driver power rating half that wouldn't be recommended. Some common sense is needed. Running about 2 to 5kw of amp per cab depending on the drivers used and application is about right. The amps would be clipping or limiting the peaks well before the average power is reached with normal music.
  23. 1 point
    Good to hear more people are seeing the shelf filters put in place by studios and we now can at least do something about them. I wish we would not lose the object based metadata with BEQ, but oh well. BEQ was always a 'preference', not 'reference'. Unfiltered, reference soundtracks are still out there, and we still get a few of them every now and then. It seems that we got more of them in the past, though. Given the fact that even after BEQ and MV compensation for same, most BEQ'ed films do not clip nor go above a 7.1 WCS (Worst Case Scenario), the studios should be able to do the same, and with better dynamics. But the loudness war is alive and well in cinema, for many reasons. Mixing stages are often geared toward a different target response than your typical High-End HT; they try to equal the majority of decent movie houses out there, which start rolling off under 30Hz, with haphazard response above that given the current calibration standards. Due to many factors, I simply do not have the time I used to have to devote to measuring films and coming up with BEQ solutions. I will still do so for films that I like (like RP1, my current BEQ favorite), but not in the numbers I used to be able to. Good to see others giving BEQ a shot with 3ld00d's app. It is not that difficult to do, once you get a method down. But screening your BEQ is necessary. Some films simply do not improve. K:SI is one of them that is very LOUD&LOW w/ BEQ, but not much better. It is a bit of a ham-handed mix, IMO, but fits right in with PacRim1 and Godzilla(2014), although Godzilla is probably the best of the three, sound-wise. Again, IMO. JSS
  24. 1 point
    I've seen it, even posted in the thread. There are many ways to fold this style of cab up. There are a couple of other ones floating around also. Other than that I try not to comment on other people's designs too much. Many times they aren't ever built, or if they are there is never any reliable objective results shown. Who knows. In other news I have picked back up on working on a single driver version finally. I've basically got the cab layout and fold nailed down. I just need to decide on bracing and hatch then put the models and print together which takes a bit. Hopefully I'll have it done by the end of the month.
  25. 1 point
    Finally some pics of the assembly process. The MW's of @lilmike are finished on Wednesday.
×