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Posts posted by peniku8

  1. 5 hours ago, Ricci said:

    This is a beastly looking sub. Shew it's huge and expensive though. It's the size of 2 Skhorns or 3 Skrams. That'd be a fun comparison. 

    Fun fact it's 25% bigger than the MAUL cabs and weighs about the same. The tunings are much different though. 

    Definitely 21DS115's...The p2p excursion listed is probably mechanical maximum. Not linear xmax. Looks like they doubled up on the wall thickness near the hatches. This is one spot I was wondering about potentially being a vibration concern. 

    Regardless it looks like a beast. 



    DSP presets can be protected in Armonia. 

    Right, I haven't even really looked at the size, but it's like 30-35% bigger than my quad 21" design. And I thought my cab would be cumbersomely huge, but this is nuts! The only other cabs that makes this look kinda reasonable that I know of are the F132 (a tad bigger) or the Danley monster (BC218), which is 50% bigger than the Bassboss.

    And yea, then I don't understand why they haven't made the network connection available if they can lock the dsp.

  2. 4 hours ago, SME said:

    Last I checked, the vast majority of DnB and Dub Step music go below 40 Hz.  Plenty gets down to 30 Hz if not lower.  A sub synth processor can also add more bottom.  If done well, I believe adding extension is often impressive enough (in perceived intensity) to justify the SPL that was sacrificed.  The biggest issue is that too much content is filtered too high.

    Random example of SubHarmonic Synthesis, which illustrates this point well, since he switches it on and off and also plays it solo later on:

    This is used on a low string section now, but the same thing works with basically any source. I have something like that as effects channel on my live mixing console to fatten up the kick drum/low toms if needed. Or to turn a Cajon sound into a bass drum sound (which is amazing!).

  3. 3 hours ago, SME said:

    I wonder where the vent resonance is.  That may be what limits the max usable frequency.

    21DS115!  I have a couple of those I bought to make some compact vanilla vented subs for a kind of semi-pro demo system for my audio processing, but I got distracted by other projects and then the pandemic happened.  Now I wonder if I should put them into a pair of SKRAMs instead, for what purpose?  I don't know.  The apocalypse?  I'm already very satisfied with the capabilities in my living room, and I don't even know where I'd store them.

    This Kraken looks real snazzy but is obviously humongous and awkward shaped.  I don't see the point of going beyond a dual-opposed configuration like a SKHORN, and as evidenced by its relative popularity, the advantages of the SKRAM seems preferred by most builders over the advantage of dual-opposed configuration in the SKHORN.  I like that the SKRAM has more port area per driver, which also makes it more usable with a single port plugged for a bit more extension.

    So the Kraken gets points for going just a little lower than 30 Hz, but the SKHORN and SKRAM are configurable and can be tuned much lower when the application calls for it.  A way better deal if you ask me.  :)

    I have 4 of these drivers and am really happy with them. Two have been on a bridged clone amp and were able to take just about everything I hit them with (2x8R parallel on the bridged FP13k for the real deal). Just not sustained loads, because the amp sustains 4KW, which is pretty much 5x as much as the drivers will do for long term average. I got the 'burned' smell out of them once :D

    The advantage of high driver count cabs is mostly just power density and power to weight ratio. Look at the Kraken and now imagine the cab uses no bracing, just acoustically needed elements. You'll notice the sides and top+bottom will already have good strengthening, just thanks to the horn paths and ports, which reduces weight because you only really need a minimal amount of bracing. And ofc, showing near 150db figures from a single cab is cool too, right?

    I think the drivers share a rear chamber, so you could stuff a port if you really wanted to and lower the tuning. You will have to fight the low-cut in the internal dsp then though, which probably renders such an effort futile. Maybe open the amps up, there should be a way to connect them to your PC. The standard powersoft dsp board comes with a network port for this, maybe it's hidden away. Maybe they use LOTO?

    @Ricciyou've worked with Armonia, do you know if you can password restrict dsp access? I'm planning to release a studio monitor series based on Hypex amps, where I can restrict dsp access to certain features only. I'll leave basic stuff like gain controls, input selection and input EQ available, but (obviously) restrict access to driver EQ, crossovers and limiters. If that's possible with Powersoft I don't get why Bassboss didn't make this available. Network controlled gain, crossovers and input EQ are nice things. Presets even more so :)

  4. I've seen their Kraken sub a while ago (maybe a year?) and it's very similar to what I'm working on. Or will be working on once I get a new CNC which can fit large enough panels... (which is happening right this moment!)

    This pic can be found on the driver section of the product page:


    That's a 21ds115. Same choice I'd go with, it's a solid driver. 58mm peak to peak is a bit ambitious, maybe grossly distorted, way into non linear behaviour... unless the pic is not the correct one and it's in fact either the Eminence or the IPAL.

    The cab is basically 4 short horn paths which are open to the front and 4 vents in the corners, it's a 'cab in a cab' design like my idea, which probably makes it very sturdy. Nothing folded here. Data sheet says good to 90Hz, but the response is probably pretty decent up to like 150.

    I'm not a fan of the amp modules used. A gain knob and (presumably) a crossover knob with only analog XLRs in a 17k$ sub? What year is it, early 2000's? I'd at least expect an AES input and a network integration (remote control). The last thing I want is to go check my subs if the gain knobs are all the way up on every gig... But afaik these are Powersoft modules, so the amplification itself is top notch. If it's really 4 IPALs with 2 IPALmods, 17k sounds reasonable. If it's 4 21ds115 with regular digimods, not so much. But I guess it would still compare well to L.acoustics pricing, considering their KS28 double 18" (passive!) is 8 grand. Either way, the hardware and the implementation are great imo, it should sound great and make about as much noise as two Skhorns indeed. A bit less upper/mid bass due to the shorter horn maybe, but other than that it should be up there.

    I like the design philosophy, I don't like the form factor. Quadratic cabs look so wierd ;)

    • Like 1
  5. Yea, I typically only test up to 100db, since I mostly test HiFi components. I put DE360 into my center speaker, which would've been more annoying to test. Being inside a small room only a few feet away from a 120db HF source.. I don't know if I need that. But I know that my center speaker will also never reach those levels so it's fine for now :)

  6. I wonder how the 18sound BE driver compares, it sure is expensive too.

    Measuring tweeters shouldn't be that hard. Get a room that is big enough for a 5-10ms gate time and you can measure down to 500hz quite well. I bought and compared a bunch of tweeters and mids for current builds. Put them on the intended speaker baffle, EQ flat and compare distortions at varying levels. Of course not the massive IEC baffle :)

    In room gated distortion measurement of an inexpensive SBacoustics tweeter on a tiny 4x4" baffle. 8' ceiling height:



  7. That's a lot of data! I like that most of the distortion is the relatively inoffensive 2nd harmonic. The near 130db sweeps must've been a pain, I'm already annoyed when I take 100db sweeps with hearing protection in the studio. I have a vacuum cleaner hose which has an incredibly annoying resonance. I suspect it produces something like 110db at around 10khz. It's almost unbearable when I use over ear hearing protection with IEMs beneath, playing music.

    I'd be interested how the B&C horn with the DCX would compare. It's a fair bit cheaper too, I suppose. 1k+ for a compression driver is insane. Similar price regions to the Beryllium ones I forgot the name of.

    It's good to see that power compression doesn't distort the frequency response too much and is only 1.5db approaching 130db.

  8. I'm not a huge fan of PS audio, as Paul tends to spread misinformation to sell snake oil, but the video was alright I guess, bar the fact that he called infrasound "sub sonic" (which is a speed category). I think the rotary sub is similar to an infinite baffle arrangement in the sense that you need a lot of air volume behind the "driver" (essentially a separate room) and the SPL in that room/rear chamber will be the same as in the cinema. Typically it's easier and cheaper to integrate even a dozen subwoofers into your cinema than to basically build a cinema around one device.

    Theres also the guy from Sweden(?) who turned his floor into a subwoofer (housing 16 18" drivers iirc in a large horn made out of bricks). I'm sure it's amazing, but I think it's obvious why we don't all have something like that..

    Put 4 dual opposed sealed 21" cabs into your HT and you're gonna be pretty happy with the ULF, I'm sure. Want more? Buy/build more subs. Not enough space? Buy higher end drivers.

    Personally, I'm not a fan of ULF. I prefer to keep sub 15-20Hz purely tactical through non acoustic devices, like Crowsons or a BOSS platform. Going that route means I can go with something like the Skhorn, plug a port and get good output to about that region, add my tactile device and not be missing much.

  9. 22 hours ago, Ricci said:

    I used to use stepped sine tests for distortion testing of subs. Quickly realized that's a bit too brutal at the maximum drive levels I was using. Cooked a few learning that the hard way. 

    Yea, even at the shortest setting the signals are still half a second long. That's pretty brutal.

  10. 4 hours ago, SME said:

    I poked around on the site long enough to notice the stated figure had a footnote "[1]" that appeared to be dangling.   I could not find "[1]" anywhere else.

    Was looking for that too, but could not find anything...


    At least Klipsch is transparent about this, here is their top of the line consumer product (single 12" the size of a potato):



    And this is from Klipsch's top of the line actual cinema subs (single 18" the size of two-three Skhorns):



    which is fair enough I guess.

    But sadly there will be people bragging about how their 12" sub can do 130db, manipulated by "false" information. 122db at 20Hz is what the Skhorn did in my room. And that was on an amp as powerful as probably 20 of the amps they use in their 12" potato. 120db+ at 20Hz is no joke, it's the point where stuff in your house starts coming down from the walls!

  11. 35 minutes ago, kipman725 said:

    With the fireface loopback measurements you have a THD+N vs level graph, is this from REW? how do you do this?

    RTA→Stepped Sine→select Step level, like this


    And no, I'm not keen on doing more sustained testing. I'm tired of blowing stuff up. It's annoying and costly. If you really wanna test PA amps you could put em into an incubator at say 40°C/105°F to simulate a hot summer day and give it a beating over an hour. Pretty sure most amps will die like that.

    • Like 1
  12. New ADC arrived today, mind the new scale.


    Fireface in comparison (distortion seen comes mostly from its ADC):


    From 98db THD+N to 120db THD+N and dropping the noise floor by 20db, that's something I like to see! This is currently limited by the DAC, which will eventually be upgraded too, but I'm pretty happy with this so far. Certainly did not expect having to increase the graph range to -180db because half of the noise floor would drop off the chart even if it was set to -170! At least I can properly measure stuff now without having to worry about optimizing gain structure in my measurement chain (Fireface was distorting more starting from -10dBFS out and/or in). Pmillett measurements following.

    • Like 1
  13. 5 hours ago, m_ms said:

    I did mean and actually wrote extension and not distortion

    I did mean but not actually wrote extension lol, sorry for the confusion. Fixed now :P

    For upper/mid bass a long horn will be better than a single bandpass, since it increases efficiency, and thus decreases relative distortion levels. A simple slot 'loaded' bandpass will do the same, but a bit less overall, emphasize upper bass less and maybe yield better results in mid bass if the resulting front 'chamber' volume is larger. Been some time since I designed my last cab in hornresp and played around with this stuff, but design approaches will be pretty good for music.

    Group delay might become an issue if the front slot is very long, I'm not sure. But that's probably talking extreme lengths you'd typically not reach, which would also kill upper bass.

  14. 23 hours ago, m_ms said:

    Never cared for the Devastator variant(s) as it seems they're going rather blindly after extension, but at what cost in other areas of overall bass reproduction? They also take up more space.

    I'd not say the devs are cabs that are blindly going after extension. I'd rather attribute that to simple vented designs like the Marty line for example. The devs are band pass designs, which increase sensitivity and should decrease distortion in the mid-upper bass region, depending on the slot length (there are like half a dozen dev designs that I am aware of). Additionally they bury the driver, which protects the membrane, which is something I like.

    Never personally built/heard or dug into the measurements of these, so I can't comment on the design itself, but it theory it can be pretty good. Lately I've been very intrigued and impressed by designs with shaped/heavily flared ports, but these are extremely hard to build sadly, if you want to make everything out of wood (and sturdy).

  15. 3 hours ago, SME said:

    Is it too much to suggest adding back 20 Hz?  I mean 10 Hz is real important to the ULF crowd, but I believe some amps do start to lose a lot of output by 20 Hz, and this would affect a lot more typical sub applications.  So then it would be 10 Hz (ULF), 20 Hz (Deep bass), 60 Hz (Mid Bass), and 1000 Hz (Mid).

    I agree that power testing at 16 kHz is probably not important, and in fact, some amps may activate the protection circuit with high amplitude UHF inputs.  More useful for assessing UHF performance would be frequency responses at different impedances, which will often vary for Class D designs.

    Sure, I can do that. It's still 2 tests less than my previous set up.

    My Sanway amp actually mutes when given high amplitude HF information (above 10k), and also muted when trying to run full power into 1R, so at least some protections are working there. Just unfortunate that they don't have thermal protection, which made mine blow up. I mean, it was fan modded and on a 1 minute full output test, which was a bit unfair, but still...

  16. On 12/3/2021 at 11:22 PM, Ricci said:

    How about removing the 15, 30 and 100Hz results. 

    Report something like 8Hz ULF, 60Hz Bass, 1kHz Mid?

    Maybe 16Khz Treble?

    Yea, seeing how the results on the Hypex amp are barely any different at all, I guess we can safely classify and dumb down application types by a single frequency. 60hz for mid-bass, since that's where the kick drum will sit in most non electronic modern music, 10Hz for the HT ULF crowd and 1khz as general full range guideline, but I'm not sure if 16khz is of any value at all. Music is typically mixed to drop off by 3db per octave and then even more when approaching the last octave, so 16khz demands will already be only a fraction of even just 1khz, unless you're talking long-throw line array applications where you need lots of distance loss compensation, in which case you're most likely using specific system amps anyways (or you somehow need maximum power into a super tweeter!??).

    You can call the segments 'Full range performance', 'Bass performance' and 'Deep bass performance' I guess.

  17. On 11/28/2021 at 10:09 PM, peniku8 said:

    And the loadbank causes another casualty.. this time it's a Yamaha CR-600. Fuses are done for, but I hope everything else is still good. Measurements of my Hypex FA123 coming soon. Also ordered dedicated measurement equipment, since I already had trouble measuring the true performance of the Hypex amps... Fireface not clean enough. Getting the Cosmos ADC to use with a Topping D10b. Probably also going to get the Cosmos APU once it releases, which includes a 1khz notch and a preamp capable to delivering phantom power with lots of gain.

    Amp is up and running again, were just the fuses. 45 year old amp takes accidental 2ohm clipping like a champ and only causes 1$ of damage. I love this thing! And it's actually good THD, even by today's standards (0.007% 4V into 8R).

    I fixed some other things and mondernized the amp while I was at it, fitting it with a C14 socket (replacing the fixed cable) and clamp style speaker connectors. There are LED-sized light bulbs (!) inside the panel that lights up the tuner's signal strength, of which one still works. I put it in the middle socket and it lights up both meters now, it's great.

  18. 13 hours ago, SME said:

    Wow, these are nice!

    If I may make a suggestion for the comparisons of power at different frequencies: plot these in units of dB instead of watts!  Use 1000 Hz as a reference, so it's always "0 dB" at 1000 Hz and will typically be small or negative at the other frequencies.  (So maybe use "+1 dB" for the top of the Y-axis.)  I think this will convey information that is much more useful to the reader as it clarifies exactly out much output you lose at some lower frequency.

    The formula to calculate this is as follows:  dB(f) = 10 * log10( P(f) / P(1000) ) where dB(f) is the decibels at frequency 'f', and P(f) is the power at that frequency.  dB(1000) should always be 0.

    Other graphs may also be more useful in decibel units, but decibel units only make sense when you have a meaningful reference point as above.  When comparing different amps to one another, there isn't a good reference unless you choose one of them to compare everything else to.

    What do you think?

    I record the amp's output as WAV, so I'm logging the db values in the first place, which I then use to derive the powers from. Changing out the values with db values shouldn't be a problem at all, but like you said, if people wanna compare amps at certain frequencies (say you're looking for an amp for your tactile system, so you look at the 8Hz results), you might be better off comparing absolute powers over relative db loss, which you then have to backtrack to compare.

    For me it's easier to make out the db changes in my head (like when I'm seeing 1000W at 1khz and then I see 800W at 30Hz that's somewhere around 1db loss), than to reverse the process and I like dealing in absolutes, because we're comparing different amps in the big picture. I could maybe also display both, but I already had enough trouble with Excel to make this work as I wanted it to (it's a universal file and the graph needs to adapt to mono blocks, 4 channel amps etc...), and I think even more info would clutter the graphs a bit too much.

  19. Which of the two styles would you guys prefer? Currently it shows values for 1khz for full range reference and 30Hz for deep bass reference, but I'm not even sure if that's needed. The data table clutters the graph a lot imo




    Evaluations will additionally have these:

    Which will react like this when they're presented with differing values for bust and peak:

  20. On 11/30/2021 at 8:37 AM, chrapladm said:


    3mm?. Ok


    I was thinking most did more than that. Here is dsI1's dado if thats what they are called. I liked how it aids in assembly. I plan to make four so I figured I could make a jig for the "dado's," to help speed things up since I dont have a CNC.

    I've build 20 speakers with this dado size now and I see no reason why I'd need them to be deeper.

    And tbh, I don't think it's worth the hassle to make them when you don't have a CNC. You'll waste all the time you save on assembly with making the joints, possibly more.

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