Droogne

I did yes. Didnt use the "lossy Le" option. Here is the difference: 2 port configuration:

Ok thanks. I modelled them all out for my own reference. Here the results for everyone interested. I Xmax limited the output (15mm for the 21Sw152) 1 port operation. Xmax at ~22hz, 60 volts 2 port operation. Xmax at 30hz, 70 volts 3 port operation. Xmax at ~22hz, 80 volts

Great to know the hornresp parameters for the Skram with all vents, but how would I convert this to a configuration with only 1 vent open? Anyone who can help?

Good point. An extra reason to consider the Othorn. Skram only wins in my eyes, if it could work as a bin for 150hz too. For now I didn't realy consider the build complexity, costs, Amp requirements and size. So this will be the next step. Skram does look smaller and less complex. Gonna hear how much my carpenter would charge for each, and look at driver costs.

Picking a good kickbin is the next dilemma. I only need a -6db between 80-150hz, so.. 60-200hz -3dB. 2 kickbins coupled together for each synergy? 2 dB in this range vs 150hz crossover => kickbin that can do 80hz 123-129dB (not exceeding Xmax!)

I have decided that there are 2 options, considering my latest driver choice which will give me a 150hz -2db. (NOTE: skip to end conclusion for a more coherent text. I got caried away when typing, but I do like my thoughts included in this post). 1. for maximum SPL: use a 120 or 150hz highpass on the synergy, and place it on top of a kickbin (80-150hz) OR sub that can reach this high (Skram for example). This would end up at 2pi, 123dB at 150hz for 1 woofers, so ~135dB using 4 woofers. being able to seperate tops (synergy + kickbin) from the subs will be a big advantage IMO, which allow for better subplacement. seperating subs from the synergies, without using a kickbin would not be ideal with a 120-150hz crossover QUESTION ( @Ricci) : how many Skrams would I need. Considering 2 Skrams are 1 Skhorn and hits 146dB (125hz, continuous, 2 meter RMS, 2 pairs of vents open)? So 152dB at 1 meter? And around -6dB for 1 Skram so back at 146dB. Than 1 Skram already looks like overkill as it would have an +11dB advantage on the synergy. See dB continious, 2m for the Skhorn below. This would mean a single Skram would match the 150hz crossover down to at a little bit higher than 35hz,.. awesome!? Using he 1 pair of vents open option would still yield a powerfull enough respons up to 125hz and has a more powerfull 20hz SPL, but would be matching at 50hz intead of at 31,5hz (all vents open) For music this doesnt look like a good tradeoff. 10hz 12,5hz 20hz 25hz 31,5hz 40hz 50hz 63hz 80hz 100hz 125hz all vents open 103.8 125.6 135 139.1 139.2 140.4 144.2 145.4 146.2 1 pair of vents open 99.7 116.6 119.8 122.7 127.5 134.4 137.2 139.5 143.5 144.6 Othorn 94.3 106.1 122 128.3 132.2 131.5 133.3 133.9 135.8 136 2. for in home use I the synergy would play (1pi) 120dB 80hz before hitting Xmax. Definetely no kickbin needed as with 4x woofers Id still hit 132dB for each synergy. Having Skrams with 1 pair of vents open, Id hit ~140dB 80hz and ~117dB 20hz (which are 2 pi measured values.. so 1pi 146dB 80hz and 123dB 20hz). Only a match down to ~40hz, but mathching isnt as important in home, as I will definetely not reach those SPL levels, so I would probably still be more than fine with 2 skrams blasting 123dB 20hz in the living room (especially considering I might be able to corner load them AND use them in pairs which will add another 3dB). => this makes it obvious for me that matching the 80-150hz range is not gonna be the hardest part. Matching down to 40hz (which is an acceptable highpass for live music) seems to work fine, but then I wouldnt have any ramp up for the lower end (which I would like to be +~3dB between 40 and 120-150hz). Going even lower than 40hz will start being more problematic as the Skhorn/Skram drasticaly loses SPL. So yes the Skram/Skhorn might be a good match for 40-150hz, but it's overkill for 80-150hz. A dedicated kickbin for 80-150hz range (smaller cabinet, lower weight, lower costs etc) and then using an Othorn for a stronger respons down to 25-40hz might be a better plan. At 25hz this would be 128db (1 meter instead of 2 as listed above) so ~2dB more than a Skram all vents open, and at 40hz there would be 0dB difference. So in the sub 80hz range it looks like the Skram would outperform the Othorn for regular music/PA use, but would be outperformed by an Othorn+kickbin down to 25hz (and it would allow for seperating of synergy+kickbinfrom the subs for better subwooferplacement, subwoofercoupling, mounting on stages,..) ==> CONCLUSION: Skram is the easy option because it would allow for less bins necessary (as in: no kickbins) and stronger performance in the most common music range (40-...hz range), but sadly this is only true when comparing them in similar setups. Stacking all subs together, instead of splitting them inhalf into two equal stack gives them an extra 3dB, but this is only possible when using kickbins. When using kickbins, the big advantage of the Skram dissapears. When using the Skrams and synergies instead of Skram and Synergies+Kickbin I lose the 3dB advantage of stacking all subs together instead of splitting them in half. The Othorn is a stronger 25-80hz sub than the Skram is, the Skram on the otherhand is a stronger 40-80hz sub. I prefer a good 25-80hz range so my prefered setup would be Othorn and Synergy+Kickbin. I could already achieve a +2dB at 25hz (143dB) vs a pair of Synergies at 150hz (141dB) with only 4 Othorns. For Skrams (not coupled all together, but rather split into 2 equal stacks) to achieve this +2dB at 25hz I would need 2x4 of them. NOTE: I only used simple dB adding for calculations. The larger hornmouth that is created by coupling is not take into consideration. NOTE: all values uses, unless otherwise specified are at 1 meter RMS

Ended up buying the Beyma 12P80Fe. Very heavy and solid driver! I'm gonna start with 2.

Thanks, makes a lot of sense ;) In any case, best way might be to try it out! Best way might be to just try it out with the speaker I have right now.. Also, highest level I modelled was 120db @100hz (xmax limited with 3dB leftover to allow peak). In home highest level I ever listen to is 115-120dB, but only in very short amounts of time. Regular 'high' levels are at least 10db lower. I have the option to buy 2x 12P80Fe second hand for a very good price, so I'll use those to start with. One in each synergy. I'll make the ports for the 4 other woofers, and close them off from the inside. I'll add the woofers when I feel the need too (I only need those ridiculously high SPL levels in certain situations, which isnt any time soon). The Beyma 12MC700Nd is still for sale (the 12P80Fe is not, sadly enough) but it models almost the same so I think I can combine (especially if I just correct the 1dB difference by using a different amp, that way I dont need any extra DSP channel). If I model these woofers to allow a 80hz -6db crossover I can only reach 113dB, so I can use both of them when using limiters to make sure I dont exagerate and go for the higher levels. 12P80Fe: 12MC700Nd: 110-115dB at seat level is the absolute highest (including subs, which were running 6-10db hotter than the mains) I can take, and most of the time at least 5-10dB lower at 'high levels'. So no, I absolutely dont need this kind of levels. The fact is that is I do want more reserve AND I want to use them for the festival/live projects we regulary do with our youth movement. In that case I do want as much SPL as possible. So the focus is keeping to all the principles for absolute max quality, and within those limits go for the highest SPL.

@Ricci@SME Hey after a lot of modelling, and discussing on DIYaudio I came to the conclussion that I can both use 12" woofers instead of 15 (or 18") woofers AND that it will be the best option if I want to reach the best quality. Due to cancellation because of relative distance between the center of the cone surface and the port into/through the horn, using a 15" woofer with a 650hz crossover would be a bad idea. 12" and 650hz is fine. 650hz is also way better for the CD, so thats why I'm going that route. Using 12" woofers means its harder to get high SPL and a low crossover to the subs, so thats why I will be going for a 120hz -6db (although it will end up being 100hz -6dB) as that point will allow me to use less woofers to reach the same point. I'm probably gonna use something like the Beyma 12 p80fe, which will get me an extremely high 100hz and up level. This gets me to 100hz and lower.. I dont really want to rely on subs only, as they are spaced to far from the synergies.. Or shouldnt I worry about this? I mean, having mains that go down to a usefull 40hz looks really beneficial to me, so rolling off at 100hz might dissapoint. I was thinking about using some simple vented 15" cabs (2 for each synergy) for 40-100hz, but would love to hear your thoughts on this. The Skram looks awesome, but wont get me the 130db 100hz RMS I want. Or will it? In any case, I dont need those cabs to go down as low, 40-50hz is fine. I'll add subs for anything below that. Maybe some suggestions for some good horn loaded 40-100hz cabs? Something like the LaScala but for little bit lower (lascala loses down 100hz already) Or how do you see the sub vs main placement? Would I be able to locate the subs and recognize the sub 100hz sound coming from the subs instead of the mains themself? Because if I cant I wont bother with making new subs, and just use the synergies in home with a 100hz crossover, and give everything below 100hz to my Sundown Audio sealed subwoofer pair.

I might try out other woofers than the Em Kappas. Any suggestions? 100-700hz -3db. T/S parameter 'guideline' also welcome.

You mentioned in your first post here, that it would be possible to make the Skram as if it would be really the Skhorn cut in half. The Skram is a little bit bigger than half the Skhorn. Driver would be anything but the IPAL, I can justify the costs off almost all drivers, but not the IPAL. I would however like to model the driver's in hornresp if possible. Do you have the respective specs for the different port configurations? And yes, I know it's pa oriented, just like a Danley synergy is, doesn't make it a bad home theatre sub/speaker just build enough and use them with the lowest tuning frequency. Definitely when corner loaded.

Looks like there arent too much angled cuts etc.. so a pretty "easy" build? A few questions: 1. Do you have the hornsresp parameters? That way I can do some comparison for myself knowing modelling isnt perfect or real life) 2. What do you expect to happen with the lesser wideness of the Skram that is 'a Skhorn' cut in half? For moving situations I wouldnt be able to own a very wide cab like the Skram you propose. The smalelr version could work. I do own 2x 18" sealed subs right now, but might switch them with a single or pair of Skrams. Might be an interesting upgrade ! Definetely if I want to use them for PA situations too.

The DCX464 also looks like a contender, definitely in the SPL field. I dont know anything about its quality yet though, which will be a major deciding factor.

SKram looks awesome! Dont see any ouput measurents yet. Havent had time to go through all the pages, but dont see the Skram listed in the systems list. Looks like a better solution! Definetly with those new driver choises! Awesome!

Biggest working points right now are: 1. Making sure I can mount the woofer pad to the horn, without creating an incredibly deep port (the pad is already 3/4th inch, and I have a 1" gap between the mounting pad and the horn, due to the curve of the horn). I will be using Epoxy to fill the space between the pad and the horn. To keep the ports as shallow as possible I will be rounding them down to 1 inch away from the port itself. This will make it act less like a 1,75" deep port, and keep the chamber between the woofer and the port as small as possible. 2. Make sure all the internal bracing that is fixed to the horn can be decoupled from the surrounding box, so I can still take out the horn (with its attached woofer mounting pads and bracing) later to change out woofers etc. This will mean not gluing, but rather screwing the bracing to the box.

I'll probably end up with a Radian 951Be, TAD4002z or BMS4594 to ensure high quality high end. I'm also gonna shift the crossover to 650 -3dB/700hz -0dB to make sure I dont push the drivers to much when going for high SPL. In the synergy horn concept, there is not as big an advantage to use a lower 500hz instead of the higher 700hz crossover. Most woofers will also be able to get up too 700hz so no problem there. Low output extension is not possible in the synergy, except if you accept the fact that there is no hornloading down 120hz or something in half space. There is a huge difference when corner loaded though. In any case, trying to push the extension lower is not worth it I think as you can keep the point-source by just adding a subwoofer close enough. In my case I'm gonna use an othorn (or maybe something smaller, but with similar low end extension if possible) to make a 20-20000hz -3dB point source. Business model aside, a home-theatre Danley Sound version would be awesome! A carefully designed 2-way for LCR and smaller voice-matched versions for surrounds.

I literally have the first pair ever build. Omholt and Don Keele were inspired by the K402, but wanted some improvements, which they (say they) hit. Ibought the first ever prototype they build. You will not be able to buy the horn seperately. You can see I'm extremely lucky! I dont have any definitive measurements yet, as Omholt didnt have the correct settings to do those yet, but the in-room comparison with the K402 is remarkable! Way better in some aspects.

Full build thread will follow, for now just some pics and modelling. Idea is a big ass 2-way synergy horn, using the new horn designed by Omholt and Don Keele, measuring a whopping 108 x 75 x 38cm. Compression driver is not been chosen yet, but the horn is a 1,4" throat. I will probably start with a JBL 2447 and upgrade from there. Modelling is done in hornresp, based with these specs (and a 262L backchamber voume): Driver modelled is the one I have, the Eminence Kappa 15C. I only modelled a single driver, but I will be using 2 so you can add 6dB (due to coupling). I used full RMS power for the modelling as I use active crossovers. Crossover will be at 500hz, but for simplicity I put the off axis port at 536hz (1/4fth WL = 16CM aka L12 con), which is where the horn goes from conical to exponential. µhalf-space eight-space/corner When this driver would be mounted in a sealed configuration: To match most 2-way large compression drivers (which can hit 135dB at RMS) I was hoping to achieve this (or even +6-9dB) with the woofer section (100-500hz) and subwoofers (30-100hz). I can go up to 4x 18" woofers if need be. You can see there is almost no hornloading below 100+hz, so trying to push for lower extension is not what I'm gonna do. For Sub 100hz I will one day be building Othorns or other large horn subwoofers (recommendations welcome!) as I can bring the mouth center of large hornsubwoofers close enough to the synergy as to make it a point-source (1/4th WL of 100hz is 85cm). Design Still working out a lot of kinks, primarly the woofer mounting pads and structural stiffness of the horn, but I will be copying the follow design (without the LF ports and midbass woofers though):

I have a similar living situation (2nd floor with up and downstairs neighbours, both with little children), and I also never had any noise complaints from them. I dont have a lot of contact with them, except passing them in the hall, but they did jokingly (and friendly at that) call me 'the guy with music right?'. Both my large horn sub and my 2x 18" 2kW subs never caused any trouble.

Well I listened to the FLAC version, so I'll try out the YouTube version tomorrow to compare !

Also, on topic: One of the more terrifying ULF effects/sounds I have heard in all my listening sessions is definitely the opening song of Flume's latest album "Skin": Helix. It has that slow build up, and a heavy (+20hz) drop, but oh boy between that there was one moment which pushed my sub to all it's limit. Pretty scary!

Haha completely understandable! But if you do have some things for me to try out (which I can measure / give a subjective listening to). Well I will definetely try that out, I havent really done experimenting with that kind of stuff so thanks. Well I'm very interested (have seen his name pass a few times), so might buy it

Using 2x very cheap divers like that could maybe a way to directly start with 2x cabs instead of one. But as 2x cheap cabs would have less output than 1 good one, I have a feeling it would not be worth it.

Wow you guys just went from "cool stuff I can understand", to "waay over my head". I'm still into the first stages of learning to control my room with REW/processors so if youre ever (in like 2-3 months when my exams are done again) interested in explaining it all/implementing your technics on my room (measurements) I'm happy to be your test subject! First of I need to correctly setup all the active speakers I just put together (5x 2-way LaScalas) and integrate the 2x new DIY Subs. Using a flat response (based/with pyschoacoustic smoothing) for the moment. The book from Toole you linked seems pretty interesting! Is there somewhere I can read a few samples (like texts like that) online? Maybe some free website?