I can't say that with confidence. I made a few deviations from the design (12mm ply instead of 18mm, and two braces per panel instead of one), so I didn't build exactly to the plans. All internal dimensions were adjusted to maintain the same horn geometry, and I am certain that I did not get that wrong. I used a double thick baffle (24mm total).
I would consider these deviations minor and not ones that would result in such material changes to the frequency response. All joins were absolutely airtight and there was no leaking around the driver.
Looking at some of my measurements, I probably had efficiency approaching 100db 1w/1m in the lower end. I believe the efficiency around 100hz to be in the region of 107+db. The box I built seemed to underperform in the low bass and over perform in the upper bass.
One thing I will say for the cabinet is that it was the most hard hitting bass guitar sub I have messed with (crossing over well above 100hz). Given that, I may build another in the future, to see if the response problem is duplicated. If it is, it will form part of my bass guitar rig, if it isn't, it will being a roaring subwoofer.
Edited to add -
If you look at Circlomanen's graph in post 37, his measurement is 8db down at 50hz from 100hz and it was measured inside, where room gain could have arguably augmented the bottom end.
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Hello laxandredeyed,
To support your decision to build or not more ROAR box, find attached an Acoustical Power chart comparing the Roar design vs Paraflex C design considering the same total box volume and also the same driver.
Green = Paraflex give you better output
Yellow = Roar give you better output
Red = big dip in the upper bandwidth related to ROAR design and you saw it in your measurement.
In addition, ROAR has total of 13 panels vs 10 from Paraflex C vs 8 from Manifold, witch gives better response compared to both ROAR adn Paraflex C. Looks like Band Pass 6th Order Parallel is the way to go if you want more SPL, otherwise TL/MLTL variants gives you wider bandwidth compared to a conventional vented box for the same box size.
Find attached the 3D and also hornresp input data.
ROAR total volume = 320L
Paraflex C total volume = 319L
Driver = Snake HPX2150
Consider that each single cabinet delivered good response on the time it was designed, think about SuperScooter for instance, but hornresp has been improved and new designs has been explored, so, today you have better options. But personal tastes needs to be considered and we can't see that from charts but ROAR and SuperScooter suffer from the same issue related to the DIP.
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personally i do not build mine yet, but stll learning and reading and looking and graphs and i do not like at all designs were the graph is like a tilted line going upwards, kind of what happened to you , its harder to eq that , than a manifold or th type of response and depending on the driver there are some that they close to a flat in the middle... no vallley at the 30 to 100 region , idgaf above 100 lol!! sometimes the driver that we pick gives a horrible dip that is not practicallly to eq, as a side note
did you take a look an jbell ss15, single sheet ply design and i guess will perform better than a tham 12.
Using these poor examples is misleading . Model them yourself and not such a wild undamped appearance by comparison which is like one note blunders… every time
Those horrible dips are not low enough tuned in many cases (saggy with two peaks like batmans profile ) compounded by a poor choice if csa it seems.
find the ‘perfect’ but very tight /damped TL for the driver and fold it in half then take the cross-sectional area.( Multiply times four ) and use half that same length , as your waveguide.
Offset your driver from the closed end do not just fire these as a single from a dead end every time to see better results
same approach to paraflex, but split that big resonators crossectional area between the other side s output and the last of 3 parts which make the longer path.
this never fails … (length first), then volumetric ratios(csa 2:1 in csa split in paraflex and 4:1 in roar. But at 3:1 (paraflex) and 3 total in that folded qw resonators Top veiw
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I couldn’t keep up with demand if I was to ‘sell’ these…. It’s rediculously ‘loud’ and deep ….(these hold a record currently in a 20 hz morph in car audio from father/son (phatboys) from Oakland, california) Try a real driver with some respectable and potent TS parameters instead. It’s like you want you cake and eat it to.. but with whipped cream, cherry and your favorite ice cream 😆. …. Well, then put in the right ingredients? And keep it Simple!!
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It’s a speaker box? I don’t know if that it matters what it’s ‘for‘. We all understand what it is and can simulate it(shared earlier in this post) so hopefully it’s helpful because this stuff doesn’t seem to need to be so confusing? I keep ending up with exactly what I simulate, and that goes for the parallel versions as well lately thanks to pH one, and David McBean, allowing us to accurately portray both sides of the driver on both sides of the cone and noticing there is in fact, a sweet spot in all of this, and how the folding sequence, and pendulum swing like intervals from start to stop, and a pattern in it , really truly matter….
All roads lead to the same type of 3:1, 1/3 (pi/9x total length in ODTL) , etc approach of odd harmoinic intervals to all of this. Roar, paraflex, etc are no different if you want them to ‘work’ ideal.
0.217
0.349
0.424
0.561
0.651
0.714
0.848??
nobody seems to know exactly where these come from, but they work ….(??).
we can thank GM for them, however 💚
maybe shrink these resonators down to 4x the TL section csa instead of these obnoxiously overwelming spl grabs(paraflex is awkwardly huge too often it seems and it’s not even half as big when they ran into ratio issues ) that bias the top or dilute the akready underdamped? It’s too hard to tell with these weird driver choices or lack of consistent info from people who dont share in diy anymore (thsnkfully you’re willing!)
i dunno…. But someday maybe WE will 😆until then GMs info always pans out
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It's OK to disagree, different people have different experience and they see things from different point of view, this is the nature of diversity. But looks like you post too many words and numbers but no real data, witch is not wise from your side nether respectful, what data supports your criticism?
Let's assume I made it the wrong way and you can do it in the right way, let us see your comparison, chose your box volume and driver, post your Acoustical Power chart comparing ROAR and PARAFLEX C, attach your Hornresp inputdata as txt for both of them, and also post your CAD files for both, because we need to certify that your simulation numbers correlates with real box. Let's us see if your data leads to a different conclusion.
Sorry if that sounded offensive …. There’s plenty of data out there already in a variety of posts on this subject and I’ve shared measured and simulated data side by side when
it was just a suggestion , plenty of data has been shared and continues to be . Use it to come to conclusions instead of cad drawings maybe and sims alone ? It’s all very helpful and has been collectively over the years, collect it and you’ll see what I mean maybe? But this subject is becoming harder and harder to navigate because of ‘ideas’ not sawdust, some of us dont know what to present anymore because it simply got old trying to over and over I suppose. Now its up to you? Build one
In a world overstimulated by Instagram or TikTok, or fancy cad drawings instead of real speakers, I don’t think there’s anything anyone can present that matters if it isn’t somehow accompanied by a dog and pony show and fireworks and strippers and free beer? I don’t know what the answer is anymore, novody is ever on the same page or will be…. but I think it’s obvious once you go in the garage and get covered in sawdust Where it can be found.
use the same driver(x6) and have 6 friends do the same. All build the cabinet and spend a month with it. Then get together and compare notes. You just became the 6 smartest guys in all of this, now move to the next type of design and repeat…. There’s only a few before you learn the meat and potatoes of the most important parts in all of this , odd harmonic intervals and how to use them/find them/. Impliment them.
discover this and then spread the word so others can use it too! Otherwise it’s all just confusing and doesn’t really find ‘the sweet spot’ because there isn’t one if not, ?? There can’t be, look at 1/4 wave and not just the ‘fundamental ‘ ? Look above to see wjere below came from (It couldn’t be more obvious once you do using horn resoponse in this manner.
lined up resonators (and driver entry /offset) will show a -990dB at 860,1720,2580,3440,etc
or even 430,860,1720….hz once you look.
this is a function if the ‘ golden ratio in trigonometry or the pythagor Ther…. and 3: 1 in the odd harmonic sequence.
changing speed if sound to 345.6 vs 344.0 (also helps) make it even more obvious(because 864 instead of 860).
if it adds to 9 as a digital root it’s parts of teslas arguenets that nobody listened too as well. Horn response exposes this and it’s very helpful to use it as a guide In higher order enclosures so they aren’t ‘random’ discontinuities in the parallel versions especially or offset driver mltl. Good luck, once you ‘get it’ you’ll see what I mean and once you ‘build it’ youll never stop
use the same driver(x6) and have 6 friends do the same. All build the cabinet and spend a month with it. Then get together and compare notes. You just became the 6 smartest guys in all of this, now move to the next type of design and repeat…. There’s only a few before you learn the meat and potatoes of the most important parts in all of this , odd harmonic intervals and how to use them/find them/. Impliment them.
discover this and then spread the word so others can use it too! Otherwise it’s all just confusing and doesn’t really find ‘the sweet spot’ because there isn’t one if not, ?? There can’t be, look at 1/4 wave and not just the ‘fundamental ‘ ? Look above to see wjere below came from (It couldn’t be more obvious once you do using horn resoponse in this manner.
lined up resonators (and driver entry /offset) will show a -990dB at 860,1720,2580,3440,etc
or even 430,860,1720….hz once you look.
this is a function if the ‘ golden ratio in trigonometry or the pythagor Ther…. and 3: 1 in the odd harmonic sequence.
changing speed if sound to 345.6 vs 344.0 (also helps) make it even more obvious(because 864 instead of 860).
if it adds to 9 as a digital root it’s parts of teslas arguenets that nobody listened too as well. Horn response exposes this and it’s very helpful to use it as a guide In higher order enclosures so they aren’t ‘random’ discontinuities in the parallel versions especially or offset driver mltl. Good luck, once you ‘get it’ you’ll see what I mean and once you ‘build it’ youll never stop
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Please use screen shots of your horn response inputs. I’ll try and point some things out here and maybe it’ll make sense…. I’m not gonna sit here and double click on all the thumbnail screens with zip files, endlessly on a phone? trying to sort through them either….. just post simple pictures(?) Nobody wants/will dig through all that stuff trying to get to the important parts that are actually matter here.. it’s also far more convenient to do some of this on a phone, which doesn’t want to open any of that excess in the first place, leaving the computer for the horn response program simultaneously.
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Just checking - Does this mean that you had no problems finding the hidden "Easter Egg"? 🙂
I would recommend 18 mm (or more) plywood since the ROAR series works with very large internal pressures. I would also recommend a beefier driver. B&C 12TBX100 or similar high Bl - sturdy cone - Low Qes and Qts driver. A B&C 15DS115 in a ROAR15 would probably be better suited for bass guitar duty.
Regards,
Johannes
Oh my gosh, sorry I haven’t even been able to look at that yet the computer broke and then I was in a car accident so I haven’t been able to load up the new horn response. But thanks for reminding me because that will make all of this easier instead of being stuck in bed with broken bones, and nothing to do…
The horn response is so wonderful in ways that people don’t even recognize yet(use it to occupy your mind and explore things when you can’t). So many people did this during Covid. It was amazing.
I have an 18 DS 115 -4 with your name on it. It’s just waiting to be something instead of being put on the back burner all the time. Throw me some ideas you quartww wave guru💚
Hi Bw,
Sorry to hear of your misfortune!
Wishing both you and your computer, speedy recoveries.
Kind regards,
David