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luton_soundman
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Posted: 09 August 2022 at 12:10pm |
levyte357- wrote:
smitske96 wrote:
Things like 1W/1M only tell a small part of the story, there are many more tests that can be done to verify something. |
Agreed, and know many Reggae dudes, who actively meter sub freq response of cabs at gigs. Think it is useful, for progressing your system.
I have said years ago, one of my favorite sub cabs is the Martin WSX.
I say this, to reinforce, I don't only rate Scoops, and know other designs that excel.
Even with lowly RCF driver, WSX will do mid 40s in pairs, which is great for an FLH. With design modified for modern 18sound/B&C, who knows what SPL is possible, in 40-50hz range.
I'm sure the 1W@1M measurements state something fantastically impressive for this cab, but in reality, mid 40's in pairs, is achievable.
So I prefer to hear about what people have done with cabs, as opposed to what the specs say.
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I was going to mention the Tapped horns if thats what you are reffering to? Heard them on couple occasions. They even asked another engineer down to set them up properly and made no difference.
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luton_soundman
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Posted: 09 August 2022 at 12:15pm |
People dont use scoops on reggae because of the image. They just use what does the right job for them. I go up and down the country listening, trying different boxes, drivers, etc. Many others are the same, hence why you see so many reggae sounds now with all different types of bass cabs instead of scoops.
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luton_soundman
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Posted: 09 August 2022 at 12:21pm |
toastyghost wrote:
smitske96 wrote:
Things like 1W/1M only tell a small part of the story, there are many more tests that can be done to verify something.
Personally, I design something with the helps of being it hornresp, winisd etc. (and in the future akabak) and knowledge I am steadily building over the years. After that stage a prototype is build, it gets verified by measurement. Why? because when designing something I have some specs in mind like F3, size, efficiency etc. If not good, possible adjustments would be made, and verified by measurement again until satisfactory. After that, give it a good listen and possibly use it in the field and ask for feedback. If those last two are not any good (personally and for others) I would move on to something different even if the response looks perfect.
I have to add, i have not yet encountered a case were it was not good enough in the end sound wise.
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This is a really common problem. Most lumped element models are axisymmetric and straight. People simply don’t build what they model, because of failing to account for the acoustic behaviour of bends or rectangular sections when folding the design and doing the CAD work.
Verification is an absolutely vital step, and you have to measure for that. If the electrical impedance and axial responses of the prototype & model don’t match, one of them is ‘wrong’.
The typical modelling software is also purely linear acoustics and doesn’t include high order modes, thermal rise, or diffraction effects. That means the high power output in things like Hornresp is to be taken with a very large pinch of salt. Even AKABAK 3's coupled LEM & BEM is only valid in the linear domain, and loudspeakers are often far from linear devices.
Nonlinear modelling is possible but is hugely complex & computationally expensive. However nonlinear behaviours can be easily measured, with tools like an oscilloscope, thermal sensor & microphones. Those items used to be obscenely expensive and strictly available at serious laboratories, but can now be yours with a laptop & a few hundred bucks expenditure. So prototyping & measurements are still a massively important part of the design process.
Either way, scoops aren’t some magical cheat code to get around physics either. They’re very, very well understood acoustically - and don’t behave like a horn at low frequencies either.
The problem is that all of these comparisons are not apples to apples. As has been stated many times in this thread, stacks of different sizes are taken to venues and put in different places, driven with different signals (music, filtering/preamp, engineer, amplifiers) at different levels. That’s not scientific, although it is fun.
There’s plenty of room for both, and no serious speaker designer or manufacturer would ever claim otherwise. Let alone develop & release a product without doing one or the other, extensively.
Sadly, the only scoop design for which I've seen this process followed & data reported in remotely standard ways is Mikko's Polar Bear. That's despite several offers on the part of myself & others - for free - to find out [i)why & how these 'subjectively observed behaviours' occur 🤷🏻♂️ in the face of such evidence & many, many threads just like this one, it's not surprising that people assume those who love & promote scoops simply don't want to know or care.
Anyway, back to the navel gazing! |
Problem with the polar bears every time i heard them was probably nothing below 45hz in a stack of 4 yet the owner would always say its set and doing 30hz or something like that 🤷🙈 and make reference to the sims etc. Another reason why im more inerested in real world performance but still not against the data.
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sarsen1
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Posted: 09 August 2022 at 12:37pm |
luton_soundman wrote:
toastyghost wrote:
smitske96 wrote:
Things like 1W/1M only tell a small part of the story, there are many more tests that can be done to verify something.
Personally, I design something with the helps of being it hornresp, winisd etc. (and in the future akabak) and knowledge I am steadily building over the years. After that stage a prototype is build, it gets verified by measurement. Why? because when designing something I have some specs in mind like F3, size, efficiency etc. If not good, possible adjustments would be made, and verified by measurement again until satisfactory. After that, give it a good listen and possibly use it in the field and ask for feedback. If those last two are not any good (personally and for others) I would move on to something different even if the response looks perfect.
I have to add, i have not yet encountered a case were it was not good enough in the end sound wise.
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This is a really common problem. Most lumped element models are axisymmetric and straight. People simply don’t build what they model, because of failing to account for the acoustic behaviour of bends or rectangular sections when folding the design and doing the CAD work.
Verification is an absolutely vital step, and you have to measure for that. If the electrical impedance and axial responses of the prototype & model don’t match, one of them is ‘wrong’.
The typical modelling software is also purely linear acoustics and doesn’t include high order modes, thermal rise, or diffraction effects. That means the high power output in things like Hornresp is to be taken with a very large pinch of salt. Even AKABAK 3's coupled LEM & BEM is only valid in the linear domain, and loudspeakers are often far from linear devices.
Nonlinear modelling is possible but is hugely complex & computationally expensive. However nonlinear behaviours can be easily measured, with tools like an oscilloscope, thermal sensor & microphones. Those items used to be obscenely expensive and strictly available at serious laboratories, but can now be yours with a laptop & a few hundred bucks expenditure. So prototyping & measurements are still a massively important part of the design process.
Either way, scoops aren’t some magical cheat code to get around physics either. They’re very, very well understood acoustically - and don’t behave like a horn at low frequencies either.
The problem is that all of these comparisons are not apples to apples. As has been stated many times in this thread, stacks of different sizes are taken to venues and put in different places, driven with different signals (music, filtering/preamp, engineer, amplifiers) at different levels. That’s not scientific, although it is fun.
There’s plenty of room for both, and no serious speaker designer or manufacturer would ever claim otherwise. Let alone develop & release a product without doing one or the other, extensively.
Sadly, the only scoop design for which I've seen this process followed & data reported in remotely standard ways is Mikko's Polar Bear. That's despite several offers on the part of myself & others - for free - to find out [i)why & how these 'subjectively observed behaviours' occur 🤷🏻♂️ in the face of such evidence & many, many threads just like this one, it's not surprising that people assume those who love & promote scoops simply don't want to know or care.
Anyway, back to the navel gazing! |
Problem with the polar bears every time i heard them was probably nothing below 45hz in a stack of 4 yet the owner would always say its set and doing 30hz or something like that 🤷🙈 and make reference to the sims etc. Another reason why im more inerested in real world performance but still not against the data. |
Genuine question; was Rog's design process of the Super Scoop non-standard? Or perhaps sims and design processes have moved on from whenever it was designed (2006 or something?)
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Contour
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Posted: 09 August 2022 at 1:12pm |
I think Rog already used Akabak at that time.
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levyte357-
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Posted: 09 August 2022 at 1:30pm |
Contour wrote:
I think Rog already used Akabak at that time. |
Obviously, nothing wrong with utilizing scientific and mathematical means of designing a cab for particular speaker, or group of speakers with similar parameters.
As long as prototypes are built, tested with music at some point, and refined.
Loudspeaker cabinets are designed and built, with an end purpose of playing music, placing priority on how cabs measure, as opposed to how well they actually meet acoustic specifications/design, by playing music, will always lead to self denial.
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Global Depopulation - Alive and Killing.
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Contour
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Posted: 09 August 2022 at 1:40pm |
Simulations indeed don’t say everything, first prototype of the X-tro cabinet we build simulated very well but in reality really had poor midbass, caused by improper cone loading, in this case the common letterbox throat did not work at all, and we changed to BHP design.
Best regards,
Walter
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toastyghost
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Posted: 09 August 2022 at 4:24pm |
Contour wrote:
I think Rog already used Akabak at that time. | That was a different software entirely to the newest version of AKABAK. It was an ‘unlimited’ series/parallel lumped element model, whereas the new version has a Boundary Element Model for 2D & 3D mesh solving via the Kirchhoff-Helmholtz integral. That part is a major upgrade, as it accounts for the behaviour of (linear) 3D acoustic effects such as reflections, and diffraction - so long as you have the correct meshing parameters, among many other things.
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lawbadman
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Posted: 29 August 2022 at 3:45am |
Since the Hog scoop is old and it seems as if many people have retired their enclosures, which design is a good upgrade?
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HighPressureSound
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Posted: 15 April 2024 at 9:35pm |
Greetings. I am hoping these Hog Scoop plans and parts list are available elsewhere since the links are not working for me.
any help would be greatly appreciated.
thanks, Jake
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RealitySound
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Posted: 15 April 2024 at 11:51pm |
Just google "hog scoop plans" then click 'images'. lots of links.
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When you gonna send me some $$ mate ?
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HighPressureSound
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Posted: 16 April 2024 at 12:59am |
thanks! I always forget about Pinterest as a resource.
Jake
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