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double 18" reflex boxes question!

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msoundsystem View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote msoundsystem Quote  Post ReplyReply Direct Link To This Post Topic: double 18" reflex boxes question!
    Posted: 27 February 2019 at 2:47pm
hi guys. iv been wanting to design my own 2x 18" Bass reflex cabinet but haven't learnt how to use bassbox pro or winisd but im perfectly capable of building cabs and have done for years.
i currently have x6 scoops pd1850 loaded that absolutely rip up medium to big venues apart  
including outdoors but are no good for smaller venues as we know (all the sub outside the building)
so want something more suited to smaller and bigger spaces at the same time (bigger venue more cabs i will take) 
i have 12 pd186 drivers and 12 pd1850 drivers and i know the pd186 is suited to bass reflex better so thats my choice of driver for now. i will always be using minimum of x6 double reflex cabs in on stack sometimes x12 cabs in a stack venue size dependent.
i already have es18 above so covering the kick region is no issue untill i build some 15" midtops to meet the bass. SO i want to design or someone to design some 2x18" bass and spl heavy reflex boxes, im looking for that aggressive spl that makes your eyes wobble and chest hurt. im aware if i want louder i must sacrifice some low end extension but to me if i can get down to 35hz while still maintaining silly spl then thats what im after (please correct me if i have said anything wrong here). 
i have seen the b&c Sub 18 design and was thinking of building it into a double as i know its great with the pd186 but im still not sure thats the right move.. all the heavy weight cabs are not free designs i know, also looked at the fane designs and more. i have enough amps to power them (vz5000).
iv set aside £1600 for cab building and design, like i say i already have the drivers and amps so thats a huge saving.

so who could recommend what? iv got great knowledge of scoops and bph as thats all iv ever used and setup for customers, now im trying reflex and i know these will play a wider spectrum of frequency than the scoops.

what can you recommend me? for £1600 i should be able to build some killer loaded doubles (pd186) but i will need help in choosing the design.
music is anything from reggae to DNB to dubstep plus more on hires but bass heavy either way is what we want to achieve.. iv heard a few double loaded cabs out preform scoops on the low and even sometimes in the spl range no joke and this is what im after!!! but the owners will never disclose whats in the boxes or what design they are (i dont blame them) 
so always brings me back to the question what do i need to achieve this? my friend has gsubs and im not a fan after hearing them in different environments, even with different settings on processor and different amps powering them they just didnt do it for me (xb and 186 loaded). i dont want to go down the horn route must be reflex.
if im going to build these they need to be right, built once and be done with it, i do not want to change again for many years or piss the money up the wall.
i am willing to pay for a design as every man needs to eat but it must be a great design. the boxes will be built as prototypes out of mdf and then all being well after they have been put through their paces and we are happy my friend who has access to cnc machine will then cut them into flat packs for me out of ply. 

iv looked at many reflex cab designs over the years on the internet but haven't actually built many for test purposes.
is there any designs hiding deep down somewhere that can achieve what im after? or do i really need a custom designed cab?
for me a custom designed cab will be what im after to be honest unless a plan jumps out and will do everything i want and more and so far i haven't found one. so please feel free to give me advice on what i should be looking at.?

anyone who takes the piss or offers silly advice i will ignore so save your posts and your fingers from writing :)
i have been doing hires on a weekly basis for about 5 years now for small to big headliner shows and have lots of kit always being hired so can justify
building quite a few boxes as they will soon make back the money spent on them.

what are my best options? if BR cannot offer me what im after or match, better the scoops output then i will look at other options..

many thanks! 

love! 

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Crashpc View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Crashpc Quote  Post ReplyReply Direct Link To This Post Posted: 27 February 2019 at 7:38pm
Hello.
Hard to answer. To my knowledge, bassreflex box still can give most SPL for (small) volume once you look at power density. It needs beasty drivers though. In bassreflex box, you look for most displacement volume in the upper range, most motor force in the bassreflex tuning range, and biggest bassreflex ports for greatest efficiency due to the port compression. All balanced for best compromise. Bassreflex boxes are not exactly known for chest pounding bass, but it is doable with multiple boxes. They're known for "browner" bass, which might be more satisfactionary even at lower volumes.

The bass that moves your stomach is between 45-70Hz. For most accoustical pressure, you want to tune the box relatively high, at around 40Hz. But it is more complex than that.

Although PD.186 can sound like herd of stomping elephants, it is kind of outdated, and can be outclassed by many drivers with more cone  excursion and more motor force. I believe that PD.1850 is mightier driver in that regard, and if you want to save money, and the amp is potent enough, it will be better choice Than 186s. With stronger drivers, it is harder to push the required power into the speaker, as it has higher impedance across usable range. You need amplifier with greater voltage swing to be able to push enough power in there. You either save money, do what you want to do and be happy with the outcome in just new bassreflex boxes, which is not bad at all, or you choose completely different and more efficient approach with most efficient drivers, having greater displacemant volume, more motor force, etc. These beasts also need mostly different amps.
Nikon and Canon people should not be married to each other. Why did you let this happen?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote boots-hifi Quote  Post ReplyReply Direct Link To This Post Posted: 28 February 2019 at 7:09pm
B&C sub 18 design will work well with PD186’s. I have 4 for DJ mobs and they work really well.
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toastyghost View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote toastyghost Quote  Post ReplyReply Direct Link To This Post Posted: 28 February 2019 at 8:14pm
Try reading the Speaker Freakers dual 18"

https://drive.google.com/file/d/1vZNm7abMOv0yO85s7kBx4nS_vtQ1bgiA/view?fbclid=IwAR1sk_5xQ8I-Qr6St1xJdNADoTe_iQ0Ge2Dmt6ZrKFoLzcqam1MSJRTHK0Ihttps://drive.google.com/file/d/1vZNm7abMOv0yO85s7kBx4nS_vtQ1bgiA/view?fbclid=IwAR1sk_5xQ8I-Qr6St1xJdNADoTe_iQ0Ge2Dmt6ZrKFoLzcqam1MSJRTHK0I

You won't find a better documented, tested, verified dual 18" reflex design for free anywhere else. It'll help you design and tweak your own for your drivers.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote osse Quote  Post ReplyReply Direct Link To This Post Posted: 01 March 2019 at 6:00am
I tried some simulations of the PD186 with winISD in a bass-reflex box and it will need a big box, extends low and looses about ~3dB >35hz but gradually expanding SPL <30hz vs a 25% smaller box with 18rbx100-8, which is one of the recommended drivers in speaker freakers 2x18.

the speakerfreakers box is a very good design, not very optimised for the pd186 which seem to need a bigger box to extend low


Edited by osse - 01 March 2019 at 6:09am
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corell View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote corell Quote  Post ReplyReply Direct Link To This Post Posted: 01 March 2019 at 7:08am
....


Edited by corell - 01 March 2019 at 7:09am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote toastyghost Quote  Post ReplyReply Direct Link To This Post Posted: 01 March 2019 at 3:45pm
Originally posted by osse osse wrote:

I tried some simulations of the PD186 with winISD in a bass-reflex box and it will need a big box, extends low and looses about ~3dB >35hz but gradually expanding SPL <30hz vs a 25% smaller box with 18rbx100-8, which is one of the recommended drivers in speaker freakers 2x18.



the speakerfreakers box is a very good design, not very optimised for the pd186 which seem to need a bigger box to extend low


I wasn’t suggesting to build it, but to read and understand the process to develop your own for the drivers at hand.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote msoundsystem Quote  Post ReplyReply Direct Link To This Post Posted: 09 March 2019 at 9:34am
cheers everyone. Toasty, thanks iv Had a read and found it very informative.. Boots hifi, what frequency u running the sub 18s? And what power into each box?, do they really output alot of bass? Heard many good things about them but always been unsure if they will do the job well enough in multiples to actually build some. 
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