ROAR12 in the livingroom... 
Sunday, August 27, 2017, 18:54
Posted by Anders
Johannes came by and dropped of the ROAR12 for me to have a listen to, a really nice experience, it quickly became clear though that the ROAR 12 is not suited for indoor duty, at all, but again that was never the intended use.

Given a corner placement in this room 30z was not a problem to reach, with a very tactile character, even at very low levels you feel it everywhere, it's not a very neighbor friendly device at all.

Crossed over at 153Hz (24dB/Oct LR) it blended nicely with the FCAM's even though it took some crossover and gain tuning to get it to not dominate the reproduction, it is indeed very efficient.

Bare in mind that these are indoor low level usage impressions and the room contributes a lot, both good and bad.

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ROAR prototype build 
Tuesday, March 14, 2017, 17:44
Posted by Anders
Prototype build pictures courtesy of Johannes Rodin who also designed and built it, this is a 2x12" TPQWR (or 6:th order series tuned bandpass) loaded with Beyma 12P80Nd :

The result spurred us to get the ROAR designs finalized and published, although still purely theoretical they all follow the same basic premise and theory as the prototype shown above but with a lot more iterations and careful tuning to get the best result out of each driver size.
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ROAR family overview 
Thursday, March 2, 2017, 18:02
Posted by Anders

The ROAR designs are all made up of a constant area tapped system coupled with a quarter wave resonator, the TPQWR abbreviation aims to describe this as Tapped Pipe (constant area segment) + Quarter Wave Resonator (another constant area segment).

In theory this results in the passband range of a tapped constant area system (wider then its corresponding TH) with a in passband efficiency grater then that of their corresponding TH equivalent.

Regarding the naming, putting together a name based on the design principles involved proved to be an impossible task, so we opted for Johannes Rodin's surname initials and something that described the prototype build characteristics.... ROAR! :)

ROAR15 and ROAR18 is IPAL compatible!

With only minor adjustments to the original design the ROAR15 is 18IPAL compatible, as is ROAR18 with the 21IPAL, according to simulations, the adjustments required is limited to adapting the driver cut out, adding some additional rear panel bracing and in the case of ROAR15 an upward offset of the mouth brace by approx. 20mm.

Please note that the only ROAR design that has been built so far is the ROAR12, and it shows a lot of promise, you can find pictures in the ROAR12 link below, courtesy of Johannes Rodin.

Links to ROAR design proposals intended for professional use :

370x550x750mm (WxHxD)
152,6dm3 external volume

450x640x800mm (WxHxD)
230,4dm3 external volume

580x820x820mm (WxHxD)
390dm3 external volume

600x960x960mm (WxHxD)
553dm3 external volume

Prototype build pictures :

ROAR prototype build

size comparioson :

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Thursday, March 2, 2017, 17:48
Posted by Anders
This is the ROAR10, it is a 10" TPQWR design proposal.
Please note that this design has not been built yet, this far it reside purely in the theoretical domain.

HR input data from 3D:

FaitalPro 10FH520 HR input:

FaitalPro 10FH520 HR spl response:

FaitalPro 10FH520 HR displacement:

FaitalPro 10FH520 HR phase:

FaitalPro 10FH520 HR Groupdelay:


Parts overview:

Other driver examples:

B&C 10NW64

B&C 10FW64

18sound 10W500

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Thursday, March 2, 2017, 17:30
Posted by Anders
This is the ROAR12, it is a 12" TPQWR design proposal based on 18mm Plywood.

The ROAR12 has been built, and measured loaded with a B&C 12PS100, you can find pictures from the build below courtesy of Johannes Rodin, measurements will be posted as soon as the driver has softened up to give a more fair result.

Further tests and measurements needs to be conducted before we can make more definitive comments on the ROAR12 performance, but so far it shows a lot of promise and it sounds really nice, and much :)

HR input data from 3D:

B&C 12TBX100 HR input:

B&C 12TBX100 HR spl response:

B&C 12TBX100 HR MAX spl response:

B&C 12TBX100 HR displacement:

B&C 12TBX100 HR phase:

B&C 12TBX100 HR Groupdelay:


Parts overview:

Other driver examples:

18sound 12LW1400

FaitalPro 12HP1020

FaitalPro 12HP1060

ROAR12 build pictures (courtesy of Johannes Rodin) :

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