Thursday, March 2, 2017, 17:23
Posted by Anders
This is the ROAR15, it is a 15" TPQWR design proposal.
This design has been built yet by yours truly.

HR input data from 3D:

B&C 15TBW100 HR input:

B&C 15TBW100 HR spl response:

B&C 15TBW100 HR spl response 88Hz:

B&C 15TBW100 HR spl response 45Hz:

B&C 15TBW100 HR max spl:

B&C 15TBW100 HR displacement:

B&C 15TBW100 HR phase:

B&C 15TBW100 HR Groupdelay:


Parts overwiew:

Other driver examples:

18sound 15LW2400:

B&C 15TBX100:

Beyma 15P100FeV2:

Driver hole pattern (for B&C 15SW115):

The otherwise unseen view:

Driver mounting envelope check (B&C 15SW115 geometry):

The quick setup:

The measurements below where take a in room, so don't stare yourself blind at the results, yet they should suffice as an indicator of the performance.

frequency resonance at the appreture ROAR15:

Distortion at the appreture ROAR15:

Complete system, bare in mind that this is a room completely devoid of any form of acoustic treatment, the ROAR's are gained up a bit from what I usually like.

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Thursday, March 2, 2017, 17:04
Posted by Anders
This is the ROAR18, it is a 18" TPQWR design proposal.
This design has been built and the DIY'er has reported good results, a picture from the build can be seen below.

HR input data from 3D:

Beyma 18PW1400Fe HR input:

Beyma 18PW1400Fe HR spl response:

Beyma 18PW1400Fe HR spl response (additional frequencies):

Beyma 18PW1400Fe HR displacement:

Beyma 18PW1400Fe HR phase:

Beyma 18PW1400Fe HR Groupdelay:

Parts overview:


Build picture:

B&C 18SW115

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Line source adventures 
Monday, January 16, 2017, 13:27
Posted by Anders
After having seen several compact line source designs based on small full range drivers pop up in the product offerings from big name manufacturers I became intrigued and decided to give this a try.

The Faital Pro 3Fe22 driver seemed too be a good choice since they perform very well, have decent power handling and are affordable in larger quantities.

I decided on a sealed system with ~1,3dm3/driver when sectioning them in groups of four, and it works fine when combined with some low end support, in this case by two THAM10's loaded with Faital Pro 10HP1020.




I'm currently using a Linux loaded skylake I3 NUC with a HRT microstreamer D/A as source, processed by a DBX Drivereack 260 and powered by two LabGruppen IP450's.

The system sound very clean and hints of having a lot of headroom if needed, no doubt it is overkill in the current application, but it sounds really good so I'm happy.

I also tested them together with the ROAR12 with impressive results in an outdoor environment, I really need to do this again, the FCAM123 seems to really like the outdoors, and they sound just fine at a distance.

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More TPQWR ponderings... 
Thursday, December 31, 2015, 11:03
Posted by Anders
The previously mentioned mix of principles we choose to call TPQWR seems to have a lot going for it, below you can see an 15" example model and a comparison to the THAM15 loaded with the same driver.

TPQWR is short for Tapped Pipe (meaning a constant area segment) coupled with a Quarter Wave Resonator (another constant area segment).

These two segments are tapped at the driver and the resonator is the last segment leading up to the mouth.

The middle peak in the response is the result of the QWR segment, this also boosts the efficiency in the entire passband, the upper and lower bandpass limits are a product of the pipe segment length.

The typical TPQWR enclosure will be bigger then it's THAM equivalent, that much is certain, how much bigger is not yet known since we have yet to optimize the TPQWR folding and size to the same level as for the THAM designs.

Example model :

THAM15 (grey) TPQWR115 (black) 15TBX100 2PI comparison :

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TPQWR - an easy to build mix of principles  
Wednesday, November 11, 2015, 21:16
Posted by Anders
Johannes Rodin came up with something very interesting...

The following images serves to describe the principal idea and is not to be regarded as any form of optimized DIY build plan, for example the oh so necessary bracing is left out.

Named TPQWR since it seems to describe the mix of principles involved in the best way, a Tapped Pipe coupled with a Quarter Wave Resonator.

The front resonator is the key according to Johannes, it boosts the tapped pipe's entire pass band efficiency and also adds a bit of extra efficiency in a region where it usually is beneficial to have it.

Simulations seems to indicate (speculative) that it will have very low "in pass band"-distortion due to extensive upper harmonics cancelations and that it will show less tonal deviations due to power compression compared to other design principles.

This mix of design principles is also very simple to build and it has about as good of a volumetric efficiency as it is possible to achieve being completely devoid of unused volumes when folded.

Principal model without necessary bracing:

Principal drawing without necessary bracing:

Faital Pro 10PR330 in 2PI:

B&C 10NW64 in 2PI:

Faital Pro 10HP1020 in 2PI:

Faital Pro 10HP1020 in 1PI:

Faital Pro 10HP1020 in 0,5PI:

More driver examples may be added in the future.
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