Bracing for dipole subwoofer

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I am building a modified w-frame dipole subwoofer. It is made to go in the corner and is based off an audioxpress article from 2004.

The original plans did not have any bracing and I noticed that the linkwitz dipole has no braces.

However I am thinking of connecting the panels internally with a length of 2”x2” hardwood. Are there any cons to this approach? Can’t fit a window brace

I’m also considering adding strips of wood on the outside to raise the frequency of panel resonance. Any thoughts on this? See pic
 

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Those Eminence woofers have a low QTS, so open baffle is an option, but would require a lot of EQ.

It depends on what your goal is, you will get more boom from a vented cabinet but better articulation and sound quality from an open baffle design.

I don't have a lot of free time so it might be a month or so before I can give a report on how this corner dipole design sounds.
 
Those Eminence woofers have a low QTS, so open baffle is an option, but would require a lot of EQ.

It depends on what your goal is, you will get more boom from a vented cabinet but better articulation and sound quality from an open baffle design.

I don't have a lot of free time so it might be a month or so before I can give a report on how this corner dipole design sounds.



Mi objetivo es complementar dos gabinetes grandes ( DTQWT II by Troels ) que son excelentes a mis oidos, pero me gustaria un poco más de profundidad y articulacion en las notas bajas, observo esa falta en la escucha de cuerdas punteadas como el contrabajo y en las octavas mas bajas de musica de organo. Yo estoy casi decidido por sealed, porque justamente quiero evitar el violento roll off de los BR por debajo de la sintonia, lo cual los hace inviables para mis necesidades auditivas .
Sé que necesitare algo de EQ, porque desperdiciare parte del potencial ( alto SPL) de estos parlantes Emienence Delta Pro , pero tengo a mi favor ( espero ) una buena integracion tonal con los parlantes traseros de mis gabinetes actuales, ( Eminence Delta Lite 2510II , ellos usan las mismas tecnologias y materiales de conos y suspension que Delta Pro 18 A ) .
Me interesó tu proyecto porque es un diseño especificamente pensado para un rincon de una sala y ese tambien es mi caso....
Gracias por tu respuesta, cuentanos por favor el resultado, me sumo al interes que ha despertado en otros foristas.

PD: ( los parlantes trabajan en configuracion push pull, como yo imagino ? )

1170/5000
My goal is to complement two large cabinets (DTQWT II by Troels) that are excellent to my ears, but I would like a little more depth and articulation in the lower notes, I observe that lack in listening to strings like the double bass and in the Lower octaves of organ music. I am almost decided by sealed, because I just want to avoid the violent roll off of the BR below the tuning, which makes them unviable for my hearing needs.
I know I will need some EQ, because I will waste part of the potential (high SPL) of these speakers Emienence Delta Pro, but I have in my favor (I hope) a good tonal integration with the rear speakers of my current cabinets, (Eminence Delta Lite 2510II, they use the same cones and suspension technologies and materials as Delta Pro 18 A).
I was interested in your project because it is a design specifically designed for a corner of a room and that is also my case ....
Thanks for your answer, please tell us the result, I join the interest that has awakened in other foristas.

PD: (the speakers work in push pull configuration, as I imagine?)
 
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I am building a modified w-frame dipole subwoofer. It is made to go in the corner and is based off an audioxpress article from 2004.

The original plans did not have any bracing and I noticed that the linkwitz dipole has no braces.

However I am thinking of connecting the panels internally with a length of 2”x2” hardwood. Are there any cons to this approach? Can’t fit a window brace

I’m also considering adding strips of wood on the outside to raise the frequency of panel resonance. Any thoughts on this? See pic


Thanks for sharing your interesting project.


The original plans may not have had bracing cause it want needed. Open baffle designs are meant to be low on resonance due to the relatively low pressures produced.


It would be good to measure pre and post braces to see if they are needed.



Braces in the output might create diffraction and reflections, but that might not be heard. I suppose braces that are rounded in profile and thinner would have less effect on the sound waves. Take that idea to the limit and wire tensioned up could be effective. Otherwise thin dowelling should be fine as the forces will be longitudinal along the dowel.
 
Hi all, just wanted to give an update on the sound of these corner dipoles.

I'm still playing with the DSP but I really like the clarity of bass reproduction. Acoustic bass is reproduced clear with no smearing of the notes. When you play a kick drum through these you can actually here the peak of maximum SPL. Bass extension is very strong down to 28 hz.

Movies and hiphop bass with 30-35 hz notes will shake the floor, and this was the biggest surprise to me.

I've built a 20hz tuned 200 liter 12" subwoofer, a sealed peerless xxls 10" subwoofer for the car and a sealed 12" subwoofer with an f3 of 30 hz but I've never experienced such clean 30-35 hz output.

However if massive deep bass SPL is your thing I would not recommend this approach as i can easily get these to bottom out above 95db at 30hz and I have applied a 30 hz high pass because 20 hz is basically a distortion machine.

I know in room measurements don't mean much but I've included some distortion measurements of these in the corner of a small bedroom with the mic about 1.5 meters away.
 

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Those are harmonic distortion plots for 31.5 and 60 hz. I play a sine wave and then turn up the volume until distortion is around 5%. These measurements are taken at the listening position that is about 1.5 m away.

Let me know if you want more detail.
 
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Those are harmonic distortion plots for 31.5 and 60 hz. I play a sine wave and then turn up the volume until distortion is around 5%. These measurements are taken at the listening position that is about 1.5 m away.

Let me know if you want more detail.
RTAs. Thanks. A nice way to present it, at least as a complement to the usual freq plot for a given constant-input sweep.

B.
 
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