Since I've found these intriguing and have not seen any real discussion, I thought it might make sense to start a focused thread on them. Perhaps, they are best not labeled 'Woden Design' as all I've seen are on MarkAudio's site, but it seems appropriate.
Some Initial Questions:
1) Do these result in a similar sound field to that of the MBL RadialStrahler systems and, perhaps others similar (Manger?, Ohm Walsh?)? Without the added complexity of crossovers for omnidirectional considerations.
2) Does the need to site them around four feet from the nearest walls diminish if they are not square to the walls of a rectangular room?
3) There are quadrupole designs for three of the MA 11CM drivers (MAOP11ms, Alpair 11MS, CHN110). Each has different interior dimensions. Could the same dimensions be used for all three with adjustments to the vent length and diameter without any real compromise?
4) If I would like to be able to readily change vent length and diameter without needing to do work inside the cabinet, would using exterior mounted vents without any protrusion into the cabinet work? I'm thinking of round cylinders of wood that would attach to the cabinet with a larger hole in the cabinet, large enough to not alter the vent function.
I'm interested to see the responses and would love to know about any builds.
Skip
Some Initial Questions:
1) Do these result in a similar sound field to that of the MBL RadialStrahler systems and, perhaps others similar (Manger?, Ohm Walsh?)? Without the added complexity of crossovers for omnidirectional considerations.
2) Does the need to site them around four feet from the nearest walls diminish if they are not square to the walls of a rectangular room?
3) There are quadrupole designs for three of the MA 11CM drivers (MAOP11ms, Alpair 11MS, CHN110). Each has different interior dimensions. Could the same dimensions be used for all three with adjustments to the vent length and diameter without any real compromise?
4) If I would like to be able to readily change vent length and diameter without needing to do work inside the cabinet, would using exterior mounted vents without any protrusion into the cabinet work? I'm thinking of round cylinders of wood that would attach to the cabinet with a larger hole in the cabinet, large enough to not alter the vent function.
I'm interested to see the responses and would love to know about any builds.
Skip
A good imitation, with "radiating sides" = n =4, an MBL has a larger n. these designs are inpired by the EPI Tower & miniTower.
They are best out in a room, i would not put them orthogonal to the walls.
Many single &ntwin driver boxes can fairly easily be turned into qudrapoles.
Depends on the design. Most of Scott’s are ML-TLs, so height, cross-section, Zd, Ventd, and its tuning.
dave
They are best out in a room, i would not put them orthogonal to the walls.
Many single &ntwin driver boxes can fairly easily be turned into qudrapoles.
Depends on the design. Most of Scott’s are ML-TLs, so height, cross-section, Zd, Ventd, and its tuning.
dave
Lean in that direction, like all omni variations; in this case inspired by the old EPI designs. Quadrupoles have their own radiation pattern, but so do most others and in practice because the object is to significantly increase the ratio of reflected to direct radiation at the listening position, if you're not on a nearfield null things tend to average out, so they end up with more similarities than otherwise.
Definitely not -see Dave's notes above.
Depends what you call 'compromise'. You can ram any drivers into any of the enclosures & they'll make a noise, but I wouldn't have created different enclosures if all I needed to do was to change the vent. Mine may be a sad, lonely, futile and ultimately worthless life, but I prefer not to waste what time I've got. 😉
Not even close to MBL RadialStrahler or Ohm Walsh. They are true 360 degrees designs.
Similar to Manger and EPI, yes.
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The Ohm is, the MBL is a (good0 polygonal approximation.
A quadrapole is a poorer approximation.
dave
A quadrapole is a poorer approximation.
dave
I stand corrected - yes, polygonal approximation, but it is close to an ideal omnidirectional 360 dispersion. I have heard MBL on a show more than 15 years ago - very good sound with excellent spaciousness. After that experience, I made a loudspeaker very similar to EPI design - but even my heavily biased observation tells me it was not good enough, not even "close, but no cigar".
Quadrupoles are poor approximation. In a big room with big distance from listeners maybe they will work somewhat better.
The total cost of a pair of CHN-110 quadropoles would likley do little to dent just the VAT on a pair of MBL.
Each MBL driver is by itself should have even hotizontal place, vertical too except at the poles. Haven’t spent much time thinking about a disparate stack of them ….
Them and the continied evoliion of the Walsh driver are examples of a llt of development .
dave
Each MBL driver is by itself should have even hotizontal place, vertical too except at the poles. Haven’t spent much time thinking about a disparate stack of them ….
Them and the continied evoliion of the Walsh driver are examples of a llt of development .
dave
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As noted, quadrupoles like the EPI type speakers were / are not intended to be exactly akin to a [nominally] 360 degree source or very close approximation. They're a quadrupole by design, with their own balance of qualities rather than being something else. That being said, & as I mentioned above, the majority of the results with omnidirectional variations depends very much on the room response, how much energy the speakers put into swamping / averaging out the modes, and also what, if any, degree of directionality you want, both of which also heavily depend on the driver polar characteristics. Outside the nearfield things tend to average out between different approaches, so they have more similarities than otherwise, but the word there is 'similarities', not 'identical', as they aren't meant to be that, but related variations on a broad theme, with bipoles & other hybrids e.g. front & upward-firing as Castle, Infinity etc. have done being still others.
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