baffles
I have played a bit with supra baffles. firstly, I have to say that I really feel GM's comment. the edge diffraction should be used more as a tool than anything else.
in my most recent project...
I have not tried it yet, but I am considering removing the brass rings from the 206 es-r horns I just built. why? the response has an audible (but as of yet not measured) hole in the 500 hz region. it is predicted by the frequency response and when I add eq to that region the response gets subjectively flatter. it seems from the various charts posted earlier that a square baffle at roughly 2 ft. would add to this region.
the shape of the baffles that terry uses was arrived at as far as I could tell through trial and error. the 6 inch and 8 inch versions have a different shape to them.
to me, their effect is quite audible, having played with and without them. the circular shape just seems to sound "right" to me. instead of looking at a two dimentional frequency response graph and get scared away by unevenness realize that with triode sound we want *three* dimentional effects sound stage. this is the effect of a good supra baffle to me. it gives a greater feeling of sound place - in the room-, instead of simply the loudness level. it is an illusory effect. it eases the mind from constantly trying to place instruments where they should be based on their perceived loudness level. the circular shape to me seems like it would have an easier to predict effect than say a square... in so much that it has a constant radius, and therefore a more certain frequency effect. the curve back on the shape would spread out this frequency effect over a wider range it seems to me at least.
if y'all are just dying of my pseudo scientific explainations, the you will have to wait till I go to grad school in acoustics. kay?
additionally, I have had to play with CC volume fill (blocks of walnut) to compensate for the extra volume created by the ring. still, there is lack of definition in upper bass that should not be there. it sounds like it is caused by the airflow patterns in the horn. (don't ask how I know this... it is a hunch).
further, there seems to be a greater than there should be (in my crappy room) midbass suckout. perhaps caused by waveguide from the spacing of the magnet of the driver too close to the internal side of the baffle.
additionally, it seems there are issues with reflections directly behind the magnet to the internal panel. (panel number nine in the assembly figure). this was arrived at by spacing a panel of wood directly behind the driver magnet. approximate depth of 3/4 inch. (this was the peice that I cut out from the front baffle tack nailed in temporarily). this helped...it also did the trick for volume...subjectively. but that is not the end of the story.
as far as waveguide goes, it seems that the chamber created by the long baffle hole "tunnel" serves essentially as the initial compression chamber, then the air squeezes out of a pseudo "throat" into the real compression chamber and then finally into the real throat. this problem, naturally varies wildly depending on specific internal dimmentions and magnet size, etc. when hand building, this comes up especially in a stereo matching scenerio...accuracy counts - at least get the same colour in both speakers.
the CC/throat structure on the cain and cain stuff is quite different, for instance. not nearly sensitive to internal waveguide problems as the nagaoka BLH style. the drivers have smaller magnets being the "normal" versions of the drivers rather than the special edition fostex stuff and ample space is left for air flow.
in the abby, there is no throat.
in the end, I have really only had major problems with this waveguide effect when dealing with the big magnet stuff.
I encountered this same issue with the 166es-r, which has WAY less room for baffle width than the 206es-r
so there is my null hypothesis after a few nights of playing with the horns. While I desire more measurement equipment, in the end, givven my current tools I have learned to value infinite patience with the process of cut and try. with these horns we create, it seems that all values are floating. change one aspect, every other aspect changes.
additionally, it should be noted that suprabaffles, especially those made out of high specifiic gravity woods (hard maple, walnut, etc) will not only contribute their own sonic signature but will increase the sense of speed of the musical signal. more detail comes out because of the mass loading.
in the end, I like the idea of the swan... it has almost zero point of baffle. then there is no baffle plane resonance, and high ridgidity. the disadvanntages? low mass, so brass rings are near necessity to get the highest speed sound. refinemment don;t come cheap or quick.
but also, that is just my detail freak side speaking... most horns, tls, I feel SHOULD be a musical instrument with its own inherent color. I think it goes without saying that in the process of making enclosures out of hard ply, solid woods, as little damping as possible, while using drivers with hardly flat frequency responses (especially the big ones), out of amps, sources and recording techniques which are not without their inherent colorations and unneutrality. to think that somehow, in the end, if everyone does their job (by creating neutral components) we will have an uncoloured speaker or that it is even possible to make an uncoloured speaker. why not embrace this colouration, but make it nice colour (s) in an interesting combination with a pleasing amount of brightness. an "interesting" shape to the frequency response hmmmm... this is starting to sound like a painting. something that captures the imagination. course, what has always attracted me to audio as an art is the fact that it is neither two dimentional nor stagnant in time. hyperspace.
god IS in the details. in audio we pay due to many devils to get there...
I have played a bit with supra baffles. firstly, I have to say that I really feel GM's comment. the edge diffraction should be used more as a tool than anything else.
in my most recent project...
I have not tried it yet, but I am considering removing the brass rings from the 206 es-r horns I just built. why? the response has an audible (but as of yet not measured) hole in the 500 hz region. it is predicted by the frequency response and when I add eq to that region the response gets subjectively flatter. it seems from the various charts posted earlier that a square baffle at roughly 2 ft. would add to this region.
the shape of the baffles that terry uses was arrived at as far as I could tell through trial and error. the 6 inch and 8 inch versions have a different shape to them.
to me, their effect is quite audible, having played with and without them. the circular shape just seems to sound "right" to me. instead of looking at a two dimentional frequency response graph and get scared away by unevenness realize that with triode sound we want *three* dimentional effects sound stage. this is the effect of a good supra baffle to me. it gives a greater feeling of sound place - in the room-, instead of simply the loudness level. it is an illusory effect. it eases the mind from constantly trying to place instruments where they should be based on their perceived loudness level. the circular shape to me seems like it would have an easier to predict effect than say a square... in so much that it has a constant radius, and therefore a more certain frequency effect. the curve back on the shape would spread out this frequency effect over a wider range it seems to me at least.
if y'all are just dying of my pseudo scientific explainations, the you will have to wait till I go to grad school in acoustics. kay?
additionally, I have had to play with CC volume fill (blocks of walnut) to compensate for the extra volume created by the ring. still, there is lack of definition in upper bass that should not be there. it sounds like it is caused by the airflow patterns in the horn. (don't ask how I know this... it is a hunch).
further, there seems to be a greater than there should be (in my crappy room) midbass suckout. perhaps caused by waveguide from the spacing of the magnet of the driver too close to the internal side of the baffle.
additionally, it seems there are issues with reflections directly behind the magnet to the internal panel. (panel number nine in the assembly figure). this was arrived at by spacing a panel of wood directly behind the driver magnet. approximate depth of 3/4 inch. (this was the peice that I cut out from the front baffle tack nailed in temporarily). this helped...it also did the trick for volume...subjectively. but that is not the end of the story.
as far as waveguide goes, it seems that the chamber created by the long baffle hole "tunnel" serves essentially as the initial compression chamber, then the air squeezes out of a pseudo "throat" into the real compression chamber and then finally into the real throat. this problem, naturally varies wildly depending on specific internal dimmentions and magnet size, etc. when hand building, this comes up especially in a stereo matching scenerio...accuracy counts - at least get the same colour in both speakers.
the CC/throat structure on the cain and cain stuff is quite different, for instance. not nearly sensitive to internal waveguide problems as the nagaoka BLH style. the drivers have smaller magnets being the "normal" versions of the drivers rather than the special edition fostex stuff and ample space is left for air flow.
in the abby, there is no throat.
in the end, I have really only had major problems with this waveguide effect when dealing with the big magnet stuff.
I encountered this same issue with the 166es-r, which has WAY less room for baffle width than the 206es-r
so there is my null hypothesis after a few nights of playing with the horns. While I desire more measurement equipment, in the end, givven my current tools I have learned to value infinite patience with the process of cut and try. with these horns we create, it seems that all values are floating. change one aspect, every other aspect changes.
additionally, it should be noted that suprabaffles, especially those made out of high specifiic gravity woods (hard maple, walnut, etc) will not only contribute their own sonic signature but will increase the sense of speed of the musical signal. more detail comes out because of the mass loading.
in the end, I like the idea of the swan... it has almost zero point of baffle. then there is no baffle plane resonance, and high ridgidity. the disadvanntages? low mass, so brass rings are near necessity to get the highest speed sound. refinemment don;t come cheap or quick.
but also, that is just my detail freak side speaking... most horns, tls, I feel SHOULD be a musical instrument with its own inherent color. I think it goes without saying that in the process of making enclosures out of hard ply, solid woods, as little damping as possible, while using drivers with hardly flat frequency responses (especially the big ones), out of amps, sources and recording techniques which are not without their inherent colorations and unneutrality. to think that somehow, in the end, if everyone does their job (by creating neutral components) we will have an uncoloured speaker or that it is even possible to make an uncoloured speaker. why not embrace this colouration, but make it nice colour (s) in an interesting combination with a pleasing amount of brightness. an "interesting" shape to the frequency response hmmmm... this is starting to sound like a painting. something that captures the imagination. course, what has always attracted me to audio as an art is the fact that it is neither two dimentional nor stagnant in time. hyperspace.
god IS in the details. in audio we pay due to many devils to get there...
GM said:
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Re: baffles
I have talked to Terry about this issue, and I recall his confirming
that it was developed through trial and error. It serves as a
tribute to his good taste and hard work.
From a measurement standpoint, the result is counter-intuitive,
but subjectively it points toward the possibility of a better way
of doing things.
Which is why it's so interesting...
blumenco said:
I have talked to Terry about this issue, and I recall his confirming
that it was developed through trial and error. It serves as a
tribute to his good taste and hard work.
From a measurement standpoint, the result is counter-intuitive,
but subjectively it points toward the possibility of a better way
of doing things.
Which is why it's so interesting...
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