Hartono,
Blind man front and center. Now, where is that elephant?
I recommend that you return to your first cone treatment survivor. Purchase some Tamiya clear coat acrylic paint and coat the main cone surface first. Listen to the cone while it is still recently coated with the clear coat. This will be pretty close to what it should sound like in 2 or 3 days.
What you are listening for is an even clearer sound as the information becomes more dense, so use orchestral music. If the Tamiya material is fast enough it will allow the block rows to control the entire cone and those improvements you have already had will become even better.
If the Tamiya clear coat is not fast enough you may even hear a slight change in pitch.
The next step after this is to treat the back side of a cone that has the front side treated. This will provide even greater clarity. You have about 70% of all that the EnABL pattern I know about can acheive. If Sonngsc has had the time to look into more driver shapes and find the "sweet spot" for removal of the major storage frequency of more samples, then we may be able to form a theory that allows another step forward in treatment. One that can be predicted from experience.
Later this year I hope to be in a sound lab, with anechoic chamber, test gear, lots of different drivers to treat and an acoustician to help guide the experiments. I will, one way or another, make relevant information available to those who are actively participating in this investigation. May have to be privately, with some restrictions about public comments, due to legal issues surrounding license agreements. This is still some time off, so I can still trade knowledge and I am about to post the details of treating another Lowther, the PM6A, for Lowther America. After that a set of A45 Lowthers and then another set of PM6A's, with backside treatment of both main cone and whizzer.
Bud
Blind man front and center. Now, where is that elephant?
I recommend that you return to your first cone treatment survivor. Purchase some Tamiya clear coat acrylic paint and coat the main cone surface first. Listen to the cone while it is still recently coated with the clear coat. This will be pretty close to what it should sound like in 2 or 3 days.
What you are listening for is an even clearer sound as the information becomes more dense, so use orchestral music. If the Tamiya material is fast enough it will allow the block rows to control the entire cone and those improvements you have already had will become even better.
If the Tamiya clear coat is not fast enough you may even hear a slight change in pitch.
The next step after this is to treat the back side of a cone that has the front side treated. This will provide even greater clarity. You have about 70% of all that the EnABL pattern I know about can acheive. If Sonngsc has had the time to look into more driver shapes and find the "sweet spot" for removal of the major storage frequency of more samples, then we may be able to form a theory that allows another step forward in treatment. One that can be predicted from experience.
Later this year I hope to be in a sound lab, with anechoic chamber, test gear, lots of different drivers to treat and an acoustician to help guide the experiments. I will, one way or another, make relevant information available to those who are actively participating in this investigation. May have to be privately, with some restrictions about public comments, due to legal issues surrounding license agreements. This is still some time off, so I can still trade knowledge and I am about to post the details of treating another Lowther, the PM6A, for Lowther America. After that a set of A45 Lowthers and then another set of PM6A's, with backside treatment of both main cone and whizzer.
Bud
Lowther,
I have finished treating the PM6A's for Lowther America. There are some important differences in how these units were treated, from the DX4's. The most important is a need for about one half of the amount of Gloss coating required to contain local area excursion.
When some transient emphasis is applied by a musician, piano players are a good example, to specific notes that excite the natural resonance mode of some section of an emitter surface, a sharp sonic bloom can occur. This is quite irritating to hear, really sets off the threat assessment correlator. The Gloss coating is used to redistribute that energy across the emitter surface and cause more of it to be controlled by the diffraction grating of the EnABL pattern blocks.
Sonngsc shows in post Post #279 that this sort of resonance can be controlled with a specific application of EnABL block rings. This may lead to no gloss coat at some point in time and for Lowthers this might be a good thing.
The DX4 required three coats of gloss over the main cone and two 50% coats on the whizzer. This does control the DX4 surfaces, but the speakers become unbelievably dynamic and ruthlessly revealing. Plus, they can easily run an audio system right out of ground side electrons needed to support the extremely high levels of resolution these items will attempt. This causes notes to become thin and "hard" sounding.
I have developed the Electron Pool scheme, laughed about in another thread, to help supplement the ground side electron supply and have provided Lowther America with two versions for the PM6A and will shortly send a set to Limono for his DX4's. In an untreated driver these provide enough support to change a large clapping audience, that sounds as if it has been augmented with white noise to enhance the effect from that white noise dominated sound, into a large group of individual pairs of hands clapping, with the transient peaks intact.
The PM6A's required only a single coating of Gloss over the main cone and a second coating from the whizzer shadow out to the edge surround. Both were at 50 % strength. The whizzer did require two coats and these were also at 50 % strength.
The patterns were identical between DX4 and PM6A except for two areas. The whizzer ledge received a full two ring pattern instead of the single ring shown in the DX4 photos. An additional ring pair was applied to the PM6A outer surround, where it is glued to the cast frame, and to the frame outer ring top surface. One block ring in both places, offset to make a pair of rings. No bloss coating was applied over these two block rings.
This was done to balance the front and back wave and allow a 180 degree angle of emission for the front wave, with the driver not supported by a baffle of any kind. This is the first driver I have ever had that had NO null zone between front and back wave. There is a mixture zone which makes the threat correlator go a bit crazy but the sound field is truly spherical. Very interesting to stand behind the drivers, where the sound is very like what you experience when behind a performer, and then to walk forward into the listening area and have the front wave "painted" onto that back wave, without any lapse in sound field.
The PM6A is an extremely well behaved driver, even without the EnABL patterns. Much less prone to dynamic excursions and very coherent in sound field portrayal. The EnABL pattern just multiplys these characteristics, adds headroom and detail and removes the already low "hash" of inter instrument spaces that makes for a "noisy" presentation that is not really noticeable until it is gone. Also Lowther's claim that the famous "shout" has been tamed is quite true. The dynamic punch is still there but it no longer has the sharp threshold found in the untreated, older, DX4's.
So, you can treat a PM6A quite successfully, using the patterns from the DX4, with two additions and a bit less Gloss coat.
Now. here is a dangerous secret. You can take a fine point, sable, water color brush and bend the ferrule to a 120 degree included angle, so that the brush tip points back towards you at a 60 degree angle. Then use a 50 % Gloss coat material and apply ONE THIN COAT on the back of the Whizzer cone ledge only.
This is a very dangerous thing to do, especially to DX4 drivers, because it removes the confinement that the ledge has been providing. Every sort of dynamic demon possible will be released into the music. Just rips the ceiling right off of the dynamics from these drivers, without seeming to alter anything else.
To support this you really must have some form of below signal return ground storage of electrons, right at the driver. I know, this just sounds ridiculous, but the approaching Canadian adventurers will be subjected to this phenom and can make their own subjective assessment. And, there is also Lowther America, who will be able to comment upon these little idiocy's, as their pair of PM6A's will arrive before this coming weekend. So, shortly, others will be beguiled by this electron bog thinking.
The next installment of Lowthers will be with a 15 ohm voice coil pair and I will be treating the backside of the main cone to it's own EnABL termination. This treatment, at least in every other driver I have treated, will increase transient headroom another 30% or so and make the perceived sound field transparent to all reflections and other large scale coherent noises.
I did not do this to either of the previous Lowther drivers or the Fostex 127E's for some good reasons. I am concerned that it will just be too much information, and these drivers are already at the head of the class in that department, with just one side treated, and I cannot always predict what frequency response alterations may occur. That added to the utter transparency to back wave reflections that all drivers suffer, when treated on both sides, literally stayed my hand. I own these 15 ohm Lowther PM6A drivers and so I will fearlessly experiment and report back.
Bud
I have finished treating the PM6A's for Lowther America. There are some important differences in how these units were treated, from the DX4's. The most important is a need for about one half of the amount of Gloss coating required to contain local area excursion.
When some transient emphasis is applied by a musician, piano players are a good example, to specific notes that excite the natural resonance mode of some section of an emitter surface, a sharp sonic bloom can occur. This is quite irritating to hear, really sets off the threat assessment correlator. The Gloss coating is used to redistribute that energy across the emitter surface and cause more of it to be controlled by the diffraction grating of the EnABL pattern blocks.
Sonngsc shows in post Post #279 that this sort of resonance can be controlled with a specific application of EnABL block rings. This may lead to no gloss coat at some point in time and for Lowthers this might be a good thing.
The DX4 required three coats of gloss over the main cone and two 50% coats on the whizzer. This does control the DX4 surfaces, but the speakers become unbelievably dynamic and ruthlessly revealing. Plus, they can easily run an audio system right out of ground side electrons needed to support the extremely high levels of resolution these items will attempt. This causes notes to become thin and "hard" sounding.
I have developed the Electron Pool scheme, laughed about in another thread, to help supplement the ground side electron supply and have provided Lowther America with two versions for the PM6A and will shortly send a set to Limono for his DX4's. In an untreated driver these provide enough support to change a large clapping audience, that sounds as if it has been augmented with white noise to enhance the effect from that white noise dominated sound, into a large group of individual pairs of hands clapping, with the transient peaks intact.
The PM6A's required only a single coating of Gloss over the main cone and a second coating from the whizzer shadow out to the edge surround. Both were at 50 % strength. The whizzer did require two coats and these were also at 50 % strength.
The patterns were identical between DX4 and PM6A except for two areas. The whizzer ledge received a full two ring pattern instead of the single ring shown in the DX4 photos. An additional ring pair was applied to the PM6A outer surround, where it is glued to the cast frame, and to the frame outer ring top surface. One block ring in both places, offset to make a pair of rings. No bloss coating was applied over these two block rings.
This was done to balance the front and back wave and allow a 180 degree angle of emission for the front wave, with the driver not supported by a baffle of any kind. This is the first driver I have ever had that had NO null zone between front and back wave. There is a mixture zone which makes the threat correlator go a bit crazy but the sound field is truly spherical. Very interesting to stand behind the drivers, where the sound is very like what you experience when behind a performer, and then to walk forward into the listening area and have the front wave "painted" onto that back wave, without any lapse in sound field.
The PM6A is an extremely well behaved driver, even without the EnABL patterns. Much less prone to dynamic excursions and very coherent in sound field portrayal. The EnABL pattern just multiplys these characteristics, adds headroom and detail and removes the already low "hash" of inter instrument spaces that makes for a "noisy" presentation that is not really noticeable until it is gone. Also Lowther's claim that the famous "shout" has been tamed is quite true. The dynamic punch is still there but it no longer has the sharp threshold found in the untreated, older, DX4's.
So, you can treat a PM6A quite successfully, using the patterns from the DX4, with two additions and a bit less Gloss coat.
Now. here is a dangerous secret. You can take a fine point, sable, water color brush and bend the ferrule to a 120 degree included angle, so that the brush tip points back towards you at a 60 degree angle. Then use a 50 % Gloss coat material and apply ONE THIN COAT on the back of the Whizzer cone ledge only.
This is a very dangerous thing to do, especially to DX4 drivers, because it removes the confinement that the ledge has been providing. Every sort of dynamic demon possible will be released into the music. Just rips the ceiling right off of the dynamics from these drivers, without seeming to alter anything else.
To support this you really must have some form of below signal return ground storage of electrons, right at the driver. I know, this just sounds ridiculous, but the approaching Canadian adventurers will be subjected to this phenom and can make their own subjective assessment. And, there is also Lowther America, who will be able to comment upon these little idiocy's, as their pair of PM6A's will arrive before this coming weekend. So, shortly, others will be beguiled by this electron bog thinking.
The next installment of Lowthers will be with a 15 ohm voice coil pair and I will be treating the backside of the main cone to it's own EnABL termination. This treatment, at least in every other driver I have treated, will increase transient headroom another 30% or so and make the perceived sound field transparent to all reflections and other large scale coherent noises.
I did not do this to either of the previous Lowther drivers or the Fostex 127E's for some good reasons. I am concerned that it will just be too much information, and these drivers are already at the head of the class in that department, with just one side treated, and I cannot always predict what frequency response alterations may occur. That added to the utter transparency to back wave reflections that all drivers suffer, when treated on both sides, literally stayed my hand. I own these 15 ohm Lowther PM6A drivers and so I will fearlessly experiment and report back.
Bud
Great work, Bud! Looking forward to results. I've treated my open baffles with 2mm thick foam tape (blocks in an EnABL pattern near the edges, and am happy with the improvement - still getting my ears around it tho, so not too much comment at this point other than it was well worth the effort.
Have you ever thought of, or tried, putting the EnABL pattern on cymbals? I reckon that would be a good application.
Cheers,
Mike
Have you ever thought of, or tried, putting the EnABL pattern on cymbals? I reckon that would be a good application.
Cheers,
Mike
Hi Mike,
Have not treated cymbals. Always thought that reflected energy was part of their charm and interest as musical punctuation.
Thanks for the note on baffle treatment. It has been my assumption for a while that the portion of diffraction that is objectionable is that which becomes reflected energy in a standing wave on a baffle of any type. The "diffraction" energy that just goes on around the corner and continues to radiate into the air does not seem to be the culprit for corruption of the emitted sound field, at a baffle edge.
Quite a discussion of this erupted over in the Beyond the Aerial thread but no one seemed interested in exploring the possibility of their being more than one form of diffraction, though JohninCR did begin to think about it. I would be interested in any observations you might make, no matter how much scientific rigor they contain. I am really looking for some further exploration into what is left over, after the standing waves have been tamed.
OzMikeH,
Good question, long answer.
The Gloss coat is performing one major function. The idealization of emission of all frequencies as they emit from the surface of the cone, within, before, between and beyond the discreet locations of the EnABL block patterns. This material has it's own natural resonance characteristics and if applied in a capricious fashion does as much harm as good.
Figuring out how much is just an educated guess. This is the reason that I advocate experimenting with many cheap cone drivers first and then moving on to stuff you will be irritated to ruin.
Romy the Cat has some very clear words to say about the "intentions" of those of us who dabble in DIY Audio. His typical rude verbiage covering some very acute thinking. His contention is that just making something different, because you can is a waste of your life. He advocates finding some internal goals that are more advanced than just doing it because you have finally learned how circuits work or how to apply the EnABL process to a speaker. Romy does not understand hobbies, though he would strongly contest that statement.
In the process of treating many many speakers I have slowly climbed my way out of moronism and begun to look for specific areas where this EnABL pattern provides more connection with the Art that any particular musician is applying in his expression of a piece of music. This means that I am interested in those tiny musical emphasis applications that show me where this other persons heart is going and hopefully leading me.
So, the least amount of Gloss coat possible is what I am aimed at. Just enough to tame a consistently ballooning piano key stroke to within the rest of the portrayed musical venue, rather than shrieking out into the listening room in an unconstrained fashion. I use Jessica Williams for this particular investigation, her studio pieces rather than the live performances, though she can put some terrific force into those rooms too.
Once those piano notes are just illuminating the walls of the performance hall, without quite getting loose from the rest of the music being portrayed, the rest of music portrayal is quite well taken care of. The SACD of the Romero's performing Rodriguez and Vivaldi on Mercury will pretty much confirm that you have enough control for large, complex sources as well as small complex sources and if you can get those violins to play without shrieking you do deserve a medal.
Large surfaces need more Gloss than small ones as the area between control grates is larger and will ring if properly excited, for just the moment that it overpowers the combination of abrupt surface, from the Gloss, distributed energy, from the Gloss and removal of standing waves, from the EnABL pattern.
I do not know of any more I can say about this, except to mention that I process one driver at a time, over one part of it's surface, with the Gloss. I then bring the second driver to that level and perform the next step on the first driver. For the Lowther's this is a thin coat on the whizzer, down into the triangles between the ring radiator fingers, wait a few minutes and then coat the rest of the whizzer cone. Wait a day to confirm this was a good thing to do and coat the second driver. Then coat the main cone, in a radial pattern as described in other posts, wait a day and if satisfactory coat the second driver. The judgments as to satisfaction come from listening to the same music many times. I am blessed with a wife with a sharp tongue, but no impetus to the use of sharp implements, to control this irritating activity.
Again, the Gloss coat really is to taste. First you have to understand what you are tasting for and then get a body of knowledge to make judgments from. I have, in the first Lowther post, discussed what turns out to be the typical coating pattern for typical low sensitivity drivers in typical speaker boxes. It also turned out to be what was needed, to just barely restrain the DX4 Lowthers.
Bud
Have not treated cymbals. Always thought that reflected energy was part of their charm and interest as musical punctuation.
Thanks for the note on baffle treatment. It has been my assumption for a while that the portion of diffraction that is objectionable is that which becomes reflected energy in a standing wave on a baffle of any type. The "diffraction" energy that just goes on around the corner and continues to radiate into the air does not seem to be the culprit for corruption of the emitted sound field, at a baffle edge.
Quite a discussion of this erupted over in the Beyond the Aerial thread but no one seemed interested in exploring the possibility of their being more than one form of diffraction, though JohninCR did begin to think about it. I would be interested in any observations you might make, no matter how much scientific rigor they contain. I am really looking for some further exploration into what is left over, after the standing waves have been tamed.
OzMikeH,
Good question, long answer.
The Gloss coat is performing one major function. The idealization of emission of all frequencies as they emit from the surface of the cone, within, before, between and beyond the discreet locations of the EnABL block patterns. This material has it's own natural resonance characteristics and if applied in a capricious fashion does as much harm as good.
Figuring out how much is just an educated guess. This is the reason that I advocate experimenting with many cheap cone drivers first and then moving on to stuff you will be irritated to ruin.
Romy the Cat has some very clear words to say about the "intentions" of those of us who dabble in DIY Audio. His typical rude verbiage covering some very acute thinking. His contention is that just making something different, because you can is a waste of your life. He advocates finding some internal goals that are more advanced than just doing it because you have finally learned how circuits work or how to apply the EnABL process to a speaker. Romy does not understand hobbies, though he would strongly contest that statement.
In the process of treating many many speakers I have slowly climbed my way out of moronism and begun to look for specific areas where this EnABL pattern provides more connection with the Art that any particular musician is applying in his expression of a piece of music. This means that I am interested in those tiny musical emphasis applications that show me where this other persons heart is going and hopefully leading me.
So, the least amount of Gloss coat possible is what I am aimed at. Just enough to tame a consistently ballooning piano key stroke to within the rest of the portrayed musical venue, rather than shrieking out into the listening room in an unconstrained fashion. I use Jessica Williams for this particular investigation, her studio pieces rather than the live performances, though she can put some terrific force into those rooms too.
Once those piano notes are just illuminating the walls of the performance hall, without quite getting loose from the rest of the music being portrayed, the rest of music portrayal is quite well taken care of. The SACD of the Romero's performing Rodriguez and Vivaldi on Mercury will pretty much confirm that you have enough control for large, complex sources as well as small complex sources and if you can get those violins to play without shrieking you do deserve a medal.
Large surfaces need more Gloss than small ones as the area between control grates is larger and will ring if properly excited, for just the moment that it overpowers the combination of abrupt surface, from the Gloss, distributed energy, from the Gloss and removal of standing waves, from the EnABL pattern.
I do not know of any more I can say about this, except to mention that I process one driver at a time, over one part of it's surface, with the Gloss. I then bring the second driver to that level and perform the next step on the first driver. For the Lowther's this is a thin coat on the whizzer, down into the triangles between the ring radiator fingers, wait a few minutes and then coat the rest of the whizzer cone. Wait a day to confirm this was a good thing to do and coat the second driver. Then coat the main cone, in a radial pattern as described in other posts, wait a day and if satisfactory coat the second driver. The judgments as to satisfaction come from listening to the same music many times. I am blessed with a wife with a sharp tongue, but no impetus to the use of sharp implements, to control this irritating activity.
Again, the Gloss coat really is to taste. First you have to understand what you are tasting for and then get a body of knowledge to make judgments from. I have, in the first Lowther post, discussed what turns out to be the typical coating pattern for typical low sensitivity drivers in typical speaker boxes. It also turned out to be what was needed, to just barely restrain the DX4 Lowthers.
Bud
Thanks Bud, a bit more info on the baffles: 1200 high by 750 wide, 15" P.Audio custom coax mounted mid-height and towards inside edge. Baffles made from 25mm MDF tiled with 5mm cork tiles on the reverse. The 2" comp drivers are run open-backed and the crossover is about 2kHz 6dB/oct with a Fostex Ft17 helping at the top. The amps are based on John Swenson's EL84/IRF820 transconductance design, giving flat response to 40Hz.
The EnABL blocks are about 20mm x 12mm and the pattern repeats about every 110mm. At this point the pattern is only applied to the inside front of the baffles, about 8mm in from the edge. Hope you can picture this.
My hearing is such that any system-related HF distortion results in the image drifting towards the left. I purposely treated the left speaker first and then listened. The image drifted towards the right! This NEVER happens... When I completed the right speaker, the "balance" was back.
First impressions: The music sounded "slower' somehow - a result of better DDR which reveals the decay structure of notes more clearly. The other obvious benefit was in the way the soundfield is energised - more direct, and better retention of structure with complex music.
My system has many faults, and I need more time to evaluate as I'm wary of snap judgements. Hopefully I can contribute something useful to the discussion.
Best regards,
Mike Spence
The EnABL blocks are about 20mm x 12mm and the pattern repeats about every 110mm. At this point the pattern is only applied to the inside front of the baffles, about 8mm in from the edge. Hope you can picture this.
My hearing is such that any system-related HF distortion results in the image drifting towards the left. I purposely treated the left speaker first and then listened. The image drifted towards the right! This NEVER happens... When I completed the right speaker, the "balance" was back.
First impressions: The music sounded "slower' somehow - a result of better DDR which reveals the decay structure of notes more clearly. The other obvious benefit was in the way the soundfield is energised - more direct, and better retention of structure with complex music.
My system has many faults, and I need more time to evaluate as I'm wary of snap judgements. Hopefully I can contribute something useful to the discussion.
Best regards,
Mike Spence
hi guys
guess I will have to go back and re-read it all, lucky I managed to catch it as it started, might not be so hard second time around.
Seems like the mamboni part has fallen by the wayside, has it dissappeared as a matter of interest??
Mike, howsabout a photo?? Piqued my interest as I'm working towards a wide baffle too (750 mm) but might go 1350 high. Experiments will tell.
Bud, as I say I will re-read it, but from what I recall most of the drivers treated seem to be full rangers. What sort of results might we get on say my 18's??
Regarding say baffle treatments, what proportion of the results is attributable to the material of the treatment used (eg the special paints etc) compared to say breaking up the surface with 'blocks' that are not made of these special paints, eg small regular pieces of veneer.
That question is very poorly worded, hope you can peer into the murk and glean what I'm asking! In other words, just by breaking up the surface /edges by almost any means will we go some way towards achieving the results. I'll stop there, feel I'm getting even more tangled up verbally.
guess I will have to go back and re-read it all, lucky I managed to catch it as it started, might not be so hard second time around.
Seems like the mamboni part has fallen by the wayside, has it dissappeared as a matter of interest??
Mike, howsabout a photo?? Piqued my interest as I'm working towards a wide baffle too (750 mm) but might go 1350 high. Experiments will tell.
Bud, as I say I will re-read it, but from what I recall most of the drivers treated seem to be full rangers. What sort of results might we get on say my 18's??
Regarding say baffle treatments, what proportion of the results is attributable to the material of the treatment used (eg the special paints etc) compared to say breaking up the surface with 'blocks' that are not made of these special paints, eg small regular pieces of veneer.
That question is very poorly worded, hope you can peer into the murk and glean what I'm asking! In other words, just by breaking up the surface /edges by almost any means will we go some way towards achieving the results. I'll stop there, feel I'm getting even more tangled up verbally.
Hi Terry,
I am also disappointed that the Mamboni process has not been worked with. I have suggested that both should be investigated together and intend to do this with my own OB project.
This will be a fairly small item, only a meter high, with a Lowther PM6A on top of that and without any baffle around it. I intend to use a pair of Eminence's Beta 8 drivers in a push push bi polar array, driving a TL. The baffle will be a U with swept back wings that Edge says has no step function in plane form. Seems unlikely this will translate into the U. In any event, Mamboni will decorate the back and EnABL paint, the front
As for large diameter bass and full range drivers, the biggest change comes in lack of spurious signal. The driver will mate seamlessly with a horn loaded compression driver. In the typical treatment the upper frequency narrowing does not occur to anything like as great an amount as the driver exhibits before treatment. Bass notes will stop "rumbling", tone will predominate, Bass extension will perceptively deepen and transients will express effortlessly.
The usual jagged frequency response near the top end roll off usually cleans up, but high frequencies may become more pronounced and require dissimilar crossover frequency centers in the cross over. I always start a crossover to one of these where theory says to and adjust to suit my own goals.
The amount of Gloss coat used can get pretty extreme if the cone is a short fiber slurry cast type with fairly thick, soft walls.
I sort of quit worrying about Bass drivers a few years ago and just treat them in the standard fashion with a set of rings at the outer diameter, a three ring set at the cone / dome junction and a center of dome six block set, in two rings, to kill any beaming. A final drop of PVA in the center of the dust cap dome to open up high frequency dispersion, one coat of gloss on the dome and three on the cone. Let it dry for a few days and see what it sounds like. If it is clear enough, use it. If not, add a another gloss coat to the cone and wait and listen. This is usually all that is needed.
As for the difference between using paint or substances that are similar in content to the material the boundary layer is forming on, I have very little to tell you. I am told that later this summer I will be in an anechoic chamber, looking at this very question on commercial drivers, with a world famous acoustician in charge, but until this fortuitous happening comes about, I have no direct experience to share.
A recent post here describes using foam tape on a solid baffle OB speaker with considerable success, but no one has reported on veneer pattern blocks or other innovative methods yet. So, experiment, the coast is clear and the wind is favorable.....
Bud
I am also disappointed that the Mamboni process has not been worked with. I have suggested that both should be investigated together and intend to do this with my own OB project.
This will be a fairly small item, only a meter high, with a Lowther PM6A on top of that and without any baffle around it. I intend to use a pair of Eminence's Beta 8 drivers in a push push bi polar array, driving a TL. The baffle will be a U with swept back wings that Edge says has no step function in plane form. Seems unlikely this will translate into the U. In any event, Mamboni will decorate the back and EnABL paint, the front
As for large diameter bass and full range drivers, the biggest change comes in lack of spurious signal. The driver will mate seamlessly with a horn loaded compression driver. In the typical treatment the upper frequency narrowing does not occur to anything like as great an amount as the driver exhibits before treatment. Bass notes will stop "rumbling", tone will predominate, Bass extension will perceptively deepen and transients will express effortlessly.
The usual jagged frequency response near the top end roll off usually cleans up, but high frequencies may become more pronounced and require dissimilar crossover frequency centers in the cross over. I always start a crossover to one of these where theory says to and adjust to suit my own goals.
The amount of Gloss coat used can get pretty extreme if the cone is a short fiber slurry cast type with fairly thick, soft walls.
I sort of quit worrying about Bass drivers a few years ago and just treat them in the standard fashion with a set of rings at the outer diameter, a three ring set at the cone / dome junction and a center of dome six block set, in two rings, to kill any beaming. A final drop of PVA in the center of the dust cap dome to open up high frequency dispersion, one coat of gloss on the dome and three on the cone. Let it dry for a few days and see what it sounds like. If it is clear enough, use it. If not, add a another gloss coat to the cone and wait and listen. This is usually all that is needed.
As for the difference between using paint or substances that are similar in content to the material the boundary layer is forming on, I have very little to tell you. I am told that later this summer I will be in an anechoic chamber, looking at this very question on commercial drivers, with a world famous acoustician in charge, but until this fortuitous happening comes about, I have no direct experience to share.
A recent post here describes using foam tape on a solid baffle OB speaker with considerable success, but no one has reported on veneer pattern blocks or other innovative methods yet. So, experiment, the coast is clear and the wind is favorable.....
Bud
Photo? yep can do - guess that means I have to tidy up... 
Bud, do you think a "reverse" EnABL pattern could work well on surfaces? In other words, with the pattern recessed or cut out rather than built up?
I also am keen to try other treatments, such as the Mamboni, on my OB's. When I post some photos y'all gotta offer some advice!
Cheers,
Mike
Bud, do you think a "reverse" EnABL pattern could work well on surfaces? In other words, with the pattern recessed or cut out rather than built up?
I also am keen to try other treatments, such as the Mamboni, on my OB's. When I post some photos y'all gotta offer some advice!
Cheers,
Mike
4.5" hempcone drivers offer
Bud,
I tried to email you, but am not yet allowed...
I have read all the threads...(?/!)
You have my sincere regards...as well as all others involved...
I offer drivers for your attention and machinations...
I assume you can contact me via e-mail/PM...
Richard
or FE126E
Bud,
I tried to email you, but am not yet allowed...
I have read all the threads...(?/!)
You have my sincere regards...as well as all others involved...
I offer drivers for your attention and machinations...
I assume you can contact me via e-mail/PM...
Richard
or FE126E
Hi Mike,
Sorry about not responding. My head was off hunting in other cloud formations.
I do think that a physical interruption of any type will provide some portion of control. How much, compared to the process I use, I cannot comment on from experience, but, I would not expect that through holes would be needed, just indentations that are noticeable. After all, the surface of the cone is part of the boundary layer and that interface is quite fragile, so a compression of material and a depression of surface should work too.
Bud
Sorry about not responding. My head was off hunting in other cloud formations.
I do think that a physical interruption of any type will provide some portion of control. How much, compared to the process I use, I cannot comment on from experience, but, I would not expect that through holes would be needed, just indentations that are noticeable. After all, the surface of the cone is part of the boundary layer and that interface is quite fragile, so a compression of material and a depression of surface should work too.
Bud
BudP said:
For treatment of open baffle and cabinet edges it would be quick and easy to make a stamp from steel bar with a short segment of the pattern welded onto the end. Use it like a nail punch and work your way around the edge with a big hammer using previous indents to align the tool.
I remember you saying the proportion of the shapes is important, rounded edges do not matter so much. Now we're getting into three dimensions. What would the optimum depth be? I don't expect it would matter very much as long as there is an interruption.
the blocks are a 2:1 shape, so would the depth be 2 : 1 : 0.5 ?
Driver's sizes are related to the frequencies they produce, so the standard number of blocks per ring works well. Now what size should the blocks around the perimeter of a multi-way cabinet or baffle be? The size of the blocks on the smallest or the largest driver? Multiple rows of indentations sounds reasonable, 2 or 3 patterns next to each other getting progressively smaller. Now do we put the smallest pattern on the inside or the outside.
While considering the scale of the blocks in relation to frequency... This process appears to be all about diffraction to reduce reflections from transitions in materials in the speaker or at the edges of cabinets. This treatment should work extremely well on terminating the edges of front loaded horns similar to the Bert Doppenberg's. In that situation what size would the blocks be? should they be treated like a great big speaker, or should the block size be kept the same as those on the drivers inside the horns. The coating on these horns is acrylic paint already, so what material would the blocks be? something harder or just something different?
I don't expect any answers if you have a lot going on at the moment so don't left this distract you. I just wanted to put a few thoughts down where they won't be lost. Most of this stuff is way over my head but I have a feel for impedance mismatches and reflections.
OZ MikeH,
Really, you do not need any more than the paint and the EnABL pattern to control a diffraction occurring at a baffle edge. It will not stop the energy that is going to bend around the cabinet edge anyway, but it will force all other energy off of the baffle, in phase/time coherence with the completing compression wave. And it will do this up to some startling SPL and over some very large surfaces.
I think you should go ahead and brand the baffle anyway. It will be interesting to see how much it helps and how much it harms the emitted wave front.
When I treat a baffle I think of it a a speaker cone and use the same scaling parameters. The easy way is to make a linear distance measurement of the shape that needs control. Treat it like a circumference, divide the total into 36 parts. Then divide that length into five parts.
Each block is two of those parts long and the space between the bocks, between the rows of blocks and the width of the blocks themselves, are all one of those spaces wide.
It has yet to matter that the driver is 4 inches in diameter, with little tiny blocks and the baffle that is handling the same frequencies has much bigger blocks. I am sure that there is some extreme mismatch that will confound this pleasant relationship. If you want to search for that limit, please do so. I will be every bit as interested in your results as you are.
Truly, using the boundary layer to control the reflections on a surface is an example of having found the proper lever and a very useful fulcrum. The EnABL pattern uses this boundary layer, the Mamboni process uses it just a effectively and I strongly suspect that a driver built to the specs contained in the patent I have listed a url for below, also uses it effectively. This last one might mean that you could cover your baffle with your favorite fur and have a furry driver too.... or perhaps have a fur covered floor baffle, in front of the fire place and enjoy your favorite music, wine and etc......
http://www.google.com/patents?id=ULEeAAAAEBAJ&dq=5689093
Bud
Really, you do not need any more than the paint and the EnABL pattern to control a diffraction occurring at a baffle edge. It will not stop the energy that is going to bend around the cabinet edge anyway, but it will force all other energy off of the baffle, in phase/time coherence with the completing compression wave. And it will do this up to some startling SPL and over some very large surfaces.
I think you should go ahead and brand the baffle anyway. It will be interesting to see how much it helps and how much it harms the emitted wave front.
When I treat a baffle I think of it a a speaker cone and use the same scaling parameters. The easy way is to make a linear distance measurement of the shape that needs control. Treat it like a circumference, divide the total into 36 parts. Then divide that length into five parts.
Each block is two of those parts long and the space between the bocks, between the rows of blocks and the width of the blocks themselves, are all one of those spaces wide.
It has yet to matter that the driver is 4 inches in diameter, with little tiny blocks and the baffle that is handling the same frequencies has much bigger blocks. I am sure that there is some extreme mismatch that will confound this pleasant relationship. If you want to search for that limit, please do so. I will be every bit as interested in your results as you are.
Truly, using the boundary layer to control the reflections on a surface is an example of having found the proper lever and a very useful fulcrum. The EnABL pattern uses this boundary layer, the Mamboni process uses it just a effectively and I strongly suspect that a driver built to the specs contained in the patent I have listed a url for below, also uses it effectively. This last one might mean that you could cover your baffle with your favorite fur and have a furry driver too.... or perhaps have a fur covered floor baffle, in front of the fire place and enjoy your favorite music, wine and etc......
http://www.google.com/patents?id=ULEeAAAAEBAJ&dq=5689093
Bud
BudP said:
This has been a very interesting thread and I am keen to try out some enABL patterns.
Am I correct when I read the above and understand it to mean that for an open baffle that is say 22"wide X 42"high - one would add 22+22+42+42=128/36=3.5" divide by 5 = .7 inches
then each block is 1.4" X .7" with .7" between blocks and .7" between rows.
would there also be two rows of blocks around the edge of the baffle? and would they be like the pictures I have seen of the speakers with the outer row being:
[1.4 X .7] (.7) [1.4 X .7] (3.5) [1.4 X .7] (.7) [1.4 X .7] (3.5) . . .
where [is a block] and (is a space)
and an inner row spaced in by .7" that was staggered to the outer row so that two blocks (separated by a .7 space, of course) go in the 3.5" spaces.
and also that further it wouldn't make much difference to the size and spacing of the blocks as long as the perimeter is the same.
so that in effect a baffle of 12" X 52" would use the same size of blocks and the same spacing between them as a baffle of 32" X 32".
do I have that right?
also would the same hold for a box speaker? and you would treat the entire front outside edge in the same way.
Now 2 more questions -
are there benefits of treating the baffle with the pattern even if the speakers are not treated? also in your opinion what would be the relative merit of each - 80% for the speaker and 20% for the baffle ? or?
and also if doing a baffle edge would you expect it to have the same effect if you were to use say pieces of painters tape instead of painting the blocks? (was just thinking that it would be a fairly easy and reversible way to test.
thanks for all of the work you have done and shared on this, it is very interesting.
Leonard
Leonard,
I do not work in the sizes you are so I am only going to say yes, you have the layout math correct. I would intuitively use the same size blocks on short and long sides of a rectangular baffle. I also do not worry too much about perfect meeting in corners and often end up with an angled block to close off a corner gap. Again, absolute precision here is not required for the pattern to work.
I am not certain what you mean about the "edge". When I treat a box I apply the pattern to every surface panel perimeter, if there is a 90 degree angle at that perimeter. If there is less of an angle, then I usually only treat the top, far edge and bottom of that particular, angled face and allow the edge of the driver mounting panel to control the joint between that mounting panel and the angled face.
I also do not know what plumber's tape is but if it is at least 0.005" thick then it will suffice, possibly even permanently. In an earlier thread Mike reported success using foam tape on a large baffle.
As for what will happen to a driver that is not treated, when mounted on a treated baffle...? I suspect that what ever corruptions are propagating from the driver will be suppressed by a small amount, but I have never tried it, so, do so please and report back. Even just impressions are valuable information.
If you have a baffle thick enough that you could treat the perimeter edge, 90 degrees from the front baffle surface, I think I would do so. It will allow the front and back energy, that wraps around the baffle, to eliminate each other, wherever they meet. And yes I would apply the pattern on the back too. Or, even use the Mamboni triangles discussed in the beginning of this thread and in the Walsh thread, though how they would be scaled is a matter of cut and try at this time.
Also I would, and do, apply an appropriate sized pattern right around the periphery of the driver mounting bezel, just beyond where it meets with and covers the baffle.
With treated drivers and baffles, the baffle treatment eliminates those diffractions that localize your spatial perception of the box as the sound source. Same for the drivers. Treating the baffle also insures that the speaker cannot "overdrive" the baffle and cause it to emit a standing wave corruption from the baffle surface. There was evidence of this in the recent visit of the Fonken boxes, with treated Fostex 127 E drivers mounted. We were playing at elevated levels, using the Levine/CSO rendition of Rhapsodie in Blue, which, being the Groff orchestration, has nothing whatsoever to do with the usual dreamy symphonic rendition.
Bud
I do not work in the sizes you are so I am only going to say yes, you have the layout math correct. I would intuitively use the same size blocks on short and long sides of a rectangular baffle. I also do not worry too much about perfect meeting in corners and often end up with an angled block to close off a corner gap. Again, absolute precision here is not required for the pattern to work.
I am not certain what you mean about the "edge". When I treat a box I apply the pattern to every surface panel perimeter, if there is a 90 degree angle at that perimeter. If there is less of an angle, then I usually only treat the top, far edge and bottom of that particular, angled face and allow the edge of the driver mounting panel to control the joint between that mounting panel and the angled face.
I also do not know what plumber's tape is but if it is at least 0.005" thick then it will suffice, possibly even permanently. In an earlier thread Mike reported success using foam tape on a large baffle.
As for what will happen to a driver that is not treated, when mounted on a treated baffle...? I suspect that what ever corruptions are propagating from the driver will be suppressed by a small amount, but I have never tried it, so, do so please and report back. Even just impressions are valuable information.
If you have a baffle thick enough that you could treat the perimeter edge, 90 degrees from the front baffle surface, I think I would do so. It will allow the front and back energy, that wraps around the baffle, to eliminate each other, wherever they meet. And yes I would apply the pattern on the back too. Or, even use the Mamboni triangles discussed in the beginning of this thread and in the Walsh thread, though how they would be scaled is a matter of cut and try at this time.
Also I would, and do, apply an appropriate sized pattern right around the periphery of the driver mounting bezel, just beyond where it meets with and covers the baffle.
With treated drivers and baffles, the baffle treatment eliminates those diffractions that localize your spatial perception of the box as the sound source. Same for the drivers. Treating the baffle also insures that the speaker cannot "overdrive" the baffle and cause it to emit a standing wave corruption from the baffle surface. There was evidence of this in the recent visit of the Fonken boxes, with treated Fostex 127 E drivers mounted. We were playing at elevated levels, using the Levine/CSO rendition of Rhapsodie in Blue, which, being the Groff orchestration, has nothing whatsoever to do with the usual dreamy symphonic rendition.
Bud
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