Just a little progress update.
Second speaker has had what I call the Mamboni Magic applied and is awaiting BudP's EnABL pattern. BudP and I have been working on developing a process by which to apply his pattern with a stencil and we have the pattern sized pretty well for the Pioneer 10 inch speaker that Mamboni specks in earlier post. Now to get the silkscreen stencil produced and tested - should be in the next day or two - providing that it is successful we will be able to show those interested what all is involved.
I still trying to get my MDF carved up for the speaker end caps and center brace. I thought that I would be able to rent a plunge router but have not had any luck finding a rental unit - or any buddies that have one either. Might wind up bitting the bullet and making a purchase - that will blow the budget - sigh
Only took an hour to apply the Mamboni Magic to the second speaker! Much less time than the first - getting over the learning curve is great!
Considering a future in consulting, speaking engagements, and how to do it DVD's -
- Ok maybe for a soda.
Cheers
Second speaker has had what I call the Mamboni Magic applied and is awaiting BudP's EnABL pattern. BudP and I have been working on developing a process by which to apply his pattern with a stencil and we have the pattern sized pretty well for the Pioneer 10 inch speaker that Mamboni specks in earlier post. Now to get the silkscreen stencil produced and tested - should be in the next day or two - providing that it is successful we will be able to show those interested what all is involved.
I still trying to get my MDF carved up for the speaker end caps and center brace. I thought that I would be able to rent a plunge router but have not had any luck finding a rental unit - or any buddies that have one either. Might wind up bitting the bullet and making a purchase - that will blow the budget - sigh
Only took an hour to apply the Mamboni Magic to the second speaker! Much less time than the first - getting over the learning curve is great!
Considering a future in consulting, speaking engagements, and how to do it DVD's -
- Ok maybe for a soda.Cheers
ultrakaz,
Well, I have the same goals as Lynn, Romy the Cat, Island Pink, the moderators of this forum, you and very many others involved in DIY audio. I want a performance in my living room that satisfies my musical needs. I am used to extreme detail, correct depth of field, jubilant dynamic color as added by the musicians, a natural micro dynamic coherence and it's resultant stage setting for the musical event.
At the moment I am working on developing an amp and preamp of pretty simple circuit design and outstanding usefulness in developing audio transformers. The speakers have not changed in five years, except that I remounted the Linnaeum tweeters down on the speaker box and a recent trial addition of a Pioneer half can super tweeter, that may stay and may not.
I have recently discovered a method that allows me to uncover the back half of the musical notes, with the sort of clarity that the front half exhibits. This has added a depth of note decay and a coherence to chord structures in orchestras and piano's that I have not quite gotten used to yet.
Mostly I am just working towards a time when I have no further complaints with the equipment and I can explore the music I have collected, without constantly being distracted by my correlator warnings going off about this or that uncategorized and potentially dangerous noise.
I have to warn you, the speakers are not impressive looking. They were originally designed and built as workhorses, to allow me to audition the R&D from my transformer explorations. Just as the user adjustable dynamic color, true Litz wire, cables were invented, so I could listen for faults without having to worry about spurious cable colorations or loss of information content.
My contributions to this forum are meant to be a stepping stone for other people to use, so they might feel confident enough to explore and enjoy what this odd EnABL pattern brings to the reproduction of music, which is all I really care about
Bud
Well, I have the same goals as Lynn, Romy the Cat, Island Pink, the moderators of this forum, you and very many others involved in DIY audio. I want a performance in my living room that satisfies my musical needs. I am used to extreme detail, correct depth of field, jubilant dynamic color as added by the musicians, a natural micro dynamic coherence and it's resultant stage setting for the musical event.
At the moment I am working on developing an amp and preamp of pretty simple circuit design and outstanding usefulness in developing audio transformers. The speakers have not changed in five years, except that I remounted the Linnaeum tweeters down on the speaker box and a recent trial addition of a Pioneer half can super tweeter, that may stay and may not.
I have recently discovered a method that allows me to uncover the back half of the musical notes, with the sort of clarity that the front half exhibits. This has added a depth of note decay and a coherence to chord structures in orchestras and piano's that I have not quite gotten used to yet.
Mostly I am just working towards a time when I have no further complaints with the equipment and I can explore the music I have collected, without constantly being distracted by my correlator warnings going off about this or that uncategorized and potentially dangerous noise.
I have to warn you, the speakers are not impressive looking. They were originally designed and built as workhorses, to allow me to audition the R&D from my transformer explorations. Just as the user adjustable dynamic color, true Litz wire, cables were invented, so I could listen for faults without having to worry about spurious cable colorations or loss of information content.
My contributions to this forum are meant to be a stepping stone for other people to use, so they might feel confident enough to explore and enjoy what this odd EnABL pattern brings to the reproduction of music, which is all I really care about
Bud
Hi Bud,
Thanks for sharing your thoughts. I agree that we all do share a similar final goal. How to get there is something I've been attempting for the last 23+ years. And needless to say, I would certainly welcome a time where I don't have to worry about the sound of my equiptment.
I'm going to try the Manboni Walsh speaker with a pair of 15" Altecs. My crude experiment suggests that it is worthwhile to pursue. And I will use the Enabl treatment on the cone; Manboni on the inside and Enable on the outside (facing outward).
Where might I learn more about your litz wires and your method of uncovering the "back half of musical notes"?
Thanks for sharing your thoughts. I agree that we all do share a similar final goal. How to get there is something I've been attempting for the last 23+ years. And needless to say, I would certainly welcome a time where I don't have to worry about the sound of my equiptment.
I'm going to try the Manboni Walsh speaker with a pair of 15" Altecs. My crude experiment suggests that it is worthwhile to pursue. And I will use the Enabl treatment on the cone; Manboni on the inside and Enable on the outside (facing outward).
Where might I learn more about your litz wires and your method of uncovering the "back half of musical notes"?
ultrkaz,
Email me about the wires. Email c2cthomas about the Mamboni / EnABL treatment details.
The back half of the notes comes from having a method of preserving micro dynamic detail, the E Field portion of that detail, which becomes B Field. I do it by providing low threshold, dielectric dipole attached, sheet oriented electrons, on the ground plane. You can do this with poured ground planes and guite a lot of PCB varnish, or some huge stranded wires, 8 gauge or more and a measured amount of dielectric material both surrounding the wires and melted into them. You might even be able to use low threshold voltage Teflon, audio bipolar capacitors shorted to ground on both ends. What ever method you use will entail providing ground plane storage for an abundance of electrons so they do not return to service ground or further.
The research I have done on dielectrics in transformers, audio cables and now ground planes has shown me that while we have a very excellent handle on signal side electron manipulation we really have ignored the manipulation of the ground side signal of our equipment. I do have a solution, it is easy to apply, but it is very much applied voodoo physics.... more or less like the EnABL process is.... makes perfect sense after you understand how it works and why you might need it.
So, email me and we can talk about your interests.
Bud
Email me about the wires. Email c2cthomas about the Mamboni / EnABL treatment details.
The back half of the notes comes from having a method of preserving micro dynamic detail, the E Field portion of that detail, which becomes B Field. I do it by providing low threshold, dielectric dipole attached, sheet oriented electrons, on the ground plane. You can do this with poured ground planes and guite a lot of PCB varnish, or some huge stranded wires, 8 gauge or more and a measured amount of dielectric material both surrounding the wires and melted into them. You might even be able to use low threshold voltage Teflon, audio bipolar capacitors shorted to ground on both ends. What ever method you use will entail providing ground plane storage for an abundance of electrons so they do not return to service ground or further.
The research I have done on dielectrics in transformers, audio cables and now ground planes has shown me that while we have a very excellent handle on signal side electron manipulation we really have ignored the manipulation of the ground side signal of our equipment. I do have a solution, it is easy to apply, but it is very much applied voodoo physics.... more or less like the EnABL process is.... makes perfect sense after you understand how it works and why you might need it.
So, email me and we can talk about your interests.
Bud
Hi Guys,
This is a fascinating thread!
I’m in the process of designing an omnidirectional speaker myself. It is sort of a meld between what Duevel has done with their concave cone diffusers and the BeoLab 5. Below is a pdf of the current plan. I’m about 90º complete with building a prototype for design testing. There is a thread about it over at HT guide forum, here, if you want to read more. Mentor2 Omni Thread
Essentially it is a 3way comprised of all up or downfiring drivers, two 8” woofers (RS225 metal cones), which fire at each other, but are separated by a diffuser, an upfiring 2” metal dome (RS52) which uses a modified PE 8” waveguide and fires into a concave cone diffuser, like the Duevel’s use. Housed in this diffuser is an upfiring ¾” soft dome neo tweeter (Dayton ND20FB), in a modified 6.5” MCM waveguide, firing up into a 7-1/2” dia. concave cone diffuser. Also attached is a photo of the incomplete test system. I have done a quite a lot of measurements to try and determine the right drivers, right diffuser types, diffuser heights, etc. The attached graph is a preliminary plot of the 3 driver’s outputs with the waveguides and diffusers intact.
I’m not trying to hijack this thread. I’m posting for a couple reasons. One, there is clearly some serious interest in omnidirectional speakers amongst you all. Second, I’m thinking that the Mamboni felt-BudP Enable-or Olsen modified Mamboni felt treatment might be of use in my design. What do you all think?
I was thinking that it would most surely help the woofers to do one or several of these treatments, but possibly all the drivers. Also, it might be helpful to treat the front side of both waveguides. It might also be helpful to treat the bottom side of the concave diffusers. Any thoughts?
Finally, it occurs to me that perhaps my tweeter implementation, using the waveguide/concave cone diffuser might be of interest to you all in your omni efforts, since it might allow you to continue the omni sound through the entire FR of the speaker, rather than switching over to directional for the tweeter.
I’d be happy to provide any measurements I can (I use SoundEasy, but I’m relatively new to it) and do some experimenting with the various processes you are working on/providing before and after measurements, etc.
BTW, have you all thought about adhesive backed felt? They sell it at many hardware stores or you can buy better stuff at McMaster-Carr online? This would seem to be a quicker way to install the felt treatments at lest ofr testing and yet let them remain removable if the experiment needs to be altered.
Also, we used to use adhesive backed printed sheets at work. They are of a pretty thick mylar-like material and might work as templates for the enable process. Also there are clear acetate that you can print on that could be cut into a template. I also wonder if there would be a non-permanent enable product that might be used. For example, take a bunch of the enable rectangles, print them on the adhesive mylar, cut them out and stick them on individually or in pairs if that was ok. They would be easy for anyone to make and fully removable, though that adhesive is very aggressive.
Just some food for thought. I’d like to hear any of your thoughts on how the ideas you guys are testing might work with my omni application, etc.
Thanks!
This is a fascinating thread!
I’m in the process of designing an omnidirectional speaker myself. It is sort of a meld between what Duevel has done with their concave cone diffusers and the BeoLab 5. Below is a pdf of the current plan. I’m about 90º complete with building a prototype for design testing. There is a thread about it over at HT guide forum, here, if you want to read more. Mentor2 Omni Thread
Essentially it is a 3way comprised of all up or downfiring drivers, two 8” woofers (RS225 metal cones), which fire at each other, but are separated by a diffuser, an upfiring 2” metal dome (RS52) which uses a modified PE 8” waveguide and fires into a concave cone diffuser, like the Duevel’s use. Housed in this diffuser is an upfiring ¾” soft dome neo tweeter (Dayton ND20FB), in a modified 6.5” MCM waveguide, firing up into a 7-1/2” dia. concave cone diffuser. Also attached is a photo of the incomplete test system. I have done a quite a lot of measurements to try and determine the right drivers, right diffuser types, diffuser heights, etc. The attached graph is a preliminary plot of the 3 driver’s outputs with the waveguides and diffusers intact.
I’m not trying to hijack this thread. I’m posting for a couple reasons. One, there is clearly some serious interest in omnidirectional speakers amongst you all. Second, I’m thinking that the Mamboni felt-BudP Enable-or Olsen modified Mamboni felt treatment might be of use in my design. What do you all think?
I was thinking that it would most surely help the woofers to do one or several of these treatments, but possibly all the drivers. Also, it might be helpful to treat the front side of both waveguides. It might also be helpful to treat the bottom side of the concave diffusers. Any thoughts?
Finally, it occurs to me that perhaps my tweeter implementation, using the waveguide/concave cone diffuser might be of interest to you all in your omni efforts, since it might allow you to continue the omni sound through the entire FR of the speaker, rather than switching over to directional for the tweeter.
I’d be happy to provide any measurements I can (I use SoundEasy, but I’m relatively new to it) and do some experimenting with the various processes you are working on/providing before and after measurements, etc.
BTW, have you all thought about adhesive backed felt? They sell it at many hardware stores or you can buy better stuff at McMaster-Carr online? This would seem to be a quicker way to install the felt treatments at lest ofr testing and yet let them remain removable if the experiment needs to be altered.
Also, we used to use adhesive backed printed sheets at work. They are of a pretty thick mylar-like material and might work as templates for the enable process. Also there are clear acetate that you can print on that could be cut into a template. I also wonder if there would be a non-permanent enable product that might be used. For example, take a bunch of the enable rectangles, print them on the adhesive mylar, cut them out and stick them on individually or in pairs if that was ok. They would be easy for anyone to make and fully removable, though that adhesive is very aggressive.
Just some food for thought. I’d like to hear any of your thoughts on how the ideas you guys are testing might work with my omni application, etc.
Thanks!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Whoops, I forgot to post the responce graph I mentioned above.
An externally hosted image should be here but it was not working when we last tested it.
dineubec,
Pretty neat stuff. I have had thoughts on this sort of speaker for years but knew better than to attempt so much precision wood work.
The EnABL process will work on all of the drivers and all of the surfaces but will be quite an undertaking to do. I would recommend that you finish first. Then begin to categorize what you do not find satisfactory in the actual audible performance. My method here is to start with the fundamentals first, up to 1 k or so and listen for inaccuracies in the left hand of piano's and all bowed and plucked strings larger than a violin. I will often deliberately reduce very low frequency performance at first just to help clarify what is actually going on.
What I listen for is a garble of tones, at any particular frequency. Once I am familiar with what I am hearing I add a higher frequency driver and listen to how it modifies what I am familiar with. This sort of listening teaches me what is incorrect in only one driver and what is a multi driver problem.
Were these my speakers I would use a Vifa 3" mid in place of the metal dome and phase screen. The EnABL process can not control "systemic" resonances, those caused by materials and physical obstructions used in driver construction. I think it likely that you will find a garble from that mid dome that is directly related to the material used and treating with EnABL will only make it more pronounced, because everything else will work better around that frequency band..
Does not mean that you should change your plans, you may have already worked around what ever difficulties this particular driver exhibits, and they all exhibit many problems.
The EnABL process will ease the transition off of the round to square baffle and likely can control those surfaces and force them into phase and time coherency. The tweeter would work well with the process but you will have to disassemble it and treat the backside of the dome also. Neither of the dome drivers can be treated with other than a pen and guide pattern process, at least from my experience.
I will post any other thoughts I have on your thread.
Bud
Pretty neat stuff. I have had thoughts on this sort of speaker for years but knew better than to attempt so much precision wood work.
The EnABL process will work on all of the drivers and all of the surfaces but will be quite an undertaking to do. I would recommend that you finish first. Then begin to categorize what you do not find satisfactory in the actual audible performance. My method here is to start with the fundamentals first, up to 1 k or so and listen for inaccuracies in the left hand of piano's and all bowed and plucked strings larger than a violin. I will often deliberately reduce very low frequency performance at first just to help clarify what is actually going on.
What I listen for is a garble of tones, at any particular frequency. Once I am familiar with what I am hearing I add a higher frequency driver and listen to how it modifies what I am familiar with. This sort of listening teaches me what is incorrect in only one driver and what is a multi driver problem.
Were these my speakers I would use a Vifa 3" mid in place of the metal dome and phase screen. The EnABL process can not control "systemic" resonances, those caused by materials and physical obstructions used in driver construction. I think it likely that you will find a garble from that mid dome that is directly related to the material used and treating with EnABL will only make it more pronounced, because everything else will work better around that frequency band..
Does not mean that you should change your plans, you may have already worked around what ever difficulties this particular driver exhibits, and they all exhibit many problems.
The EnABL process will ease the transition off of the round to square baffle and likely can control those surfaces and force them into phase and time coherency. The tweeter would work well with the process but you will have to disassemble it and treat the backside of the dome also. Neither of the dome drivers can be treated with other than a pen and guide pattern process, at least from my experience.
I will post any other thoughts I have on your thread.
Bud
Hi Bud,
Thanks for the feedback!
Do you have some specific recordings that you use for your piano and string listening session?
Are you talking about eh 3" Vifa Dome? I looked at it, but was concerned about what looked to be very quick off axis roll off. It looks like the new version might be better, but I could not find a performance graph on it. Since we are essentially listening 90º off axis with an up firing driver, there tends to be a very quick roll off with many drivers that severely reduces the range you can use it in. The concave cone diffuser helps, but it is good to start with a driver that has very good off axis performance to start with. I hear you on the phase screen, however. I wish it was removable. I can always go back and try the Vifa, if the RS52 is not satisfactory. However, it has gotten very good testing reviews, for example here:http://206.13.113.199/ncdiyaudio/mark/Testing/Midrange2/midrange_2_test_data.htm
and here:http://www.zaphaudio.com/smalltest/
I'm not clear on your thoughts about the EnAble use with the wave guides? Do you think it would help? If so, how would it be applied? Also, what about on the concave cone diffusers? I know there will be diffraction issues that will result from those round wave guides and diffusers and thought maybe the EnAble pattern would be an option help attenuate them.
Thanks for the feedback!
Do you have some specific recordings that you use for your piano and string listening session?
Are you talking about eh 3" Vifa Dome? I looked at it, but was concerned about what looked to be very quick off axis roll off. It looks like the new version might be better, but I could not find a performance graph on it. Since we are essentially listening 90º off axis with an up firing driver, there tends to be a very quick roll off with many drivers that severely reduces the range you can use it in. The concave cone diffuser helps, but it is good to start with a driver that has very good off axis performance to start with. I hear you on the phase screen, however. I wish it was removable. I can always go back and try the Vifa, if the RS52 is not satisfactory. However, it has gotten very good testing reviews, for example here:http://206.13.113.199/ncdiyaudio/mark/Testing/Midrange2/midrange_2_test_data.htm
and here:http://www.zaphaudio.com/smalltest/
I'm not clear on your thoughts about the EnAble use with the wave guides? Do you think it would help? If so, how would it be applied? Also, what about on the concave cone diffusers? I know there will be diffraction issues that will result from those round wave guides and diffusers and thought maybe the EnAble pattern would be an option help attenuate them.
Construction update:
Well yesterday I bit the bullet and purchased a plunge router - and seeing how I thought it unwise to sit on my butt and spin in order to cut circles I also purchased a circle cutting jig. Other item purchased included a respirator rated for toxic dust and fumes, safety goggles that would fit over my glasses, a disposable dust suit, router bits, and some lumber and braces to make a work stand out of. About the only thing I had on hand were some general carpentry tools and ear plugs.
So I banged together a work stand and placed it on a tarp outside in the fresh air where the breeze would blow the light dust away from me and after reading the instruction manuals (yeah, I read those things), I got to it and routed up some MDF and plywood.
Good thing I measured the inside diameter of the SonoTube before I started because the 14 inch stuff that I'm using measures more like 14.75 inches ID.
Guess I'm going to have a little more bass than I expected!
Cold day outside today - still 45f at noon so I got a late start. Will finish cutting things up tomorrow and then it's on to putting things together!
Well yesterday I bit the bullet and purchased a plunge router - and seeing how I thought it unwise to sit on my butt and spin in order to cut circles I also purchased a circle cutting jig. Other item purchased included a respirator rated for toxic dust and fumes, safety goggles that would fit over my glasses, a disposable dust suit, router bits, and some lumber and braces to make a work stand out of. About the only thing I had on hand were some general carpentry tools and ear plugs.
So I banged together a work stand and placed it on a tarp outside in the fresh air where the breeze would blow the light dust away from me and after reading the instruction manuals (yeah, I read those things), I got to it and routed up some MDF and plywood.
Good thing I measured the inside diameter of the SonoTube before I started because the 14 inch stuff that I'm using measures more like 14.75 inches ID.
Guess I'm going to have a little more bass than I expected! Cold day outside today - still 45f at noon so I got a late start. Will finish cutting things up tomorrow and then it's on to putting things together!
Hi R Jamm,
Working on EnABL pattern to be used with a stencil type application now. BudP has been super with providing different size patterns shaped for the basket side of the Pioneer 10 inch and I have obtained some flexible silkscreen sheets that look fairly easy to use from http://www.store.cbridge.com/pc/STP-KIT/KIT-STP-001/Basic+Starter+Kit+with+StencilPro
I'm also wondering if plain old photo sensitized silkscreen that you can get at just about any arts craft store will work - but that stuff usually needs UV lamps to expose the pattern with. Still - it could be worth a try.
Not nearly as difficult a process as doing a framed silkscreen for a circuit board - and doesn't require any UV lamps either! The basic kit comes with everything you'll need except the pattern - which will be made available by BudP or me after a little bit of refinement and debugging. Still some details to work out with exposure times, pattern application, - specific step by step stuff - which I will be working on this weekend and should have some preliminary results to report. I had to order the paint and conformal coating at my local hobby shop and hopefully it will arrive tomorrow. Then some testing to see what a successful application method will be. The paint is a thin acrylic and that is going to take some fooling around with to see how I can prevent it from running down the cone as it's being applied. The conformal coating is simply brushed on but BudP wants me to do some testing first to see how much needs to be applied.
I'm considering a nice veneer wood finish for the base units that I will put into my living room - but the test rig I'm simply going to primer a sort of medium gray because it's going to get beat up quite a bit while I fool around with different damping treatments of the SonoTube. I am also considering using a padded leather finish to match the furniture or some short fiber carpet - the padded coverings would also be to damp the SonoTube. OR I could slap on a bunch of LED's and go with the scoreboard look - hmm - NO!
Hope this helps - after this weekend I'll know a lot more!
Working on EnABL pattern to be used with a stencil type application now. BudP has been super with providing different size patterns shaped for the basket side of the Pioneer 10 inch and I have obtained some flexible silkscreen sheets that look fairly easy to use from http://www.store.cbridge.com/pc/STP-KIT/KIT-STP-001/Basic+Starter+Kit+with+StencilPro
I'm also wondering if plain old photo sensitized silkscreen that you can get at just about any arts craft store will work - but that stuff usually needs UV lamps to expose the pattern with. Still - it could be worth a try.
Not nearly as difficult a process as doing a framed silkscreen for a circuit board - and doesn't require any UV lamps either! The basic kit comes with everything you'll need except the pattern - which will be made available by BudP or me after a little bit of refinement and debugging. Still some details to work out with exposure times, pattern application, - specific step by step stuff - which I will be working on this weekend and should have some preliminary results to report. I had to order the paint and conformal coating at my local hobby shop and hopefully it will arrive tomorrow. Then some testing to see what a successful application method will be. The paint is a thin acrylic and that is going to take some fooling around with to see how I can prevent it from running down the cone as it's being applied. The conformal coating is simply brushed on but BudP wants me to do some testing first to see how much needs to be applied.
I'm considering a nice veneer wood finish for the base units that I will put into my living room - but the test rig I'm simply going to primer a sort of medium gray because it's going to get beat up quite a bit while I fool around with different damping treatments of the SonoTube. I am also considering using a padded leather finish to match the furniture or some short fiber carpet - the padded coverings would also be to damp the SonoTube. OR I could slap on a bunch of LED's and go with the scoreboard look - hmm - NO!
Hope this helps - after this weekend I'll know a lot more!
Construction Update:
We have been having a record setting cold wave for the last 5 days now and that really slowed me down on my construction of Mamboni's Walsh 5 remakes but I did manage to get some work done over the weekend.
The 1st thing to report on is the stencil test for BudP's EnABL pattern. The test was a bust - the Polly S coating that Bud uses is simply to thin to be used with a silkscreen type stencil. We will try to thicken it up some with some acrylic thickener and see if that works next.
The 2nd thing is the construction of the Mamboni SonoTube base units and assembly went fairly well after I got over the learning curve of using my new plunge router. I purchased the Hitachi KM 12VC unit after I read some reviews on different routers and I have to say that I'm pleased with this unit. I wish it had a vacuum hose port because it sure makes a lot of dust when carving up MDF and I needed to manually vacuum stuff up between carving / cutting up pieces. I did wear a respirator, dust suit, safety goggles etc. but it took me as much time to clean up the work area as it did to do the actual work!
Once I put the base plate and center brace into the Sonotube and had everything glued up, braced, etc. I performed a knuckle test on the tube and determined that this thing really needs sound damping BAD! I'm not sure if simply filling it up half way with ACOUSTA-STUF POLYFILL is going to be enough damping because the tube resonates like a - well like a big cardboard tube! I believe that Mamboni's outter covering of carpet serves to deaden the tube quite a bit but I'm going to also apply some damping treatment to the inside of the tube in addition to the Acousta-Stuf and then adjust the stuffing to my personal taste. Hopefully I can finish this test unit tomorrow and start to break it in for a week or so.
We have been having a record setting cold wave for the last 5 days now and that really slowed me down on my construction of Mamboni's Walsh 5 remakes but I did manage to get some work done over the weekend.
The 1st thing to report on is the stencil test for BudP's EnABL pattern. The test was a bust - the Polly S coating that Bud uses is simply to thin to be used with a silkscreen type stencil. We will try to thicken it up some with some acrylic thickener and see if that works next.
The 2nd thing is the construction of the Mamboni SonoTube base units and assembly went fairly well after I got over the learning curve of using my new plunge router. I purchased the Hitachi KM 12VC unit after I read some reviews on different routers and I have to say that I'm pleased with this unit. I wish it had a vacuum hose port because it sure makes a lot of dust when carving up MDF and I needed to manually vacuum stuff up between carving / cutting up pieces. I did wear a respirator, dust suit, safety goggles etc. but it took me as much time to clean up the work area as it did to do the actual work!
Once I put the base plate and center brace into the Sonotube and had everything glued up, braced, etc. I performed a knuckle test on the tube and determined that this thing really needs sound damping BAD!
I'm not sure if simply filling it up half way with ACOUSTA-STUF POLYFILL is going to be enough damping because the tube resonates like a - well like a big cardboard tube! I believe that Mamboni's outter covering of carpet serves to deaden the tube quite a bit but I'm going to also apply some damping treatment to the inside of the tube in addition to the Acousta-Stuf and then adjust the stuffing to my personal taste. Hopefully I can finish this test unit tomorrow and start to break it in for a week or so.
Construction update:
After a night of thinking about my available options as far as damping the megaphone like resonant reverberations from my SonoTube base units I decided to keep things within the boundary of DIY and select materials available to the average builder. Lead is difficult to obtain - and is fairly costly as well. I considered a dense heavy rubber matting but the material is costly and requires ordering - but there are some internet sites that offer it for around $6.00 a square ft. - ugh
Heck - I can purchase some nice wood flooring for less than that! Foam rubber as used under indoor carpeting is available for a reasonable price but the materials I found were not dense enough for my taste - but I will keep them on my list for future usage. Rubberized asphalt is available at the local hardware store and might be useful - but is messy, hard to clean up, and smells very much like you have just tared your speakers and now all you need to do is find some feathers to finish the job with.
I wound up with a couple of things that looked affordable and workable. 1st was some automobile undercoating in an aerosol can. I tried a can of this material and for my uses I found it to be a waste of time and money. I was supposed to provide some degree of sound insulation but in fact provided little more than simply spraying the inside of the speakers black - plus it's messy!
I had considered gluing cut to fit wool blankets (purchased used at the local Army surplus or thrift store) or felt to the inside of the speaker - but I wanted more damping that they would provide.
In the end I stopped off at the local carpet store and purchased a 9ft. by 12 ft. carpet remnant for $65.00. That should provide enough material for my two personal speakers plus my two test speakers. At around $0.60 per sq. ft. - plus $5.00 bucks for a can of spray adhesive I'm thinking that this pretty much fits the bill without braking the bank.
I cut up a piece for the bottom of the SonoTube bass and glued it down - large improvement in reducing reverberations were noted. Still had quite a bit from the side walls - so I cut up a bit more carpet and hand fit it in for testing (no glue - yet) - great improvement and I now fell that using this oversized toilet paper roll for a speaker enclosure just might have a chance of coming out fairly decent.
I still have Acousta-Stuf to play with if more "tuning" is needed but I think the 1st speaker is about ready to fire up and get burned in.
Stay Tuned!
BTW - my little four legged supervisor is named Murphy and today is her 2nd birthday
After a night of thinking about my available options as far as damping the megaphone like resonant reverberations from my SonoTube base units I decided to keep things within the boundary of DIY and select materials available to the average builder. Lead is difficult to obtain - and is fairly costly as well. I considered a dense heavy rubber matting but the material is costly and requires ordering - but there are some internet sites that offer it for around $6.00 a square ft. - ugh
Heck - I can purchase some nice wood flooring for less than that! Foam rubber as used under indoor carpeting is available for a reasonable price but the materials I found were not dense enough for my taste - but I will keep them on my list for future usage. Rubberized asphalt is available at the local hardware store and might be useful - but is messy, hard to clean up, and smells very much like you have just tared your speakers and now all you need to do is find some feathers to finish the job with. I wound up with a couple of things that looked affordable and workable. 1st was some automobile undercoating in an aerosol can. I tried a can of this material and for my uses I found it to be a waste of time and money. I was supposed to provide some degree of sound insulation but in fact provided little more than simply spraying the inside of the speakers black - plus it's messy!
I had considered gluing cut to fit wool blankets (purchased used at the local Army surplus or thrift store) or felt to the inside of the speaker - but I wanted more damping that they would provide.
In the end I stopped off at the local carpet store and purchased a 9ft. by 12 ft. carpet remnant for $65.00. That should provide enough material for my two personal speakers plus my two test speakers. At around $0.60 per sq. ft. - plus $5.00 bucks for a can of spray adhesive I'm thinking that this pretty much fits the bill without braking the bank.
I cut up a piece for the bottom of the SonoTube bass and glued it down - large improvement in reducing reverberations were noted. Still had quite a bit from the side walls - so I cut up a bit more carpet and hand fit it in for testing (no glue - yet) - great improvement and I now fell that using this oversized toilet paper roll for a speaker enclosure just might have a chance of coming out fairly decent.
I still have Acousta-Stuf to play with if more "tuning" is needed but I think the 1st speaker is about ready to fire up and get burned in.
Stay Tuned!
BTW - my little four legged supervisor is named Murphy and today is her 2nd birthday
c2cthomas said:Construction update:
After a night of thinking about my available options as far as damping the megaphone like resonant reverberations from my SonoTube base units I decided to keep things within the boundary of DIY and select materials available to the average builder. Lead is difficult to obtain - and is fairly costly as well. I considered a dense heavy rubber matting but the material is costly and requires ordering - but there are some internet sites that offer it for around $6.00 a square ft. - ugh
How about trying this? Why not use concentric tubes, and fill the space in-between with sand? They don't even need to be made of the same material - you can use a plastic tube and a cardboard tube, for example.
Be sure the sand is dry - I think the dry variety is called Silver Sand. Oh yeah - once it's filled with sand it'll be VERY HEAVY, fair warning here.
Hi Lynn,
Thank you for the feedback!
I have considered double wall construction using sand, or expandable foam, or as I'm fond of kidding BudP about - pudding
(no particular flavor). I acutually looked into the silicon rubber used to make those artificial soft rubber fishing lures because I think a soft but dense jelly like rubber could be of some use - needs testing of course - but discovered that it's a two part silicon made by GE and intended for injection molding and needs to be "cured" at 300 - 400f. Seeing as how the SonoTube is to large for my regular sized kitchen range and I no longer have access to an autoclave I decided to pursue that idea at a later date. 
I have checked the next size of SonoTube and that is 18 inch ID and yeah - I have it on my short list.
I just use "playground" sand available at the local hardware superstore chain. I would love to get my hands on some of that very fine grain white sand you can find at places like Panama City Fla. - but I believe the local officials rather frown upon people stealing their beach front!
BTW - I'm loving your thread and thoughts on "Beyond the Ariel"
Thank you for the feedback!
I have considered double wall construction using sand, or expandable foam, or as I'm fond of kidding BudP about - pudding
(no particular flavor). I acutually looked into the silicon rubber used to make those artificial soft rubber fishing lures because I think a soft but dense jelly like rubber could be of some use - needs testing of course - but discovered that it's a two part silicon made by GE and intended for injection molding and needs to be "cured" at 300 - 400f. Seeing as how the SonoTube is to large for my regular sized kitchen range and I no longer have access to an autoclave I decided to pursue that idea at a later date. I have checked the next size of SonoTube and that is 18 inch ID and yeah - I have it on my short list.
I just use "playground" sand available at the local hardware superstore chain. I would love to get my hands on some of that very fine grain white sand you can find at places like Panama City Fla. - but I believe the local officials rather frown upon people stealing their beach front!
BTW - I'm loving your thread and thoughts on "Beyond the Ariel"
Hi R. Jamm,
I just finished hooking up the test unit and began it's "burn in" using the HT system to just run stuff through it for a week or so. Put on a collection of oldies that have Nat King Cole, Perry Como, Julie Andrews and a bunch of others singing classics. It is not critical listening at all - simply a break-in period. Could not help myself from doing a little bit of A - B sampling tho. I have the other ESS AMT2 that was the mate to the damaged unit being morphed into this speaker and I chose it for the mate during burn-in. I also have some Fostex 167e full rangers to compare with and they are my normal base test units - I'll fire them up for an A-B test after break these units in. Right from the get go the test speaker kicked the AMT2's butt. Much cleaner sound - much better resolution - much less coloration especially in the mid range. I haven't even had a chance to tweak 'em any (yet)
The EQ is a little off as they stand right now. The Heils are a little hot and the bass needs to come up a bit - but I'll wait a little to allow the Pioneer to break in a bit before I do anything. Most likely I'll up the resistor value going to the Heil up a peg or two and see how that works 1st. Mamboni was using a dome tweeter on his design and that most likely explains the difference in balance between the Pioneer and the tweeter. Heils are darn efficient compared to just about anything else so cutting them back a bit is the place to tweak. Heck - the Pioneer is hooked up straight to the amp - so there really isn't anything to do there except use the bass control on the amp.
I bought the wife in to give it little listen as she plays both organ and piano and she walked over the the Walsh Mamboni unit and then the ESS unit - looked up and said - "turn that one off" as she pointed to the AMT2 - "the other one is so clear that it isn't even a contest". Then she gave me a little smooch and went off to bed.
I'm attaching a photo of the test tube speaker - it's not even been positioned yet - it will sit about where it is at now but will start out at about 3 ft. from both the back and side wall to start with - and then go from there. I currently have the Heil just hanging from a support pole to play around with height adjustment before I commit to final design of the speakers I'll use day to day. The height of the tweeter in this photo is at 40 inches center.
For the real speakers I'm currently of a mind to do something like the attached photo using epoxy resin and a piano black gloss finish. But that's what I'm thinking today -
I cut the circle with a jig I purchased at the local hardware superstore. The problem there is that the fine print on the box didn't say that it would not cut circles less than 6 inches in diameter! I wound up making my own little jig out of thin plywood for the small cuts on the baffle. Guess I'll need to break down and get the Jasper jig from PE after all.
Now that the 1st unit is built I'll have some time to get back to BudP's EnABL pattern for test tube #2.
I just finished hooking up the test unit and began it's "burn in" using the HT system to just run stuff through it for a week or so. Put on a collection of oldies that have Nat King Cole, Perry Como, Julie Andrews and a bunch of others singing classics. It is not critical listening at all - simply a break-in period. Could not help myself from doing a little bit of A - B sampling tho. I have the other ESS AMT2 that was the mate to the damaged unit being morphed into this speaker and I chose it for the mate during burn-in. I also have some Fostex 167e full rangers to compare with and they are my normal base test units - I'll fire them up for an A-B test after break these units in. Right from the get go the test speaker kicked the AMT2's butt. Much cleaner sound - much better resolution - much less coloration especially in the mid range. I haven't even had a chance to tweak 'em any (yet)
The EQ is a little off as they stand right now. The Heils are a little hot and the bass needs to come up a bit - but I'll wait a little to allow the Pioneer to break in a bit before I do anything. Most likely I'll up the resistor value going to the Heil up a peg or two and see how that works 1st. Mamboni was using a dome tweeter on his design and that most likely explains the difference in balance between the Pioneer and the tweeter. Heils are darn efficient compared to just about anything else so cutting them back a bit is the place to tweak. Heck - the Pioneer is hooked up straight to the amp - so there really isn't anything to do there except use the bass control on the amp.
I bought the wife in to give it little listen as she plays both organ and piano and she walked over the the Walsh Mamboni unit and then the ESS unit - looked up and said - "turn that one off" as she pointed to the AMT2 - "the other one is so clear that it isn't even a contest". Then she gave me a little smooch and went off to bed.
I'm attaching a photo of the test tube speaker - it's not even been positioned yet - it will sit about where it is at now but will start out at about 3 ft. from both the back and side wall to start with - and then go from there. I currently have the Heil just hanging from a support pole to play around with height adjustment before I commit to final design of the speakers I'll use day to day. The height of the tweeter in this photo is at 40 inches center.
For the real speakers I'm currently of a mind to do something like the attached photo using epoxy resin and a piano black gloss finish. But that's what I'm thinking today -
I cut the circle with a jig I purchased at the local hardware superstore. The problem there is that the fine print on the box didn't say that it would not cut circles less than 6 inches in diameter! I wound up making my own little jig out of thin plywood for the small cuts on the baffle. Guess I'll need to break down and get the Jasper jig from PE after all.
Now that the 1st unit is built I'll have some time to get back to BudP's EnABL pattern for test tube #2.
Zen Mod
Most cone speakers will benefit from the Mamboni on the backside. This should take care of 70 to 80% of the problems emited from the front side. C2C's comments seem to back this up. The EnABL process is supposed to control only the refracted energy from surface terminations, like the edge of a cone or the glue pad of a surround. This should be the remaining 20 to 30% of what needs to be cleaned up on the front.
Treating only the back with the EnABL process will provide the same results. I am not certain that they are exactly identical but certainly everything Mamboni and C2C speak of is very familiar to me from just applying the EnABL treatment. Treating only the front side with EnABL blocks also provides only 70 to 80% of all you get when both sides are treated
The two processes are going to interact and we do not yet know how. It is good that C2C is a few thousand miles from either of us, so he cannot get his hands on our necks in case things go awry.....
Seriously, I expect the two processes to be throughly compatible and highly complementary. I will use them together on a test driver myself, but only after C2C has had his fun first.
I do not think I would deviate much from Mamboni's plan, though I would explore Lynn 's notion of variable geometry sets of sizes just to see if that adds an audible benefit. I don't think I would try to duplicate the EnABL pattern with that many small Mamboni triangles but I have no experience at all, so try it, who knows what you will discover.
Bud
Most cone speakers will benefit from the Mamboni on the backside. This should take care of 70 to 80% of the problems emited from the front side. C2C's comments seem to back this up. The EnABL process is supposed to control only the refracted energy from surface terminations, like the edge of a cone or the glue pad of a surround. This should be the remaining 20 to 30% of what needs to be cleaned up on the front.
Treating only the back with the EnABL process will provide the same results. I am not certain that they are exactly identical but certainly everything Mamboni and C2C speak of is very familiar to me from just applying the EnABL treatment. Treating only the front side with EnABL blocks also provides only 70 to 80% of all you get when both sides are treated
The two processes are going to interact and we do not yet know how. It is good that C2C is a few thousand miles from either of us, so he cannot get his hands on our necks in case things go awry.....
Seriously, I expect the two processes to be throughly compatible and highly complementary. I will use them together on a test driver myself, but only after C2C has had his fun first.
I do not think I would deviate much from Mamboni's plan, though I would explore Lynn 's notion of variable geometry sets of sizes just to see if that adds an audible benefit. I don't think I would try to duplicate the EnABL pattern with that many small Mamboni triangles but I have no experience at all, so try it, who knows what you will discover.
Bud
BudP said:
tnx for reply
I must say that you boyz pretty good succeeded in basic explanation how Mamboni and EnABL thingies (hehe) works; I'm more than enough educated in elementary physics to understand this (even if I can hardly wait to see (if ever) can I understand your findings in OPT area
) , but more important thing is that these two techniques (two sides of one coin etc . ) aren't in any way and in any moment in same league as many Fi-FI tricks .........anyway- what I meant with this little idea is :
one side of cone treated with "classic" EnABL (two circles of many little rectangles of paint )
other side of cone - two circles of relatively bigger (EnABL like) felt rectangles .....
I don't know when I'll have time to try difference between already established Mamboni-EnABL treatment and this small idea of me .......
too many everyday things to do,and just 24 hours in day......
anyway- in nearest future I have obligation to decide what to do with probably no less than 3 pairs of Sonido FR 8" ,so my time will be limited even more .......
but- I'm sure that at least my pair will be enabled with at least EnABL ,if not Mamboni too........
ps
I have pair of olde Philips 12".......perfect for this game
