Retsel,
Thank you for all of that. It is always best to get good and bad news interleaved.
Those drivers, siting nude on pedestals, were the most dynamic devices I have heard, other than some slight experience with compression drivers.
I agree with your comments about high frequency harshness and I did provide Limono with two electron pools, to attach to the ground lug of the driver, to help with this issue.
Something discovered later, with the Hemp FR 8 drivers, is application of a damping compound to the back of the whizzer cone. What I used is an ever tacky, acrylic, paper cement, similar to the glue on post it notes. This material subdued the backside break up mode, that was exiting in a fashion similar to Walsh drivers, at right angles to the cone axis.
These Lowthers were the first FR drivers I have EnABL'd and I suspect I would be able to do a bit better today. Other materials and processes, done to quell the whizzer difficulties, as applied by Planet 10 Dave might be an even better choice, than the glue I used on Perry's FR8c's. It is unfortunate that EnABL doesn't provide a fix for irregular frequency response, in a predictable fashion. It just clarifies what is already there.
I also treated a set of PM6A drivers for Joh Ver Halen. They do not have the difficulties I encountered with the DX 4 and I now own a pair of them.
I have turned down a few requests for treating DX 4 drivers, since Limono's. This primarily because they were in front loaded horns and I did not think the process would be successful. Limono originally had his drivers in, I believe, Azura front horns and the combination wasn't successful, at all.
Probably the best thing to do, after you have had all you can stand, is to pack them up and send them back to me, at my expense, and let me apply what I have learned, subsequent to the DX 4 drivers, about the peculiar problems that whizzer cones provide.
Bud
Thank you for all of that. It is always best to get good and bad news interleaved.
Those drivers, siting nude on pedestals, were the most dynamic devices I have heard, other than some slight experience with compression drivers.
I agree with your comments about high frequency harshness and I did provide Limono with two electron pools, to attach to the ground lug of the driver, to help with this issue.
Something discovered later, with the Hemp FR 8 drivers, is application of a damping compound to the back of the whizzer cone. What I used is an ever tacky, acrylic, paper cement, similar to the glue on post it notes. This material subdued the backside break up mode, that was exiting in a fashion similar to Walsh drivers, at right angles to the cone axis.
These Lowthers were the first FR drivers I have EnABL'd and I suspect I would be able to do a bit better today. Other materials and processes, done to quell the whizzer difficulties, as applied by Planet 10 Dave might be an even better choice, than the glue I used on Perry's FR8c's. It is unfortunate that EnABL doesn't provide a fix for irregular frequency response, in a predictable fashion. It just clarifies what is already there.
I also treated a set of PM6A drivers for Joh Ver Halen. They do not have the difficulties I encountered with the DX 4 and I now own a pair of them.
I have turned down a few requests for treating DX 4 drivers, since Limono's. This primarily because they were in front loaded horns and I did not think the process would be successful. Limono originally had his drivers in, I believe, Azura front horns and the combination wasn't successful, at all.
Probably the best thing to do, after you have had all you can stand, is to pack them up and send them back to me, at my expense, and let me apply what I have learned, subsequent to the DX 4 drivers, about the peculiar problems that whizzer cones provide.
Bud
Limono may be interested in some additional treatment to his Lowthers. He will come hear the Enabled drivers in my open baffle system first, though, to get another perspective from his past experience with his horns. He will also try his amps at my house with your special transformers.
Actually, while there seems to be some increased harshness, my initial impression is that it is not present on all music and it is not overwhelming, at least not yet. I need more time to make a more determined assessment. The other improvements are very noteworthy. Of course, I will make my final determination after I switch my nonEnabled drivers into place.
For open baffle speakers, the 15 ohm drivers are better suited because of the increaed x-max, which allows for a lower crossover frequency.
What about trying different coatings besides the one that you chose? What are they like?
Retsel
Actually, while there seems to be some increased harshness, my initial impression is that it is not present on all music and it is not overwhelming, at least not yet. I need more time to make a more determined assessment. The other improvements are very noteworthy. Of course, I will make my final determination after I switch my nonEnabled drivers into place.
For open baffle speakers, the 15 ohm drivers are better suited because of the increaed x-max, which allows for a lower crossover frequency.
What about trying different coatings besides the one that you chose? What are they like?
Retsel
Retsel,
Ok. This is a good plan to follow.
As for coatings other than the gloss. I have tried , at various times, musical instrument coatings, spar varnish, plastic furniture varnish and various model finishing clear coats, from testor's, Tamiya and others. The Micro Scale Gloss, which smells suspiciously like industrial grade floor wax, is the only reliable material , other than the original varnish concoction, from the two brothers who started the Micro Scale company, 30 years or so ago. That was a very light varnish of some sort and was superior to the current material, but just slightly, in high frequencies. The two died before sending me a formula, which they had decided to do, for the original material.
For the most part, all of the other materials suffer from not being flexible enough, or being too soft, and add problems rather than removing them. What is needed is a materials science guy to look at the current stuff and make recommendations. Only problem being, they should be paid for their efforts and I cannot.
My PM6A pair is the 15 ohm version. It is going to sit on top of an OB, nude, as an omni radiator, just because of how glorious it sounds when doing so.
Bud
Ok. This is a good plan to follow.
As for coatings other than the gloss. I have tried , at various times, musical instrument coatings, spar varnish, plastic furniture varnish and various model finishing clear coats, from testor's, Tamiya and others. The Micro Scale Gloss, which smells suspiciously like industrial grade floor wax, is the only reliable material , other than the original varnish concoction, from the two brothers who started the Micro Scale company, 30 years or so ago. That was a very light varnish of some sort and was superior to the current material, but just slightly, in high frequencies. The two died before sending me a formula, which they had decided to do, for the original material.
For the most part, all of the other materials suffer from not being flexible enough, or being too soft, and add problems rather than removing them. What is needed is a materials science guy to look at the current stuff and make recommendations. Only problem being, they should be paid for their efforts and I cannot.
My PM6A pair is the 15 ohm version. It is going to sit on top of an OB, nude, as an omni radiator, just because of how glorious it sounds when doing so.
Bud
Hi there
When I found out that Retsel lives only 30 min away from my cave and has Basszilla based speakers with DX4 I thought it would be perfect to try enabled drivers in OB and as a "sanity check". He also is way more experienced Lowther user than I am. Since Bud mentioned that he is going to build himself an OB setup with his Lowther
and also mr.Lowther and others remarked how good it sounds I decided to try it too. Now, OB seems simple but it actually takes as much time (or more) to optimize or get good results as any other project. I've narrowed my choice to Visaton NoBox Basszilla version with vintage Jensen 12" FC (field coil) midbass and separate subwoofer (klipschorn) .Due to personal circumstances (work related , laziness &winter blues , lack of work shop ) and my side horn projects progress is slow . Also Bud sent me his wonderful SET OPTs to try with Lowther but I hooked them up to my back- up trusty Jensen coaxials ,forgot lowthers and let Retsel do all the hard work ;0) Yes, I provided him with electron pools and a pair of interconnect cables. I have to say that while I was trying to fight with DX4 in Azura horns there were a moments, that I was on my knees in disbelieve how good they sound and at midnight I wanted to call my friends to come over and listen also hug Bud and wish him Merry Christmas -next day I was close to tearing off damn wizzer and rolling a joint out of it
Normal Lowther -owner behavior . I report back when (if ) I finish my OB's.
PS. Did any of you tried Tonian Lab's modified Fountek ribbon tweeter (as per Dick Olsher ) and can offer some insight ?
Regards , L
When I found out that Retsel lives only 30 min away from my cave and has Basszilla based speakers with DX4 I thought it would be perfect to try enabled drivers in OB and as a "sanity check". He also is way more experienced Lowther user than I am. Since Bud mentioned that he is going to build himself an OB setup with his Lowther
and also mr.Lowther and others remarked how good it sounds I decided to try it too. Now, OB seems simple but it actually takes as much time (or more) to optimize or get good results as any other project. I've narrowed my choice to Visaton NoBox Basszilla version with vintage Jensen 12" FC (field coil) midbass and separate subwoofer (klipschorn) .Due to personal circumstances (work related , laziness &winter blues , lack of work shop ) and my side horn projects progress is slow . Also Bud sent me his wonderful SET OPTs to try with Lowther but I hooked them up to my back- up trusty Jensen coaxials ,forgot lowthers and let Retsel do all the hard work ;0) Yes, I provided him with electron pools and a pair of interconnect cables. I have to say that while I was trying to fight with DX4 in Azura horns there were a moments, that I was on my knees in disbelieve how good they sound and at midnight I wanted to call my friends to come over and listen also hug Bud and wish him Merry Christmas -next day I was close to tearing off damn wizzer and rolling a joint out of it
Normal Lowther -owner behavior . I report back when (if ) I finish my OB's. PS. Did any of you tried Tonian Lab's modified Fountek ribbon tweeter (as per Dick Olsher ) and can offer some insight ?
Regards , L
Alan Hope
The thought of that much work staggers my imagination!
I suspect you will find a considerably more coherent signal coming out of the horn portion. As Dave points out, it may not be what you actually want to have coming out. I probably would not do it, for myself, if I was interested in building such an object. But I probably would pattern the exit edges, just to relieve their interaction with the room.
I simply don't know enough to make any more useful comment than this. The driver itself is going to be more coherent, even with a treatment just on the front side. So, the event within the maze is also going to be more coherent. No question that you will see this phenomena with a bass reflex device, but how much this would compromise what is being attempted by the maze, is not known to me. And, how much the maze, without a pattern set on all panels will compromise this back wave coherence, is also a question I don't have enough experience with, to have an opinion.
Bud
The thought of that much work staggers my imagination!
I suspect you will find a considerably more coherent signal coming out of the horn portion. As Dave points out, it may not be what you actually want to have coming out. I probably would not do it, for myself, if I was interested in building such an object. But I probably would pattern the exit edges, just to relieve their interaction with the room.
I simply don't know enough to make any more useful comment than this. The driver itself is going to be more coherent, even with a treatment just on the front side. So, the event within the maze is also going to be more coherent. No question that you will see this phenomena with a bass reflex device, but how much this would compromise what is being attempted by the maze, is not known to me. And, how much the maze, without a pattern set on all panels will compromise this back wave coherence, is also a question I don't have enough experience with, to have an opinion.
Bud
FrankWW said:Alex from Oz,
What sort of bandaid? The ones with smooth thin plastic skin, or the rough fabric skin?
I looked at a picture of the the thing and that's not much of a flare.
You may have modified the impedance seen at the end of a duct. The impedance at the end of a duct causes some of the sound to bounce from one end to the other causing coloration of sound.
G'day FrankWW,
Smooth thin plastic skin bandaids.
Thanks for finding a picture.
I refer to the flare to describe the positioning of the EnABL pattern - on the straight part of the port just before the flare begins. See pic below.
I really don't know what is going on with regard to impedance or anything else.
What I can say is that whatever is happening does make an audible difference.
I'm focussing on EnABLing baffles, horns and ports at the moment.
These are much easier to do than the drivers, less risky and far easier to reverse if you don't like the result or want to play around with positioning, block sizes and materials.
Attachments
Alan Hope said:
G'day Alan,
I've attached a picture of where I would try EnABL the horns.
This is a massive amount of work to EnABL the horns this way.
I'm thinking that EnABLing the horn this way may help to minimise the resonance of each section.
Let me stress this is just an idea which has flowed from my experimenting with baffles, ports and compression horns - so results are unknown for BLH.
Picture on left - I have only drawn the bottom half because the top is a mirror image.
EnABL pattern is in red and goes around all four sides of the horn duct (ie. the circumference of the horn) at the places marked.
The dotted red line behind the driver is EnABL on the back side of the baffle immediately surrounding the driver.
Picture on right - shows EnABL on the front baffle.
This is how I would tackle this:
1. Make both horns with a removable side panel.
2. Listen to the horns untreated until you get an idea of how they sound.
3. EnABL one horn only and listen to them in stereo and A - B in mono - you will hear the changes.
4. Adjust according to what works - and tell us about it!!
As for the stepped resonators near the mouth I would leave them as is.
Cheers,
Alex
Attachments
I have 2 10" speakers out of a bass guitar cabinet. I listened to them a while without a baffle and they were honky, plus cymbals sounded like white noise. They also beamed quite a bit. First, I put on two coats of Modge Podge mixed 50% with water over the whole cone and dust cap. Then I put on the wood glue drop on the center of the dust cap and turned them upside down to dry. After that I freehanded the enable pattern (the blocks are obviously too big, but they seem to do the job). At this point, I noticed that the cymbals sounded like cymbals and the speakers sounded very musical off-axis. The beaming was reduced. Then I applied the micro-gloss and probably overdid it as I lost some of the highs. HOWEVER, I loaded them into my bass cabinet and played a gig at the beach. I have never heard the harmonics from my bass so clearly. They also work well for electric guitar and voice sounds pretty good with a little eq. Although I really don't understand why, I can hear my bass at a lower amp volume than before, so I don't have to turn up as loud. This is a MAJOR improvement. Thanks, Bud.
Alan Hope,
Well, you have read the words of the only EnABL baffle and port master on the planet. I concur with his choices of position. The only addition being to allow a block width of distance from the panel edge to the nearest block edge. Very nice work Alex. The front panel center section can be round or rectangular, with round being only slightly more efficient.
Nicely done.
Bud
Well, you have read the words of the only EnABL baffle and port master on the planet. I concur with his choices of position. The only addition being to allow a block width of distance from the panel edge to the nearest block edge. Very nice work Alex. The front panel center section can be round or rectangular, with round being only slightly more efficient.
Nicely done.
Bud
Alex from Oz said:
Thanks Alex.
Hmmm. I will not be able to EnABL one and leave the other for A-B comparisons because the EnABLing will have to be done during the construction process. Sorry guys.
It now sounds like a bit of a risk to me. The resonators are central to the speaker design so I may mess things up here.
Dum de dum ... what to do ...
What the heck - The EnABL effect on sound has produced very little in the way of critical comments. So I WILL EnABL them. Live dangerously.
I can only then report on the speaker sound in relation to other DIY hobbyists reports. Just need a break in the weather now to start construction.
Got my silver in teflon hook up wire ready, and silver plated binding posts. These are going to be my final speakers.
Maybe
Hey Bud,
What the heck is going on here?
http://www.diyaudio.com/forums/showthread.php?postid=1440686#post1440686
What the heck is going on here?
http://www.diyaudio.com/forums/showthread.php?postid=1440686#post1440686
Hi Cal,
Looks exactly like a Harry Olson RCA speaker. These things are rare as hens teeth and should be preserved intact. I have some pics and specs and stuff I can mount on my Picassa site if you like.
Really this is early history for audio. I understand that they sound quite good. It was Olson's way to breakup modal resonances and is quite similar in use to the Mamboni patterns and EnABL in it's reason for being.
I have to go back to the link and see if he also has the cabinet as that is just as important as the driver.
What a find!!!!!
Here is my collection of photos.
http://picasaweb.google.com/hpurvine/HarryOlsonLoudspeaker
Bud
Looks exactly like a Harry Olson RCA speaker. These things are rare as hens teeth and should be preserved intact. I have some pics and specs and stuff I can mount on my Picassa site if you like.
Really this is early history for audio. I understand that they sound quite good. It was Olson's way to breakup modal resonances and is quite similar in use to the Mamboni patterns and EnABL in it's reason for being.
I have to go back to the link and see if he also has the cabinet as that is just as important as the driver.
What a find!!!!!
Here is my collection of photos.
http://picasaweb.google.com/hpurvine/HarryOlsonLoudspeaker
Bud
Well i have finished up with company demands. Problems solved and answers established.
The following is OT but still applied to acoustics.
1: An interface of different density/elastic values will cause a given amount of energy to reflect at that interface.
2: The amount of energy reflected will be directly related to the mechanical values of the changes from the initial medium to the interface of the secondary medium.
3: A refracted compression wave that traveles thru the interface and is reflected from the opposite wall will undergo a change in the refracted/reflected angle at the interface and will change again as the wave encounters the same interface on the returning trip ( given that the values are the same at the two (2) different points.
4: By adjusting a recieving transducer to obtain a maximum signal and adjusting the signal amplitude to a given value an equatable evaluation can be achieved.The change in refraction values at the interface (thru two (2) trips) is an evaluation of the mechanical values of the interface and can be observed and evaluated by the change in distance between the two (2) transducers , one being the generator and the second being the reciever. BY establishing a three (3) transducer system in which there is one (1) transmitter and two (2) recievers the first evaluates the initial reflected energy and the second evaluates the refracted energy the mechanical values at the interface can be established.
Yall see the endless BS i have to put up with?
So i am open to suggestions as to how to set up the EnABL question test? Lets please all agree on the basis of the test/requirements.
ron
The following is OT but still applied to acoustics.
1: An interface of different density/elastic values will cause a given amount of energy to reflect at that interface.
2: The amount of energy reflected will be directly related to the mechanical values of the changes from the initial medium to the interface of the secondary medium.
3: A refracted compression wave that traveles thru the interface and is reflected from the opposite wall will undergo a change in the refracted/reflected angle at the interface and will change again as the wave encounters the same interface on the returning trip ( given that the values are the same at the two (2) different points.
4: By adjusting a recieving transducer to obtain a maximum signal and adjusting the signal amplitude to a given value an equatable evaluation can be achieved.The change in refraction values at the interface (thru two (2) trips) is an evaluation of the mechanical values of the interface and can be observed and evaluated by the change in distance between the two (2) transducers , one being the generator and the second being the reciever. BY establishing a three (3) transducer system in which there is one (1) transmitter and two (2) recievers the first evaluates the initial reflected energy and the second evaluates the refracted energy the mechanical values at the interface can be established.
Yall see the endless BS i have to put up with?
So i am open to suggestions as to how to set up the EnABL question test? Lets please all agree on the basis of the test/requirements.
ron
chuck55,
PM me and I will email you back so you can forward the picture to me. I have the tools to reduce it so it can be posted and I will put the virtual pattern on it for you.
The puzzle coat is no equivalent to Micro Scale Gloss for use with an EnABL pattern. On it's own it. like other PVA materials is a pretty useful treatment to reduce systemic ringing nodes.
Bud
PM me and I will email you back so you can forward the picture to me. I have the tools to reduce it so it can be posted and I will put the virtual pattern on it for you.
The puzzle coat is no equivalent to Micro Scale Gloss for use with an EnABL pattern. On it's own it. like other PVA materials is a pretty useful treatment to reduce systemic ringing nodes.
Bud
Hi Ron,
Appears to me that we are still looking at a boundary layer issue. Alex in Oz has, possibly inadvertently, set up a classic boundary layer test tube, with blown air, as a port driven by a driver in a fixed volume. His application of the pattern at one end and report of effects dovetails nicely with what an actual treated driver exhibits in the bass and upper bass regions. How would you look for such an event with your test techniques?
Assuming boundary layer control is again on the table, as a method of operation, you seemed to have a model, that applied to how a boundary layer modification might show up. Is this model something you can test?
Will you need to add smoke and mirrors to be able to show the progress of a wave, forming as a compression wave, as it crosses the driver surface? Literally, would smoke make something like this visible, along with the laser to look at the event occurring on the cone surface?
I don't see much value in looking at the ordinary sorts of tests. Dave and John K have shown us what to expect from them, in a general sense. It might be interesting to see a CSD run on both untreated and both treated drivers, just to see what sort of trends show up. And then look at the driver surface. John K did provide some direction, a bunch of posts ago, as to what he would consider a reliable data set. Should I dig it up?
I do not not expect much help from the skeptics, but I am willing to be surprised.
But, first and foremost, how can we look for evidence of your model of wave propagation in a boundary layer, on a cone driver?
Bud
Appears to me that we are still looking at a boundary layer issue. Alex in Oz has, possibly inadvertently, set up a classic boundary layer test tube, with blown air, as a port driven by a driver in a fixed volume. His application of the pattern at one end and report of effects dovetails nicely with what an actual treated driver exhibits in the bass and upper bass regions. How would you look for such an event with your test techniques?
Assuming boundary layer control is again on the table, as a method of operation, you seemed to have a model, that applied to how a boundary layer modification might show up. Is this model something you can test?
Will you need to add smoke and mirrors to be able to show the progress of a wave, forming as a compression wave, as it crosses the driver surface? Literally, would smoke make something like this visible, along with the laser to look at the event occurring on the cone surface?
I don't see much value in looking at the ordinary sorts of tests. Dave and John K have shown us what to expect from them, in a general sense. It might be interesting to see a CSD run on both untreated and both treated drivers, just to see what sort of trends show up. And then look at the driver surface. John K did provide some direction, a bunch of posts ago, as to what he would consider a reliable data set. Should I dig it up?
I do not not expect much help from the skeptics, but I am willing to be surprised.
But, first and foremost, how can we look for evidence of your model of wave propagation in a boundary layer, on a cone driver?
Bud
Just chiming in here for what its worth with a random note. There has been some pretty heated debate here regarding enabling and some saying it is just the extra weight etc. Just over the last few weeks I have been building case work for my complete DIY system. In the last few days I sealed and then sanded the cases, no big deal but one thing struck me when you tapped the casework that was sealed and sanded and the cases just sealed and those just pre sanded but unsealed the sound totally different. And I have some identical cases so it is a valid comparison, of course this is no great revelation I am sure we have all noticed similar characteristics in all sorts of things
The sanded and sealed cases have a much higher pitched sound, it seems to ring a bit, the sealed but still rough surfaced ones are dull and deep, the sanded but unsealed ones are sharper sounding without ringing. (note all are still rough/unsanded inside)
Anyhow my point is that its not hard to conceive that cones and tubes etc with minor surface changes could sound different too. In this case weight has very little to do with it.
None of this would be of any surprise to an instrument maker of course and its a bit off the track of the debate here but it just has me now pondering a few related ideas.
The sanded and sealed cases have a much higher pitched sound, it seems to ring a bit, the sealed but still rough surfaced ones are dull and deep, the sanded but unsealed ones are sharper sounding without ringing. (note all are still rough/unsanded inside)
Anyhow my point is that its not hard to conceive that cones and tubes etc with minor surface changes could sound different too. In this case weight has very little to do with it.
None of this would be of any surprise to an instrument maker of course and its a bit off the track of the debate here but it just has me now pondering a few related ideas.
BudP said:
That's largely because there has not been a thorough set of "ordinary" tests conducted by anyone. Not a single set of even the most rudimentary off-axis tests and not a single one of the many distortion tests that make up those "ordinary" tests that every and all reputable driver manufacturers use in their research. Yet you dismiss them without having conducted a single one. I suggested that from the beginning, yet there has been no effort by anyone to perform those, not one. Funny, driver manufacturers must have been deluding themselves all these decades in using these "ordinary" tests.
No, there you go again. I can't speak for John and I expect that he's going to stay out of this as he recognized this for where it was headed. I have not shown anyone what to expect because even my examples of those "ordinary" tests were far from a complete set that is required to fully evaluate the acoustic response of a driver.
I don't believe that the issue has anything significant with regard to boundary layer and I suspect john would agree with that. Whatever that impact, it is not the significant one. I believe that he's shown through his analysis that the dimensions of the treatment do not support there being any significant alteration of any BL effect.
In any case, I don't want to be associated in any way with this "research". You guys have at it, everyone seems to "know" that it is all BL, all efforts are geared towards proving that rather than simply determining the real root of any driver alterations. No one wants to step up to the plate and do those "ordinary', but necessary tests. Every anecdotal report, and they are all nothing but that, is on the BL bandwagon. No proof, nothing serious, just speculation, but that seems to be good enough for most here. They been told that this must be it, therefore that is it, they truly believe what they read. No questioning, no doubts, no concerns of expectation (placebo effect), nothing scientific at all.
As for the effect on surfaces such as baffles and ports, everyone is deluding themselves. Of that I have no doubt. People still swear by Totem beaks and swore to the effects of Tice clocks. I for one put no credibility in the ears of anyone reporting changes due to this, it taints everything they report anecdotally.
It's all in your (as in plural) competent, anecdotal hands. I'm out of this nonsense. Bud, please stop associating me with any of this.
Dave
- Status
- Not open for further replies.