GG said:
I used to, but given the much larger amounts at the frame, magnet juncture, i found that i was happy leaving the legs undone. The insides of the legs benefit from something that reduces HF reflections, but there is not a whole lot of room to work in there.
And don't foget Morays circles of felt mod. This reduces reflections from the spider.
Do keep in mind that the poly craft felt is not very effective, and some applications of it will be as effective as nothing.
dave
MarkMcK said:
I am working on it Mark. I've even been bugging the guy who writes my measuring software to add a linear frequency scale as an option.
In the case of the FE126 & FE127 there is little question that the mods make a superior driver. The cone mods can likely be improved on (and i'm hoping measurements may give some clues as to how & where). But you just letting us know that dramatic measured improvements could be made, and leaving a few critical pieces of data to work from, have led to a better FE126/127.
As we all know, there are things that the human ear/brain system -- despite its shortcomings in terms of expectation -- can detect that we have not figured out yet how to measure. 30 years of training have taught me a lot, and in the end, it is the ear/brain that needs to be pleased. Measurements are a useful analytical tools, but the machines don't have to listen, and i won't let them tell me whether i can enjoy my system or not.
I'm sure all here would really like to see how you achieved the improvements, as opposed to my stubling around in the twilight.
And if i could find a better driver for the price i'd be using it.... i suspect we have a different set of attributes we are searching for in a music producing system, but still, you have been the catalyst for my being able to improve on those i value most highly.
dave
this one is easy...
You use either copper foil to make a 36- degree wrap on the magnet slug once around the outside which does not touch the backplate or topplate. If you don't have copper foil use multiple turns of solid copper wire to cover the width of the magnet. In either case you solder the thing together. Foil just needs the joint at the end and wire wrap (bare/solid core) can get solderedat north south east and west. Dont use insulated wire as this is not supposed to be a multi turn inductor. Then when you have the shorted turn in place you can experiment with grounding the copper turn to the driver top plate via the basket. Remember to check to see if your basket makes electrical connection to your driver top plate. There you go done.
You use either copper foil to make a 36- degree wrap on the magnet slug once around the outside which does not touch the backplate or topplate. If you don't have copper foil use multiple turns of solid copper wire to cover the width of the magnet. In either case you solder the thing together. Foil just needs the joint at the end and wire wrap (bare/solid core) can get solderedat north south east and west. Dont use insulated wire as this is not supposed to be a multi turn inductor. Then when you have the shorted turn in place you can experiment with grounding the copper turn to the driver top plate via the basket. Remember to check to see if your basket makes electrical connection to your driver top plate. There you go done.
Here's another idea that works...
you make an electrical contact point on the top plate and tie it to the negative speaker terminal then you make an electrical connection on the speakers backplate (which is the pole piece) and tie that to the speakers positive terminal. now the top plate and the pole piece are biased by the driving amplifier. give it a try and see what you think. I have done this and find that the easiest method of making contact to the backplate is to simply drill a small hole into it and the attach a small terminal tag with a small self tapping machine screw.
you make an electrical contact point on the top plate and tie it to the negative speaker terminal then you make an electrical connection on the speakers backplate (which is the pole piece) and tie that to the speakers positive terminal. now the top plate and the pole piece are biased by the driving amplifier. give it a try and see what you think. I have done this and find that the easiest method of making contact to the backplate is to simply drill a small hole into it and the attach a small terminal tag with a small self tapping machine screw.
did anybody mention Dammar varnish
I haventseen any mention in this thread of applying Dammar varnish to the cone I have tried it on many drivers , and there was an obvious improvement in every case.
one or two thinned out coats is plenty do not use too much or performance actually degrades.
I haventseen any mention in this thread of applying Dammar varnish to the cone I have tried it on many drivers , and there was an obvious improvement in every case.
one or two thinned out coats is plenty do not use too much or performance actually degrades.
Just looked in my papers - some dry facts
Dammar is a fine resin from a special tree mostly from around Borneo or Sumatra
Earlier very commonly used
Now a days mostly used in cellulose lack, but there is a soft variant useable in terpentineoil
But probably very good fore musical instruments because its very low on acid and dont turn yellow in light
Dammar is a fine resin from a special tree mostly from around Borneo or Sumatra
Earlier very commonly used
Now a days mostly used in cellulose lack, but there is a soft variant useable in terpentineoil
But probably very good fore musical instruments because its very low on acid and dont turn yellow in light
dammar
dammar is also used as a protective coating on oil paintings .
It is available at art supply shops.
if you do a google search on dammar speaker cones
you will find several sites of particular interest is a japanese
site (in english) that details how it is done.
I would reccomend trying first with some cheapie speakers first
before a pair of lowthers!
dammar is also used as a protective coating on oil paintings .
It is available at art supply shops.
if you do a google search on dammar speaker cones
you will find several sites of particular interest is a japanese
site (in english) that details how it is done.
I would reccomend trying first with some cheapie speakers first
before a pair of lowthers!
Hi Guys,
Lots of ideas and claims, but still no proof. Why do you think that is? It is not because measurement systems are available for virtually no cost.
It is amazing how after all the experience we have had that there are still people who still "do" when someone says, "just trust me." Although I understand it has been a number of years since anyone has purchased the Brooklyn Bridge, so maybe we are getting better.
Sorry guys, but there are still considerable questions about superiority. There is even a question about what the person who claims superiority means. Without some evidence beyond one's own self serving claims, I am unlikely to try to duplicate your efforts.
I find this perspective amazing (and evidence of dogma). While all sorts of claims are made about how certain people can hear what you can't measure, the same people cannot hear what can be measured. I can't speak for everyone, but I can hear what I can measure. And there is published research on the limits of what we can hear that supports the claim that you should be able to hear what we can measure. I have an idea why some cannot, but that is mostly pure psychology.
If you are going to make claims that you have improved a transducer or a loudspeaker, provide evidence that can be examine and even further tested.
I am not providing modification instructions or making claims of improving a transducer. I am providing an illustration of what you should be able to see when someone else makes such claims (like the person who started this thread).
To this message I have attached IR and frequency response for the Pioneer A11EC80 transducer. This transducer has been in production, with few changes, for 30 or 40 years. Some diyer even jumped into a thread I had been participating to offer this transducer as an excellent sounding alternative. Apparently that person cannot hear what can be measured and cannot hear what human beings are said to be able to hear.
Anyway, here are the stock test results.
Lots of ideas and claims, but still no proof. Why do you think that is? It is not because measurement systems are available for virtually no cost.
It is amazing how after all the experience we have had that there are still people who still "do" when someone says, "just trust me." Although I understand it has been a number of years since anyone has purchased the Brooklyn Bridge, so maybe we are getting better.
Sorry guys, but there are still considerable questions about superiority. There is even a question about what the person who claims superiority means. Without some evidence beyond one's own self serving claims, I am unlikely to try to duplicate your efforts.
I find this perspective amazing (and evidence of dogma). While all sorts of claims are made about how certain people can hear what you can't measure, the same people cannot hear what can be measured. I can't speak for everyone, but I can hear what I can measure. And there is published research on the limits of what we can hear that supports the claim that you should be able to hear what we can measure. I have an idea why some cannot, but that is mostly pure psychology.
If you are going to make claims that you have improved a transducer or a loudspeaker, provide evidence that can be examine and even further tested.
I am not providing modification instructions or making claims of improving a transducer. I am providing an illustration of what you should be able to see when someone else makes such claims (like the person who started this thread).
To this message I have attached IR and frequency response for the Pioneer A11EC80 transducer. This transducer has been in production, with few changes, for 30 or 40 years. Some diyer even jumped into a thread I had been participating to offer this transducer as an excellent sounding alternative. Apparently that person cannot hear what can be measured and cannot hear what human beings are said to be able to hear.
Anyway, here are the stock test results.
Attachments
Now, one modification that has become popular has been to remove the dust cap and replace it with a bullet shaped plug. Then unsupported claims are made about how the transducer is superior.
Well, most of the time it is not that simple. Replacing a dust cap with a plug will change the performance. It is, however, less clear that the transducer is really better instead of just different.
The documentation of IR and frequency response provided here is the performance of the same A11 transducer, but with the dust cap removed and a bullet shape plug of familiar design installed.
In some ways the performance has improved, in some ways it has become worse. Still, I am glad I don't have to listen the either the stock or dust cap/plug modification.
Well, most of the time it is not that simple. Replacing a dust cap with a plug will change the performance. It is, however, less clear that the transducer is really better instead of just different.
The documentation of IR and frequency response provided here is the performance of the same A11 transducer, but with the dust cap removed and a bullet shape plug of familiar design installed.
In some ways the performance has improved, in some ways it has become worse. Still, I am glad I don't have to listen the either the stock or dust cap/plug modification.
Attachments
Last, I am posting the performance documentation of the same A11EC80 Pioneer transducer with a "whispered" (trademark don't you know) cone. No coatings, no damping rings, nor other odd modifications were made to the cone, the basket or any other unimportant aspects of the support structure.
I will not describe in greater detail the changes. The patent application will be published this year and I will let you read that document when the US Patent Office makes it available.
The changes to the cone total less than two % of the cone's area. This makes the modification a high skill endeavor. Indeed, I messed up, over did the modification and induced a small notch in the response at around 8 kHz.
Is the difference I document here audible. Yes. The change is easily audible, even on test signals. A 15 dB reduction in magnitude (indeed a total elimination) of a cone material vibration mode is easily audible.
Despite the improvement, I would not recommend the modified driver. I would not recommend it because of the errors still detectable in the IR and frequency response as shown below.
To sum, if modifying transducers is something you believe you are competent to do, do it. If you are going to makes claims about the competence of your modifications, you ought (as a moral claim) to document how the performance has changed.
Best,
Mark
I will not describe in greater detail the changes. The patent application will be published this year and I will let you read that document when the US Patent Office makes it available.
The changes to the cone total less than two % of the cone's area. This makes the modification a high skill endeavor. Indeed, I messed up, over did the modification and induced a small notch in the response at around 8 kHz.
Is the difference I document here audible. Yes. The change is easily audible, even on test signals. A 15 dB reduction in magnitude (indeed a total elimination) of a cone material vibration mode is easily audible.
Despite the improvement, I would not recommend the modified driver. I would not recommend it because of the errors still detectable in the IR and frequency response as shown below.
To sum, if modifying transducers is something you believe you are competent to do, do it. If you are going to makes claims about the competence of your modifications, you ought (as a moral claim) to document how the performance has changed.
Best,
Mark
Attachments
MarkMcK said:
Mark,
Have you figured out a way of measuring what is 20 or 30 or 40 dB down? The FR charts are all well & good, but they are like trying to describe the volume of the ocean by examing the surface, As such your measures show an improvement in that aspect of the drivers performance, but are far from a proof.
It has been the experience of many that pursuit of ruler flat FR without consideration of anything else will often lead to a less involving musical experience.
My measuring kit is ready to go. I just need to figure out how to use it. I hope it helps me do things better, but it will not be a substitute for ears.
To quote a giant of a man in audio (and who measured many, many things), upon whose shoulders we all stand.... ""In all things audio, the ear is the final arbiter." Harry Olson
dave
The following patent might interest some;
Reduction of standing waves and intermodulation distortion in electro-acoustic transducer
The inventor gave a how to on goodsoundclub.com/ some time ago.
Has anyone tried battery bias from the pole piece to the speaker chassis,through the magnet, similar to some Audio cables?
Regards
James
Reduction of standing waves and intermodulation distortion in electro-acoustic transducer
The inventor gave a how to on goodsoundclub.com/ some time ago.
Has anyone tried battery bias from the pole piece to the speaker chassis,through the magnet, similar to some Audio cables?
Regards
James
planet10 said:
Dave and All,
I agree that a flat FR is not the end-all, be-all of sound, but measuring it does allow for us to gain, over time, a sense of what correlation exists between what we're hearing and what the FR appears to be. As Dave has pointed out, and many pro speaker designers have stated on other forums, is that a really flat straight FR often or never sounds quite right and in many cases is "doctored" to gain listening appeal. Measurements are a tool, that used with discretion and experience result in art.
BTW: Uncle Harry really wouldn't have liked everybody standing on his shoulders.
To quote a man of lesser stature:
"If I have failed to see as far as others, it is because I stood on the shoulders of midgets." Terry Olson
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