Now I'm using wooden wedges to help me slide the magnet into the pole piece. Now that you mentioned, I do have stainless steel tongs. Might try them out.
I have friends who think I'm crazy, but i just get bored once i figured out how to build stuff on my own. Like loudspeaker system and ribbon tweeters which i design and manufacture., I got bored and decided to do something else. That's how i end up with fullrange driver design.
This driver took me quite a while, start around March 2015. Did lots of analyzing on other fullrange like lowther, fostex, AER, Voxativ
If you want to venture into this, i can recommend some head start on where you could get the basic materials.
I also have plans and material i bought recently to roll my own copper in oil capacitors.
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I was actively involved in the cosmetic design layout of custom Amplifiers
some time ago. Collaborations have some great virtues but the drawback is you can never do exactly what you want. It always involves compromise by concensus. I think I understand loudspeakers well enough to go it alone. I no longer want compromise. Any advice or assistance is most welcome. Going it alone you still need help.
Cheers and thanks
some time ago. Collaborations have some great virtues but the drawback is you can never do exactly what you want. It always involves compromise by concensus. I think I understand loudspeakers well enough to go it alone. I no longer want compromise. Any advice or assistance is most welcome. Going it alone you still need help.
Cheers and thanks
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No problem, you can message me anytime. I might not be the guru, but I always open to sharing of ideas.
The other point you made, I toally agree that sometimes or most of the times we can never do exactly what we wanted, but that the spirit of learning. The cone and damper for my design took me several attempts with many types of paper and material to reach this stage.
Sometime we might feel discourage but golden rule... always find alternative ways to resolve one issue and don't give up. That's how we learn
Yup, I always like those retro style dampers. They are also seen in Goodmans, Altec older speakers.
One key advantage of them is I can control the damping factor by simply increasing or reducing the width or the shape of the phenolic cutout. And they return to equilibrium much faster compared to cloth type.
Now cloth type will have issues if I want to customize it in order to control damping factor. This means I need to build a jig for it and make them from scratch. Off the shelf dampers wouldn't have the inner diameter size that might be suitable for me needs.
I also find cloth damper even though they are porous but they still can trap small amount of air when they move.
Cheers ghemmi for your generosity in sharing.
There are many that claim that the early phenolic style dampers have a more lifelike transient attack on brass and jembe & the like. Mostly on German forums (helps me brush up on my German!)
With your experience did you find an improvement in that area? Also Voxativ uses cones made of wood veneer. Did you contemplate that? What kind of paper did you settle on finally as the best balance of tonal
quality vs self damping. Voxativ seem to have very low stored energy in the cone & motor that gives very impressive CSD for a full range. Did you look into how they achieved this? Sorry for the flurry of questions but this really has my curiosity.
Cheers Mark
There are many that claim that the early phenolic style dampers have a more lifelike transient attack on brass and jembe & the like. Mostly on German forums (helps me brush up on my German!)
With your experience did you find an improvement in that area? Also Voxativ uses cones made of wood veneer. Did you contemplate that? What kind of paper did you settle on finally as the best balance of tonal
quality vs self damping. Voxativ seem to have very low stored energy in the cone & motor that gives very impressive CSD for a full range. Did you look into how they achieved this? Sorry for the flurry of questions but this really has my curiosity.
Cheers Mark
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Voxativ wood veneer cone does look very temping for me to give it a try. And I have a been looking around at the weight and thickness of the veneer available to me. Might try it out in my next build
The paper I end up with is hemp, but of course I have other types of paper with me like Lokta, Washi, Cotton, rice paper(Which I ordered recently) which I wanted to try them out too.
There is a behavior sound reproduction difference with different hardness and thickness of the paper. Thicker(around 0.3mm) and harder paper(hemp) produce a warm focus sound, but when I tried paper like cotton which is commonly available in art shop they sound bit more hollow. Paper that are too soft, the sound becomes too warm and muddy. I always use the tapping test on the sheet of paper to determine.
I also did find that harder the paper gets, more focus the sound it produce.
Voxativ CSD response probably is due to the low Qms, and maybe due to smaller and tighter damper design to prevent wobbling of the cone(based on my observation). Most of the energy is lost through the damper and so eventually how well the damper is designed will also determine the reflex speed of the cone. That's one reason why I decided to take the phenolic damper approach.
From my test observation from phenolic damper , they don't have the "memory" effects like normal dampers do, like when you use your finger to press on it and release. It takes a bit of time to return to normal.
So normal damper still have some memory effects after depress unlike phenolic dampers(does have abit, but way lesser).
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Cheers ghemmi
Hemp is one of the strongest cellulose fibres known. Apparently the original Levi's jeans that were tested for strength by two oxen trying to pull them apart were made out of it. The design of a loudspeaker APPEARS so simple but there are so many little things that all interact to make an excellent design such a tightrope balancing act.
Hemp is one of the strongest cellulose fibres known. Apparently the original Levi's jeans that were tested for strength by two oxen trying to pull them apart were made out of it. The design of a loudspeaker APPEARS so simple but there are so many little things that all interact to make an excellent design such a tightrope balancing act.
And hemp is alot cheaper than some of the other paper materials i got.
And i glad that i used phenolic for my damper, give me full control on the Qms. Indeed many things on a loudspeaker interact with each other. I still think i have barely scratch the surface.
Totally agree as that is as true for humanity as it is for all of us individually. I have to say what has intrigued me is some of the double magnet voice coil and spider designs that address the motor limitations of a basic speaker of conventional design.
ie higher x max, better control, less nonlinear distortion. Less compression. The list goes on. Have to commit this idea to paper right now.
ie higher x max, better control, less nonlinear distortion. Less compression. The list goes on. Have to commit this idea to paper right now.
Most fullrange has very small Xmax parameters. Likewise same with my design:
VC Height = 7mm
Magnetic Gap Height = 6mm
Xmax: (7-6)/2 = 0.5mm
So technically its a overhung VC design and I'm a hardcore believer that for fullrange the linear movement must be kept as low as possible to reduce inter-modulation distortion
Of couse I have very high Qms which still allows the Xmax to be increase to over-compensate when injected with more power(wattage) to increase the dB. but inter-modulation distortion will also increase.
Common problems with fullrange drivers, can't have best of both worlds...
VC Height = 7mm
Magnetic Gap Height = 6mm
Xmax: (7-6)/2 = 0.5mm
So technically its a overhung VC design and I'm a hardcore believer that for fullrange the linear movement must be kept as low as possible to reduce inter-modulation distortion
Of couse I have very high Qms which still allows the Xmax to be increase to over-compensate when injected with more power(wattage) to increase the dB. but inter-modulation distortion will also increase.
Common problems with fullrange drivers, can't have best of both worlds...
What you say is entirely true. Most double magnet voice coil & spider designs are for bass orintented speaker designs. They appear to be overly complex. Doing it the way I've thought up doubles your x max with virtually no mass penalty while keeping the voice coils in the sweet spot/s. I have to do some patent research so until I do that I will keep my cards close to my chest. My philosophy is extended range drivers that have got nothing below 80 Hz -100 Hz. Use subs below that. That way you avoid the full range schizophrenia of trying to do bass & treble @ the same time. That is where most fr driver distortion gets ugly. Around 100 Hz. I say don't fight the im distortion issue but use it to your advantage. Eliminating that fr range frees you design wise to optimise the design for the rest of the fr response. To me the holy grail of one driver that does it all is as rare as rocking horse poop if such a thing exists at all.
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Here the field coil I designed for my fullrange.
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.
Way to go Ghemmi! I guess Field Coils with modern regulation electronics may give you that rare elusive beast you seek.
I hope it does. Reminds me for some stupid reason of the tv series Breaking Bad. Where the anti hero Walter White the Meth Cook uses a wrecking yard electromagnet to erase a computer file in police evidence storage. With hillarious consequences.
Can't wait for you to share the results of this with the DIY community. Cheers mate awesome!
I hope it does. Reminds me for some stupid reason of the tv series Breaking Bad. Where the anti hero Walter White the Meth Cook uses a wrecking yard electromagnet to erase a computer file in police evidence storage. With hillarious consequences.
Can't wait for you to share the results of this with the DIY community. Cheers mate awesome!
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LOL, I always have people and friends telling me field coil on fullrange will make it look exotic.
This is one of the field coil I did for a customer's Altec 15" woofer
My phase plug and terminals will be sent to me by next week and past 3 days I been looking for my microphone stand... damn it... I think I miss placed it, probably I need to buy a new one
This is one of the field coil I did for a customer's Altec 15" woofer
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.
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.
My phase plug and terminals will be sent to me by next week and past 3 days I been looking for my microphone stand... damn it... I think I miss placed it, probably I need to buy a new one
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