Hello!
New forum member here who is in the process of building my first loudspeaker pair, separate thread regarding the build found here: Studio 3-way reference monitor build, need help choosing drivers
I have been reading a lot on the subject in recent weeks/months and I have been sharing this new found interest with my brother who has responded in kind and now we are 2 really interested persons who would like to really get serious when it comes to loudspeaker design. I am currently studying to become a medical doctor, which is not really applicable to loudspeaker design (if you're not counting human hearing, maybe there is a future for me in studying and advancing our knowledge of human perception of sound?? Any input/thoughts/available paths forward regarding this would be greatly appreciated).
My brother has finished his phd in chemical engineering/material design. His graduating work (not sure what you call this in english speaking countries? Graduate work/project?) was concerned with synthetisizing novel polymers based on a set of wanted characteristics.
We have now developed a vision of using his knowledge/skill to develop new materials for loudspeaker drivers and loudspeaker enclosures, materials tailor-made to the needs of the frequency range in which the driver/enclosure operates.
Imagine a midrange driver that utilizes a tailor-made membrane-material for its specific frequency range which results in perfectly matched characteristics resulting in frequency response linearity and extremely low levels of distortion. Then imagine using this same material for the enclosure for this driver. Then imagine using this same methodology for all drivers in the design of a complete/full range loudspeaker. Maybe there is a possibility of creating something great sounding and economical?? I can specify what (modern) techniques of polymer synthetization we are planning on utilizing if there is an interest in knowing more about the potential of polymer materials.
I would be extremely grateful for all input/ideas/information pertaining to our quest. What is the function of the membrane of a loudspeaker? What is the source of its inherent structural instability (break-up etc.)? How is this instability related to the self-oscillating frequency? How is this related to the molecular make-up of the material? What would be the ideal material characteristics of a membrane for a specific frequency range of a loudspeaker driver?
Any sources (books, links) will be gladly accepted and researched, any insight/input/ideas regarding the topic is extremely welcome!
What would be the ideal loudspeaker membrane/enclosure material? Discuss
New forum member here who is in the process of building my first loudspeaker pair, separate thread regarding the build found here: Studio 3-way reference monitor build, need help choosing drivers
I have been reading a lot on the subject in recent weeks/months and I have been sharing this new found interest with my brother who has responded in kind and now we are 2 really interested persons who would like to really get serious when it comes to loudspeaker design. I am currently studying to become a medical doctor, which is not really applicable to loudspeaker design (if you're not counting human hearing, maybe there is a future for me in studying and advancing our knowledge of human perception of sound?? Any input/thoughts/available paths forward regarding this would be greatly appreciated).
My brother has finished his phd in chemical engineering/material design. His graduating work (not sure what you call this in english speaking countries? Graduate work/project?) was concerned with synthetisizing novel polymers based on a set of wanted characteristics.
We have now developed a vision of using his knowledge/skill to develop new materials for loudspeaker drivers and loudspeaker enclosures, materials tailor-made to the needs of the frequency range in which the driver/enclosure operates.
Imagine a midrange driver that utilizes a tailor-made membrane-material for its specific frequency range which results in perfectly matched characteristics resulting in frequency response linearity and extremely low levels of distortion. Then imagine using this same material for the enclosure for this driver. Then imagine using this same methodology for all drivers in the design of a complete/full range loudspeaker. Maybe there is a possibility of creating something great sounding and economical?? I can specify what (modern) techniques of polymer synthetization we are planning on utilizing if there is an interest in knowing more about the potential of polymer materials.
I would be extremely grateful for all input/ideas/information pertaining to our quest. What is the function of the membrane of a loudspeaker? What is the source of its inherent structural instability (break-up etc.)? How is this instability related to the self-oscillating frequency? How is this related to the molecular make-up of the material? What would be the ideal material characteristics of a membrane for a specific frequency range of a loudspeaker driver?
Any sources (books, links) will be gladly accepted and researched, any insight/input/ideas regarding the topic is extremely welcome!
What would be the ideal loudspeaker membrane/enclosure material? Discuss
While I admire your enthusiasm, it sounds almost a bit like reinventing the wheel. However, if there is something that could be done:
- very high stiffness
- very high internal damping
- low density
- enough strength to survive cone resonance
- very high fatigue strength
As for the rest, it will behoove you to do a lot more self-study. Google alone can teach you all you need to know.
- very high stiffness
- very high internal damping
- low density
- enough strength to survive cone resonance
- very high fatigue strength
As for the rest, it will behoove you to do a lot more self-study. Google alone can teach you all you need to know.
Oh, and don't forget adequate surface energy, because you don't want any customers coming back with separated glue joints.
As much as i personally enjoy escapism, it is not something i would recommend to young man. Forget it.
Standing and gazing uphill on Dunning–Krugerr-Road 1, the climb doesn't look too bad - but believe us, it is a transforming long and steep climb. Happy hiking and Good luck!
From where in Sweden are you?
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From where in Sweden are you?
//
I'm reading a bit into your post, but it seems like you're imagining that the cone/dome/diaphragm material is driving nearly everything about the speaker's performance. You seem to be neglecting the magnetic system (magnet, pole piece, voice coil, shorting rings, etc.), the surround, the spider, the former, etc. They all interact to differing degrees. It's a complex system.
There are also countless ways that cones have been approached, with each being perceived as superior by their designer. Lossy materials, incredibly stiff/resonant materials, papers, plastics, metals, ceramics, composites, various fillers, and combinations of many of these.
You're going to have a hard time finding a consistent answer about the optimal material or its characteristics. Optimal will be determined by your preferences more than some grand unified speaker theory. There are many trade-offs involved in designing a real-world speaker. Some things that may look like errors to one person are actually designed into a speaker to produce a specific result.
It's also difficult to suggest a couple books that will adequately cover the breadth of knowledge necessary to undertake a project like this if you're truly trying to do something unique with commercial potential. If you just want to experiment and make speakers for fun, that's a different discussion.
A couple publications of interest that are geared toward speaker designers:
Voice Coil magazine
Voice Coil Magazine | audioXpress
Loudspeaker Industry Sourcebook
Loudspeaker Industry Sourcebook | audioXpress
There are also countless ways that cones have been approached, with each being perceived as superior by their designer. Lossy materials, incredibly stiff/resonant materials, papers, plastics, metals, ceramics, composites, various fillers, and combinations of many of these.
You're going to have a hard time finding a consistent answer about the optimal material or its characteristics. Optimal will be determined by your preferences more than some grand unified speaker theory. There are many trade-offs involved in designing a real-world speaker. Some things that may look like errors to one person are actually designed into a speaker to produce a specific result.
It's also difficult to suggest a couple books that will adequately cover the breadth of knowledge necessary to undertake a project like this if you're truly trying to do something unique with commercial potential. If you just want to experiment and make speakers for fun, that's a different discussion.
A couple publications of interest that are geared toward speaker designers:
Voice Coil magazine
Voice Coil Magazine | audioXpress
Loudspeaker Industry Sourcebook
Loudspeaker Industry Sourcebook | audioXpress
And, here's a relatively new company that's on a similar quest to decrease distortion and improve overall performance. Cost is not their primary concern though.
Purifi Audio
PTT6.5X04-NFA-01 (PTT6.5W04-01) - PURIFI transducer loudspeaker
Blog - PURIFI
Purifi Audio
PTT6.5X04-NFA-01 (PTT6.5W04-01) - PURIFI transducer loudspeaker
Blog - PURIFI
The purifi drivers do look good. Based on the plot they have, the 2nd harmonic is 60dB down, and the 3rd is about 70dB down (at 1KHz). I was wondering how the modern quads compare. Based on my checkout measurements of a set of 988's I just did, at 1KHz, the second harmonic is 55dB down and the 3rd harmonic is about 60db down.
I'm pretty sure that my harmonic measurements are bumping into my measurement noise floor so they might be artificially high. I'll have to crank up my measurement levels to see if I can get my harmonic measurements more accurate. My measurements are predominantly for QA purposes.
Sheldon
I'm pretty sure that my harmonic measurements are bumping into my measurement noise floor so they might be artificially high. I'll have to crank up my measurement levels to see if I can get my harmonic measurements more accurate. My measurements are predominantly for QA purposes.
Sheldon
At 100 dB at 1 meter, the Quad ESL 2805 manual specs distortion as:
0.15% above 1000 Hz
0.5% above 100 Hz
1% above 50 Hz
Sounds like you're pretty close, for what that's worth.
A close measurement should also help with the noise, though obviously it'll cause the frequency response to be inaccurate.
0.15% above 1000 Hz
0.5% above 100 Hz
1% above 50 Hz
Sounds like you're pretty close, for what that's worth.
A close measurement should also help with the noise, though obviously it'll cause the frequency response to be inaccurate.