Ive started this thread as a discussion on effective Whizzer Cone treatments, i.e. what work and what don't. For example I know some that dope them to increase stiffness but then does the damping effect lower the top end?? Fire away 🙂
The difficulty with this is that it's no different to cone 'treatments' -there is no one-size-fits-all approach / solution, and what you do or 'works' depends on what you are trying to address in the first place.
For example, you may wish to stiffen the cone -or you may wish to increase its self-damping (i.e. the opposite). Sometimes the two go together inasmuch as adding stiffening material means you've added mass, so it's a question about which dominates or cancels out the effects of the other -a question of materials used.
Then you've got issues with profile -not all have the same, and any alterations to one will not necessarily carry over to a different type, or be appropriate. Damping material between main and sub-cone -potentially of most use with larger types, but the main cone profile & type of material comes into play. About the most universal adjustment is the old $.099 tweak, not least because it's entirely reversible 😉 so I'd suggest that contributions note the specific driver used which should provide some useful guidance / ideas for readers.
For example, you may wish to stiffen the cone -or you may wish to increase its self-damping (i.e. the opposite). Sometimes the two go together inasmuch as adding stiffening material means you've added mass, so it's a question about which dominates or cancels out the effects of the other -a question of materials used.
Then you've got issues with profile -not all have the same, and any alterations to one will not necessarily carry over to a different type, or be appropriate. Damping material between main and sub-cone -potentially of most use with larger types, but the main cone profile & type of material comes into play. About the most universal adjustment is the old $.099 tweak, not least because it's entirely reversible 😉 so I'd suggest that contributions note the specific driver
I suggest just play with it. After all, all you are trying to do is make a $2 speaker into a $3 speaker.
Seems some magic DIY to improve a driver comes up every now and again. I ask you, what do you think you know or can do the manufacturer doesn't? If it was that easy, don't you think they would? Not that I have not modified drivers. Doping some FE85's helped with breakup up. I was adding a tweeter so increased mass was actually an advantage. I played with cutting out the duct cap on some Silver Flutes ( bad breakup) and installing phase plugs to good effect. I tried every DIY out there to help a Mark Audio and nothing helped the things. Fun. Give it a try, but expect to just toss it all when you are done.
Seems some magic DIY to improve a driver comes up every now and again. I ask you, what do you think you know or can do the manufacturer doesn't? If it was that easy, don't you think they would? Not that I have not modified drivers. Doping some FE85's helped with breakup up. I was adding a tweeter so increased mass was actually an advantage. I played with cutting out the duct cap on some Silver Flutes ( bad breakup) and installing phase plugs to good effect. I tried every DIY out there to help a Mark Audio and nothing helped the things. Fun. Give it a try, but expect to just toss it all when you are done.
Not necessarily they wouldn't. Manufacturers are often obliged to put out a product that sacrifices the ultimate in performance the unit may be capable of, simply because it isn't economically viable to achieve those last xyz percentage points.
Take coatings, just to give one example. These need to be done consistently, and especially if these are applied to specific locations (e.g. edge-damping) these are difficult to apply on an automated / semi-automated basis. They have to be done by hand, and in many cases when the unit is fully assembled. Fine for small-scale artisanal production, more problematic for series production on a larger scale, with drivers that need to sell in a given market segment. Consistency is difficult to achieve in those cases as it's not possible to spend a large number of man-minutes on it, so your QC failure rate increases, and your profits decrease. On top of that, it's another process, requiring more staff, more space, and more time, all of which cost money.
Take coatings, just to give one example. These need to be done consistently, and especially if these are applied to specific locations (e.g. edge-damping) these are difficult to apply on an automated / semi-automated basis. They have to be done by hand, and in many cases when the unit is fully assembled. Fine for small-scale artisanal production, more problematic for series production on a larger scale, with drivers that need to sell in a given market segment. Consistency is difficult to achieve in those cases as it's not possible to spend a large number of man-minutes on it, so your QC failure rate increases, and your profits decrease. On top of that, it's another process, requiring more staff, more space, and more time, all of which cost money.
Interesting replies. I asked to see if such treatments would affect the frequency curve in the same way a notch filter would. Wharfedale on their DDRS series used a ring of foam stuck to the underside of the whizzer? Applied in the factory. Was it to alter the response, correct a peak or help with cone breakup for example.
Well, you've rather answered your own question there, since correcting a peak and / or helping with cone breakup is another way of saying 'affect the frequency response'. 😉
Be that as it may -yes, indeed, they all affect the FR, albeit to different extents, and in different ways, so you take the approach that are appropriate to whatever issue a specific driver might have. For e.g., a peripheral resonance on the whizzer might be addressed by a small amount of damping. Conversely, an over-damped cone may benefit from a coating that increases the overall structural rigidity. A large whizzer cone blanking part of the main cone might see some advantages with a ring of damping material between the two to kill any phase-related cancellations. And so on & so forth.
Be that as it may -yes, indeed, they all affect the FR, albeit to different extents, and in different ways, so you take the approach
If you want a better speaker, buy a better speaker, not some 1950's hack. Or have fun playing with a few.
Your advice being, and definition of '1950s hack'? Moving coil drive units have basically remain unchanged since the 1930s other than detail refinements and a few new materials, and some of the highest performing examples were produced by the pioneers back in the '40s, when budgets were essentially unlimited.
Last I checked, you couldn't build, say, a Lowther for $2 or remotely like. Not that many Lowther drive units are to my own taste, but that doesn't alter the fact of it, or the facts I mentioned above.
Last I checked, you couldn't build, say, a Lowther for $2 or remotely like. Not that many Lowther drive units are to my own taste, but that doesn't alter the fact of it, or the facts I mentioned above.
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Here are some things i have seen, tried or seen recommended.
1/ coat the whizzer. I use slightly thinned modpodge. As little as possible.
2/ a damping coat (or 2) on the back edge of the unfixed end of the whizzer
3/ similar is the use of a damping weight on the back… like small felt pads placed around the back. Sansui F10 is a good example.
4/ almost a;l whizzer cone drivers really work better with phase plugs.
5/ the 98¢ tweak. A bit of damping under the whizzer. I most offten use low desity opencel foam which also is best for support of the unfixed edge, but often things like polyfluff or even a air scrunchy.
6/ massage the outer edge of the whizzer (a GM trick i have used successfully)
Whizzrrs have there purpose but so far, drivers without tend to more smooth response.
dave
1/ coat the whizzer. I use slightly thinned modpodge. As little as possible.
2/ a damping coat (or 2) on the back edge of the unfixed end of the whizzer
3/ similar is the use of a damping weight on the back… like small felt pads placed around the back. Sansui F10 is a good example.
4/ almost a;l whizzer cone drivers really work better with phase plugs.
5/ the 98¢ tweak. A bit of damping under the whizzer. I most offten use low desity opencel foam which also is best for support of the unfixed edge, but often things like polyfluff or even a air scrunchy.
6/ massage the outer edge of the whizzer (a GM trick i have used successfully)
Whizzrrs have there purpose but so far, drivers without tend to more smooth response.
dave