Custom DIY 6.5" Fullrange Driver

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#104
Started the design for the field coil with a over a size 120mm diameter by 100mm height.

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Using 18 AWG wires with 2180 turns based on calculation

@1.5 Amperes
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@2 Amperes
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#111
This is super cool! I can't believe how great they sound from the youtube video.

That damper design is incredible. I never knew anything like this existed.

I could never do anything even close to this, so please don't take this as me being critical, but have you ever heard of Arboform? It's about 90% wood and has been dubbed "liquid wood". You buy the pellets from the company which you then injection mold into your desired shape. I always wondered why we've never seen this take over the polypropylene cone designs.

If you could pull this off, to my knowledge, you would be the first person to produce a speaker driver using Arboform!

The only audio product I've seen use Arboform is Audioquest on their Nighthawk headphones.

https://en.wikipedia.org/wiki/Arboform

http://www.tecnaro.de/english/avsk.htm

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#112
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Thanks for the information, now then I realized how people make those wood looking cast. Interesting stuff about Arboform, maybe I might need to find a source where to get hold of these raw Arboform materials. I also find it interesting to use this to cast it into speaker enclosures 🙂
 
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#114
*Update: Found some mid range shout even after so many hours of running in.

So I have been doing quite a bit of investigations, and probably the main issue is with the whizzer cone which is also found in the old lowther whizzer cone design(aka Lowther Shout).

Lowther America Prices

Whizzer Dampening​
Without going into the technical mumbo-jumbo, one of the things that occurs with the old style Lowther cones is that the whizzer resonated at about 2 KHz, creating what many referred to as the Lowther shout.� This has been addressed by the new cone design, but since few of you have the new cone design, lets talk about what can be done.​
The easiest thing to do is to turn the drivers so that they face 15 to 20 degrees away from your listening position.�​
I personally tried and liked the effect of Marc Wauters 98 cent fix. This consists of placing a lightweight piece of foam between the outer edge of the whizzer and the middle of the main cone. As a result, it drastically reduced the resonance peak of the whizzer. Sadly, Marc has recently removed his site.​
Another approach is to take 2 cotton balls for each driver.� Pull them out, and then twist lightly so that you get a 2 or 3 inch long cylinder.� Then place this between the whizzer and main cone.� It is not as effective as the Marc Wauters fix, but does create a noticeable drop in the upper midrange peak.​
You can purchase the new style phase plug without upgrading the cone.� It does make the highs very directional, so that you must listen with the speakers aimed directly in line with your ears.​
Click to expand...
​

Will be trying out some cotton damping by stuffing them between the whizzer cone and the main cone to see if the peaky-ness can be resolved.

I also considering folding the whizzer cone with a bend edge like Lowther's
 
#117
ghemml said:
*Update: Found some mid range shout even after so many hours of running in.

So I have been doing quite a bit of investigations, and probably the main issue is with the whizzer cone which is also found in the old lowther whizzer cone design(aka Lowther Shout).

Lowther America Prices

[/LEFT]

Will be trying out some cotton damping by stuffing them between the whizzer cone and the main cone to see if the peaky-ness can be resolved.

I also considering folding the whizzer cone with a bend edge like Lowther's
Click to expand...

You can also try to "kill" the shout by making maybe 3 small incisions into the edge of the whizzer cone. That way, the energy that would otherwise bounce back from the edge of the whizzer cone to the center and then back and forth, could partially dissipate in the 3 "flaps" the incisions form.
Writing this, I so see that I'm not an engineer. :S
Zigzag pattern of the edge could also work, and even foamy pads, glued underneath, but it goes against my ideas to add mass to a speaker.
 
#118
peroz said:
You can also try to "kill" the shout by making maybe 3 small incisions into the edge of the whizzer cone. That way, the energy that would otherwise bounce back from the edge of the whizzer cone to the center and then back and forth, could partially dissipate in the 3 "flaps" the incisions form.
Writing this, I so see that I'm not an engineer. :S
Zigzag pattern of the edge could also work, and even foamy pads, glued underneath, but it goes against my ideas to add mass to a speaker.
Click to expand...

Good idea, I was also thinking of trimming down the whizzer cone size. Lots of energy dissipating from it when I tried putting my finger on it.

I will try the foam pads before I decided to trim and cut the whizzer cone.

Thanks 😀
 
#119
By trimming, do you mean making the whizzer smaller? That won't work, I think. It will only take your shout higher, and you will lose some of the "lower" whizzer freqs.
You need to disrupt bell modes in the cone. And you kill bell modes by breaking the bell. 🙂
Sometimes I wish I knew what I'm talking about, and to be able to express better...
 
#120
peroz said:
By trimming, do you mean making the whizzer smaller? That won't work, I think. It will only take your shout higher, and you will lose some of the "lower" whizzer freqs.
You need to disrupt bell modes in the cone. And you kill bell modes by breaking the bell. 🙂
Sometimes I wish I knew what I'm talking about, and to be able to express better...
Click to expand...

I was thinking of trimming the edges, making them look like a flower. I saw this in on of the old lowther design.

something like this:
299786-stamm_lowther_pm6c.jpg
 
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