OK, sorry for hijacking the thread.
Bottom line: Visaton BG20 needs substantial modifications to became merely a passable fullrange loudspeaker. Modifications should be done with easily available, off-the-shelf, cheap materials. - exactly the opposite of Dekalin 689 (or whatever).
Bottom line: Visaton BG20 needs substantial modifications to became merely a passable fullrange loudspeaker. Modifications should be done with easily available, off-the-shelf, cheap materials. - exactly the opposite of Dekalin 689 (or whatever).
Me, but both need modifications… B200 is one of 2 8” i have heard that i like. They absolutely need phase plugs. (this size also works in SEAS FA22 (my other favorite 8”)
http://www.planet10-hifi.com/downloads/B200-phase-plug.pdf
Without phase plugs top is either (painfully) laser like on axis and non-existant off. This can be seen in the response curve in the extreme rising FR and unrealistic sensitivity.
Add the phase plug and things dramatically flatten out and top end is good across a wide axis. Whizzer cone drivers in general benefit from phase plugs, the B200 is somewhat unique (IME).
Some sort of glue, but this particular one is not findable on their website. What are its characteristics?
I use various “adhesives” to tweak drivers. Puzzlekoat/ModPodge (PVA), and ZIG 2-way glue (sort of like sticky noite glue). The first is used to coat paper cones, the second on the surround/cone interface on the back of thge Fostex and on the backside edge of whizzer cones (in general).
EnABLing takes things a bit further.
If you are addinga woofer to the FR OB as is most often teh case, almost any midTweeter can be used.
dave
What would I do to make a Visaton BG20 (or any other fullrange) sound better with diy work?
Without touching the driver (conservative approach) :
1. Use a transconductance amp
2. Use Fir or IIR EQ to equalize the Frequency response.
Most people would not believe how well this would do.
If you want to touch the driver:
any of the here mentioned diy tweaks like damping the surround and / or tuning the cone itself would bring further improvements (redoing then the EQ).
What is elegant using a transconductance amp is the fact that it can help drivers without Faraday ring to perform like these.
Most drivers in the world come without a Faraday ring.
But you can do it on your own :
"50 cent trick"
https://www.diyaudio.com/community/...loudspeaker-sandwich-cone.402917/post-7499239
https://www.diyaudio.com/community/threads/current-drive-for-loudspeakers.250272/post-7446451
Without touching the driver (conservative approach) :
1. Use a transconductance amp
2. Use Fir or IIR EQ to equalize the Frequency response.
Most people would not believe how well this would do.
If you want to touch the driver:
any of the here mentioned diy tweaks like damping the surround and / or tuning the cone itself would bring further improvements (redoing then the EQ).
What is elegant using a transconductance amp is the fact that it can help drivers without Faraday ring to perform like these.
Most drivers in the world come without a Faraday ring.
But you can do it on your own :
"50 cent trick"
https://www.diyaudio.com/community/...loudspeaker-sandwich-cone.402917/post-7499239
https://www.diyaudio.com/community/threads/current-drive-for-loudspeakers.250272/post-7446451
Attachments
So, to be (almost) on topic:
Here is the photo of my modded B200 (sorry for a poor quality)
I did all the mods as sugested by Dave (Phase plugs + Enabl). And, the transconductance amp. Then it was singing 🙂
I guess the same can be applied to B20 (and even more).
Here is the photo of my modded B200 (sorry for a poor quality)
I did all the mods as sugested by Dave (Phase plugs + Enabl). And, the transconductance amp. Then it was singing 🙂
I guess the same can be applied to B20 (and even more).
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I bought Visaton LTS50 and coated some old paper membrane drivers with it to save them (two coats). I even coated a pair of Dynaudio D28 AFs (just one coat) and they worked nice after treatment. The original damping dried out due to age, and the ferrofluid was also replaced earlier. What is your opinion on that LTS50 membrane coating?
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That's a bold statement. Without having done all the mods it is impossible to know which speaker sounds better.
Yes EnABLing was very noticeable.
Puzzlekoat/ModPodge was exactly what I used. Thanks for not making it a secret.
I will join the Visaton forum to find out more about the specific Dekalin.
Adding additional coating to cloth edge surround
Has been used before to improve speaker performance.
But it is nice to see and interesting to Note
what a significant improvement there was to second harmonic
distortion. Shown with actual measurements.
I wonder if the usual typical PVA sealer used for cloth surround sealing
for manufacturing could just be used.
Just a matter of adding more or additional coating of what is normally
used. For Diy is as simple as ordering small 8 ounce bottles sold for
re cone kits.
Or if the Dekalin used is a more heavy like but still flexible like latex.
Could be as simple as using body paint latex. Which comes in a wide
variety of colors as well.
Has been used before to improve speaker performance.
But it is nice to see and interesting to Note
what a significant improvement there was to second harmonic
distortion. Shown with actual measurements.
I wonder if the usual typical PVA sealer used for cloth surround sealing
for manufacturing could just be used.
Just a matter of adding more or additional coating of what is normally
used. For Diy is as simple as ordering small 8 ounce bottles sold for
re cone kits.
Or if the Dekalin used is a more heavy like but still flexible like latex.
Could be as simple as using body paint latex. Which comes in a wide
variety of colors as well.
I'm not interested in full range speakers anymore. None that I tried had hights that could compete with those of a good coax like the 8" Radians.
Fullrangers do allot of things right and I enjoyed them for many years but after I purchased a pair of Radian Studio Monitors there is no going back.
Coming from a full horn system they were the next best thing to me.
I have similar feelings about fullrange.
But high end can be improved with just a tweeter.
Interesting thing about the mod is the 2nd harmonic distortion
improvement was more towards the low end.
So still a feasible mod as fullrange/ wideband or 2 way.
Since it is still within the bandwidth if used as 2 way
But high end can be improved with just a tweeter.
Interesting thing about the mod is the 2nd harmonic distortion
improvement was more towards the low end.
So still a feasible mod as fullrange/ wideband or 2 way.
Since it is still within the bandwidth if used as 2 way
I did get a bottle to see how it compares to ModPodge — certainly WAY more pricey — but haven’t had a chance to test it out.
dave
PVA descries many receipes. White glue is PVA. ModPodge is aldo a PV, looks, smells. and feels like the same stuff but dries more flexible which is a good thing. So maybe…
Coatings that stiffen the cone can have positive affects, but too much can kil the driver. Damar and C37 are examples of those. I will say that how C37n applies to the paper on a Visaton B200 or CSS FR25 is kinda surreal.
Add too much, you tend to wipe out the highs. I have used that to advantage with woofers. On the CSS SDX7 it was a bit unexpected, turning the whoop at roll-off into a nice smooth roll-off extending the usualble respons eup to ≈1.7 kHz.
dave
Except for the XO and (unless you use DSP, the time discontinuity. Also tend to be much pricier.
dave
- is that 8 inch Sica available in the US? PRV makes a whizzer cone 8 inch FR - dunno how it sounds - -qt suitable for open baffle
https://prvaudio.com/products/8fr250/
https://prvaudio.com/products/8fr250/
@NIXIE62
Look here
https://www.diyaudio.com/community/...vers-ff125wk-and-fe103sol.390479/post-7347325
And my post 11 in this thread.
Look here
https://www.diyaudio.com/community/...vers-ff125wk-and-fe103sol.390479/post-7347325
And my post 11 in this thread.