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Fixed my tweeter, beyond happy

gags11

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#1
Today was one of those gratifying days. I was doing some measurements, specifically looking at the tweeter output of my active speakers. Noticed my left channel had distortion way higher than the right channel (see graphs below). What the heck!

So I got these vintage Pioneer / TAD beryllium ribbon tweeters that I had purchased from Japan. Started examining the tweeter. It is old, let me say, so does not look pretty. You got the beryllium leaf and a metal thin mesh in front. Someone had pushed the grill in. Could it have touch the leaf and cause distortion?

I disassembled the unit, straightened the from mesh grill. Viola, distortion down to the level seen in my right channel. I thought the tweeter was bad and did not have any real hopes. But now I am so happy, finding a bit of joy in these horrible times..

Figure 1. Left channel distortion compared to right. Right has much lower distortion. Tweeter response 3khz high pass active filter. About 93db spl at 1 meter.
881F5238-6948-43EB-87DC-F9A4D2B54187.jpeg


Figure 2. Same as above with fixed left tweeter. Impressive improvement in distortion.

F2A39AAF-EB7A-4B4E-A1D6-2701708E228B.jpeg


Figure 3. Frequency response, distortion and level before and after the fix. Left tweeter only.

000A9C63-891F-4A07-878C-0F44C7C8B1C9.jpeg


59B45FBF-8080-4713-94FF-FFA7A00A1927.jpeg
 

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Doodski

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#2
Today was one of those gratifying days. I was doing some measurements, specifically looking at the tweeter output of my active speakers. Noticed my left channel had distortion way higher than the right channel (see graphs below). What the heck!

So I got these vintage Pioneer / TAD beryllium Rubin tweeters that I had purchased from Japan. Started examining the tweeter. It is old, let me say, so does not look pretty. You got the beryllium leaf and a metal thin mesh in front. Someone had pushed the grill in. Could it have touch the leaf and cause distortion?

I disassembled the unit, straightened the from mesh grill. Viola, distortion down to the level seen in my right channel. I thought the tweeter was bad and did not have any real hopes. But now I am so happy, finding a bit of joy in these horrible times..

Figure 1. Left channel distortion compared to right. Right has much lower distortion. Tweeter response 3khz high pass active filter. About 93db spl at 1 meter.
View attachment 57360

Figure 2. Same as above with fixed left tweeter. Impressive improvement in distortion.

View attachment 57361

Figure 3. Frequency response, distortion and level before and after the fix. Left tweeter only.

View attachment 57362

View attachment 57364
Nice repair job! :D Diagnosed issue, confirmed issue, confirmed fault, repaired unit and then confirmed fix. Perfect.
 

McFly

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#5
Wow! Nice. And nice repair. May I ask, before you started did you suspect you could hear an issue/something off? Or were you just measuring out of curiosity?
 
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gags11

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Thread Starter #6
Wow! Nice. And nice repair. May I ask, before you started did you suspect you could hear an issue/something off? Or were you just measuring out of curiosity?
I really did not have a clue or hear a difference. I was just tuning my crossover, levels, etc. It was just luck. If I did not measure, I would have never known.
 

Laserjock

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#7
Beryllium is supposed to be very toxic if any particles are breathed in.

Probably ok but I would have taken extra precautions.
We use it in our beam steering mirrors.
 
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gags11

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Thread Starter #8
Yes, beryllium is really toxic. I think one of the reasons it is not used as much now. I was as careful as I could be.
 

A800

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#9
Let it Be.
 
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