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.
Figure 2. Same as above with fixed left tweeter. Impressive improvement in distortion.
Figure 3. Frequency response, distortion and level before and after the fix. Left tweeter only.
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.
Figure 2. Same as above with fixed left tweeter. Impressive improvement in distortion.
Figure 3. Frequency response, distortion and level before and after the fix. Left tweeter only.