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SMONEY
02-23-2016, 05:12 PM
These are 70's 4333a units. The tweeters tweet at a low volume even when cranked up. Is this a problem with the crossover, or some kind of pattern failure due to age of the units? They still sound really good, but not as good as they could with the tweeters working properly. Any ideas? My brother has the same speakers and they exhibit the same trouble as mine.

Challenger604
02-23-2016, 06:06 PM
These are 70's 4333a units. The tweeters tweet at a low volume even when cranked up. Is this a problem with the crossover, or some kind of pattern failure due to age of the units? They still sound really good, but not as good as they could with the tweeters working properly. Any ideas? My brother has the same speakers and they exhibit the same trouble as mine.

Very hard to say but if both do the same, could maybe be moisture. Your bro has the same problem? This is weird! Same system? Could you take them out and test it? Yeah, could be the crossover. Could be oxidized contacts... A good clean up may need to be done... I would begin by that. Also clean up L-Pad, rotary selector if you have one in the back.

please let us know!
c

BMWCCA
02-23-2016, 06:18 PM
These are 70's 4333a units. The tweeters tweet at a low volume even when cranked up. Is this a problem with the crossover, or some kind of pattern failure due to age of the units? They still sound really good, but not as good as they could with the tweeters working properly. Any ideas? My brother has the same speakers and they exhibit the same trouble as mine.
They're probably working properly. What you call the "tweeter" is probably the 2405 Ultra High Frequency (UHF) driver. In your system it's crossed around 8,500 Hz. That's pretty high up there! Your High-Frequency driver is actually the 2420 compression driver and horn assembly and it covers the frequencies from 8,500 Hz down to 800 Hz.

First, how old are you and your brother, and when did you last have your hearing checked? Have you run a full-range test-tone through the system to see where your ears (or the 2405!) cut off?

Next you can check to see if the L-pads are working correctly in that when you adjust the "UHF" pot, there's a smooth but slight change in the driver's sound with no drop-outs or static. You should also check the L-pad for the "HF" because you'll likely hear more upper frequency material out of that driver, anyway.

Does music sound full and balanced? Are you just sticking your ear in the 2405 and expecting to hear a lot more program material than the driver actually produces?

Great old speakers. I hope you have enjoyed them for some time. What's their history? :dont-know:

mech986
03-01-2016, 04:42 AM
The other thing to do is to open up the back panel or take out the woofer and inspect the wiring to the tweeter(s) to make sure they are actually hooked up. Shine a light into the tweeter slot and take a picture if you can and see if the diaphragm is visible, and if it looks complete (hard to do this way).

Otherwise, you may have to take the tweeter out and check it for DC resistance, and then test with just HF content and at low volumes to see if it works or not.

then we get to taking the tweeter horn off for inspection.