I just picked up a pair of Realistic Optimus T-120 speakers for free and I would like to use them as kick-*** surrounds in my 5.1 setup. They sound tremendous except one of them has a broken tweeter that produces no sound. Can anyone give me any suggestions on where to find a replacement. I would like the tweeters in both speakers to match without having to replace both so ideally I would like to find the same/very similar tweeter to the one that is currently installed and working in the other speaker. All it says on the back of the broken tweeter is SD-55 6 ohms. Any help would be appreciated! Thanks!
Hi. A lot of advice you'll likely see on these forums will be to replace the tweeters with the exact tweeter. People will often say that if you replace the components with anything other than stock, then the sound will change... and usually not for the better. Since those speakers are 27 years old, Radio Shack won't have any replacement parts in stock. So you're best bet is to find a used pair of t-120 speakers that you can use for parts. You may end up find a pair where the cabinets are in really bad shape and in which case you only need the tweeters for now anyway. Craigslist and ebay are likely good places to start.
I'm refurbishing a pair of t-120's for myself at the moment. My plan is to replace the original parts with upgraded ones. I have a pair of Dynaudio Esotec D-260 tweeters and Vifa mid-ranges and a pair of Pioneer woofers. I also have crossover components from www.solen.ca to build a custom x-over based on the drivers specs. The T-120's were some of the nicest looking speakers Radio Shack sold. I'm trying to find another pair for sale in my area.
I'm refurbishing a pair of t-120's for myself at the moment. My plan is to replace the original parts with upgraded ones. I have a pair of Dynaudio Esotec D-260 tweeters and Vifa mid-ranges and a pair of Pioneer woofers. I also have crossover components from www.solen.ca to build a custom x-over based on the drivers specs. The T-120's were some of the nicest looking speakers Radio Shack sold. I'm trying to find another pair for sale in my area.
Yeah...that's what I thought. I wish they still carried the parts though because I can't find a used pair anywhere near me.
Some other ideas
Some other ideas to try. Can you smell a burned electrical smell from the tweeter that does not work? A tweeter that was overpowered has a unique 'fried' smell to it. Compare both tweeters.
Test your current tweeters. Remove them both, and switch them. If the tweeter that was not working, works in the other speaker then the wiring or crossover is the problem. Replacing a capacitor or re-soldering a wire would be easier than finding those tweeters.
Since you're not likely to find an original replacement without buying a set of t-120's, I'd suggest going the route of replacing the tweeters. When you get the replacements, just replace one tweeter so that you can compare how it sound against the original. It may even sound better.
Then replace the working tweeter so that both speakers match.
Both of the tweeters on my T-120's were pushed in. I removed the tweeter, removed the plate, and lifted the dome off. Then, I pushed it out from the back side. I did end up getting some of the cooling fluid on my fingers, which likely lowered the power handling, but they look much better and still work fine.
Some other ideas to try. Can you smell a burned electrical smell from the tweeter that does not work? A tweeter that was overpowered has a unique 'fried' smell to it. Compare both tweeters.
Test your current tweeters. Remove them both, and switch them. If the tweeter that was not working, works in the other speaker then the wiring or crossover is the problem. Replacing a capacitor or re-soldering a wire would be easier than finding those tweeters.
Since you're not likely to find an original replacement without buying a set of t-120's, I'd suggest going the route of replacing the tweeters. When you get the replacements, just replace one tweeter so that you can compare how it sound against the original. It may even sound better.
Then replace the working tweeter so that both speakers match.
Both of the tweeters on my T-120's were pushed in. I removed the tweeter, removed the plate, and lifted the dome off. Then, I pushed it out from the back side. I did end up getting some of the cooling fluid on my fingers, which likely lowered the power handling, but they look much better and still work fine.
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Thanks for the great advice! I will try swapping the tweeters this weekend. I noticed that the wires going into the tweeters are different colors. I would assume that you just match the colors when putting the tweeter in the other speaker?
Ok so I swapped the tweeters and it works in the other speaker. So both tweeters are working which means there must be another problem. I opened the broken speaker up and checked all of the connections. All of them were crimped on except for one which looked like it was soldered and repaired. I took the soldered one off, cut the end off, and restripped it before soldering it on again. No luck. The tweeter is still not working. I don't really know where to go from here as I have never done this before. I assume there must be a broken component on the crossover? Or maybe the dial to adjust the frequency is defective? Any advice? Thanks in advance!
I am not familiar with Radio Shack speakers, per se, but it would be likely that one of two items has failed, if changing the tweeter to the other cabinet caused it to work. The most likely item would be a capacitor in the crossover. The crossover will have leads going to to both the tweeter and woofer. Again, I'm not familiar with this exact speaker, but the crossover will have coils (of wire), and at least one capacitor ( a tubular shaped item with leads on one or both ends). Perhaps your speaker uses only a capacitor. Anyway, I'd replace the capacitor. It should have a value marked on the outside, so replace it with the exact same thing. If you carry it into Radio Shack, they should be able to match it up with a bi-polar electrolytic replacement. If you can read the value, you may wish to replace it with a polypropylene film capacitor, rather than an electrolytic, which will improve the sound quality. If you find this solves the problem, then I'd replace all the capacitors in both speakers, as electrolytic caps do go bad over time.
If this doesn't fix it, then it is likely that the level control for the tweeter has "opened up". It controls the level, or "loudness" of the tweeter, and not the frequency. Again, Radio Shack should be able to provide a replacement for this item.
If this doesn't fix it, then it is likely that the level control for the tweeter has "opened up". It controls the level, or "loudness" of the tweeter, and not the frequency. Again, Radio Shack should be able to provide a replacement for this item.
Ok so I will try bypassing the level control first to see if that is the problem. If not I will look into replacing the capacitors. Thanks for the advice!
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