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Please help me decide what speakers to keep/sell/give away

Disconnect the speaker terminals, and do a resistance check on the speaker drivers. Infinite and zero are both very bad. You should see somewhere from 4 to 8 ohms, although I don't remember what the original drivers specs were. But if you're in that ballpark, you're probably OK. The level controls may be dirty as well. I had a similar pair with that very problem.

Good luck with your move, it's never fun (for me, at least). I can definitely understand paring down the stable in anticipation of moving!
 
What jhoyt said. No voltage, resistance. Range your meter at it's lowest resistance setting, probably 200 or 300 ohms (not 200k or 300k).
 
I have to agree with the comment about "dad's" former speakers. You could regret it later. If you get them working, and later tire of them or no longer enjoy them, at least you got them working the way they worked for him. Then you can part with them.

Rattle? Maybe vibrating or farting (sorry, seems to be a popular description around here). If more like the latter you could have surrounds separating from the cone or frame or both. Other rattling sounds can come from dust cap coming free. Another is too much bass or using loudness and bottoming out the drivers (voice coil hitting the cap of the magnet, where the pole piece is attached).
 
Yeah, I guess it could be describe as "farting." However, at this point I've been convinced to say goodbye to the fishers and sony's. Will try to get a few bucks on c'list for them and put it towards the moving gas money. $10 for each pair sound reasonable? Or should I ask more? I appreciate all the advice and knowledge that has been shared!
 
Deoxit is available @guitarcenter.But most of us probably get it online or at partsexpress for cheaper $.Oh yeah,I'm partial to the 4311b's as I restored a pair...they give me the sound I remember in the 70's!
 
I suggest you start a new thread about troubleshooting the JBL to keep things a little neater. These guys are telling you to connect a multimeter to individual speaker drivers that you remove - not the terminals on the box. Before even doing that - just pop the woofer out and see if maybe one of the input wires broke off at the back of the box or something. If you get a resistance reading on the woofer, connect your stereo directly to the woofer and see if you get sound.
 
Keep the JBL's due to sentimental reasons, drop the rest at the thrift so someone else can post up a "score" thread!:banana:
 
Keep the JBL's.If you are handy you should be able to get them back sounding great again with not too much effort.
 
Awesome. Thanks for the encouragement. I'm excited to dig into the JBL's a bit, and I'm sure I'll be back to start a new troubleshooting thread ;)

I'm considering hanging onto the qb's too. I just really want to hear what they sound like with new tweaters - people really seem to like them. But I'll def. try the dioxit trick first. My buddy said he has a bottle that I could borrow to try the suggested trick. So again, just put a coupla sprays into the tone knob on the back?
 
Do your Qb have a fuse? I am seeing a tweeter fuse when I look them up, but Infinity did like to confuse things with different versions and different speakers with the same name.
 
Yeah, there is a fuse right next to the terminals and the tone knob, however, both fuses look to be intact. Probably a bad tweeter then? Thanks.
 
Well, probably, but the 6.8uf cap could be bad, the fuse could be blown and not showing it, and the pot could be bad. You can temporarily bypass the pot with a piece of wire. Lots of ways to go about it, but I guess I would...
- measure to make sure the tweeter capacitor is not shorted
- replace the fuse and test
- disconnect the tweeter and connect a working speaker in it's place, see if signal is getting to the tweeter now. If not...
- bypass the pot and test
- replace the capacitor and test.

Actually, I would just pull the tweeter, put a 4-7uf cap in series, and connect it to something at low volume. But, assuming I had no capacitors around, I would do that other stuff.
 
Sold the Qbs in my retail days and liked them. They would be my pick from that group. With quality electronics, they were good performers. If your troubleshooting indicates that the emit tweeters are bad, they have replaceable diaphragms. Maybe infinity would still have them. I would call them, never know. Easy repair.
 
Thanks for the suggestions, dumptruck. I will try the mentioned tests and report back, or start a new thread.

pcb, not sure if the diaphragms are still available anymore. It was mentioned in a coupla places that they are no longer being made, but someone has to have a pair sitting around. Hopefully the issue is simpler to solve though. Thanks!
 
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i'd keep 'em all.

the least valuable are the su-45's.

and yet -

they are modeled after a famous British speaker.

should you put plastic caps in the place of the electrolytics,

in the xover, they really do sound good.


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As a total speaker noob, i'm proud to report that I figured out what is wrong with the Infinity's. Not surprisingly, the tweeters are bad. After swapping tweeters with the sony's, I realized that all of the internal junk was functioning and intact. A closer look at the emit diaphragms showed disconnects in the ribon's spiraling circuit. Tomorrow I'm going to try and bridge the disconnects with a little solder. Not sure if it's going to work but I'll try - can't hurt any. At this point, I just really want to hear what these emit tweeters are all about, and i'm determined to do so even if it means I have to find some new tweeters! Tonight I gave the fishers away to a friend. Sony's are going up on c'list. Cheers!
 
One question: Are all emit tweeter ribbons the same? In other words, can I buy Emit K ribbon tweeters, pul the ribbons, and stick them in my Qb ribbon tweeters?
 
4311b's I think have a main fuse for protection, don't they? Next time you fumble with the TT, for God's sake, turn the volume down! :nono:

The JBL's are sentimental to you, no? I would toss everything else to the wolves and keep them if it were me, but taht's just me. :)
 
markshan said:
But do NOT do this with the mids or tweeter.
Click to expand...
You actually can do that with the mid or tweeter, you just have to make sure the output is neutral with bass completely de-accentuated, no EQing and no loudness, and keep the volume low.
 
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