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First time speaker repair

L

Lord o' mash

New Member
Hello,

Complete newb. Apologies if the questions are silly. I have just purchased a pair of used PSB T55 speakers from craigslist. One sounds great the other sounds like there's a blanket over it, muffled and significantly quieter. From what I've read here it might be a blown tweeter which is apparently a common issue with these. My questions are these: How can I be sure before I buy a replacement? Will playing these speakers while I'm waiting for the replacement hurt anything in the speaker or my system? Is there a good overview somewhere online of how speakers and stereos work that will give me a better understanding moving forward? Thanks in advance for any advice.
 
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Just listened again and the muffled speaker really isn't quieter. Just muffled. Also, I looked at the crossover and there wasn't any visible sign of trouble.
 
Swap the tweeters. If the muffled sound follows the tweeter you know it's the tweeter, if not, it's probably the crossover.
 
If you have an ohmeter, test for continuity in the tweeter in doubt. If there is no continuity then the voice coil in the driver is cooked and the tweeter will need to be replaced.
 
to basically check tweeters bring your ear next to it.. or stay close and wave your hand on an d off it to test if its producing sound..
swap as suggested above.. and check the impedance of both as well.. if issue switches to other channel you're either looking at a gunky ferrofluid (if those tweeters are ferro cooled) or hardened membrane or suspensions on that tweeter.. if they're ferro cooled open up a tweeter and check if it feels sticky.. if so , replace it and 99% it will fix the issue..
if not .. well we get into a whole new world of possibilities.

edit:
yes they're ferro fluid cooled aluminium dome tweeters
1- check impedance on both tweeters, use a multi meter, make sure you re touching the probes firmly.. loose touch will alter the readings.. they should be equal and do the swap
2- check the ferro as mentioned above, when tweeter is dismantled you will see this on the voice coil, it looks like engine oil.. you can touch with finger and it should feel liquid.. not like water but like cooking oil.. not sticky.. if it feels sticky or gunky it's bad. use extra care to be gentle on tweeters during or after dismantle.. one bad move can ruin the whole thing.. they're "delicate"
3- check if the suspension on problem tweeter if it is harder than the other.. either use finger carefully, or use a pointy thingy like chopsticks or bamboo skewers to gently push tweeter down from suspension edge on all 4 corners and compare them.

edit 2: simplified a bit in regards to the points @gdmoore28 made below
 
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Welcome to the group, 'O Mash!

All the above suggestions are right on the mark, but maybe a little too much for a self-described "total newbie?" May I translate?

- Get yourself a cheapie "multi meter." A $10 one will do just fine for this adventure.
- Use the directions to set the meter to read in "ohms"
- Disconnect, or better, remove the tweeter from the cabinet
- Connect one of the meter cables to one terminal on the tweeter, the other cable to the other
- The meter, depending on the tweeter impedance, should read between 2 and 12 ohms.
- Or somewhere in that range, at least
- If there is a zero reading (or, much much more), the tweeter is bad
- If the reading is good, then it's possible that the tweeter voice coil is stuck by it's old ferrofluid
- Ferrofluid is a liquid substance that is injected around the voice coil - for several reasons
- If the fluid has dried out and become sticky, the tweeter cone or dome can't move
- No movement, no sound
- Let us know what you find, and we'll go from there

The above is dramatically simplified and some will find my numbers not exact, but this will at least tell you if the tweeter is bad. If you really are a complete newbie, just replace it. And, no, you will not damage your equipment by continuing to use the speakers while waiting for a new tweeter.

As for your other question regarding how all of this stuff works, just Google the subject and you will find a plethora of guides for beginners.

Have fun,
GeeDeeEmm
 
Figure out where the tweeter is.
Get the tube from a roll of paper towel or similar.
Place one end by your ear and the other in front of the tweeter.
If the tweeter is good you will hear it; otherwise, further diagnosis is called for.
 
Thanks everyone for the replies. It's clear there is no sound coming out of the tweeter. I tried to switch them but the clamps that connect the wire to the tweeter won't come undone. I yanked and got after em with a screw driver but was worried I would damage something. They wiggle but won't pull off. It's embarrassing but I have to now ask for advice on how to undo a simple wire connection. Anyone patient enough to reply to this?
 
Do they look something like this?
TwistedWire.jpg

You just need to carefully pull them apart. Two pairs of needle nose pliers could help. I've used one pair and a flat head screwdriver to slowly rock it off. You can sometimes spread the female connector (the one on the wire) apart some with a skinny enough screwdriver.
 
teal'c said:
Do they look something like this?
TwistedWire.jpg

You just need to carefully pull them apart. Two pairs of needle nose pliers could help. I've used one pair and a flat head screwdriver to slowly rock it off. You can sometimes spread the female connector (the one on the wire) apart some with a skinny enough screwdriver.
Click to expand...

Excellent answer. I think we've all run into this problem at one time or another. Use one set of pliers to stabilize the connector mounting pad (especially if it's made of phenolic or paper!) and the other set to wiggle and pull the connector off the pin.

GeeDeeEmm
 
Hello Lord o' mash. Welcome to AK. Maybe the crossover caps are going in the crossover. The electrolytic caps tend to dry out after so many years. The cap value can change. The internal resistance of the cap can go up (ESR), thus changing the sound level of the mids or tweeters. I had to recap my mission 737Rs in order to bring the tweeters back up to normal. Replaced the Ecaps with film caps from Parts Express.
 
The best way to see if the problem is with the xover is to work out how to remove the clips from the drivers - disconnect all your drivers from the crossovers on both speakers, then test all of the speakers using the xover in the speaker with the muffled sound.

If you do establish that it is the xover thats faulty, then I agree - replace the caps.
 
Those tweets... they just go bad without any abuse. I've worked on a few psb projects it's a common issue. Some sort of design flaw i beleive and psb kinda did nothing about it (shame). Contact psb as they still stock the tweets. They will run you about $110.

I have been saving my pulled replacement for some time as these always go bad. Also there plate amps tend to blow up on most of there budget subs.
 
I had read that about the tweeters and assumed it was the case. Even bought one for 20 bucks on ebay. Swapped all three of them though and its definitely not the tweeter. So, I guess its the crossover. The speakers are only 8 years old though. We live in Texas, perhaps the heat caused it to go bad? Could it just be a bad connection?

I'm not sure what you mean by testing all the speakers on the crossover in the muffled speaker.

Thanks to everyone for all the help so far. I had been told that I should just get rid of them before coming to this forum. Glad to know there is something that can be done and its fun to learn too.
 
I think you don't have to worry about more testing of drivers. Either it's the tweeter cap, or a bad connection somewhere in the crossover or between the crossover and tweeter.

Do you have that multimeter yet? :-D You can do a recap without a meter, as long as the wiring is OK which it looks like it is from your pic. So maybe a soldering iron should be your first purchase.

Post some pics of the crossover and what the cap values are. We can help you get replacements and it won't cost much. Cheap entertainment and very satisfying.
 
toxcrusadr said:
as long as the wiring is OK which it looks like it is from your pic.
Click to expand...
Which pic?

Like tox said, you've determined the tweeters aren't the problem so your testing is done.
Do you have a soldering iron, or know someone who does? It's not difficult, and if you youtube "how to solder" you can see what is involved.
 
Welp, so I was getting in there to look at the crossovers and noticed that the little gold links that connect the binding posts was missing on the muffled speaker! Complete newb status confirmed. So I guess I should just bi-wire both speakers then?
 
Well that will do it! :biggrin:

Just so I understand what's happening, you mean there are two sets of input terminals on the back of the speaker, and the jumpers were missing on that speaker?

You can either run a second parallel set of wires, or just find some short wires to make jumpers to connect the binding posts.

Don't feel bad, we've all been there one way or another. :smoke:
 
That's the best case scenario! Like Tox said, just use some bits of wire to connect the binding posts and you should be good to go. No soldering or multimeter needed.
Enjoy your speakers, and please report back if the problem is solved!
 
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