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Thread: PSB speaker sounds weirdly muted |
    
New member Username: Mor10
Post Number: 1
Registered: Jun-08
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| Posted on Saturday, June 28, 2008 - 09:32 pm: |
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I discovered a strange problem with one of my speakers: It sounds muted somehow - like the top mid-range is gone and it's playing through a blanket.
I did all the standard tests: switched channels on my receiver, switched cables etc. It's definitely the speaker that is acting up.
Now the really weird part: While rewiring the speaker I noticed that when only one of the cables was connected and I touched the other cable to the receiver (grounded it), I could hear the music!
I'm guessing there's some sort of cable crossing going on inside the speaker and that's what's causing the muting. thought I'd ask some people who know more about this than me before I crack it open and start messing around with the innards. |
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Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 12765
Registered: May-04
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| Posted on Saturday, June 28, 2008 - 10:52 pm: |
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"Now the really weird part: While rewiring the speaker I noticed that when only one of the cables was connected and I touched the other cable to the receiver (grounded it), I could hear the music!"
What's that mean? Connected to what? The speaker? The receiver? When you touched both legs of a single cable to the receiver? Or just one leg to the receiver and the other was connected to the speaker but not to the receiver? The speaker ground is tied to the receiver chassis. If you touched the receiver chassis and it worked but it didn't work when you connected to the speaker output, you probably have a bad connection at the receiver's speaker output. Are these speakers biwired? A speaker output either works or it doesn't, it's not frequency selective. |
New member Username: Mor10
Post Number: 2
Registered: Jun-08
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| Posted on Sunday, June 29, 2008 - 04:31 am: |
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ok so my explanation was a little wonky:
I disconnected the speaker wires from the receiver to check if it was the receiver channel that was bust. as I was connecting the red wire to the red output, the black wire touched the chassis and the speaker started playing. However this only happened with the busted speaker: the other one only works when both wires are properly connected to the same outs.
I swapped the cables between the two speakers: no difference
I swapped the channels between the two speakers: no difference
the sound coming out of my (now left) speaker is significantly worse than the other one, as if it is being played through a carpet with very heavy compression. |
Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 12769
Registered: May-04
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| Posted on Sunday, June 29, 2008 - 01:07 pm: |
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Sorry, from that description I can't tell you where to look. Call PSB and ask for advice. |
Platinum Member Username: Nuck
Post Number: 10436
Registered: Dec-04
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| Posted on Sunday, June 29, 2008 - 04:05 pm: |
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It is a receiver issue. The reference for the speakers should be fully independant from the chassis of the receiver.
Open the thing up MR, you might have over tightened the post and shorted the post to the case, which might explain it.
You have reference from the good channel, so break out the meter, or visually compare the 2 channels.
I think thats it. |
New member Username: Mor10
Post Number: 3
Registered: Jun-08
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| Posted on Wednesday, August 06, 2008 - 04:18 pm: |
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OK. Here's some more puzzling information:
The speaker issue is definitely separate from everything else. I ran it through a different receiver with the exact same result. I removed the actual speaker and switched it with the working one and the sound remains muffled on the speaker box which in my mind means it is a problem with some other internal component in the speaker.
now what do I do? I guess I need to get some transistor or something else replaced? I really need some help on this one because the crappy sound is driving me crazy and my extended warranty expired 4 months ago. |
Platinum Member Username: Nuck
Post Number: 10630
Registered: Dec-04
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| Posted on Wednesday, August 06, 2008 - 07:49 pm: |
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Call PSB and get a replacement x-over?
switch the tweeters side to side.
Beyond that?
there are not likely any transistors in the crossovers, but resistors, coils and some other snake oil. |
Gold Member Username: Nickelbut10
Post Number: 1730
Registered: Jun-07
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| Posted on Wednesday, August 06, 2008 - 08:08 pm: |
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I didn't fully read. But by skimming through I would agree with Nuck on the x-over. Either that, or the wire to you negative(-) binding post has just come off and therefore the speaker line is not grounding leaving you with a fraction of the sound. Kinda would sound like throwing the speaker in a pool. |
Gold Member Username: Mike3
Wylie,
Tx
USA
Post Number: 1410
Registered: May-06
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| Posted on Wednesday, August 06, 2008 - 10:41 pm: |
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Nick, how much experience do you have with throwing speakers into pools? |
New member Username: Mor10
Post Number: 4
Registered: Jun-08
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| Posted on Thursday, August 07, 2008 - 01:41 am: |
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lots of interesting advice here. I'm thinking of ripping out the circuit board in the back (assuming that's what you guys are referring to as the crossover?) and putting it in the other cabinet to see if it makes a difference. that should give a clear indication of where the problem is located.
I don't know about speaker in a pool but the blanket analogy is pretty close. I wish I could record the difference but it only becomes aparent when you pan left to right and back so you have a comparison. I notice it most if I sit directly in front of the stereo because it sounds as if my left ear is busted - it's muffled and weak. |
Platinum Member Username: Nuck
Post Number: 10635
Registered: Dec-04
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| Posted on Thursday, August 07, 2008 - 07:23 am: |
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Morten, that board is the crossover, and yes, you can swap it out.
If that is the problem, you can compare componant values between the two to find the fault. Remember that each componant will eventually have to be released from it's mount and isolated from the rest of the circuit, so have solder tools handy, as well as a meter for capacitence. |
Gold Member Username: Nickelbut10
Post Number: 1731
Registered: Jun-07
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| Posted on Thursday, August 07, 2008 - 08:37 am: |
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"Nick, how much experience do you have with throwing speakers into pools?"
lol none. I guess the Blanket over the speaker would had been more accurate.lol The speaker under water would be fun. |
Bronze Member Username: Afj
Gaborone
Botswana
Post Number: 98
Registered: Jan-08
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| Posted on Thursday, August 07, 2008 - 10:43 am: |
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morten, if you find the rest of the people in this thread crapping over me dont do it (i dont have technical knowledge) but if by earthing the speaker it works, why dont you do just that? |
