blown a pair of speakers?

[scottbott]

listening to the radio this morning,then all of a sudden a loud screeching noise that did not alter when I adjusted the volume,tried the radio tonight and only one side of radio has volume the other dead,have I somehow blown a speaker?,never heard a noise like it before,will have a look this weekend as these dark evenings are a real pain in the a***

[syncroandy]

Sounds like the head unit power amp went unstable on one channel and popped a transistor. Speaker could be OK.

It wasn't by any chance made in China was it ?

[ghost123uk]

Yep, very likely the output I.C. in the head unit has blown, not the speaker, though it could have damaged the speaker on it's way out.
The only way to be sure is connect another head unit up, even if just temporarily, then, if the speakers sound ok, time to invest in another head unit.

When fitting head units, it is a VERY good idea to take a wire from it's outer casing (from a suitable bolt or summat) to a good body earth. This can result in better sound quality, better radio reception and help prevent instabilities that can cause component failure.

[scottbott]

thanks for the replies,hope the head unit is ok as the unit is a sony but is a bit different as it is a "tune tray" type and my iPod actually fits inside the unit so there are no cables or USB sticks showing,I do not think they are available any more,not that I have actually looked yet,will have a looksee tomorrow

[ghost123uk]

thanks for the replies,hope the head unit is ok

If it's not, I can repair it for you, at mates rates.
Output chip replacement on car stereos was a bread and butter part of my trade (a good few years back).

[scottbott]

thank you for the offer of the repair,it is very kind of you,will have a poke around this afternoon and it it is kaput I will contact you

[ghost123uk]

Try swapping the two wires from the speaker that is currently working to the output of the radio that is not currently working. That way you can establish if indeed one side of the radio output is dead, or whether it is a speaker fault.

Tip = if you don't hear any sound at normal volume settings, don't be tempted to turn up the volume above what it would normally be. Reason = if there is a fault in the speaker or the wiring, cranking up the volume can easily blow the other output chip (seen folk do that TOO often )

[ghost123uk]

Another tip = to do a basic test on a speaker and it's wiring = take a normal torch battery, any size (but note = NOT a re-chargeable one !!!!!) and very briefly, touch the two wires from the speaker onto each end of the battery. It doesn't matter which way round. When you touch the wires on, and when you remove them, you should hear a click from the relevant speaker. This doesn't test the full quality of the speaker, but it will show if it is completely blown, or if there is a wiring fault. i.e., if you don't hear a click, there is summat amiss.

The above is also a good method of finding which speaker wires go to which speakers when you are faced with sometimes 4 pairs of speaker wires behind the dash and you don't know which one goes to which speaker.