Audio Systems: Sony CD Player, sony cd player, cdx l350

Question
Tom,
I've checked the wiring with a multimeter. It all seems correct (bno earthing or crossed wires) except the polarity of the speakers is backwards. Could this becausing the problem? If it is, is it possible to rewire an ISO socket without cutting and splicing the wires (i'd prefer to leave this reversable for when I replace the car.

For information sakes the stereo is 4ohm and so are the sonys (the skoda speakers are as well but i've left them disconnected)

Thanks.

Phil

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Followup To
Question -
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Followup To
Question -
I have a Sony CDX-L350 which has done me well for years.

It works fine in my old Rover with two cheap Sony speakers in the front and two original speakers in the rear (usually 75% power forward - 25% rear). I recently transfered the stereo and sony speakers to my fathers Skoda Felica. The Radio installed really easily (all ISO fittings). The radio function seems to work OK, however when listening to CD's , ATT-ON (Attenuate function) will appear and the stereo will only produce a low level of static until the unit is turned off and back on again.

Could this be over heating or the original Skoda speakers in the rear? I've reduced the rear power to the lowest the stereo allows and the problem still occurs. Once the problem has occured on a trip it will occur more regualarly for the rest of the trip.

Also the skoda mounts the player at about 40 degrees where as the rover has it mounted flat.

Any ideas?

Thanks
Phil

Answer -
Phil,
A few things may be causing the problem that you mentioned.  1-the wire for muting the sound when using a cell phone is grounding out?.  2- the amplifier may be over heating due to using the Skoda speakers?. 3- the angle at which the CD player is mounted, is making the unit malfunction. Try moving the CD player on a flater angle and see what happens.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net

Tom,
Thanks. I tried disconnecting the rear skoda speakers. The unit still brings up the ATT-ON but it seems to take longer to do so. I've touched the back of the unit when ATT-ON pops up and it is very hot (almost too hot to touch). The Unit is far more enclosed in the skoda than the rover which is probably restricting airflow a lot. I'm therefore guessing its a heating problem. Any ideas how to cool it down? (its definatly not the ATT wire - its got nothing touching it)

Phil
Answer -
Phil,
The over heating may be caused some of the speaker wires being crossed or the speakers are too low of an impedence. Double check the output impedence of your stereo (8 ohms, 4 ohms etc.) also check the speakers to see what the impedence of them are rated at. If the stereo requires 8 ohm speakers and you connect 4 ohm speakers the stereo will run very hot and may cut off or the amplifier IC's will burn up! lastly, make sure that none of the speaker outputs from your stereo are grounded to the Skoda chassis.


TOM,
T&D ELECTRONICS

Answer
Phil,
As for the polarity of the speakers, it doesn't really matter as long as the speaker wires are connected to the same terminals +&-. If you connect more than 1 speaker on any speaker line you will drop the line impedence down to 2 ohms and that will make the amp/s heat up. If the stereo worked OK in your rover, but doesn't in the Felica, I would think that a speaker problem exist? If the Sony stereo only has four speaker outputs, be sure to only connect four speakers if you haven't already. If you only have four speakers connected correctly and your stereo still goes into ATT mode, a fault in the stereo circuits may be the cause. You may want to try connecting up the stereo on your work bench with four speakers connected and let it play to see/listen how it works.

TOM,
T&D