Added 2 speakers/ sound cutting out

I am looking for some input from the experts.  I have a Sony CDX-CA720X Stereo/CD player which has worked fine with only two speakers until yesterday.  I installed two additional speakers (Sony XS-MP61) and now the stereo cuts out when I turn the volume up to a good listening level.  I have not touched any of the existing wiring, I added the speakers using the speaker wires that came with them.  What gives?

You can hook up 4 speaker to your cd player. 2 fronts and 2 rears. From your post, it look as if you are hooking up more than one speaker on the same speaker line. You are dropping the impedence too low for the cd player to handle. The cd will cut in and out to protect itself from further damage. To remedy the "cuts out when I turn the volume up to a good listening level". You can tap your new speaker in to the 4 sets of speaker output of your cd player. You should be able to find two sets that are not being and just tap it in there. The speaker output wire are mark with the colour grey,grey black,white,white black, purple,purple black, green and green black.Be careful whose advice you buy, but be patient with those who supply it.

Are you connecting the speaker with speaker terminal or just twisted the wire on to the speaker? If the connection come loose they can give you the cutting in and out affect. Check your grounding on the cd player. It is the black wire. Make sure you have a good connection to the chassis of the car. Be careful whose advice you buy, but be patient with those who supply it.

The speakers are connected using the standard "push on" terminals and the cd player is still grounded the same way it was two days ago.  As I said, I have not touched ANYTHING on the cd player as far as wiring goes except the speaker wires.  I have ONLY added two rear speakers.

If everything that you have done is correct. I can only think that the headunit is the problem. Have you try connecting just the front speaker to the rear speaker output to see if the problem is there? Be careful whose advice you buy, but be patient with those who supply it.

it's either going to be a pinch or short on a speaker wire or else the HU is shutting down thermally... unplug the harness at the back of the HU and meter all speaker wires for continuity to ground, if you dont get a reading at all that only really leaves a HU output problem.... either it doesnt like the new impedence and is shutting down or else it is running hotter than it should the the thermistor circuit is shutting the output stage down to prevent a melt down.... either way you may need to add an amp for your rears and not use deck powerKevin Gerry

Certified Electronics Technician

MECP First Class Installer

Owner/Installer

Classic Car Audio

since 1979

your deck could push 2 spkrs just fine with a bad ground ... check the ground wire on the back of the deck .. re-ground it make sure that wire goes to a good ground..dont be a pet monkey ..use your dmm

Did you check to see if the terminals for the newly installed speakers are grounding???  That could also be your problem!