Why am I getting speaker distortion?

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Allen

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I managed to find a pretty cool all-in-one stereo at Goodwill, RCA 5-Disc Changer, record+playback cassette deck, 6 ohms, came with 6 ohm speakers. SO:
6 ohms, 6 ohms speakers
120 volts
60hz
80 watts.

So, taking a chance (Come on,electronics frome Goodwil...) I buy this puppy for 15$.

I get home and hook it up, and to no suprise, the speakers aren't working. I try 3 different sets to no avail.
I plug in some headphones to the headphone jack, works great.
So after pondering, I had an idea:

I hooked up an FM transmitter to the headphone jack, grabbed an old Panasonic boombox (detachable speakers), take the speakers off and hook up the ones that came with the system. I set it on top of the stereo, set the speakers in they're proper places. and tune in on the boombox's radio. Work's like a charm.

Only one problem:

I'm getting speaker distortion.

The speakers that were attached to the boombox were rated at 2.7 ohms, and the boombox itself is rated at 2.7-8 ohms.

So why am I getting speaker distortion with these 6 ohm speakers.

I'm going to try a 8 ohm set now, I'll let you know how it works.

By the way, the boombox is 35 watts, but since the speakers are 80, this shouldn't be a problem, right?
Also, I never had distortion with the boombox alone.
 
The impedance mismatch on the speakers isn't going to make much of a difference. You're probably just overdriving the input to the FM transmitter with the headphone audio output. That or you're overdriving the amplifier that feeds the headphone audio output, due to circuit incompatibilities with the input to the transmitter.

That FM transmitter wants to see about 100 millivolts at the audio input. And, a headphone amplifier circuit might put out a watt or two, which is way to high of an input signal.

Try turning the volume to the headphones all the way down and turn up the volume on the boom box to about midrange. Now increase the volume to the headphone jack very slowly until you start to get distortion, then back it down a bit. Now adjust the volume on the boom box.

If there is no volume level to the FM transmitter that gives you no distortion, the headphone output and the FM transmitter input are probably simply not electronically compatible.
 
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