Radio- speaker question

[manny1973]

I have a 73Z with the orginal radio. As you know it only has one speaker hooked up in the back. I was wondering if I can hook a 2nd speaker up to the radio. I want to add a 2nd speaker in the back on the other side. Will this work and how would I wire it?

I don't want to add a different sound system just the 2nd speaker.

[5thhorsemann]

you will need to put a cross over transformer in before the speakers to ballance the impeadence at the output of the radio, works like a splitter if you will. I would also reccommend you replace the original speaker with a new set of speakers to insure the speakers are ballanced as well.

[Arne]

Agreed. Don't simply hook up two speakers to the stock radio, you can (will?) damage the radio. Extra circuitry as described by the previous post is required.

As for using better speakers back there instead fo the very rudimentary stock unit, you need to use a fairly shallow depth speaker. I used a pair of poly-cone 5 1/4" Kenwoods in mine. Don't worry about co-axial speakers with separate tweeters and such - the stock radio doesn't have the ability to make those sound much better than a single-cone.

[manny1973]

Thanks, Can I get a cross over transformer at say Radio shack?

[EScanlon]

Don't OVER complicate the simplest of issues. You do NOT need the additional circuitry if you do things right.

This has been covered before, has been done NUMEROUS times, and the answer is really bone simple. It's all in the wiring of the TWO (again TWO) speakers. Instead of Series wiring, you wire in parallel, this changes the load on the radio properly.

Bottom line, use TWO 8 ohm speakers, Monaural, 5-1/4" (Ideally should be 5-1/8", but good luck finding that), and no more than a 10 watt rating is more than sufficient. Wire them in parallel, i.e. + to + on each speaker and - to - then the OEM wiring direct to one of the speaker terminals.

See these 3 other posts:

http://www.classiczcars.com/forums/showthread.php?28953

http://www.classiczcars.com/forums/showthread.php?38942-stock-speaker-locations.&highlight=parallel+series

http://www.classiczcars.com/forums/showthread.php?19340-Looking-for-original-1970-Radio-Stereo&highlight=parallel+series

Don't expect Blaupunkt type of sound, but more along the line of the "free" el-cheapo give away radio you can score out of a gumball machine... just a tad louder. The OEM radio had 3.5W of power with a THD of 10% into a 4 ohm speaker with a very light magnet... as yoiu can imagine, it's by no means the equivalent of an iPod.

Don't turn the volume all the way up (even with just ONE speaker) and you'll be fine. I've had this setup in my car for the last 10 years and have always been able to enjoy "stereo"...

FWIW

E

[5thhorsemann]

This is all correct, I assumed the stock speaker was an 8 ohm, my bad.

Edited October 21, 2011 by 5thhorsemann

[manny1973]

Thanks

[manny1973]

I am having a problem finding 8 ohm speakers They all seem to be 4 ohm. Advise?

[EScanlon]

Not trying to be "cute" but... keep looking?

Radio Shack, your local Audio Shop, Wal-Mart, just to name a few places. I've even found 5-1/4" speakers in hardware stores, Lowe's, Home Depot, True Value, Ace, again, you just started today.

But don't, as in DO NOT hook up two 4 ohm's in series or parallel as that will more than likely cause problems.

E

[5thhorsemann]

Crutchfield? Critchfield? Something like that.............

[beermanpete]

You can connect 2 4-ohm speakers in series. This will result in an 8-ohm load which will not damage the radio. It will reduce the total power output but the acoustic output of 2 speakers is better and will offset it some.

[5thhorsemann]

Speakers are inductive loads, not resistive loads, the speakers will sound like crap in series, you need the crossover to run two 4 ohm speakers and get any kind of sound quality.