Speaker help

[RetiredBob]

I posted this on another forum, so it may look familiar to some of you.



I need some help from the electronics experts out there figuring out what I did wrong and how to fix it.

My motorhome radio has three sets of speakers--Living Room (LR); Kitchen (K) and Bedroom (BR). From the factory, F and K were wired so they operated together and BR were separate. When I used Fade on the radio, the "front" setting operated both LR and K speakers and "back" operated the BR speakers. Wiring from the radio was as follows:

Front negative to LR neg
Front positive to K neg
and LR pos to K pos

Back positive to BR positive
Back neg to BR neg

BR speakers were also switched, so they could be turned on or off independently.

I want to be able to operate LR and K speakers independently, so I can get better balance between the two, and also be able to turn off (fade) one or the other. My wife often sits at the kitchen table and may not want to listen to what I'm listening to in the living room. To do this, I thought I could switch the wiring between the K and BR speakers. Since I would need to run an extra set of wires, I decided in the meantime to temporarily disable the K speakers by disconnecting the wire LR pos to K pos and connecting radio front pos to LR pos. This would work fine for 15-20 minutes, but then (after warming up?) the speakers would cut out. This happened for a day or two, but now I have no speakers. I tried rewiring as it originally was, but still nothing. The radio still operates; that is, I can tune it to different stations, change bands, switch to Auxilliary, etc., just no sound from speakers. Hope this all makes sense.

So, how did I mess up? Is the radio toast? Is there an internal fuse for just the speakers? If I can get the speakers working, how do I wire it to accomplish my original objective? Thanks in advance for any assistance.

[bigstonebay]

Bob, I just put a new radio in ours and the wiring diagram that came with it was the same as on the radio I took out. Seems to be an industry standard. Hope it helps.

Black - ground
Yellow - 12v all the time
Red - Accessory terminal
Blue - Power antenna
Orange/white stripe -Light control switch

Speakers
White - LF positive
White/black stripe - LF negative

Gray - RF +
Gray/black stripe - RF -

Green - LR +
Green/black stripe - LR -

Purple - RR +
Purple/black stripe RR -

[Luv2go]

Bob, it looks like they wired the front and kitchen speakers in series. By disconnecting the kitchen speakers and wiring the LR speakers to the radio directly you reduced the impedance the radio saw by half. Normally this is not a problem as the radio's amp can handle different speaker impedances. Evidently this is not the case with this particular radio. BTW, what model radio is it?

Since you rewired it back to the way it was and you get nothing out of any speakers you probably have fried the speakers. Perhaps you can use this opportunity to get a better quality radio that can handle the front speakers alone.

Good Luck!

["007"]

I have my kitchen spk's on the fader control of radio to do what you are tring to do. You have to run some wiring to do it and break up the kitchen multiple with front spk's. Post # 18
If you look at the wiring with a magnifier glass the wires are marked as to what spk's they are going to.
If you go to Quick Tips link and fine the area with pictures when I put in the DVD SOUND System its explained with more detail there.
DO all your rewiring up in over head cabinets not plug into radio.
Once you are done bedroom spk's will work of normal volume control on radio.
I have a Sony radio.
What is your radio and model number?

[Luv2go]

Quote:

Originally Posted by Luv2go Since you rewired it back to the way it was and you get nothing out of any speakers you probably have fried the speakers. Perhaps you can use this opportunity to get a better quality radio that can handle the front speakers alone. Good Luck!

Sorry, I was thinking radio and I typed speakers, The radio has probably been fried.

[RetiredBob]

Quote:

Originally Posted by Luv2go Sorry, I was thinking radio and I typed speakers, The radio has probably been fried.

Okay, that makes more sense.

It is (was) a Jensen VR209. Obviously, I'm not an electronics expert, but why would reducing impedance destroy the radio?

[GaryKD]

Hi RetiredBob,
Before doing anything else, consider what 007 posted in post #4. It's worth a try and might save spending $s.

[offthewall]

Quote:

Originally Posted by RetiredBob Okay, that makes more sense. It is (was) a Jensen VR209. Obviously, I'm not an electronics expert, but why would reducing impedance destroy the radio?

Review Ohms law from your high school science.

The current gets too high for the amp. 0 ohms is a short.

[RetiredBob]

Gary and 007,

As you'll see in my original post, I rewired the speakers as they originally were and get nothing. That's why I think Luv2Go is correct and the radio is toast. Otherwise, things would work as they initially did.

[offthewall]

Quote:

Originally Posted by RetiredBob Gary and 007, As you'll see in my original post, I rewired the speakers as they originally were and get nothing. That's why I think Luv2Go is correct and the radio is toast. Otherwise, things would work as they initially did.

That could happen. Most home/semi-pro/pro amps have some sort of overload protection that will reset when the load is reduced but a cheap (no offense, I have the same unit) car stereo like this may not.

You may want to try a super simple setup with just one speaker directly wired to each channel to test the amp.

[Luv2go]

Quote:

Okay, that makes more sense. It is (was) a Jensen VR209. Obviously, I'm not an electronics expert, but why would reducing impedance destroy the radio?

Putting speakers in series increases their impedance (assuming they are the same impedance) which reduces the current the radio has to provide. By removing one speaker you halved the impedance which doubled the current requirement.

According to the manual the VR209 is rated at 4 to 8 ohms nominal speaker impedance. Most speakers meant for car radio use are 4 ohm. Assuming Newmar used 4 ohm speakers, by putting the speakers in series they doubled the impedance to 8 ohms and stayed within the radio's specs.

I'm quite surprised that having only one speaker connected (which should have been 4 ohm) messed up the radio, since it is actually rated for either one 4 ohm speaker or two in series. Maybe you could try getting the radio fixed under warranty before you replace it, IMHO it should not have died just by rewiring as you stated in your first post.

Also, maybe there's something else going on. Does any other entertainment system in your coach use the same speakers? Our Newmar has some kind of speaker switching/combining system on our entertainment system, maybe yours has something that does not work right when you rewire the speakers as you did.

["007"]

Looking at this PDF of what I think is your radio I see no cautions when hooking up your spk's. If wire incorrectly says to correct.
Stay tuned I'm looking for a spk wiring drawing.

MANUAL

TROUBLE SHOOTING GUIDE

Before you started did the fuse for radio get pulled?
Where were you rewiring the spk's?
Have you rechecked all wiring to each spk for good insulated connections for both +&- leads.
If your spk's are blown you would have heard them.
There is a reset they talk about but before you do that read the two PFD's and double check wiring.

[RetiredBob]

Thanks for all the input folks.

007, to answer your questions:

No, I didn't pull the fuse. But the fuse isn't blown and, in fact, the radio still works, as stated in my original post. Just no audio.

Rewiring in the cabinets.

Will recheck the wiring, again.

Agree, I don't think the speakers are blown.

Already tried the reset--no luck.

I have emailed Jensen, describing the situation, and am waiting for their reply. I'll post back as things progress.

P.S. I'm beginning to understand more about impedance!

["007"]

Your impedance should not matter the radio has spk impedance range from 4-8 ohms and adjusts for that you could have 6 ohm spk's and they would work.
Double check wiring on spk leads as to where they are going and double check the bedroom ones because they have switch.
TRY leaving the bedroom disconnected for now and get forward ones to work.
The switch in bedroom may be the problem.
When you know your pairs to SPK'S decide which wire of pair will be positive and use all spk pairs the same way so your spk's are not out of phase.