Stereo Problem

[karlt5503]

Wanted to see if anyone could help me with a problem. I recently installed a new Sony radio in my 97 Crownline. The unit played fine over the two factory(6 inch) speakers. I then installed a 400 watt Sony amp and two 10 ' woofers. I also installed a new battery(650CCA) that the amp is run off of. Now, as I start to turn up the volume on the radio the display on the radio starts to pulse as the bass hits. Then the radio shuts off, then comes back on. I can't turn it up very far before the radio shuts off.

The radio is run to the original battery, which has a good charge and will start the boat. The amp is the only thing running to Bat. #2. This is all occuring while the engine is OFF. I've been told the system is pulling too much power, causing the radio to turn off. But if the amp is on a seperate bat. shouldnt the radio be able to have enough power?

Originally I had all this running off one bat.The radio was cutting off when I started to turn up the volume. I then installed a second bat., only put the amp on it. The radio still cuts off when I turn up the volume though.

Any ideas?
Thanks for any advice.

Karl

 

[slasmith1]

Re: Stereo Problem

sounds like you need to put a capacitor in your power line to the amp. any quality car stereo shop will have one and make sure that your power wire is large enough to handle the load the farther it is from the battery the larger wire you will need.

 

[karlt5503]

Re: Stereo Problem

Someone mentioned the capacitor before I bought the second battery. It seems like the radio is the problem though. The radio and amp are on seperate batteries, so I wouldn't think the amp would affect it. I know the amp pulls a little power from the radio through the rca outs, but shouldn't be pulling it down that much, right?

 

[burp]

Re: Stereo Problem

Electronics often have a safety circuit in it to protect the device when the voltage to the unit falls below a set level. For Sony, I think it's 10.5 volts. As you increase the volume, the current (amperage) that flows through the wires to produce the increased volume increases also. If there was no resistance in the power and ground wires, then there would be no problem as all the voltage potential (12.8 volts) provided by the boat's battery would be available at the stereo. That is an ideal situation.

In real life, the power and ground wires to the stereo have a resistance. The length or the wire, the wire size, number of connections, and corrosion will impact the resistance of the wire. Let's say the power wire to the stereo has 1 ohm resistance and the ground wire from the stereo has 1 ohm resistance for 2 ohms total resistance. If 1 amp of current is flowing through the wires, then there would be 2 volts lost along the stereo wires. (voltage =current X resistance) So if your battery voltage measured 12.8 volts, the voltage available at the stereo would be 2 volts less, or 10.8 volts. As you increase the volume, the current required to produce the increased volume increases also, resulting in a larger voltage drop along the stereo wires and even less voltage potential available at the stereo. Thus the sound cuts out as you increase the volume as the voltage at the stereo falls below that acceptable by the safety circuit.

One option is to increase the wire size (power and ground wires) as larger wires have a lower resistance and can carry higher currents with a lower voltage loss along the wire.

 

[karlt5503]

Re: Stereo Problem

Thanks for the advice. I was thinking about runing the power wire for the radio directly to the battery.Right now it is just run off the old power wire for the original radio. I will increase the wire size as well.

 

[slasmith1]

Re: Stereo Problem

Thanks for the advice. I was thinking about runing the power wire for the radio directly to the battery.Right now it is just run off the old power wire for the original radio. I will increase the wire size as well.

It is the power wire for the amp that you should be concerned about if it does not supply enough current it will try to draw more power through the remote wire thus killing your stereo I have seen improperly wired amps burn out the remote power lead in a head unit numerous times. make sure the power wire to the amp is large enough and use a capaciter it will fix your problem. to test this theory install a temporary toggle switch direct to the battery powering your amp and connect it to the remote in on the amp disconect the remote lead from the stereo and it will be isolated to the other battery. if your problem goes away you need bigger or shorter wire run to your amp.

 

[karlt5503]

Re: Stereo Problem

slasmith,

Thanks for the advice. I wanted to make sure I understood your example. Are you saying to run a wire from the new battery to the remote turn on on the amp, then disconnect the remote turn on wire running from the stereo to the amp? I must have misunderstood your example, as I dont think you can do that. I didnt think there was much power through the remote turn on wire, thats why its so small. Thought its just simply turned on the unit. Sony has it rated at .3 amp for my unit.

My power wire is from an amp install kit, think it was rated over 400 watt rms. I'm only pulling about 370 watt. The wire is fairly long, about 18ft. That is the way it came, havent cut the excess off yet.

Thaks again for any help.

 

[slasmith1]

Re: Stereo Problem

thats what i was saying i know it sounds funny but i have seen it more than once and i have built systems that leave dents in the car for spl competitions.

 

[karlt5503]

Re: Stereo Problem

slasmith,

Just wanted to let you know I did what you suggested, hooked the remote in of the amp to the new battery. It seems like it will allow me to turn up the volume a little farther, but the radio still cuts off. I turned down the gain on the amp to around 3/4, but the radio still shuts off when I start to crank the volume. I ordered a cap, so I'll see when it comes in.

One more question. I have the amp and radio grounded together. The amp is in the front of the boat, so i was a little limited on where I could ground it. Is this a problem? Should they be grounded seperatly?

Thanks again.

 

[slia67]

Re: Stereo Problem

before you buy the capacitor,...

My first thought when I read this was a bad ground. Take some extra wire that you have and run temporary wires from your head unit and your amp to your battery, both power and ground. I have a feeling your problem will be corrected.

It won't take more than just a few minutes.

 

[slasmith1]

Re: Stereo Problem

and since that didn't make the problem go away how are these batteries charged?
if they are working off the same alternator then they are not truly separate.

 

[karlt5503]

Re: Stereo Problem

Slia,

You tha man!! That fixed the problem 100%. I was going to re do the ground because it wasn't the best connection, plus it was grounded with the radio. But, I had no idea that would have caused the problems I had. Too bad I already ordered that cap, maybe I can send it back. I knew this system could run on this battery, let alone two batterys with the engine off.

Thanks for your help

 

[slia67]

Re: Stereo Problem

No problem, glad I could help. How does it sound?

 

[Splat]

Re: Stereo Problem

Good catch Slia!!! I too was thinking along the lines of this being simple. With electronics, always looks for stupid piddly stuff. More often than not that's your problem.

Prime examples of stupid stuff are,
bad connections(this includes things likebad crimps, wires only twisted together, etc.)
Corroded connections,
Bad grounds,
Broken wires(you'd be amazed how many things I've fixed by simply grabbing the power wire and shaking it to find a broken wire),
And my personal favorite man made rat nests(these are usally a combination of all of the above )

More often than not going back to the basics will fix you up quick.

My other idea here was too much draw on one circuit, or too much amperage throught to little gauge wire.

Glad you got it all straightened out.

The remote wire is a switching circuit totally different than the amplification circuit in an amp. Browning out through the remote wire to the head unit is impossiable.

Bill

 

[karlt5503]

Re: Stereo Problem

It sounds really good. The system ended up having more bass than I expected. I have the two 10 inch subs in the rear area with the engine. It sounds really good though, pretty clean bass.

Thanks again

 

[freddyata]

Re: Stereo Problem

im having the same issue with my boat...i asked my buddy and he said something about grounding the radio and the head unit ground as well?....it sucks when you cant play your music loud...i got 3 12" subs, 4 6 1/2,
and 4 6x9s now...2 batteries as well...the stereo would cut out with the stock head unit and 4 6 1/2 from the factory too..

 

[slia67]

Re: Stereo Problem

Freddy,

Start a new thread and you will probably get a better response. Tell us exactly what is going on. I'll keep an eye out for it.