Sterio basics....

DRAGON88 · Posted: Jun 19, 2003 6:55 pm Post subject: Sterio basics....

ok Im gonna try to rewire my sound system in my boat this weekend. i have the wire exc exc.. would some one give me the basics? that would be ultra helpful!

George · Addict Joined: 12 Jan 2003 Posts: 552 City: Chattanooga

what are you rewiring headunit, amps, speakers. Give us some more info.

DRAGON88 · Posted: Jun 19, 2003 7:25 pm Post subject:

Headunit to the 4 main Speakers

twitch88 · Posted: Jun 19, 2003 11:06 pm Post subject:

that is no problem, there should be eight output wires on the back of the head unit one pos one neg to each speaker. if you are lucky there will be tags telling which is which as far as the fader and balance goes but if not you will have a little guessing and checking to do. try not to mix up the pos and neg because if you do your speakers will be "out of phase". it is fairly simple though and you should have no problems.

Steelerguy · Addict Joined: 12 Jan 2003 Posts: 518

Is it possible to keep the right phase and conect both rear speaker wires together to get max watts from the channel. For example. my head unit is 25x4. my tower speakers are connected by one set of wires, the right rear. thus leaving a set unused on the deck, left rear.

twitch88 · Posted: Jun 20, 2003 8:13 am Post subject:

ok so you are going to connect 2 speakers with 1 output right? if so i'm not sure that you should do that as you will not be able to get the proper impedance.

or if you are talking about putting two outputs to one speaker then yeah that will be fine go ahead.

if i didn't answer your question feel free to ask again.

twitch88 · Posted: Jun 20, 2003 8:17 am Post subject:

oh i just read your post again yeah go ahead that should be fine. you are talking about putting both outputs up to your tower speakers. right?

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

It is better to have one speaker connected to each channel. I'd only connect more than one if you have more speakers than channels.

Nick
________
Yamaha motif specifications

twitch88 · Posted: Jun 20, 2003 9:10 am Post subject:

yeah if you wire one output to multiple speakers your impedance will be off and the head unit is designed to have a 4ohm load.

Steelerguy · Addict Joined: 12 Jan 2003 Posts: 518

well my dilma starts with i only have 2 pair of wires coming down from my tower... I know I know.. so i have to make do... on the tower i have to lights and two speakers........ 1st pair is for the lights. and yes they are connected together..... + wire to + light and + light to - 2nd light and 2nd light + to - wire works great just not as bright as could be...

Next is the speakers.... wired the exact way but only to the right rear of the radio leaving left rear.. Can i do something with those wires?

twitch88 · Posted: Jun 20, 2003 9:30 am Post subject:

so you have two speakers to wire and two outputs to use. just go one output to each speaker. don't wire your speakers like you did the lights i think that would result in a 2 ohm load and your head unit is most likely designed for 4 ohms.

89comp · Posted: Jun 20, 2003 9:48 am Post subject:

red does not always mean positive!!!

Steelerguy · Addict Joined: 12 Jan 2003 Posts: 518

IM not familiar with ohms... thats why im asking here.... To clearify. I have one pair of wires to use for speakers and 1 pair to use for lights. so i have the speakers connected together wire + to 1st speaker + wire - to 1st speaker -

Then from 1st speaker + to 2nd speaker - and 1st speaker - to 2nd speaker +

is that the right way or do should it be + to + and - to -??

and lastly can I double up the last pair of wires on the deck that is not being used.

Thanks

MrBlean · Posted: Jun 20, 2003 10:23 am Post subject:

That wiring system puts the speakers in parallel and halves their impedance. Impedance is another name for resistance but takes account of how it varies with the signal frequency. For your purposes, impedance is measured in ohms.

If you have speakers that are of too low resistance, they can pull more current than your amp is designed to deliver and bang - output transistors blown, amp ****ed.

If you have only one set of speaker wires and two speakers, you'll probably have to wire them in series. This doubles the impedance. The downside is that the volume will be halved because the signal is being dropped across twice the impedance - but you won't blow your amp. The same logic applies to your lights. Each one has to share the 12 voilts from the battery with the other so they only get 6v each!

The way to wire your speakers in series is this: Imagine that the signal has to go through one speaker and then the other. The way to wire it that way is one wire to the red on speaker 1, connect the black on speaker 1 to the red on speaker 2, the black on speaker 2 back to the amp.

Having said all the above, why don't you simply run one speaker off one set of wires and the other speaker off the other set. If it's a stereo set-up, surely that's how it's designed to be used?

Steelerguy · Addict Joined: 12 Jan 2003 Posts: 518

Ok here is an updated pic..... and my other wire is for the lights.

Steelerguy · Addict Joined: 12 Jan 2003 Posts: 518

Is this illistration correct now?

twitch88 · Posted: Jun 20, 2003 12:38 pm Post subject:

wiring in that way will result in a 2 ohm load and i am pretty sure that most head units are not stable at 2 ohms. i thought that you said that you had 2 free outputs that would be 4 free wires 2 pos 2 neg. one pos and one neg to each speaker.

twitch88 · Posted: Jun 20, 2003 12:40 pm Post subject:

however if you only have 1 output (2 wires) then just go that way, in the long run it will probably not hurt anything. the manufacturer of your head unit probably just doesn't recommend it.

Hyperryd · Addict Joined: 03 May 2003 Posts: 604 City: Central Cali

Steelerguy, not to say anybody is wrong here, but the illustration you have shows you are wired in series not parallel. That means you are at 8 ohms not 2 ohms. This means you are running half the power, but it is easier on the radio. To run parallel you would need to connect the + of the second speaker to the + of the first speaker and likewise on the -. However if you run in parallel off of the deck your stereo will probably overheat and possibly blow a channel. Your best bet, besides running more wires through the tower, would be to run a small amplifier that is 2 ohm stable bridged and run that to your tower speakers. Hope this helps.

DRAGON88 · Posted: Jun 20, 2003 8:36 pm Post subject:

uugh!! CD player just burnt out today! Mad

any surgestions for a new head unit

i needs to push 4 100 watt(max) Clairion co-axles....

twitch88 · Posted: Jun 20, 2003 8:45 pm Post subject:

i hate sony speakers but i like their head units for some reason.

MrBlean · Posted: Jun 21, 2003 1:51 pm Post subject: Series orn parrallel?

Hyperryd - You've just said what I die previously. wiring the speakers in series will reduce the volume but not damage the amp. Wiring them in parallel will get more volume but the lower impedance MAY damage the amp when the volume is high.

Steelerguy - The illustration shows the speakers wired in series (safe on your amp) as are the lights. This will result in the lights being dimmer than they should be. If you wire them in parallel you will likely blow the bulbs as they will pull twice as much current than they are designed to. The only way to either not have them dim or risk blowing bulbs is to run a set of wires to each lamp independently.

Parallel wiring is where you run say, a black wire to the black terminal on one lamp (or speaker) and a red wire to the red terminal on that same lamp. You then just run a wire loop the red terminal on one lamp to the red terminal on the other lamp and the same for the black.

Having two "devices" wired up in this way ends up with the total resistance of the pair being half of that for one device alone. Weird, I know, but that's Ohm's law and the laws of physices for you. Ohms law also states that the current that flows thro' a devive is equal to the voltage divided by the resistance. So, if you halve the resistance, the current doubles. That's what happens when things are wired in parallel and the extra current MAY blow your amp.

When things are wired in series, the resistance doubles so at any given voltage, the current halves. That's why your lamps are dim 'cos they're only getting half the power (power is voltage multiplied by current and haldf the current gives half the power) When you wire the speakers in series, exactly the same thing happens. The volume is a lot less than when you have only one speaker connected 'cos the power to each speaker is halved.

If your amp head has outputs for two speakers, do it right and run wires from each output to each speaker independently. Any other way is a fudge.

Hyperryd · Addict Joined: 03 May 2003 Posts: 604 City: Central Cali

Ralph · Posted: Jun 22, 2003 5:10 pm Post subject:

Hey Dragon,
You might not have to get a new deck, your've probably just blown the in-built amp. If you connect your deck to a amp using the RCA's it will probably still play fine & you will have enough power to run the speakers properly. Also I would strongly recommend running another set of wires through the tower, it should be easy with an existing set already there, Just attach two pair's of wire to the existing & pull the old one out running the new pair in.

DRAGON88 · Posted: Jun 22, 2003 5:20 pm Post subject:

Ralph it refuses to take cds... and the radio works just fine so i dont think its the build in amp :X!!

mmm... I dont like the sony line... my bro had a 300$ X-plode in his car... it scratches the fuunk out of cds...

Im thinking I'll jut get another Clarion Marine CD player....

Hyperryd · Addict Joined: 03 May 2003 Posts: 604 City: Central Cali

Dragon, look for a small reset button behind the face. If it is there use a pin to push it in. Alot of decks have this reset button and if the deck gets confused or won't accept CD's this will fix it. I hope you have one and I hope that is your problem. Good luck!

DRAGON88 · Posted: Jun 22, 2003 10:55 pm Post subject:

Hyperryd, no such luck, i just removed the faceplate no button... Sad

criminally_minded · Posted: Jun 23, 2003 12:42 am Post subject:

There should always be a reset button somewhere on there.... mine is on the face plate but it's impossible to find without the instructions, thats how small it is.

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

Mr Blean, I'm disappointed in you!

"This will result in the lights being dimmer than they should be. If you wire them in parallel you will likely blow the bulbs as they will pull twice as much current than they are designed to."

If the bulbs were designed for 12 volts then you want to wire them in parallel. Your concern isn't the bulbs in this case, you will pull more total amps, but the bulbs will have the intended current. You need to be sure the wires running up your tower can handle the current. If each bulb is 48 watts, then each bulb has a resistance of 3 ohms. This is becuase current is voltage divided by resitance, 12/3=4 amps and power is current times voltage, 4 amps * 12 volts is 48 watts. If you wire them in series, each will only have 6 volts, so they will only pull 2 amps and will run at only 12 watts, which will be much dimmer. Even if you wire ten of them in parallel each bulb will only see 4 amps, but you'll be pulling 40 watts. Your house is an example of parallel wiring, each outlet offers 120 volts AC, probably different in the UK though. If you have your TV running and then you plug in an iron, you will pull more current from the power company, but plugging you iron in won't put more current through your TV.

Why don't you run another set of wires up for your other speaker? The ideal setup would be 2 wires for your lights, connect them in parallel, and 4 wires for your speakers, one to each channel. If you can't do this I'd do the lights in parallel and try the speakers in series, if they aren't loud enough then put them in parallel.

Nick
________
DODGE LANCER

MrBlean · Posted: Jun 23, 2003 7:27 am Post subject: Error

Nick - You are right to be disappointed. I was wrong about blowing the bulbs. You are correct in that It’s the wiring you need to be worried about. Or, in the case of the stereo amp, the ability of the output stage to deliver the extra current.

I’d correctly predicted that the resistance of two resistors of equal value in parallel is halved i.e the resistance of two 4 ohm lamps in parallel is 2 ohms. As you know, at a fixed voltage, this means twice the current would flow.

What I had forgotten to take account of is that this doubled current is shared equally between the two lamps so they individually enjoy the same current as if wired on their own across a 12 volt supply.

It's the wiring up to the point that it breaks to feed the lamps independently that has to take the doubled current.

Basic error. My mistake!

DRAGON88 · Posted: Jun 23, 2003 3:58 pm Post subject:

No reset buton, i dont have the instructions, when we baught the boat from the dealership in 99 they gave us the instructions for the tape player (which we dont have) over the CD player (they installed).... I think im just gonna buy a new head unit! I'm gonna stick with Clarion... the middle class marine one its puts out 50Wx 4 channels... that should be plenty to run the 4 Marine 100W (peak) co-axels... they were running on 35Wx 4 chanells.... Shocked

MrBlean · Posted: Jun 24, 2003 1:08 am Post subject: Wattage matching

Dragon

Just be aware there's quite a difference between rms power and peak power. A 100 watt rms output amp will deliver significantly more power than 100 watt peak speakers are designed to run at. But 50 watts rms (if that's how the amp is rated) shuld be OK into 100 watt peak speakers.

This peak power business is just specmanship to make kit look powerful than it really is.

porter · Outlaw Joined: 23 Jan 2003 Posts: 109 City: Sammamish

First stereo basic: How to spell stereo...

MrBlean · Posted: Jul 02, 2003 1:05 pm Post subject: Stereo basics

Thanks Porter - that was a really useful input to help someone who isn't too embarassed to admit they don't know much about things electrical. Some things are best left unsaid.