Does anyone have directions on how to create a mono speaker wire to
stereo rca cable. I am trying to hook a mono radio, in a volvo 122s, to
a new amplifier. I realize the signal will still be mono, but I would
like it to come out on both the left and right speakers of my car.

Can I determine which speaker wires are - and +, using a multimeter?

Thanks,

lollipop

"lollipop" wrote in message
oups.com...
Does anyone have directions on how to create a mono speaker wire to
stereo rca cable. I am trying to hook a mono radio, in a volvo 122s, to
a new amplifier. I realize the signal will still be mono, but I would
like it to come out on both the left and right speakers of my car.

Can I determine which speaker wires are - and +, using a multimeter?

Thanks,

lollipop


No, but if it's mono, it doesn't matter which is + and which is -. Polarity
problems only happen when there's more than one speaker.

You need a speaker-to-line level converter. They are available from most car
audio stores and electronic hobbie stores like Radio Shack. I believe even
Walmart sells one now. You will need to "split" the speaker wires to both
the input sides ensuring the polarity is the same. As long as the polarity
is the same it doesn't matter whether you have them backwards or not. Then
run RCA cables to your amp.

Kevin Murray


"lollipop" wrote in message
oups.com...
Does anyone have directions on how to create a mono speaker wire to
stereo rca cable. I am trying to hook a mono radio, in a volvo 122s, to
a new amplifier. I realize the signal will still be mono, but I would
like it to come out on both the left and right speakers of my car.

Can I determine which speaker wires are - and +, using a multimeter?

Thanks,

lollipop

On 22 Sep 2005 04:50:35 -0700, "lollipop"
wrote:

Does anyone have directions on how to create a mono speaker wire to
stereo rca cable. I am trying to hook a mono radio, in a volvo 122s, to
a new amplifier. I realize the signal will still be mono, but I would
like it to come out on both the left and right speakers of my car.

Can I determine which speaker wires are - and +, using a multimeter?

Thanks,

lollipop


Since it's mono, the polarity doesn't really matter. Take the speaker
outputs and feed them to both inputs of a line-level converter
(connect one speaker wire to both positive inputs on the converter,
and connect the other speaker wire to both negative inputs on the
converter). Connect the red/white RCA cables to the outputs of the
converter, and you should be set. Both RCA cables will have the same
signal, and they'll be at a voltage that's appropriate for your EQ or
amplifier.


--
Scott Gardner

"Marge, dont discourage the boy. Weaseling out of things is important to learn. Its what separates us from the animals...except the weasel." (Homer Simpson)

I am feeding the speaker level inputs into a clarion EQS744 which has
an aux input with gain control, in this case do I need a LOC? I figured
I wouldn't, which is why I asked how I would make the cable to feed
into the clarion

thanks for the help,

lollipop

On 22 Sep 2005 07:56:01 -0700, "lollipop"
wrote:

I am feeding the speaker level inputs into a clarion EQS744 which has
an aux input with gain control, in this case do I need a LOC? I figured
I wouldn't, which is why I asked how I would make the cable to feed
into the clarion

thanks for the help,

lollipop

Unless your EQ specifically says that it can take speaker-level inputs
for the AUX input, you're better off with a converter. The gain
control adjustment on the AUX might be adequate if your head unit was
only putting out 0.7V or maybe 1 or 2 volts, but it's probably putting
out significantly more than that.

You can give it a try, though. Turn the gain all the way down and
connect the head unit. Put the volume control on the head unit about
3/4 of the way up, and slowly increase the gain on the EQ until the
sound level is appropriate.

If the sound is loud and distorted even with the EQ gain all the way
down, or if you find that you can hardly move the gain adjustment at
all without the sound getting too loud and distorting, then you'll
know that the voltage from your head unit is too high and that you'll
need a converter.
--
Scott Gardner

"The POP3 server service depends on the SMTP server service, which failed to start because of the following error: The operation completed successfully." (Windows NT Server v3.51)

To determine the + and - on a speaker, you can use any 1.5v battery. Using a
larger then 1.5v battery can possibly damage the speaker.
put the battery terminals to the speaker terminals, and look at the speaker
cone. it will move up or down when the voltage is applied.
reverse the battery on the speaker terminals will make the speaker move the
opposite direction. when the cone move up, whatever speaker terminal has the
+ battery lead on it is the speaker + terminal.

"lollipop" wrote in message
oups.com...
Does anyone have directions on how to create a mono speaker wire to
stereo rca cable. I am trying to hook a mono radio, in a volvo 122s, to
a new amplifier. I realize the signal will still be mono, but I would
like it to come out on both the left and right speakers of my car.

Can I determine which speaker wires are - and +, using a multimeter?

Thanks,

lollipop

To determine the + and - on a speaker, you can use any 1.5v battery. Using
a
larger then 1.5v battery can possibly damage the speaker.

Whoa. I've never seen that happen...

On Thu, 22 Sep 2005 18:51:28 GMT, MZ wrote:

To determine the + and - on a speaker, you can use any
1.5v battery. Using
a
larger then 1.5v battery can possibly damage the speaker.

Whoa. I've never seen that happen...

oh I have. I was foolish enough to do it with a pair of Morel
components using a 9v battery. The speakers were just never the
same after that...

On Thu, 22 Sep 2005 14:51:28 -0400, "MZ"
wrote:

To determine the + and - on a speaker, you can use any 1.5v battery. Using
a
larger then 1.5v battery can possibly damage the speaker.

Whoa. I've never seen that happen...


I've always used a 9-volt. I wouldn't leave it connected for five
minutes or anything, but even that might not hurt it. Alkaline
batteries can't really deliver very much current, so they're kind of
self-limiting.

--
Scott Gardner

"I've been accused of vulgarity. I say that's bull****." (Mel Brooks)

Whoa. I've never seen that happen...

oh I have. I was foolish enough to do it with a pair of Morel
components using a 9v battery. The speakers were just never the
same after that...

How were they "never the same"? You blew them with a small 9v battery? 9v
batteries can't deliver 2+ amps into a 4 ohm speaker load (2A=~9V/4ohms).
You'll be doing good to deliver a few watts into the speaker. Typical size
alkaline 9v batteries are capable of what? 5w at their ideal load? 4 ohms
is most assuredly lower than their output impedance, so their actual output
should be significantly less than 5w.

On Thu, 22 Sep 2005 22:22:42 GMT, MZ wrote:

How were they "never the same"? You blew them with a small
9v battery? 9v batteries can't deliver 2+ amps into a 4
ohm speaker load (2A=~9V/4ohms). You'll be doing good to
deliver a few watts into the speaker. Typical size
alkaline 9v batteries are capable of what? 5w at their
ideal load? 4 ohms is most assuredly lower than their
output impedance, so their actual output should be
significantly less than 5w.

Well after I did it, the tweeters sounded slightly scratchy and
distorted from then on. Maybe it had nothing to do with the
battery, but I still refuse to try it again with another
speaker...

Applying DC to a tweeter is bad news. Not thermally for the voice
coil, but the one way constant excursion can hurt their little
surrounds and diaphrams since they are definatly NOT made for a large
xmax...LOL

Applying DC to a tweeter is bad news. Not thermally for the voice
coil, but the one way constant excursion can hurt their little
surrounds and diaphrams since they are definatly NOT made for a large
xmax...LOL

Hehe yeah, they're certainly not build for excursion. But you get the same
kind of transient all the time at turn on. All those systems that get pops
with turning off. Or crackling with loose cabling. But they don't usually
kill tweeters. The "static" that you get when connecting a tweeter to a 9v
source (which is actually less than 9v since the output impedance of a small
alkaline battery is nonzero) doesn't have enough power content to send it
beyond its xmax. In fact, the back emf (not the motional emf which is often
referred to erroneously as back emf) due to the tweeter turning off during
normal operation probably gives it the most excursion it'll see.

On Thu, 22 Sep 2005 18:22:42 -0400, "MZ"
wrote:

Whoa. I've never seen that happen...

oh I have. I was foolish enough to do it with a pair of Morel
components using a 9v battery. The speakers were just never the
same after that...

How were they "never the same"? You blew them with a small 9v battery? 9v
batteries can't deliver 2+ amps into a 4 ohm speaker load (2A=~9V/4ohms).
You'll be doing good to deliver a few watts into the speaker. Typical size
alkaline 9v batteries are capable of what? 5w at their ideal load? 4 ohms
is most assuredly lower than their output impedance,

On this point only: I'm no expert, I eagerly admit, and on this stuff
especially I get confused often (which is why I'm asking) but are you
saying the impedance of the speakers is actually higher than 4 ohms?
If so, isn't that because audio is AC current, but the DC of the
battery wouldn't induce any inductive impedance, and with only a
battery connected, the impedance would be the same as the resistance,
measured with a meter, Yes? Is that likely to be higher than 4
ohms?

so their actual output
should be significantly less than 5w.



Remove NOPSAM to email me. Please let
me know if you have posted also.

How were they "never the same"? You blew them with a small 9v battery?
9v
batteries can't deliver 2+ amps into a 4 ohm speaker load (2A=~9V/4ohms).
You'll be doing good to deliver a few watts into the speaker. Typical
size
alkaline 9v batteries are capable of what? 5w at their ideal load? 4
ohms
is most assuredly lower than their output impedance,

On this point only: I'm no expert, I eagerly admit, and on this stuff
especially I get confused often (which is why I'm asking) but are you
saying the impedance of the speakers is actually higher than 4 ohms?
If so, isn't that because audio is AC current, but the DC of the
battery wouldn't induce any inductive impedance, and with only a
battery connected, the impedance would be the same as the resistance,
measured with a meter, Yes? Is that likely to be higher than 4
ohms?

Sorry, I should have been clearer. What I said was that the output
impedance of a typical alkaline 9v battery is higher than 4 ohms. Output
impedance refers to the 9v battery's internal resistance. So, since the
battery has a nonzero internal resistance, its output voltage is going to
drop as you increase the current demands. For example, if you hook your 9v
battery up to a small circuit that doesn't draw much current, you'll still
measure roughly 9v across the battery terminals. But hook it up to a 4 ohm
resistor and the voltage at the battery terminals may only read 5 volts (I'm
making up numbers here, but hopefully you get the idea).

The initial question was regarding how much power you can deliver to a 4 ohm
speaker with a 9v battery. Because of the battery's output impedance, you
can't simply say the power is v^2/r, or 81/4 = 20 watts. No way is a 9v
battery going to deliver 20 watts. A quick google search seems to indicate
that the best you'll do is about 5 watts.

There's a law that states that the maximum amount of power that a voltage
source with nonzero output impedance can deliver will be delivered to a load
that has the same resistance as the output impedance. In other words, if
the battery's output impedance is 20 ohms, then you'll deliver the maximum
power from the battery if the speaker is 20 ohms. So, although it may seem
counterintuitive, you'll actually deliver more power *from a 9v battery*
into an 8 ohm tweeter than a 4 ohm tweeter.

Oh, and to answer your other question, the resistance of a typical
loudspeaker tends to be lower than its nominal impedance. For "4 ohm"
speakers, expect the DC resistance to be on the order of 3.2-3.7 ohms when
cold.

On Fri, 23 Sep 2005 18:22:33 -0400, "MZ"
wrote:

How were they "never the same"? You blew them with a small 9v battery?
9v
batteries can't deliver 2+ amps into a 4 ohm speaker load (2A=~9V/4ohms).
You'll be doing good to deliver a few watts into the speaker. Typical
size
alkaline 9v batteries are capable of what? 5w at their ideal load? 4
ohms
is most assuredly lower than their output impedance,

On this point only: I'm no expert, I eagerly admit, and on this stuff
especially I get confused often (which is why I'm asking) but are you
saying the impedance of the speakers is actually higher than 4 ohms?
If so, isn't that because audio is AC current, but the DC of the
battery wouldn't induce any inductive impedance, and with only a
battery connected, the impedance would be the same as the resistance,
measured with a meter, Yes? Is that likely to be higher than 4
ohms?

Sorry, I should have been clearer. What I said was that the output
impedance of a typical alkaline 9v battery is higher than 4 ohms. Output
impedance refers to the 9v battery's internal resistance. So, since the
battery has a nonzero internal resistance, its output voltage is going to
drop as you increase the current demands. For example, if you hook your 9v
battery up to a small circuit that doesn't draw much current, you'll still
measure roughly 9v across the battery terminals. But hook it up to a 4 ohm
resistor and the voltage at the battery terminals may only read 5 volts (I'm
making up numbers here, but hopefully you get the idea).

I do. Thanks for explaining all this.

The initial question was regarding how much power you can deliver to a 4 ohm
speaker with a 9v battery. Because of the battery's output impedance, you
can't simply say the power is v^2/r, or 81/4 = 20 watts. No way is a 9v
battery going to deliver 20 watts. A quick google search seems to indicate
that the best you'll do is about 5 watts.

I'll buy that. Even 5 watts sounds like a lot from that little thing,
unless there was a 0 ohm short, but I'm willing to believe it could
power a 5 watt item.

There's a law that states that the maximum amount of power that a voltage
source with nonzero output impedance can deliver will be delivered to a load
that has the same resistance as the output impedance.

I guess I'm not used to the term "output impedance". Yes, looking at
the top, that's what I wrote about in the first place. "Internal
resistance" is a term I know, but that doesn't mean the other isn't
valid.

In other words, if
the battery's output impedance is 20 ohms, then you'll deliver the maximum
power from the battery if the speaker is 20 ohms. So, although it may seem
counterintuitive, you'll actually deliver more power *from a 9v battery*
into an 8 ohm tweeter than a 4 ohm tweeter.

Definitely counterintuitive.

Although I think I went throught this with someone regarding
lightbulbs. That time I was on your side. Wait, no I wasn't but
that's because the situations aren't the same. I said the resistance
of a 100 watt lighbubl had to be lower than the resistance of a 60
watt lightbulb. We have the image of the electrons struggling to get
thought the wire, because of the reistance, and the more they have to
struggle, the more light must be given off. But I don't think that is
the way it works.

Oh, and to answer your other question, the resistance of a typical
loudspeaker tends to be lower than its nominal impedance. For "4 ohm"
speakers, expect the DC resistance to be on the order of 3.2-3.7 ohms when
cold.

Good to know. Of course I could have measured some and found out.
Heck, I might have done so a decade or two ago. Who can remember.

Here's another question. Chryslers use 8 ohm speakers, but all the
replacement speakers sold that I can find are 4 ohms,

IIRC, GM used 8 ohm speakers too. Or is Chrysler the only one? If
lots of cars use 8 ohm, why are all the replacement speakers 4 ohm?


One related question. GM cars had the left channel at the left front
and right rear, and the right channel at the other two corners. Do
they still do that? and does any other company do that?

It makes sense. It may not give the best left-right experience, but
since no one in a car sits in the center, especially now when few
seats, front or back hold 3 people, most only 2, and even if they hold
3, there is rarely a third person sitting there, and no one sits in
the center of the car. So the GM way means that everyone gets equal
volumes of left and right, even though they are mixed together.

The Chrysler system, straight left and right, means that if the driver
turns up the right channel since he is sitting farther from those
speakers, he's ok unless he carries a passenger. Then if he makes
them equal, neither person here's a balanced left-right sound. No?


Remove NOPSAM to email me. Please let
me know if you have posted also.

In other words, if
the battery's output impedance is 20 ohms, then you'll deliver the maximum
power from the battery if the speaker is 20 ohms. So, although it may seem
counterintuitive, you'll actually deliver more power *from a 9v battery*
into an 8 ohm tweeter than a 4 ohm tweeter.

Definitely counterintuitive.

Although I think I went throught this with someone regarding
lightbulbs. That time I was on your side. Wait, no I wasn't but
that's because the situations aren't the same. I said the resistance
of a 100 watt lighbubl had to be lower than the resistance of a 60
watt lightbulb. We have the image of the electrons struggling to get
thought the wire, because of the reistance, and the more they have to
struggle, the more light must be given off. But I don't think that is
the way it works.

Yes, the resistance of the 100w bulb is lower than the 60w bulb. Power =
Voltage squared divided by resistance; since voltage remains constant in
both cases, the only way to increase power would be to decrease
resistance.

Anyway, think of it this way. We know that the current will be greatest
when you short the output. But we also know that the voltage at the
output terminals decreases to near zero in that situation. Since power
equals voltage times current, then you want to find the resistance of the
load that will give you the right balance of current and voltage so that V
x I is greatest. It can be shown mathematically that this ideal
resistance is equal to the output impedance, or internal resistance, of
the voltage source.

Here's another question. Chryslers use 8 ohm speakers, but all the
replacement speakers sold that I can find are 4 ohms,

IIRC, GM used 8 ohm speakers too. Or is Chrysler the only one? If
lots of cars use 8 ohm, why are all the replacement speakers 4 ohm?

Most cars that don't have "premium" sound systems (which are becomign
fewer these days) use 4 ohm speakers. And most aftermarket head units are
designed to drive 4 ohm speakers. So that's why you mostly find 4 ohm
speakers out there. There are 8 ohm speakers also, but they're a bit
harder to find. It's also easy to find 8 ohm raw drivers, but those would
require a separate woofer and tweeter, which may be more than what you're
willing to do.

One related question. GM cars had the left channel at the left front
and right rear, and the right channel at the other two corners. Do
they still do that? and does any other company do that?

Nope.

On Sun, 25 Sep 2005 18:09:37 GMT, MZ wrote:


IIRC, GM used 8 ohm speakers too. Or is Chrysler the only one? If
lots of cars use 8 ohm, why are all the replacement speakers 4 ohm?

Most cars that don't have "premium" sound systems (which are becomign
fewer these days) use 4 ohm speakers. And most aftermarket head units are
designed to drive 4 ohm speakers. So that's why you mostly find 4 ohm
speakers out there. There are 8 ohm speakers also, but they're a bit
harder to find. It's also easy to find 8 ohm raw drivers, but those would
require a separate woofer and tweeter, which may be more than what you're
willing to do.

Well I found a junk yard car with dash speakers. Most don't have
them, but this one had had an Infinity radio.. So for 5 dollars a
piece, I have a pair, and my ear is not so great that I need anything
better..

It also had coaxial speakers in the rear, and I got those too.
They have connectors for four wires, each. S since I don't have the
Infinity amplifier, which they are meant for, I'll have to figure out
how to connect the tweeter to the bigger speaker.

One related question. GM cars had the left channel at the left front
and right rear, and the right channel at the other two corners. Do
they still do that? and does any other company do that?

Nope.

Nope to which qustions?

Remove NOPSAM to email me. Please let
me know if you have posted also.