rupertlssmith
Junior Member level 1
What size lead acid sealed leisure battery would I need to run a car stereo, with the volume up for an hour say? Thanks for the help
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But you forgot to say what is the impedance of your speakers. 8 ohm speaker will play all day. 4 ohm speakers will play for a few hours. A little battery might not produce enough current for 2 ohm speakers.I'm only going to run 2 speakers on it.
But you forgot to say what is the impedance of your speakers. 8 ohm speaker will play all day. 4 ohm speakers will play for a few hours. A little battery might not produce enough current for 2 ohm speakers.
But you forgot to say what is the impedance of your speakers. 8 ohm speaker will play all day. 4 ohm speakers will play for a few hours. A little battery might not produce enough current for 2 ohm speakers.
That must mean at least 500+ watts of thumping bass that rattles the windows next door.What size lead acid sealed leisure battery would I need to run a car stereo, with the volume up for an hour say? Thanks for the help
An amplifier does not regulate the output power. The amplitude of the input signal, the volume control setting, the supply voltage to the amplifier (high power car audio systems boost the DC voltage) and THE IMPEDANCE OF THE SPEAKER determines the output power because its current is higher. Use ohm's law:I thought it all depends on the output power. When you regulate the output, you control the output power and the speaker will adjust the voltage and current to deliver the power.
I even do not remember the input impedances of my speakers. Why it is critical?
An amplifier does not regulate the output power. The amplitude of the input signal, the volume control setting, the supply voltage to the amplifier (high power car audio systems boost the DC voltage) and THE IMPEDANCE OF THE SPEAKER determines the output power because its current is higher.
13V battery, amplifier output is 10Vp-p which is 3.5V RMS.
1) 3.5V squared/8 ohms= 1.5W.
2) 3.5V squared/4 ohms= 3W. It might be two 8 ohm speakers in parallel and each one gets 1.5W.
3) 3.5V squared/2 ohms= 6W. It might be two 4 ohm speakers in parallel and each one gets 3W.
Now use a bridged amplifier so that the voltage swing is almost doubled and the power is 3.5 times more.
Then the amplifier produces 10.5W into 4 ohms but the salesman says its battery is overcharging at 14.4V and the amplifier output is clipping badly almost producing a square wave so they advertise 14 Whats per channel.
We dropped a car off to get a new windshield installed, and picked it up at the end of the day. The mechanics had run down the battery listening to the car stereo for hours. It had 4 speakers. Apparently they played it loud while they worked around the outside of the car. We could not start the engine, so they had to attach jumper cables and give us a boost.
Dang! Did they give you a discount for reducing the life of your car battery doing that? :x
If you have an Optima battery with the deep discharge capability...