Connecting 10w speakers using L298n

Hello,

I have a very basic question. I am quite new to electronics so please let me know if what I am saying does not make sense.

I have some old Logitech speakers (model is Z130) rated 10W, 10V / 700mA.

I also have a couple of L298n drivers. These have an output of 12V.

I have a power source of 12V going into the L298n powering the Arduino Mega and a motor.

I need to play some WAV files on the speaker.

What would be the easiest way for me to do so in terms of additional elements?
I imagine it is not a good idea to connect the 12V output to the speakers? What would be a safe/easy way to get the 12V to 10V?

Alternatively, if this is not going to work using the L298n, what would be the most straightforward way to power these speakers using my power input of 12V and Arduino?

Thank you in advance!

The Z130 has a built-in 5W amplifier, so you don't even need the L298n.

Thank you Erik_Baas, I will try to connect the speakers directly.

If you wanted to use an H-bridge for class-D audio you'd need something a lot faster than the L298,
a MOSFET H-bridge would be more suitable.

Class D usually uses 150kHz to 500kHz or more, so switching devices need to respond in well under
1µs

Further to the above question about these Logitech Z130 speakers, would you know what would be the convention for the wires and their function? Or where would be a good place to find what each of the wires does?

What I mean by this is that I realised there are 3 wires in the cable as per the attached picture. My guess is that one is for each speaker (left and right) and one is for the ground, but I am not sure which is which or if that's at all the case. Is anyone able to help?

Thank you

What I mean by this is that I realised there are 3 wires in the cable as per the attached picture. My guess is that one is for each speaker (left and right) and one is for the ground, but I am not sure which is which or if that's at all the case. Is anyone able to help?

If there used to be a 3.5mm stereo plug, that's correct. The bare wire and the foil are ground and the other wires are left & right. If it's mono, you can connect the left & right wires together* and you'll get sound from both speakers. Otherwise, you can just experiment to see which one is left & right. If you just touch the wires** with the speakers powered-up you should hear a buzz so you can identify left & right. (Touch ground first to discharge any static charge on your body.)

I imagine it is not a good idea to connect the 12V output to the speakers? What would be a safe/easy way to get the 12V to 10V?

2V extra is probably OK. If it was me I'd take the chance. :smiley: If you're paranoid 3 or 4 diodes in series will drop the voltage. (You get about a 0.6V drop across a silicon diode.)

However, you may get electrical noise sharing a power supply with a motor...

  • It's OK to connect two (or more) inputs together but you should NEVER connect two audio outputs together.

** The buzz is your body picking-up the electrical field from the power lines all-around you. This is low voltage (unlike the possible static dischartge) and the voltage/loudness of the buzz depends on the electrical environment and the amplifier's input impedance but you should hear something and you should be able to identify left & right.

Standard audio colour code is white = left, red = right. Sometimes black is substituted for white when
white isn't available.

Think _R_ed for _R_ight as a mnemonic.