What impedance should I shoot for speaker circuit?

Question

I would like to build a simple speaker circuit to amplify an audio signal. I plan on using the CDS-40288 speaker by CUI Devices (datasheet).

Questions:

1. How will the impedance of the CDS-40288 affect the circuit?
2. The power of the CDS-40288 is said to be 6W typical and 8W max. The CDS is a passive component? I’m confused what voltage and amperage I should aim for in my input signal to the CDS
3. What is the best way to amplify my input signal to the circuit before sending it to the speaker? Would a differential amplifier work?

Thank you!

Answer 1

When driving speaker you should aim for zero output impedance.

1. It just means that your amplifier must handle the speaker load impedance. That is a bog-standard 8 ohm speaker so any amplifier circuit intended for driving bog-standard 8 ohm speakers will work.

2. The 6W and 8W are typical and maximum rated power your amplifier should push into the speaker - if you go near these limits you will burn out the speaker. It might be unable to even work properly at these power levels, it's just the rated it can handle without damage. Expect audio quality to be barely tolerable when driven with 6W.

3. It depends. There is no best way. An audio amplifier, capable of driving the amount of watts you want into the rated 8 ohm speaker. Differential or not, that is irrelevant. It may depend on what your audio source is. You can choose to build an amplifier from discrete parts such as transistors, or use an op-amp with transistors, or buy an all-in-one D-class amp IC.