BJT Class B Amplifier with reduced cross over distortion

How do you get a 4V input ?

With a real speacker (8ohm) this is useless

Use an 8 ohm resistor instead of a 10k ohm resistor to simulate a genuine speaker. Then check the 'reduced' distortion again...

I had an error in the circuit before. I've fixed it and also simulated an 8 ohm load (speaker). Works much better now! (Thanks for pointing out that there was an issue!)

Still useless, the input is bigger than the output

You're only looking at voltage! This is a common collector (or emitter-follower) amp, so voltage gain is always going to be a little less than 1. It loses a little voltage due to the Vbe of each transistor (about 0.7V or so for silicon.) What this amp does give us (besides a higher input impedance) is current gain. I've highlighted the signal current and the load current to show this. By extension, we also get power gain. Admittedly, this circuit only gives a current gain of about 5.5 and a power gain of about 5. However, this can be increased easily by increasing the biasing resistor values (just keep them equal to each other.) In summary, not useless. :)

But, try to not use this amplifier. You'll get more voltage and more current with the same load than your amplifier and that mean more power. A little bit more, but still more that your amplifier.