Smokie amp speaker impedance matching

[Yazoo]

I've just built a Smokie amp using an old speaker scavenged from a defunct keyboard. The speaker has 4 Ohms impedance. I am running the amp on 12 volts. I read the chip would run hot with a 4 Ohm speaker so I've added 12 Ohms in series after the speaker and the LM386 chip does not get hot. It all sounds OK but is there a better way to do this?

[GibsonGM]

1) if it ain't broke, don't fix it ;o)  he he

2) It's ok to use that series resistance as you did, to add some impedance.  The REAL AC impedance (Z) will not be quite the same as the resistor values add  up to (the DC value, so to speak), but it will be reasonably close. 

I wouldn't do that on a custom build, with expensive parts and a nice speaker, but for what you're doing - hey, I say go for it!   Otherwise, use a different speaker or transformer...which would be a pain.