In your question I did not see the wattage of your amp. This is really essential to answering the question. If you give me no information about your amp I have no way to judge. Amps that are loud enough for outdoors are generally 300-800 watts. So if this is you, then you are set. If it is lower, maybe you could i guess. But, it depends. So just email me back and update the question with the wattage of your 150 watt amp.
