PA M 12 ECO MKII : Good product but the speaker is not the strongest

I own two of these ECO MKII units which I have used many times as foldback monitors at the front of the stage in rock´n´roll bar gigs(the drummer uses an active monitor), connected in series from the monitor out feed of a Behringer 250Watt per channel powered mixer. They have always done a fine job, apart from a blown speaker in one of them which had to be replaced. We are a reasonably loud band! They are light and easy to carry, and the angle is just right when on the floor. They have also taken plenty of knocks and held together well. The sound is fine and full for vocals, and a big improvement on our band´s previous midrange heavy relics. The sound was even better with the upgraded speaker.