pretty good little device for the price
Your review: used two of them in a shop environment, one as a telephone ringer amp and the other connected to a pc that acts as a buzzer for break and lunch periods. sound quality is as good as a horn speaker is going to get. i wouldn't use it for music but it very compact and worked well for our applications. you have to be careful with your signal lines as it will pick up and amplify interferance.
pros: good price, pretty loud for size, versatile with line or speaker inputs and multiple supplied power sources
cons: it's a horn speaker so don't expect booming bass or crystal tweets, magnetic bass is weak but a nice feature, is prone to interferance