There is nothing wrong with the heads in my humble opinion- its the speakers which are the problem, wooden (almost) crate with a speaker and hole, built to a budget, vanilla, missionary, cheap and nasty design-yes even the ABM range. Its our fault we do not demand better.
If you buy a loose speaker and work out the optimum size cab using win programme, the reccomended cab size is usually the dimensions nearing a washing machine to make it work efficiently.
I purchased a Mag115 in 2003 and when I looked inside it had a 150watt speaker in it instead of a 250 which is what it was rated at. Ashdown said that I could have a replacement speaker anytime in the future should it blow, it has not yet, at 8ohms it is obviously ok in the real world but you get my drift. Beware discount shops.
So there, I am not wrong this time.