Emi

Don, If the volume isn't high enough it wont sense to turn on. Anything below 40 on my Marantz wont signal it on. At low volume but you still want the sub you may have to manually switch it to on. Also, there are 3 different points for the power switch. Play around with it and see which suits you best.

If it sits there and just ticks ( tick, tick, tick, tick) the amplifier has gone out on it. Happened to my 15 after only a few years and normal use.

Get the new SPL-15 if they have "updated" the amplifier they have probably fixed the problem of the older 15SW amplifiers going bad. My 15SW amplifier went bad after only 3 years. It was always correctly connected and never over driven. The amplifier just "went out" with normal use. Frustrating at only 3 years when it wasn't cheap. Bought directly from a dealer, shipped to the house and has never moved since install. I submitted a ticket so I hope it is still covered under warranty as its a known problem Replacing just the amplifier doesn't look too hard. -Eric As appealing getting two of those things is for the average household one is enough, trust me. Also, if the new amplifier last the life of the sub its much more worth the extra cost than it burning up after only 3 years.