Hi Pepolk, I also am not familiar with which specific system you have, but I would doubt that passive subs in general will give you the low end you are looking for - unless you are driving them with large high current amps- from your question I think you are not, and especially if it is one of the Bose type subs. It won't be ideal (clean and fast) for music bass/ percussion and will be fat and muddy for explosions/dinosaurs walking, etc. In general the bose stuff is very fat and boomy down low. Bose does a great job marketing, and many people are very happy with their stuff. If you are happy, then you are right in your system. On the other hand, if you have not yet purchased the system, and I am not sure if you are talking about the Acoustimass stuff or one of the Bose complete HT systems including the processor and all, I would highly recommend looking at some other options. For pure sound production you can do a lot better for the money. If the aesthetics are of paramount importance, there are still several good options. I don't want to go too deeply into it here, but if you want , feel free to email me and I'll give you a few of my thoughts. If you already own the Bose stuff, then enjoy it. Most audiophiles poo poo Bose, and please try to look aside from the Bose bashing that will probably follow in this thread. I personally think you can do alot better with a little looking. That said, I owned a pair of 901s back in college and loved them for that time in my life. So I guess back to your question, I doubt you will get good bass from them . In additon, if they are passive, in a 5.1 system, you will need as seperate power supply (amp) for them as most sub "outs" are not amplified by the receiver and certainly not by a preamp/processor. Another concern is that the sub may not take a dedicated amp "in". Look at the back and see what type of connection it has. Hope this was helpful, and feel free to email me. Happy listening.
Todd
