Originally Posted by hydrotex
Thanks Bob! I was really hoping for the convenience of fronts handling it all. I can hear the discussion in my house now about adding a sub to our arrangement. :-)
Guess it's time to start learning about stand alone subs. :-)
When you get a good sub properly set up in your room you will be *ASTOUNDED* how much it improves the wow factor in your listening. And ARC works miracles making the setup "just right".
Subs work by "pressurizing" the entire volume of air in the listening room -- which is why bass is non-directional, i.e., it appears to come "from everywhere". That means a critical factor is getting sub that is sized appropriately for the number of cubic feet of room space it will be pressurizing. If you have openings into the rest of the house that makes it harder. So you can buy a sub that's rated to go quite low, and it doesn't do the job simply because it is too small for the room -- i.e., that rating only applies when the sub is in a properly sized (smaller) room.
Subs also vary based on how loud they get vs. how "musical" or "accurate" they are. The more the sub design tries to be accurate the harder it is for it to be loud.
My personal preference is for a very musical sub (which usually means a "servo" design), which will be really helpful handling the low end of your music listening (which only goes down to about 30Hz). Now if that sub is also big enough, and designed for deep bass reproduction (below 20Hz), then it will ALSO work well for what's sometimes called "subsonic" bass -- the bass that you feel more than hear. The bass that shakes the room. And effects tracks in movies (and some rare music tracks) WILL have content down there which is spectacular if your sub can reproduce it.
The down side is that such subs are kind of large and VERY heavy. An alternative is to get two or more subs of the next size down. That works, too, but the setup is more complicated.
Small subs that claim to go deep are either, umm, lying, or they are very inaccurate -- meaning they are not suitable for anything other than bass "noise" such as thuds from explosions in movie tracks. Their bass will either clip (as the driver bottoms out) or will have significant distortion. They are not well suited for music bass at decent volume.
Just to give you an idea, a typical living room, nothing unusually large, will want a sub with at least a 15" diameter cone. The sub will likely weigh around 100 pounds or more and be about the size of a 2 foot cube.
It is also a good idea to get a sub that has decent output at the higher frequency end of bass. LFE content in movie tracks (the .1 of 5.1 or 7.1 tracks) has content up to just under 120Hz. So ideally you want a "musical" or "accurate" sub that can do a good job from 120Hz down to below 20Hz -- with 15Hz being pretty much the practical limit. With such a sub you'll get ALL the LFE channel reproduced, *AND* ARC has maximum flexibility to blend your main speakers and your sub together. (Typical main speaker crossovers will then be in the range from 40Hz to 100Hz depending on the ability of each speaker, and of course the choices actually offered by the MRX.)
There is a whole forum here devoted to subwoofers. Paradigm, the parent company of Anthem, sells some very nice subs.