Subwoofer Question: Active or Passive?

Looking for most musical sub to fill the lower end of my Totem Arros. My budget is $500 at most new or used and my stereo amp does not have sub out. I need quick fast tight bass and read, most likely 10" with good amp should suffice. Should I buy a active sub or a good amp and passive box seperately from Audiogon or Ebay. Please give some brand recommendations
You should get an active sub. It will take some of the strain off of your main amp. If you have a preamp, you can use "Y" cables. There is no such thing as fast bass by the way. I know this will cause a lot of arguments. But consider, all things that produce bass are larger and slower. If you cross the sub over at a lower frequency, it will blend much better.
The HSU research subs are very nice for the money. Very musical and fast, for a sub.
If this is for music the Vandersteen 2W is a no brainer used for 500.00-600.00.Vandersteen includes a passive xover that filters out bass from your main amp.This piece is adjustable and once you dial it in you can get the fixed value xover from vandersteen which will go in a tape loop or inbetween preamp and main amp.A cool feature is that the sub gets its signal from the main amps output,it kind of samples the signal and retains the main amp sound.The 2W has three eight inch drivers that give you that light kinda bass I have never heard from a larger driver.It is a perfect match for the spica TC-50's.
Check out this sub
have owned an earthquake 10" and 12". (sold the 12"). also, RBH 10" aluminum sub. (sold that, too). as far as homemade subs, i made an active 10" titanic driver with a plate amp from madisound, as well as a passive 12" peerless driver with an external ashley crossover.

the peerless 12" was the fastest of the bunch, followed by the earthquakes. an active sub will be the most practical, but my passive peerless sounds fantastic. thick, fast and punchy, not boomy, like the rbh tended to be. i would say it really depends on the driver. you can make an incredible sub for under $500 - most peerless and titanic drivers go for less than $200 and a plate amp w/crossover from partsexpress or madisound will run around $150-200. a 12 or 15" SLAPS earthquake driver will only cost you $100-150 as well - i just got a new slaps 12" for $75. you can then either buy a pre-cut box or go to your local lumber yard and get them to cut down a 4'x8' sheet of 3/4" ply to your exact specs ($60). put a few coats of poly on it and you'll get a MUCH nicer wood grain and a more unique box than the black boxes that partsexpress sells and you'll spend less $.
Definitely take Ktsteamer's advice AND look up Mara's ref before you take the plunge. Building a sub with pre-cut parts will only take a few hours and is lots of fun -- one of the best ways to spend an afternoon!
The terminology "active" and "passive" have gotten all mixed up. "Active" generally refers to a subwoofer that includes a built-in amplifier. "Passive" ought to describe a subwoofer that is driven through a passive crossover network by the same amplifier that powers the main speakers. However, a subwoofer that is driven by a dedicated amplifier with electronic crossover is also "active" even if the amplifier is not physically inside the subwoofer enclosure.

The Active/Passive discussion is really about the type of crossover being used. Passive crossovers at the frequency used for subwoofers involve inductor and capacitor values that are very costly. Electronic crossovers are much more practical at subwoofer frequency.