Home Theater 101 - Subwoofer question?

I will bet this is as basic as it gets in my first H/T 101 Subwoofer class, so anyone with a decent HT system should be able to advise me.

I have a very basic and simple 2 channel system for TV and movies (music playback is performed on another system). I don't want to change anything but add a cheap, decent subwoofer to what I already have.

[SYSTEM: Pioneer Elite A35 amp (45wpc), Denon 1930 DVD, JBL HLS610 monitors, Kimber cabling]

There is a slight problem, my integrated amp does not have a preamp or sub output. I have read that it is not such a bad thing to use speaker wire from amp to sub to monitors, and better subwoofer integration is possible. I don't know if this is true but I nave no other option than this hook-up. I'm keeping this amp and would rather not add a sub if adding a sub is ill-advised.

Now that the stage is set, what cheap good quality power subwoofer will you recommend?
Definitive Technology, used, for one (among many).

"I have read that it is not such a bad thing to use speaker wire from amp to sub to monitors, and better subwoofer integration is possible."

This work fine. You can instead (if this is easier, and it usually is) connect from to the speaker wire from your speaker post to your sub "speaker level" and use the settings on the sub to blend with your main speakers. This is how I do it with great results.
Please check to make sure the sub has speaker level inputs
before purchase. A lot of them don't.
To clarify: I would run speaker wire from amp to monitors, then from monitors to sub (providing it has speaker level controls). Is this correct?

Do you have a cheap subwoofer recommendation for my modest system?
Do ensure speaker line imputs are on what ever sub you select, AND the more control of contour on the sub will be of immense help too, phase, slope, level, cut off, and the better/finer the adjustments the better... if at all possible. Not all subs wil have every mentioned option.

HSU. SVS. Def tech SC2 or SC1. Velodyne SPL series

good luck
i remember your system--the craigslist special, right? you might look on ebay for an energy or mirage sub--very musical and easily available used for under $100. paradigm pdr-8 or pdr-10 is also nice and cheap. if you can spend more, i'd parrot some of the above recommendations--def tech or hsu.
To clarify: I would run speaker wire from amp to monitors, then from monitors to sub (providing it has speaker level controls). Is this correct?

This is correct, though there are a few different ways to do it. The owner’s manual will give you a few scenarios, try them all and see which works best in your system. You can use cheap speaker wire to try different configurations. Go online and read a Def Tech sub (or other brands- like the ones blindjim suggested) owners manuals for examples.

Blindjims advice is good. Look for something that has the controls to integrate properly.

A word of advice- NOT HAVING A SUB is better than a sloppy cheap sub. You can pick up a used Def Tech Supercube 1 with speaker level inputs for under $600. Great sub, I have one in my second system.
wait for a mirage bps 150i. i went from that to an onix ufw-10 to dual svs 16-46's, back to the mirage, and now a sunfire true sub eq. to my ears and in my room, the mirage still bests them all in sound quality. the only caveat for me was i tended to bottom out the mirage, but i think, in retrospect, i asked too much of it instead of enjoying what it could do very nicely.
Sorry. My internet has been giving problems.There is a
HSU sub model VFT-2 MK3 selling from HSU for $499,plus
$59 S/h. I haven't heard it,but their products usually
give good bass for music and movies. They give a lot of
product with a lot of tuning options for the dollar,and
true low end bass,usually into the 20-30 hertz region.
This mid-fi TV/movie system is not my main concern, so the emphesis is on cheap. While I appreciate the HSU, REL and the like suggestions I think the Mirage, Paradigm and similar cheap subs are more to my liking. I will continue to keep an eye out for a bargain as it shows up used.
Let us know your budget- you'll get responses up the wahzoo!
I assume you're ok shopping used? Craigslist has a ton of decent subs under $200. The Paradigm, some Boston, Polk subs are decent for that budget. As for new, partsexpress.com has some decent Dayton subs for the little money invested.
Yes I'm looking used, mostly on Craigslist, to save shipping costs. Something will show up eventually.
I would check out REL Subs - First they are excellent and second, they have a Neutrik connection which hooks up directly to your speaker outlets on your amp - they also have a LFE if you did have a sub out on a different receiver - both connections can be used simultaneously and have their own volume controls - makes it easy to integrate 2 channel with surround if you ever went that route - But the speakes conection is what you can use - also makes it easier to integrate with your main speakers because the sub gets the same info as the speakers - Very Cool
Looks like the REL subs get the best recommendations, but are out of my price. Plus they are much better than the rest of my system, so it may shame the rest of what I have. Mirage and Definitive Tech are probably closer to a better match.

actually I would think that the better the sub the better it can be blended with the rest of your system. a donkey sub is just a boom box and is more noticeable in my opinion. I have a JLF112 and its a great sub that I often forget its there. It just goes about it's business when I have it in 2.1 music. Of course it goofs up my house in HT mode for action flicks but thats a different operating mode. Everyone says REL is good and they are likely right. I know JL is good but they are also expensive. I have heard that HSU, outlaw audio, and velodyne are also good to a varying degree and have products at many price points. Consider if you can get a good sub for your budget even if it performs better than your current stuff you will still be happy and won't have to upgrade it anytime soon.