Set-up with two subs and an integrated amp

Instead of using resistors, could a step down transformer be used on the amplified output?
For an example Jensen might have one off the shelf that could work?
I would certainly check the voltage with a multimeter after dropping the voltage for use with the sub.

Also, the sub itself has a volume control?

Your first response from "mattmiller" is a good one. First off I have several REL subs and they all have no peer in their price / performance category. Actually a pair of the entry level subs will do an amazing job when carefully set up. "Speaker level" connections are always the best way to go. Virtually all audio critics will agree to that. The REL's come with a cable that has a "speakon" connector to plug into the sub. The amplifier end can be connected parallel with the sattelite speakers. One sub parallel with each channel. The REL manual will provide info on the correct connectivity. There are also after market cables designed and terminated with quality connectors, that would be a slight upgrade from the ones supplied by REL. Also the supplied cables are quite long to accommodate almost any possible setup. Once you have determined the ideal locations for the subs, you should be able to buy the aftermarket version cut to a more appropriate length, unless you prefer to do it yourself. That's my recommendation !
"SPEAKER LEVEL CONNECTIONS" 

Congrats on interpreting the OP's query millercarbon. Good answer.

Maybe....
the OP states he owns the LM.
sometimes it is useful to ask a ? Or three before leaping...

so Dave the OP do you own the 2 subs yet ?

btw I prefer the 993 in Euro trim Adventurine Green a switchblade to the 996 X-50 Machine gun 

But it of course also leaves out the more delicate yet important surgery of high passing the amp, which if done right ( integrated w sub XO slope ) will yield incredible sonics....

in which case, I would pick a Vandersteen sub or two