Upgrade question for newbie

A few months ago I acquired my first system:

1. Magnepan 1.6 speakers
2. Emotiva UPA-2 amp (185 watts into 4 ohms)
3. Marantz DV6001 universal player running directly to amp

I am greatly enjoying my system, and I plan to upgrade it as funds allow. My room (a media room/game room) is approximately 23 x 25. I listen to music much more than I watch movies.

My question: If I were to spend about $1,000 or so for the first upgrade, which of the following options do you think would give me more bang for my buck:

1. A better/more powerful amp (although I am very pleased with the Emotiva for the price and it seems to drive the Magnepans better than a couple of different NAD models that I heard at the dealer)
2. A DAC (e.g., the new Peachtree iDecco or V-DAC)
3. A subwoofer (e.g., a used REL or Martin Logan)
4. A preamp
5. Something else

What about your room? What's it like? Dollar for dollar your best bet is to first upgrade your room
the maggies definitiely need a sub, so i'd start there, esp. since you're pleased with the sound of your amp.
A properly installed Velodyne SMS-1 sub controller @ $450 with a 12" sealed sub from Rythmik (per my system) or SVS (pretty extensive word of mouth plus great test results, but no personal experience) @ $749 for either will almost certainly provide significantly smoother bass and will probably provide deeper, more powerful bass as well. Your total investment here is $1200. You may decide (as I diid) to use a different high pass unit (mine is a $300 NHT x-2) in place of the SMS-1's high pass, but this can be added later.

Good Luck

It's not flashy, but you can't make a mistake by getting dedicated AC lines with high quality outlets.
In response to Lenny_zwik's question, my room is approximately 23 x 25. It has hardwood floors with no rug (which I assume the lack of a rug is not the best). There are a couple of large couches and some other furniture. In one wall there is a set back so that it is not a flat wall (a murphy bed could fit in there, but for now it is empty). Another wall is also broken up with a door that extends into the room so that that wall is also not completely flat. Ceiling is 9 foot.

I have tried doing the "clap" test and hear just a little bit of echo after a clap, but not alot.

As far as upgrading the room, are you talking about things like rugs or more like acoustical treatments? Do you have any suggestions for ways to test a room (e.g., test cds?, etc?) to see what types of treatment may yield the most benefit?

Post removed 
Cables all around (interconnect, speaker, and power)
In response to Bob_reynolds' question, I am currently controlling volume with the level/output control on the back of the amp. I do not have to adjust this very often, so it works okay. Certainly, I would prefer to have a preamp that has a remote control (which is why I am thinking about the possibility of using the Peachtree iDecco as both a preamp with remote and a DAC), but at present my main concern is sound quality.

As far as cables, I have anticable speaker wires and blue jean cable interconnects. No upgrades on the power cable. However, the ony thing on the electrical circuit is the audio gear and tv.
One inexpensive thing to improve the sound is to turn off your TV when you are not using it. :)

Your speakers are very nice, that's for sure. The amp sounds like a pretty good one too. There seems to be a gap with volume knob (back of the amp is not the best, probably) and in converting what is on the plastic discs into an analog signal. That Marantz model is not on the same class as the amp and specially the speakers.

If you want just the one box, the iDecco has had good reviews. The Tact dac/preamp combo is around your budget (used). The Benchmark dac includes a volume knob at no extra cost and it might still have a 30-day return period.

If you want to get two separate boxes (dac and preamp) then that's more fun because you can spend $1000 on each one. :)
If you review posts about going direct to amp, there is a common "thread" (pun intended). Many people say that the increased transparency or resolution comes at the expense of diminished weight or impact. Personally, the only time I tried running direct was w a Berning ZH-270 and I was underwhelmed. So there may be something to that. I've also found that in even a moderately resolving system, changing the pre-amp had a profound effect on the overall character of the sound. YMMV.
I'd suggest putting the money aside, and start saving for a set of III series Maggies.
I would start with a good read of the material on Rives Audio's web site, Acoustic Sciences' (ASC) and also on Cardas'. There's a lot of info on how to do this. I don't know what your budget is, and without knowing, it's hard to provide further guidance beyond this advice.
I have heard the Decco used as a preamp and it is wonderful. It responds favorably to good interconnects as well. For the money you cannot beat it most especially since you get a preamp and the Dac is FREE! You won't be disappointed.
Definitely a preamplifier if you're happy with everything downstream. I'm a fan of neutrality and unless your music calls for low end extension- your Maggies should serve you well.