Covered my TV...What next?

I am a newbie to higher end audio and recently acquired some Magnepan 1.6 speakers that I am enjoying very much. My speakers are about 5 feet from the back wall of my room which is 25 by 23. I have a 50 inch plasma tv between the speakers that is not far from the back wall. I have hardwood floor with no rug, but the windows have fairly thick drapes. Walls and ceiling are drywall.

This evening I decided to experiment and put a blanket over the tv, which I had seen suggested. I was suprised that it made a noticeable difference. Certain instruments seemed much more distinct and almost seemed louder than with the blanket off the tv. I assume this what people mean when they say the glass on the tv "smears" the image or sound.

This bit of "success" has me interested in trying to improve my room. Any suggestions for other things that might make the biggest difference -- that is, biggest bang for buck and reasonably practical? I do have the WAF to contend with, but the blanket is something that I think can be pulled out of the closet when needed.

I have also read a little bit about dealing with first reflections. Is there a particular area (e.g., back wall? floor? side wall? ceiling?) that would best respond to some type of treatment (I assume absorption) with the Magnepans?

Edge, You have an awesome room. I am sure many Audiogon members are jealous after reading about your 25'x23' room, I know I am. Actually I have a pretty good size room too and it is nice because big rooms offer a big sound.
You may have opened a huge can of worms by putting that blanket over your television. Now you will be doomed to a life of forever trying to improve the sound of your stereo system.
A good rule of thumb on walls is "live end, dead end" meaning if the wall behind the speakers is dead then the wall behind you should be live and visa versa. With Maggies you really don't have to worry about the side walls although you may want to try an area rug on the hardwood floor, but be careful not to make your room too dead or you will never have enough power for your Maggies.
I like to walk around the room clapping my hands and listening for the reverberant decay of the various parts of the room. If you try this you will find that some areas of the room will be very lively and some very dead. Try to balance this out to make the acoustic of the room even out. You can balance your room with furniture, opening or closing window treatments and with commercial room acoustic products. I use Tube Traps from a company called Acoustic Science Corporation. Tube Traps are the best, but they are not cheap.
Go for base traps in the upper corners V shape acoustic pillows. You have alot of wall space so sound panels are a must and since you have wall space it will make it easier for you to scatter them.
Put some tube traps in the corners behind the speakers if you can. You can buy pre-made traps like those from ASC or Real Traps, or you can DIY a pair very easily.

I have a DIY set (6" panel depth, but 4" would work too) that has a nice wood frame around the panels with a acoustic suede fabric covering it. They are also on stands so they can be moved around easily. If you click on my system link you can see them.

I've seen panels made from art prints as well. Lots of options when you DIY.
You basically have a soft screen where you tv is. It will have no effect below about 125 Hz and probably robs your high frequencies. I would follow Rrog's suggestion about finding live and dead areas, but I would remove the blanket from the tv first.

Your room is very close to being square, which probably means you have some prominent bass peaks. There are things to recommend, but many are expensive and have low WAF. Our tv is quite large. I would recommend lighter blankets.
more power on your amp, I don't care what amp you have now, you need more power. Wyred4Sound ST1000, that should do the trick. Or Bel Canto Ref1000 MB, more power!!!
A rug with athick pad would easily and affordably improve both acoustics and WAF. Not many things do that.
Dress up in women's clothes while listening, for @ least a 200%-300% improvement in sound quality.

Always assumed Tom Gillette does this on a regular basis.
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Do whatever you can do to improve the sound with my prior suggestions before you spend any money. You may be satisfied with the sound without buying anything.