The 12x12 room isn't great, but can be workable. If you start to read much about acoustics, you will find that cubes, or rooms with identical width and lengths, are the least desirable spaces for sound as they tend to create "standing waves," which means frequencies will be cancelled by reflections resulting in lost sound. If you have some stuff in there, like you have, it will likely help to a degree (furniture, bookshelves, pictures, draperies etc. etc.). I really don't mean to confuse things here, but you probably get the idea.
Given your Yamaha receiver does not have any pre-outs, only speaker outputs, you will need a subwoofer that has this type of input.....a "speaker level" input, sometimes also called a "high level" input.
I'd give Grenades a thumbs-up for his Dayton Audio recommendation and these DO have the speaker-level inputs! Although I have not heard this product personally, I do know a few folks who have them and they really like them. Also, Grenades' recommendation would carry some weight with me.....Here's what we're talking about:
Good tip, Grenades! Although, I think they are closer to $230 from the Dayton site (looks like about $180 from Amazon and FREE DELIVERY!!!) now but still a very worthy contender for the OP to start with.....
Good tip, Grenades! Although, I think they are closer to $230 from the Dayton site (looks like about $180 from Amazon and FREE DELIVERY!!!) now but still a very worthy contender for the OP to start with.....
https://www.daytonaudio.com/product/1049/sub-1000-10-100-watt-powered-subwoofer
This would be a terrific start to transform what you've been hearing with your system so far. Careful though, it takes some messing with things to get it set up properly. When you connect the sub to your speaker outputs on the rear of your Yamaha, you will be raising and lowering the signal that goes to the sub with your volume control, unlike when you use a
low level output (line level) where the volume control on the rear of the sub controls the volume of the sub and that's it. With speaker level inputs, you run the wires that are now going from your Yamaha speaker
outputs to the Paradigms to the sub spearker level
inputs first, and then from the sub speaker level
outputs over to your Paradigms. Then there is the matter of having the sub volume set to the correct level so that you can have your Paradigms at the volume you want them to be with the sub being perfectly blended in, without providing too much bass (which you will notice as "boomy" very likely) or too little.
Not to worry, it's kind of fun (for me, anyhow) to get it set up properly and once you do, you will not likely have to do very much afterwards aside from perhaps walking over to the sub and tweaking it up a tad, or down, whichever is necessary for an album that is recorded particularly bass-heavy, or conversely, bass-light.
Besides first paying attention to the room treatments, (e.g. if you have a large screen tv, or a lot of windows i.e. glass, make covers or get shades, preferably cellular ones to reduce reflections that can contribute to standing wave problems), and then to
establish the most ideal listening position (this simply CANNOT be emphasized enough and makes a tremendous difference) where the sound-stage really opens up and you feel like you're sitting front row, center, the sub would be my next move and then see how things sound before doing much else.
Hope this wasn't too much information amigo....just trying to move you along a bit towards your own slice of musical nirvana!
PS - Placement of the sub, while not overly critical, is important and you will need to move it around a bit to get optimal results. Generally speaking, close to a corner will give stronger bass response and I would recommend, if possible, to start there......