More Power or use subwoofer to boost bass for music

Sorry xcool, you are new and have no way of knowing the answer to every question is GIK. Even though you specifically want more bass, and everything GIK makes can only absorb bass and never enhance it, still the answer is GIK. Or EQ. Surprised he didn't say EQ. Maybe saving for later?

koestner is right. First step is always speaker placement. Closer to the walls, either front or side, will have a big effect on bass response. Also your listening position. But the walls also reflect higher frequencies as well and so if the speakers are closer than about 3 feet to a side wall the reflections begin to interfere with good imaging. So its a balance and a trade off.

You may be a minimalist, and so am I. More power won't work. One sub won't work. GIK will improve everything and your bass will have greater definition but by absorbing not enhancing. When it comes to bass the fact of the matter is the minimalist approach is four subs. Check it out. https://systems.audiogon.com/systems/8367 Read the reviews, do a search, read about DBA. 

OP you are new and don’t yet understand that the answer is 4 or more subs in a forest of box’s and wires placed quasi randomly about your room.

bass is a wide topic and for most music listeners spans from 30 HZ to the power range of 200-250 HZ. You might try to recall or ask the dealer where those speakers were placed in the demo from side and back wall. IF you do have to compromise with near surface ( back and or side wall ) coupling, then GIK or another brand of broad band absorber panel or three to address reflections will help w imaging. Finally also you might need to tweak your listening position a bit. Room modes effect. Bass , especially below 120 HZ... even a few feet can matter.

there are other ways to add great subwoofers if Indeed the problem lies below 100 HZ. One has built in EQ.

and yes, swarm aka multiple subs...works if the crossover frequency is low enough and you like the clutter.

Also IF flat frequency response in room was the only measure of bass quality why are there a plethora of bass guitars, standup bass, etc out there....?

this from a bass player of LiL reknown....

Someone should tell millercarbon to stop adding a link to every post he submits. One look at that room would send most running from the multiple sub approach.

To enhance bass you need to try to position the speakers closer to walls to amplify the lower bass, or add subwoofers. The answer is not adding multiple subs or adding bass absorption. The rational approach is to start with proper imaging using a method such as The Master Set. Imaging is key to proper sound from a stereo source. Once the imaging is perfect you can then add subwoofers for the lowest frequencies if you want more bass. It may help to use a computer and microphone to real time analyze the frequencies in your room. Then you will know how far down your speakers go. If you want 20 Hz or below you will need subwoofers. They are tricky but to get 20 Hz and below you have to move air. Lots of air. You will need 15” woofers. The idea of a “swarm” of subs is based on evening out the nodes. It’s an admirable goal but rarely practical. One well placed sub is good but not easy or perfect. Two well placed subs are better but beyond that you are spending a lot to get a little. Like horsepower. Look up Harman Kardon white paper on sub placement. Seminal work. Proper placement of stereo speakers doesn’t necessarily mean the proper placement for bass or subs. I recommend Hsu Research or SVS for affordable well made subs. That way You can afford two or three. Hsu sells pairs of identical subs. Best of luck and keep us posted.