room setup suggesion needed

@mijostyn  here is the answer, like always it lays in numbers, 8 12" mathematically 

should do better job than 2 25" but in fact they don't there fore subwoofer is backing up the system with sonic boom. I don't have that problem in a fact I need to move my speakers off the wall farther to control my overwhelming bass.

As far as the sources, my TT is just something I like to play with but I'm not using it as the main source. DAC on the other hand is what I need to develop a bit better and I'm looking for alternative to what I have. I was looking in to the streamers/servers and as of now I'm not sure if I like the idea, sending digital signal from any computer shouldn't  be a issue, it's only matter of software and file quality, DAC on the other hand can do big difference so I definitely take your advise and look in to Bricasti Design M3

@ssg308, quality, properly set up subs will not add "boom". They will not only add more detail to the lower frequencies but will enhance the sound at higher frequencies as well. You will not be able to to localize the sound from the subs, it will be a part of the soundstage.

 I have also had success taming bloated bass by closely adhering to the 1/3rds rule. Speakers moved out from the front wall at 1/3rd of the total room length and the listening position 1/3rd of the way from the back wall. Tweaking the distances from there. 

@ssg308, bass boom does not come from speakers or subwoofers. Bass boom is a product of room distortion see here.

Mike

Anyone who thinks they know anything about how their speakers sound in a room because of the specs is probably mistaken.  The room changes everything and measurements are key.

The ability to limit the bass in main speakers and move subs to ideal locations can be life changing, as are bass traps and sub EQ.

@ssg308 What you have is too much mid bass and not much really low bass. Very few speakers do much below 40 Hz particularly ported designs. You have a more complicated problem because your 15" driver is really a mid woofer. It crosses to the horn at 700 Hz which means it carries a significant portion of the midrange. You really do not want it doing very low bass because that would distort everything else it is doing. JBL needed to use a big efficient 15" midrange driver to keep up with the horn. It was not designed to do really low bass and the specs are very misleading. Ideally you would cross over to subwoofers at around 80 Hz which would clean up your midrange and pass the signal to drivers specifically designed to run down to 20 Hz flat. In my case I used 12" drivers for packaging reasons. I would have used 15" drivers but the size of the enclosures needed to house them would have been prohibitive. I use 8 drivers not to blow everyone away or impress the neighbors, but to form a linear array to match the radiation pattern of my main speakers. For people with point source systems like yours two subs, in your case at least 15", will suffice. You have to hear a system that is capable play low C on a pipe organ. It is a religious experience. 20 Hz is barely audible but boy can you feel it. 

I assume you have been to a large concert or two. The game is recreating that visceral experience in your home. Large venues breath at low frequencies. You know you are in a large space even with eyes closed. A good live recording of a stadium concert should feel the same way. 

I agree with everything @erik_squires says except I am not so impressed with bass traps, digital EQ is way more effective.