Need Audio room advice and opinions. Treatments an

Hi all, need some help here

Heres a picture of my audio room. At the moment, the room is empty and theres a lot of echo in the room. I reckon its quite bad echo wise. The walls are all painted cement walls with 1 wall made of glass. Floor are hard wood. The height is around 3m

What are some solutions to solve the echo problems? Some of the things ill do before moving in the audio systems are

-placing carpet on the left and back wall

-placing carpets on the wood floor

-drapes on glass wall

As this will be my main audio room, not much other furnitures will be in it..

Main system

- htpc -> nad m51 dac -> densen b200 preamp -> densen b330 poweramp -> neat ultimatum mf5 speakers and bower wilkins pv1d/ kef r400b

Here is how i want to place the system. Is the subwoofer location correct? Or is there other better placements? (for both movies and audio, but audio is much prioritised)

Any advice and recommendations will be much appreciated
I used to armchair-quarterback room acoustic treatments from time to time, but having seen the quality of work that a professional can do, I have backed off because my advice would fall so far short. Getting the right kind of treatment in the right quantity and in the right place, without overspending on something you don't need or overlooking something you do, is well beyond my ability to diagnose and prescribe. The analogy I use is crossover design: anybody can put together a textbook crossover, but getting the RIGHT amounts of inductance, capacitance, and resistance in the RIGHT places for a particular combination of speakers takes a professional level of expertise. Likewise, getting the RIGHT amount of reflection, diffusion, and absorption (in the right frequency ranges) in the RIGHT locations for your particular room and budget takes a professional. Most of us (myself included) don't even really know where the goal posts are.

The general tendency among us non-professionals is to over-absorb the high frequencies, because it is very easy to absorb short wavelengths, and then do little or nothing that offers much benefit elsewhere. The result is far from a natural-sounding acoustic space. On the other hand room treatment done right can make your room not only sound great, but sound like it is much larger than its actual physical dimensions.

The money spent on getting the guidiance of a professional and doing your room treatment right is probably the smartest, highest-return money you will spend on your system. If you don't have someone in mind, I highly recommend Jeff Hedback, whose studio designs have won numerous awards and produced numerous Grammys, but whose work is still affordable.

I would highly recommend reading this book -- titled for home theater but applies to 2-channel rooms as well:

If nothing else, it will give you a good foundation upon which to make your room-based decisions rather than throwing carpets, etc. up willy nilly. I have no affiliation with the author, but I have purchased several books on the subject and have found this one to be by far the most applicable and most easily approachable and understandable. Personally I wouldn't make a move until I read this so you're more informed. Best of luck.