I am on strike since 6 weeks and it will continue.
After doing my daily picketing hours, I have spent the rest of the first days on strike to read about room treatment.
Everybody agee here to say that after to buy good equipment and good speakers and after to place them at the best place possible, the next step for a good SS&I is treatment long before to buy a PEQ (audyssey, YPAO, minidsp).
Like many, I bought an EQ device first hoping that it will do miracles.
Thanks to this strike I have decided to try to built bass traps (to buy those during a strike would have been a cause for divorce!!). I must say that the places available are rare due to waf. But she let me go into the rabbit hole at one condition: do not move the furniture.
My room is small (see my system) . Where ceiling joins walls, I can put some traps on the front and the back walls jonction but not on the jonction with the left and right side walls. For corners, only 2 are available. For the jonction between floor and wall, I had only the place behind the fronts speakers and a little at the right side wall and at the back wall. Finally in the vertical jonction with 2 walls, only one (the back right side corner) could be treated and not entirely.
90 hours later more or less, 12 traps are in place. They are of various dimensions choosen by the place that I have not by the sound science ( if I understood well it must be a relation between the trap dimensions and the sound waves to treat). Some are 24 inches X 16 inches, others are 26 inches X 32 inches and others are 12 X 36. All made of wood for the frame, jute for the fabric and Roxul Safe'Nsound at least 3 inches thick and more where possible.
Now, the basses ( 15hz to 300hz) decay of 20db in the first 300ms and 80% decay below the noise floor after 450ms.
BUT THE DIFFERENCE IN THE SOUND IS BREATHTAKING!!!
The difference is near as great as the difference between my 5 PSB alpha series speakers and my B&W!!!!
It is difficult to believe!
Also, now, a little change of not more than 8 cm between fronts and 4 cm in the distance from the front wall make easily audible changes in SS&I. Also, changing the toeing by a few degrees is audible etc.
...and all changes are measurables!
Of course, I do not have perfect resoiknse curves but it is the best I ever had and the best I can for the moment.
Thanks to all of you experts here and a special thanks to JohnM for REW.
My system 5.1 :
ROTEL RSX-1562 /Fronts: B & W 804 D2 bi-amplified; surround : B&W 704 and center B&W HTM4d2/sub SVS PC 2000 /TV Samsung UN55ES8000
/BD player Cambridge CXU/ set-top (cable box) rented from cable co.
Bis Audio cables and power bar from the wall to the receiver
My room:15'4" x 11' 6" x 7'6" tv near the center of the long side wall