Acoustic Sound Treatment

so should one put panels behind listening position or behind speakers first?

so should one put panels behind listening position or behind speakers first?

I'd go for behind the listener for bass trapping first but generally more broadband bass traps is better and you can't ever really do enough in bass trapping...although you can over do it in the mid and treble frequencies if you have way too much surface area of panels =>an acoustically dead room = yuk!

First - proper speakers placement. You should start there.
First reflection points next.
Now... there are 2 schools of "live end - dead end".
1.Live front end - dead back end.
2.Dead front end - live back end.
It is hard for me to recommend which road should you choose, since everybody have a different opinion on this subject. Second I don't want somebody to think that I am an expert on that matter, because I am NOT. What I do have is a lot off experience in set-ups in problematic rooms and my own experimentation and measurements. And NO, I am not a dealer or installer. What I do , I do for my friends and fellow audiophiles. I never charge a stinking penny and I do it for pure satisfaction.
In my own room I implemented treatments according to my rooms particular problems. All room are more or less different from each other and that makes it more difficult to recommend one solution over the other.
My own preferences is semi-dead front end and live- diffused back end with just a little absorbing.
Trick is to not to over treat you listening room. Believe it or not but some reflections are beneficial and you don't want to kill all of them. Ceiling treatment and bass tweaking is another matter maybe for another thread.
Mariusz Stark

The principles of LEDE were begun in the 60s for recording studios. These were dead behind the speakers and live behind the listener. Mimicking an inversion of the recording process (i.e. performers on a live stage and microphones that were dead behind them). In our listening environment we are recreating the performance--not working as a studio engineer. In this case, live on the speaker end and dead behind the listener works best.

Here is an article that may help:
On the Soundstage

Rives, where does diffusion fit in? Does one consider a wall treated with diffusors as dead or live?

Reason I am asking, I have had some very unsatisfactory result when treating my back wall with diffusors. The same diffusors on the front wall (behind my speakers) seems to create a deeper soundstage and quite pleasant to my ear.

Thanks
Paul