Second subwoofer set-up

[EN]

Hi everyone,
I need some advice about using, setting and placing second subwoofer.
I took from my friend exactly the same woofer I’ve got – SONY 70ES (200W RMS). For the last 24 hours I’ve been trying to set up my system, but it wouldn’t sound so great as I expected.
What I’ve done:
1. Line-up: I put the front speakers in this order: left, sub 1, center, sub 2, right. I believe the two woofers must fire must fire symmetrically to the listeners. Any comments?
2. Levels: I set two subs approximately 3dB down to the previous setting with only one sub.
3. Cross over: the same frequency cut-off.
I listened to the different movies or music and the result is not straight clear. Sometimes I think only one is better, sometimes – two.
I watched THE GLADIATOR and the 15 chapter sounded so fine with a lot of punch and power.
Please, share some thoughts or experience.
EN

[Bilbo]

I run two yamaha subs and found that two sounded no better than one until I played about with the Phase switchs.Hope this is of some help.

[Ramius]

I suggest a reposition. Try running the subs side by side or if they're front firing maybe stack them. The closer the drivers are to each other, the more performance you should get as they will start acting like one big driver.
This should also eliminate any cancellation issued you may have had when running them from different points in the room.
And as Bilbo said, they should be in phase with each other.

Cheers