Center speaker lacking volume output

[Kuraudo]

Ok so I have a

Infinity C250 (91db sensitivity)
and Boston Acoustics CR67 (89db sensitivity)
Theoretically if I lower the volume of the Infinity by -3db
on my PIONEER VSX-815 Receiver the volume should be the same.

I checked all the settings and set the Speaker to be LARGE as well and the wiring is correct in the back according to polarity and tightness in the back of the speaker and receiver.

However the volume is really low, it sounds several times lower than the LR channels. The sound quality on DTS ps3 games and movies sound kind of "tunnel like"

I bought my speaker off of ebay so how do now I'm worried if I got a "counterfeit speaker" but the build quality seems all very good and heavyweight.

Since the overall volume still is low, I have it at 0db.
At this level its still very low.

Any other input on this speaker and amp combo?
Everyone complains that they can't hear the movie unless I switch to stereo mode.