6x9 speakers problem... (bass)

[Clarkeymc]

Ive fitted some 6x9s at the rear (parcel shelf). The problem I'm getting is that when set to balance (both speakers play same) the bass sounds low and poor. Yet when music is played from one only, the bass is top notch.... Any ideas?

 

[smorodina]

Sounds like they are wired out of phase. This causes loss of bass frequencies. To keep them in phase, all the connections marked + from the radio/amplifier should connect to the terminal marked + on the speakers. These can be difficult to see or I have known them simply to have a red spot. You probably have the wires wrong on one of the speakers.