Hi Moorthy,
Got your alert in my data base.
First, rotate the EP350's volume control halfway or a bit more through its rotation and set the sub's crossover to its maximum position. Disconnect the coax sub cable from your receiver and plug it into the left or right channel line audio output of any working CD player (or Dvd player) and play a CD that you know has lots of bass. Many CDs have excellent deep bass.
Are you hearing deep bass from the subwoofer? It will sound muffled and "bassy" but if it's working properly, then you'll hear deep bass frequencies.
Once you have it working, re-connect the coaxial cable to the Yamaha's Subwoofer output jack and to the EP350's RCA female line-level input jack. Do not use the Yamaha YPAO auto calibration. These are fraught with error, especially with subwoofers.
Go into the Yamaha menu and be sure you have set your main speakers to "Small" and the subwoofer to "On". Select an 80-Hz crossover frequency to start. Check the individual channel level settings one by one for each channel including the LFE (Subwoofer) channel. Raise it to at least the 0-dB setting or higher to make certain the EP350 is receiving a good voltage from the Yamaha.
Get a good calibration DVD (Avia or Sound &Vision Home Theater Tune-Up DVD) and the RAdio Shack sound level meter to do proper sub calibration.
If the 350 still doesn't produce deep bass output, call the Axiom toll-free number and have Axiom service manager Joe VAssallo call you and talk you through trouble shooting.
There is a troubleshooting guide for each subwoofer on the axiom site. Go to the on-line owner's manual and click "Troubleshooting". Follow those directions in addition to my suggestions.
Regards,
