PUMPKIN CAR STEREO SUPPORT CENTER

So i Just finished installing this radio into my 09' Honda Accord sedan w/ premium sound. The unit did not want to turn on at one point until I joined both the Ignition (red) and power wire (yellow) together. Then the unit functioned the way it should. But now I am getting feedback through the speakers when the car in on the run position/or turned on. Also, the subwoofer seems to sound really bad now.

Hi, that means one of the yellow wire or red wire doesn't get 12V power. You can try have a test if you have a multimeter. About the bad sound issue, you can contact the pumpkin customer service.
You need to tell them your order number or ebay id so that they can confirm your unit . i suggest you show them a short video to help them understand your query and find the cause.
Regards