snap or spark sound coming from speakers only with stock deck

[gpse2000]

sometimes when i turn up the tunz with the bass fairly high my back bose 6x9's (added to my so no amp) make a snap or a spark sound. I had the original radio in when i first installed these and it did it. THen i got an aftermarket one and it went way completly. Now i went back to a different factory one and it happens again. Could it be a short of some sorts with the stock radios?

[Explicit_Spade]

Sounds like you're underpowering the speakers...

[gpse2000]

Yeah thats what i started thinking. is it cuz basic factory speakers are 4 ohm and bose factory are 2 ohms.

Gotta sell the car soon anyways i was just curious