What ohms is my 2001 running at?

[01EB5.0]

2001 EB with factory 8" sub. My bro just built a box with a single 10" 4 ohm single voice coil sub. Would my stock amp work with this 10" sub just for the time being?

 

[TracerBullett]

Don't know. If I had to guess I would think factory equipment runs 4 ohm but this is just a guess. I wouldn't waste my time hooking the new sub to the stock system. That system is designed to work together and I'd bet the new sub will sound poor with the stock system.