Subwoofers producing no bass..?

[Ultrabb]

Okay so basically right now my setup consists of a sundown u12 and it's wired to 1ohm I've even checked this with a multimeter the amp is a hiphonics Zeus zxx-1800.1d mono amp. My voltages stay around 14-11 when playing music (I know I know) and im getting nothing out of this speaker. It's rated for 1500 watts and it's doing nothing. I also tried my friends powerbass speaker in my system and his bumps on 500 watts and it barely moves in mine. All fuses are working. (And I'm not saying there's absolutely nothing but it's really lackluster) 

Basically should I scrap the amp or get a new headunit??

Vehicle is a Lincoln navigator with a line out converter on the stock subwoofer no other modifications.

 

[Popwarhomie]

Well that amp puts out 700 watts RMS at 1 ohm. After impedance rise you might be seeing 300 watts. I would buy the Wolfram 2400 thats for sale on here and upgrade your stock electrical.

Buttttt  What are your gain settings on the amp?

 

[Ultrabb]

The gain is as high as it gets (I know) the reason for this is because there's no clipping at the highest level so like why not? (Don't worry I'm not completely crazy, I care about the health of my speakers) I was planning on getting that 2000w rms skar for like 170 dollars because it's a steal

 

[mestapho]

The gain is as high as it gets (I know) the reason for this is because there's no clipping at the highest level so like why not? (Don't worry I'm not completely crazy, I care about the health of my speakers) I was planning on getting that 2000w rms skar for like 170 dollars because it's a steal

What is your source?  Something is def. wrong if you have the gain all the way up and aren't clipping unless your source unit has insanely low voltage output

 

[Ultrabb]

What is your source?  Something is def. wrong if you have the gain all the way up and aren't clipping unless your source unit has insanely low voltage output

See that's what I was thinking. I'm taking my rcas through a line output converter connected to the stock sub and I've connected an amp to my rcas through an auxiliary to rca cable to see if the voltage is low and it seems like it's not. 

 

[mestapho]

Detail your entire signal chain.  I’m not understanding your wiring.  

 

[Ultrabb]

Detail your entire signal chain.  I’m not understanding your wiring.  

Stock head unit > Stock sub woofer harness > line output converter >  Rca's > Amplifier 

What I meant about the amplifier in the last post was I hooked up an rca to aux cable  on my amp and I had the aux cable going through a headphone amplifier just to test if the signal was too weak and it didn't make a difference in the bass volume, sorry I didn't explain that well

 

[mestapho]

Ok. What car? Which line output converter? Is the LOC between the HU and the factory amp or after? 

 

[Ultrabb]

2004 Lincolin Navigator, It's a Metra Two Channel Line Output Converter, It terminates right where the stock sub in the car is, I connected the Stock sub woofer wires onto the LOC (So it's after the factory amp)