Installed a new sub, seems like it isn't getting much power

[john9721]

Just got done installing a new sub and amp in my 2003 VW Jetta. My setup is a single 12" JUL GT5-12D running on a Kicker DX250.1 mono (birthsheet rated at 274 if anyone cares) Anyway, I previously had this amp in my F150 on a single 12" Rockford, and for 2500 watts I felt it, and got some decent window and mirror vibrations. In the jetta however, that isn't the case. We had the gain from 0 all the way to about 55 and not only could you only somewhat hear it, you couldn't feel a thing. My stock 6.5" speakers were hitting harder. JVC head unit, EQ on dynamic, all wires and ground checked. Its a dual 4 ohm wired at 2 ohm. Any suggestions? Thanks!

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[Babykinns 10+ year member]

Just got done installing a new sub and amp in my 2003 VW Jetta. My setup is a single 12" JUL GT5-12D running on a Kicker DX250.1 mono (birthsheet rated at 274 if anyone cares) Anyway, I previously had this amp in my F150 on a single 12" Rockford, and for 2500 watts I felt it, and got some decent window and mirror vibrations. In the jetta however, that isn't the case. We had the gain from 0 all the way to about 55 and not only could you only somewhat hear it, you couldn't feel a thing. My stock 6.5" speakers were hitting harder. JVC head unit, EQ on dynamic, all wires and ground checked. Its a dual 4 ohm wired at 2 ohm. Any suggestions? Thanks!

Are you sure the amp is coming on? Check the inline fuse in the power wire and check the fuses on the amp. If both are good pull the inline fuse then re-hook up everything and see if it works any better if not the sub is prolly blown.

 

[Jepalan]

1) Check your grounds. If you did not sand or grind to bare metal for the amp's chassis ground, go back and do that first.

2) Check the DC voltage across the amp Batt & Ground terminals with a DMM and make sure you have at least +12 (ish) when car is off and +14 (ish) when car is running

3) Double check that you have signal on *both* the L & R inputs to your Kicker monoblock.

What box are you using with the JBL sub? What are the box specs? Ported/sealed, volume, etc. Where is the box located?

 

[john9721]

1) Check your grounds. If you did not sand or grind to bare metal for the amp's chassis ground, go back and do that first.2) Check the DC voltage across the amp Batt & Ground terminals with a DMM and make sure you have at least +12 (ish) when car is off and +14 (ish) when car is running

3) Double check that you have signal on *both* the L & R inputs to your Kicker monoblock.

What box are you using with the JBL sub? What are the box specs? Ported/sealed, volume, etc. Where is the box located?

The box is an Atred with I believe .90 or .96 airspace. Sub requires 1.0 cubic feet. Will that make a difference? Also could 2500 watts not be enough?

 

---------- Post added at 10:26 AM ---------- Previous post was at 10:25 AM ----------

 

*250 watts. And its sealed

 

[mylows10 5,000+ posts]

Make sure your not of of phase ! Switch pos and neg sub wires around. See if it's louder and sounds better

 

[What was that? 10+ year member]

Check wires to to sub inside box. I have ripped a system out because ,amp, hu, etc all tested fine. Figured I would start over to find what I was not seeing. I sure did. Jamming two 8 gauge wires in to a 8 gauge terminal didn't work out well. They came loose. I went crazy testing the ground, amp, battery cable, fuses, I actually think that's when I learned to use a DMM. Anyway it was the simplest solution for me and I initially overlooked it.