Speaker Replacement 09 w/ HK System

Hey all,

Been lurking around the forums for a bit, but finally decided to post up and see if I can get some advice since audio is not my forte'.

Have an 09' GT with the HK system, which has been surprisingly good for my tastes thus far. I'm not a major (nor would consider) myself an audiophile, but I came across a good deal on some JL Audio TRs. Went to do a basic change out on the speakers this past week and when I have any more than just a single speaker hooked up, I lose all sound.

Originally had tried the rears, which made the fronts sound like they were underwater and absolutely no sound from the rear. Put the OE speakers back in then started from the front with a similar result.

Question is, I'm trying to keep it fairly stock on size, location of speakers, and rarely ever put the music up over me hearing the engine or the person I'm talking to - is this likely due to the HK amp being underpowered and the stock headunit directly wiring through it rather than to the speakers?

Or do I just need to get all four hooked up and ensure matching polarity across the board? I'd rather keep the HK amp under the seat, or at least if I have to replace then keep it stowed in the same location.

Any advice is appreciated!

Welcome.

You'll need to check the impedance of the factory speakers. This can be done with a multimeter placed on the speaker terminals. Set the MM to Ohms (Ω) and measure. This is the DC resistance of the voice coil, which is approximately equal to the impedance.

If the factory speakers are 1 or 2 ohms, then your JLs will be quite underpowered at 4 ohms.

There are a few amps which would fit in the factory location which would work with 4 ohm speakers.