aresh

anyone replace these with their stock subwoofers? I have L7 sound system, im hoping replacing these without running an amp will give me some improvement over the stock L7 subs. These are 2 ohm impedence, meaning they could be used with the stock car amp.

bruce_miranda

What is the power wattage of the Earthquakes? The 4ohm versions used to be 150W and so you needed an amp to drive them. If you drive similar wattage sub with your stock L7 amp it will struggle to even move the cone and you will get worse bass than you are getting now.

aresh

Yes but isn't it true that the L7 system uses 55w for speakers and 125w for the subs. I remember reading this in e90 post.com. If that is soN wouldn't one be ok with just a straight swap.

bruce_miranda

Contrary to popular belief, the amp needs to be higher rated than the speakers to drive them well. Anything else will put a load on the amp and won't sound nice.

bruce_miranda

The L7 drives all the speakers so if you are planning on using an after market amp you are going to have to take the output of the L7 amp and run to through a LOC or an amp that takes High inputs and then drive the new earthquakes from the output of your new AMP.

Before you buy the Earthquakes, buy the amp and try driving the L7 subs with the new amp at a slightly higher gain. You may then decide you don't need the earthquakes.

aresh

yes i am also thinking of getting an aftermarket amp before the subs, 300w RMS sound good? Should i just tell my installer to replace the stock L7 sub amp with the one i will purchase? My guess is the higher power and ability to choose lower crossover will help the L7 subs sound better, deeper.

aresh

so what Bruce has told me is one amp powers the speakers and the subs. In that case, i would need a 5 channel amp?

aresh

im just updating this thread so people with similar issues can see a resolution.

Bruce stated that i would only need a 2-channel amp to drive the subs, while keeping the old factory amp, powering the speakers. Basically, if i have this down correctly, all i have to do is take out the sub inputs from the stock amp into the new aftermarket amp. simple enough

bruce_miranda

What wiring are you using between the new amp and the earthquakes? Because if you are using the factory wiring itself then you will need to make a Y connector wherein you take the speaker outputs from the L7 as, use them as inputs to you new amp and then the output of your new amp will go back into the car's wiring to the subs. All the other wires will just need to be connected through between the two plugs.

I can draw a little picture if it helps.

aresh

im still waiting on the parts to arrive, in the meanwhile which sub should i get, the 2-ohm or 4-ohm. Im guessing getting the 2-ohm sub with the setup you provided will yield more power.