Ohms-speakers

[MR.G.]

I have a 2000 Bxtr that has an Alpine unit with output of 18 watts RMS x 4. All speakers have been replaced with 4 ohm Polks. How can I add the rear speaker upgrade kit without damageing the amp. It doesn't have the connection for the kit like the stock radio has.
Tks.,
MR.G.

[insite]

i'm confused. do the speakers run off an amp, or off the head unit? is the unit 18x4 RMS at 4 ohm or 8 ohm?

[KevinH1990]

Before I can answer your question, I need to know whether you are using an amp to power your speakers. If you are using an amp, you could just drive the speakers from the headunit. If you are already using the headunit to drive the speakers, you will probably need to install an amp and reconfigure things so that you can power 6 channels.

I have the PNP rear speaker kit. Originally, I had the 4 channel HAES (stock) amp that ran the dash and door speakers. That permitted me to run the rear speakers off the head unit.

I later added a 6 channel amp from a 996 and I am now running all the speakers from the amp.

[MR.G.]

Sorry to omit details. I am running the 4 polk 4 ohm speakers off the Alpine head unit that has 18 w/RMS x4. I am NOT running an amp because the guy at Audio Connections told me that the 18 w/RMS in the Alpine was stronger than the Haes set-up. Something about using a power output measurement standard that is NOT the same equivalent (less power than RMS rating system).
Tks.,
MR.G.

[insite]

how are the speakers wired? are all four channels used, or just two? i'm assuming you have dash speakers and door speakers. what happens when you adjust the fade (front to rear) on the head unit?

if you have the rear channels on your head unit open, you can add the rear speakers there. if you don't , then wire the dash speakers and door speakers in series (8 ohm load) and then wire in the rears to the other outputs on the head unit.

you're better off running a four channel amp here, but you can make do with the head unit.

[KevinH1990]

I think you will be better off adding an amp to your system.

I guess it depends on how much effort and money you were planning to spend on this. Harvey (harveypnp@comcast.net) sells a kit that can be wired to either the stock headunit or a stock 6-channel amp. I found an inexpensive amp on eBay and it was plug and play. I found this to be a cost-effective solution.

I'm sure that there are amps that sound better than the stock unit, but the cost of the amp and the installation will be higher than OEM unless you have the skill to do it yourself. Insite's recommendation on the wiring is probably workable, but it seems like 18 watts would be somewhat low to drive that many speakers. I'm not an expert on the subject so I could be wrong.

Good luck.