I decided to upgrade the sound in my 05 RL.
The plan is to
1) Add an Alpine Amp 4 channel amp 45 Watts RMS per channel. The front channel drives the 2 front door speakers and the 2 A pillar tweeters.

2) The bose front door speakers and front tweeter will be replace with either Alpine SPR-170S or SPX-17 Pros or Polk Audio MM5601.

3) I will also add an Alpine 10 inch subwoofer to the trunk, this will be powered by the 2 rear channels of the Alpine Amp bridged to maybe 90Watts RMS.

Anyways, that 's the plan.....

And then I spoke to the Alpine speaker salesman, and he said "you can't do that, the RL has 2 ohm speakers and either you won't be able to do it or you'll get some wierd sound."

Anyway, I know some of the forumer has done speaker/amp upgrades on their RL. If they can shed some light on what can be done and what to watch out for, I would greatly appreciate.

Plastics
05 RL silver

 

Haven't done the upgrade, but in general a 2 ohm speaker will put more of a load on the amp and as long as the amp can handle it will sound fine. In general amps put out higher wattage at lower ohms.

As an aside, Bose speakers generally are harsher on amps than most others (just one reason why they ... well ... suck. Alas the RL is still an awesome car.

 

The impedance match is what the amp is looking at as a load and this is sometimes a crossover or a speaker. If your new amp (for the front and sub) has an output impedance of "X" then your speakers should be a load of "X". Your proposal for the front and sub sounds fine because you are changing the sub and amp and the front speakers and amp - just make sure that the "X" is the same for both.
A couple of questions: How are you proposing to handle the rear speakers?
Does the new amp have a X-over (I.E. separate outputs for tweeter and woofer) or are you going to use an external one?

 

Thanks
I already have the amp, which is an Alpine MRP F200.
I won't touch the rear speakers and they will be continue to to power by the factory deck.

I think this should all work.

Plastics

 

Good luck - let us know how it all works out.

 

I have done some more research and a couple of stereo shops has told me that because the Bose is a 2 ohm system, that hooking up aftermarket amps, speaker and subwoofer may not get better sound. One shop suggested that I hook it up with a Digital Signal Proceesor (DSP) unit call Audison Bit-One ..but this unit is about $1000 so that's a lot of coin.

I would like to hear from anyone who as replaced speakers and add amps to their RL to get some advise on how to acheive better sound.

Plastics
05 RL Silver

 

I haven't replaced my speakers yet, but have a pretty good knowledge of audio engineering. Ultimately, db22 is right in that the only speakers YOU will be powering with the amp are the ones you are replacing, and you know that the rear speakers are fine with the factory amp. Therefore, you don't care how the factory speakers interact with your amplifier. Just make sure the speakers you hook up to the amplifier are within the load range of the amp.

Just for anyone's information though:
The amplifier is going to attempt to keep the amplitude of the voltage swing (signal) coming out of its mosfets (drivers) the same regardless of the load attached. Power = V*I, or = V^2/R because of Ohm's Law- V=I*R. Were V is your voltage (signal), I is the current, and R is your resistance (load). Therefore, the lower the load resistance (ohms), the higher the power you are going to get out of the speaker. However, the restriction to achieving ridiculous power by just lowering the resistance of the speaker is Ohms Law. Whenever the voltage remains the same, and the resistance is lowered, the current must increase by the same factor. The mosfets have a limited current driving capability, and when this is pushed, they will cause extreme distortion and eventually fail. Either because of current-overload protection in the amp, or essentially blowing up, they won't work temporarily or forever. If you match the resistance of the speaker to the acceptable range of the amp, you will be fine.

What is interesting is your last statement.
What do you think "better sound" is- loud or clean (not distorted)? IMHO "better sound" means the least amount of distortion possible at high volume. If you agree with me about this, then you would actually look for a higher impedance speaker, and put an amp behind it that can make it loud. The key to distortion is keeping the current range of the mosfets small so that they can accurately change the voltage at high speed. Since current goes down as resistance goes up with the same voltage, a higher impedance = better performance. Lower impedance = higher power. Decide how much "coin" you want to spend and look for the compromise between the two that will fit your definition of better sound.

Hope this helps.

 

You lost me from the get go...but I was able to program my garage door opener with no problem.

Plastics

 

OK - Let me simplify it it - if you turn the volume control clockwise then the loudness should increase. If you turn the volume control the other direction then the volume should go down. If you don't like the sound then push the volume control.