First if you are talking about normal speaker (not subwoofer), I would not recomend doing that.
There is different ways to connect multiple speaker to one amplifier chanel.
You could wire it in serie or in parralel.
If your are talking about dual voice coil or more than 2 speaker, there is even more possibility to wire two or more speaker to one channel.
Now if you are talking about single voice coil subs, in a perfect situation, by wiring them in parralel, the wattage should not get lower but the impedence will be divided by the number of sub you hook up. You will need to make sure the amp can support a lower impedance.
The Rockford Fosgate R150-2 2-channel amp puts out 50 watts RMS per channel to your speaker system, or you can bridge it to supply 150 watts RMS to a subwoofer.
In short, yes. you can add speakers to nearly ANY setup. however, you should be sure to add enough speakers with particular resistance (load/ohms) ratings in order to wire them in parallel and series so each channel has the same total ohms as the original speaker. If the total load on each channel is too high or too low, you could risk overheating the power source (head unit/amplifier), some headunits or amplifiers have built in safety mechanisms which turn off the unit if the load is either too high or too low. Keep in mind, when adding speakers, the power from each channel is split between them. For example, each speaker may get 100 watts, but if you add a speaker to each channel, each speaker will only get 50 watts. Not only this, but keep in mind Bose made some very specific connectors so you will have a hard time to add and connect the extra wires. The system is in no way made for this.
Honestly, it depends on the durabuility of the speaker. Most likely not, but I would definetly not take the chance! Soory
The speaker impedance does not match the amplifier's specified speaker impedance.
It depends on the environment, a 2 watt speaker is usually smaller and more portable but a 12.5 watt speaker is louder and usually has better sound quality.
Each speaker is rated at 200 watts rms
In laymen 's terms, yes. But the "Watts" of a speaker is not what the total power of the speaker is. The are usually two different ratings for speakers to determine the total power. One is "RMS", which means root-means square. And the terms "peak or continuose power". A speaker can be 400 Watts, 360 RMS, 390 continuous power. That means it will take an amp at least 400 Watts to drive the speaker properly. And the speaker will perform at 360 Watts RMS, and peak out at 380 Watts continuous power. Remember, u can't blow a speaker from overpowering it. Only from under power. The speaker will distort and sound horrible from overpowering, but it will not blow.
Without getting into the multitude of variables and keeping this as simple as possible, NO ...Simply connecting a 300 watt amp to a speaker (driver or cabinet) will do no harm, that is, until you make an attempt at raising the volume! A speaker rated at 60 watts means just that ...it can handle 60 watts. At low volumes, no harm will come to the speaker, driven more powerfully, harm may soon come to it.
No
Rms is watts that's the amount of watts a speaker is rated for.
Yes depending on how many channels the amp has. You usually want to place each speaker on its own channel. If this amp has at least three channels, the output of the used channels would be 1500 watts / 3 = 500 watts per speaker.
Yes you can bridge this amplifier to a 2 channel at 4 ohm per channel for 200 watts out of each channel.