I'm looking to upgrade the speakers in my 94 F150 but I don't want to get a too high of wattage and blow the factory amp. I was hoping someone could give me the specs or tips and how high I should go without tearing up the truck.

 

Speakers rated for higher wattage won't blow your amp. What will blow your amp is speakers with lower impedance (low ohms) than your original speakers. If you can find out what the impedance of your factory speakers are just be sure your new speakers are not lower. For example, if your factory speakers are 8 ohms replace them with 8 ohm speakers, not with 4 ohm speakers. Also, remember that if you connect two 8 ohm speakers in parallel to use two speakers in place of one on the same channel, you are dividing the ohms in half. This will put a larger load on your amp and may fry it.

If you still have the originals, check to see if the impedance is marked on them. If it's not stamped on them you can check their impedance with a multi-meter set to "Ohms" function.

 

The ohm rating is the resistance to current flow. The simplest way I can describe it is an 8 ohm speaker on a 4 ohm amp will cut the sound in half, because the current flow is cut in half. Most of your factory systems are going to be rated using 4 ohms as a baseline. Bose and your other specialty systems use a different ohm load to keep you from swapping in aftermarket speakers into their system. He is correct about checking the impedance of the speaker and just doing a swap of the same impedance should cause no issues. The wattage rating on the speakers you see is how much they can take. If you put a 100 watt speaker on a 25 watt amp, the speaker will play fine, just not to its full potential.

Something else that you need to look at when shopping for speakers is the RMS rating. RMS is the amount of wattage a speaker can take on a continuous basis. Peak ratings mean nothing as that number comes from what the speaker is rated to take right before blowing. These numbers are often inflated and most times just made up by the manufacturer. If you can only find a peak rating, steer clear of the product.

www.crutchfield.com will allow you to put in your vehicle and will give you a list of speakers that are compatible for your application. I use it a lot when shopping for replacement equipment for my customers. I've been in the audio world for over 20 years now.