Do I need an amp?

[vividjazz]

Short answer for most aftermarket speakers to sound good is yes.

This is even more so the case for split/component speakers which use even more power because of the crossover for the tweeters.

Speakers have a power rating expressed in RMS. If you feed them this amount of RMS power from an amp or more they will work at their best. Ignore the other power ratings which are there for marketing.

Though your new aftermarket speakers may work just off a head unit. Remember those high powered!!! aftermarket headunits 50Wx4 are really only about 15Wx4 RMS. Your speakers will sound so much better with more power that an amp can provide. If your only getting 15W from those good aftermarket head units imagine how little the factory unit produces.

If you push the volume without a powerful enough amplifier you will damage/destroy your speakers because of "clipping".

Clipping occurs when an amplifier is asked to deliver more current to a speaker than the amp is capable of doing. When an amplifier clips, it literally cuts off the tops and bottoms of the musical waveforms that it's trying to reproduce, thus the term. This introduces a huge amount of distortion into the output signal. Clipping can be heard as a crunching sound on musical peaks.

Speakers only output what they are fed. If you fed them wrong then you will do them harm.

[nick]

What if the amp's RMS is lower than the speaker's RMS? say 200W RMS for Amplifer with a 300W RMS sub? which one would get damage easily??

[vividjazz]

nick said:

What if the amp's RMS is lower than the speaker's RMS? say 200W RMS for Amplifer with a 300W RMS sub? which one would get damage easily??

The speaker only takes what its given. If you crank the volume the amp will try to put out more power than its capable of causing it to clip killing the sub. Both amp and sub could be damaged.

If you don't drive the amp too hard then you won't harm the speaker.

To get the optimum out of the sub it would be ideal to have a 300W RMS or higher amp but I know at the cost of higher powered amps this is not always possible.

I test drove a Vibe Space 12 ported sub enclosure last Saturday. My cars monoblock amp puts out about 400W RMS. This enclosure is rated at 1000W RMS. It worked just fine and sounded great but I wasn't stupid and tried to crank that sub to see if I could set a new Australian SPL record. It went louder with that setup than I could stand in the car.

[vividjazz]

If you want your music to be loud, amplifiers are definitely part of the picture. But whether you run your system wide open or softly enough for conversation, a power amplifier will breathe life into your music, bringing out all of its excitement and detail. Here are a couple of the main benefits of adding an amp:

* Better sound quality — Adding an amplifier gives you a clean power source that can drive your speakers without straining. Unlike an amplifier built into an in-dash stereo, an external power amp isn't limited by the space available — it can be designed without compromises. That means your music will sound cleaner and more defined at all volume levels.
* Power for upgraded speakers — A factory system or an in-dash receiver may not do justice to your upgraded speakers. If you're adding high-quality aftermarket speakers or component systems to your vehicle, they may require more power for peak performance than your existing in-dash receiver can provide.
* Powering a subwoofer — Subwoofers require significantly more power than a brand-name or factory in-dash receiver can provide. A separate amp is a necessity.