• Match Your Car Speakers & Car Amplifier

• Choose the Right Car Amplifier

• Accessorize Your Car Amplifier

• Install Your New Car Amplifier

• Find Car Amplifiers on eBay

• Buy Car Amplifiers With Confidence

Match Your Car Speakers & Car Amplifier

Match Your Car Speakers & Car Amplifier

Car amplifiers boost the signal your stereo sends to your car speakers, driving your speakers with an independent power source. You'll see two power ratings when shopping for a car amplifier: root mean square (RMS) power and peak power.

• RMS power: RMS power measures the amount of continuous power a car amplifier uses to drive your speakers. Make sure the RMS power on your amplifier matches the RMS power rating on your speakers and subwoofer to prevent car speaker damage.

• Peak power: Peak power indicates how much wattage a car amplifier has available for short and sudden increases in sound. The number will always be higher than RMS.

There are three types of car amplifiers: mono, two-channel, and four-channel.

• Mono car amplifiers: Mono amplifiers power a single speaker.

• Two-channel car amplifiers: Two-channel car amplifiers boost the signal to two speakers and a subwoofer.

• Four-channel car amplifiers: Four-channel car amplifiers boost the signal to four speakers and two subwoofers; two speakers and a single subwoofer; or any configuration in between.

Choose the Right Car Amplifier

Choose the Right Car Amplifier

Find the best car amplifier for your music, your car, and your pocketbook.

• Get good bass: If want a hearty bass line, make sure your car amplifier has a low-pass filter that only sends low-frequency notes to your subwoofer. It will keep your subwoofer from trying to reproduce high notes.

• Improve high-frequency audio:Car amplifiers with built-in high-pass filters prevent your tweeters from trying to reproduce low-frequency sounds.

• Look for speaker-level inputs: Most car stereos installed at the factory have a basic built-in amplifier. Look for a car amplifier with speaker-level inputs that can process these already-amplified signals.

• Provide extra amplification:You can connect one car amplifier to another to drive different speakers. If you want a multi-amplifier system, make sure your primary amplifier comes with a preamp output so that you can send a signal to your secondary amp.

You'll find both new car amplifiers and used car amplifiers on eBay. Buying a used amplifier can save you money, and you can find recent models; audiophiles regularly upgrade their equipment and sell their used amplifiers at a significant discount.

Accessorize Your Car Amplifier

Accessorize Your Car Amplifier

Make your car audio system stand out or just make installation easier with a few accessories.

• Remote controls: Control your car amplifier with remote controls, even if you mount it in your trunk.

• Voltage monitors: See exactly what your car audio system is doing at all times with voltage monitors. Some even monitor temperature.

• Control center: A control system monitors and regulates the flow of electricity to your components on high-end systems. It also contains fuses to help prevent catastrophic shorts, which can damage your car audio equipment.

• Custom covers and car amplifier bridges: Custom covers and car amplifier bridges make your system look good. Some amplifier bridges also work as expanded heat sinks to keep your car amplifier cool.

• Car wiring kits: Car wiring kits come with all the wires and fuses you’ll need to safely install and operate your car amplifier. Make sure the rating of the fuse works for the power level of your amp.

• Line-output converters: If your car stereo doesn't have RCA jacks, use an external line-output converter to lower the stereo signal and produce a signal your amplifier can use.

Install Your New Car Amplifier

Install Your New Car Amplifier

Every car amplifier comes with slightly different installation instructions. Let your installation documentation guide you and keep some basic rules in mind when you install your new amp.

• Choose amplifier location wisely: Install your amplifier more than 3 feet from your radio under a front seat or in your trunk. The electricity flowing through the amplifier can interfere with reception if you install it too close to your radio.

• Ventilate your amp: Make sure your amplifier gets enough air. The cooling fans built into most amplifiers circulate air to keep the component cool—if you place it somewhere with proper ventilation. Make sure the amplifier has at least 2 inches of clearance under a seat. If you decide to install your amplifier in your trunk, make sure to mount it right side up.

• Use the stereo preamp output:Connect your car amplifier to the RCA jacks found on the back of your stereo. The stereo preamp output sends an unprocessed music signal to your amp. If your car stereo doesn't have RCA jacks, use your amplifier's built-in converter or an external line-output converter to lower the stereo signal so that your amplifier can use it.

Find Car Amplifiers on eBay

Find Car Amplifiers on eBay

Once you know what type of car amplifier you want, go to the Consumer Electronics portal, click the Car Amplifiers link under Car Electronics, and start searching for items on eBay.

• Categories: The Categories list on the left side of each page will help you narrow down your listings by item type. You'll find links for 2-Channel Car Amps, Mono Car Amplifiers, and Multi-Channel Car Amps. As you dig deeper into the site, you'll also be able to narrow down your choices by brand.

• Product Finder: Use the drop-down menus on the Car Amplifiers Finder to quickly narrow down item listings by brand, number of channels, and condition.

• Keyword search: Search eBay title listings for specific words. For example, if you want to find 4-channel amplifiers, type "4 channel" (without quotation marks) into the Search box. Click "Search title and description" to expand your results. Visit eBay's Search Tips page for more tips on searching with keywords.

If you can't find exactly what you want, try shopping eBay Stores, tell the eBay Community what you want by creating a post on Want It Now, or save a search on My eBay and eBay will email you when a match becomes available.

Buy Car Amplifiers With Confidence

Buy Car Amplifiers With Confidence

Before making your purchase, make sure you know exactly what you're buying, research your seller, and understand how eBay and PayPal protect you.

Know your purchase

Carefully read the details in item listings.

• Figure delivery costs into your final price. If you spend a lot of money, make sure the seller will insure the item when it ships.

• If you want more information, ask by clicking the "Ask seller a question" link under the seller's profile.

• Always make sure to complete your transaction on eBay (with a bid, Buy It Now, or Best Offer). Transactions conducted outside of eBay are not covered by eBay protection programs.

• Never pay for your eBay item using instant cash wire transfer services through Western Union or MoneyGram. These payment methods are unsafe when paying someone you do not know.

Know your seller

Research your seller so you feel positive and secure about every transaction.

• What is the seller's Feedback rating? How many transactions have they completed? What percentage of positive responses do they have?

• What do buyers say in their Feedback? Did the seller receive praise?

• Most top eBay sellers operate like retail stores and have return policies. Do they offer a money-back guarantee? What are the terms and conditions?

Buyer protection

In the unlikely event that a problem arises during your transaction, eBay and PayPal are there for you.

• Pay safely with PayPal: PayPal enables you to pay without the seller ever seeing your bank account or credit card numbers. In fact, PayPal protects buyers 100% against unauthorized payments from their accounts. Plus, with PayPal Buyer Protection, your purchase can be covered up to $1,000.

• eBay Security & Resolution Center: Visit the Security & Resolution Center to learn how to protect your account and use eBay's quick and efficient resolution tools.