Why does one 1000 Watt amp cost $850 and another cost only $99? Are they both the same strength?
A great way to get an idea what an amp can do is to look at the size of the fuse in it. Here's where we refer to Watt's Law (Watts = Voltage X Current [Amps]). For example, if an amp has a 15 Amp fuse, running off a vehicle's 12-14 volts of power, it could produce a maximum of 180-210 watts of workable power if it's a well designed amp. SO if you look at that $99 1000 Watt amp and it has a 10 Amp fuse in it, guess what.
Wattage Ratings on amps can be extremely misleading. Unfortunately, the industry isn't very regulated when it comes to power ratings. Currently in car audio, the most commonly referenced types of Wattage ratings are Continuous (RMS) Power and Peak Power. Peak Power is the rating most used by low cost amp manufacturers to make an inexpensive amp appear to be as powerful as a more costly one. Peak Power measures the largest signal the amp is capable of producing. The rules for measuring Peak Power are, simply put, "No Rules". However they can get that piece of equipment to spit out a signal and get a measurement, that's OK. If they want to give it 50 Volts and measure it right before it explodes, that's OK. More credible manufacturers, like Rockford Fosgate, Alpine and Boston Acoustics, will measure Peak power under conditions that can exist in a real car.
Continuous Power is a bit more realistic. Generally, Continuous Power measures the amps under these conditions. A supply voltage of between 12 and 14.4 Volts - A 20 to 20K Hz signal input signal - Measure the amplitude of the largest signal it can produce UNCLIPPED (see Clipping in the Audio Glossary). However, there are still manufacturers out there that will bend these conditions to achieve bigger ratings by measuring the output at the frequency the amp is strongest at, not 20 to 20K Hz. For years, if you wanted to figure out what to spend on an amp, it was pretty much a dollar a watt. That figure has improved slightly with the advanced technologies of today, but not by a huge amount. Price will still tell you much more about amp capabilities than wattage ratings can.
The industry is currently working on implementing a new standard for measuring and publishing amplifier specifications called CEA-2006. The goal of this rating system is to create a level playing field for comparing ratings on products. There will be two primary ratings for amps - "Power Output with Total Harmonic Distortion plus Noise" (indicates the actual continuous power developed by the amplifier, into a 4 ohm load, over the entire design bandwidth, while producing not greater than 1.0% THD+N) and "Signal to Noise Ratio - A weighted" (indicates the amount of audible noise inherent in the product at 2Vrms ). Back To Top
Why do I need a fuse at the battery, and how big should it be?
This is not only to protect your amp(s), but more importantly, to protect your battery. If your power wire accidentally disconnects and grounds to the frame
(because your entire car chassis can be considered "negative" or ground), the fuse will blow and stop the flow of current. Otherwise, it may be your battery that blows (literally). Installing the fuse fuse close to the battery (less than 18 inches away is recommended) optimizes your protection. The size of the fuse should be slightly higher than the total fuse rating of the amp(s).
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Where should I mount the amp and how much airspace does it need around it?
Usually space is at a premium in most vehicles, so finding just the right spot to mount your amp is can be frustrating. Two popular locations are in the trunk or under a seat. Under-seat mounting is space-efficient and keeps the amp hidden from view. It also lets you run shorter cables from your receiver. In you're considering this spot, test fit the amp under the chosen seat and try out all the adjustments available on the seat (forward, backwards, seat height and tilt) to insure that part of the seat or seat frame will not hit the amp. A trunk-mounted amp requires longer power and signal cables, but is easier to wire to the rear speakers and your subwoofer. Wherever you choose to mount your amplifier, make sure it has adequate breathing room around it to help cooling. If you're going to mount the sideways,
make sure that the fins on the heat sink are running vertically so the heat dissipates easily. Don't mount your amp upside down — this causes the amp to collect heat instead of letting it escape resulting in overheating which can
can damage or destroy your amp!
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What size power and ground wires do I need for my amplifier?
You'll need to figure how much current your amp(s) will approximately need. By using the fuse value of the amplifier you can get an idea of the amount of current draw the will be used under full output power. Consult the Recommended Power Wire Tables to find out the gauge of power wire you'll need. The power and ground wire should be of the same gauge.
If you are using multiple amps in your system you can run a separate power wire for each amp, but most prefer to use one larger power wire in conjunction with a distribution block. The distribution block will give you one central connection point near all the amps. To arrive at what gauge the main power wire need to be, add up all the fuse ratings of the amps in the system. This determines the total amperage draw in your system. Then consult the Recommended Power Wire Tables to find out the gauge of power wire you'll need. From the distribution block to the amps (or when grounding each amp separately), you only need to run the recommended gauge wire that they need individually. Back To Top
How big of an amplifier(s ) can I run in my car?
That will depend on
your vehicle's ability to provide adequate current for the amplifier. In many vehicles, the alternator is only capable of supplying a little over the requirements for the standard electrical system (i.e. headlights, air conditioning etc).Depending on how you play your system will determine the amount of current you will need. For example, if you listen to your system at low listening levels, then you will probably use less than one-third the rated current draw. If you play your system loud, then you will use most of the rated current of the amplifier.
By using the fuse value of the amplifier(s) you can get an idea of the amount of current draw the will be used by your system under full output power.
Most alternators have about a 40 percent reserve capability. Order to determine how many in ampere of current you will have for your system; you will need to find out what your alternator is rated at. Most alternators have a metal tag on them stating the total amperage available. If you cannot find the tag, check with the manufacture to find out the rated amperage. Once rated current of the alternator is determined, you need to multiply this number by .40 in order to determine the reserve current available for use with your power amplifier.
For example, an 80 Amp alternator would supply about
32 Amps of reserve current. If you want to be absolutely sure of what it can do,
get your electrical system tested by a professional to determine electrical systems true capabilities.
If you find that you headlights dim when you are driving at night and your system's cranked up, this is a sign you should upgrade your electrical system.
One way is to upgrade the alternator so that it has higher amperage output. Another way is to purchase a Capacitor (see our Power Capacitor Installation and Info page). Back To Top
Where should I ground my amp?
Your ground wire should be of the same gauge as your power wire and must make direct contact with the body of the car. Try to find an existing bolt or screw that makes contact with the car body near the amp. Remove the bolt or screw, and scrape away any paint or grime.Using a star washer to secure the ground wire will help maintain solid contact with the car body. Use a ring terminal on the end of the ground wire to insure a good connection. If you can't find a convenient ground screw or bolt, drill a hole for one. Make sure you know what's behind the surface so you don't drill into anything important (like the gas tank, a gas line, or a brake line).T ry to ground each one separately if you're grounding multiple components and leave about a half-inch of space between each of the grounding points. If you prefer to use a single bolt, stack the grounds in the order of the most current greedy component on the bottom and the weakest drawing component on the top. Back To Top
What is bridging and what does it do to an amplifier?
Bridging involves taking the two channels of a stereo amp and combing them together so they act as one larger channel. Two channels bridged will generally produce a little more power than the two channels running separetly will. Bridging is commonly used when you have a two channel amp running subs, where a mono source works better. This is because you might have just a single speaker to hook up or if you're running two or more subwoofers, having all the woofers run off of one single channel reduces the chance of any phasing problems.
When you bridge two channels together, you halve the impedance load presented to them. For example, with a 2 ohm (total) speaker load, a bridged amp will run at a 1 ohm operation. Keep this in mind when choosing what impedance of subs to run with your system because underloading an amp can cause it to prematurely shut down or damage it. Back To Top
Can I bridge my mono amplifier?
No, your amplifier has only one channel. Two channels (within the same amp) are required for a bridged configuration.
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it's probably a problem with your spe
Why does my amplifier distort when I turn it way up?
A common misconception is that your speakers are unable to handle the power your receiver produces. The distortion is actually caused by lack of power. Any power amplifier has limitations. When it's driven past these limits, it causes something called “clipping” in the amp which makes the sound distorted.
Clipping is a condition caused when an amp essentially “runs out of room” to produce a large musical signal. As volume is turned up, these signals get increasingly larger. Think of it like jumping on a trampoline indoors, with the ceiling of the room representing the limits on your amplifier and how high you jump representing a musical signal. The more power your amp has, the higher the ceiling is. If you have a low ceiling, you won't be able to jump very high before hitting your head. If you hit your head hard enough, everything distorts. That's basically what happens when an amp goes into clipping. Clipping can damage speakers very easily by producing excessive heat on the voice coils.
The type of music you listen to will affect just how fast you reach this point. The more bass the music has, the less you have to turn up your receiver before it distorts. Lower frequencies require more current from your amplifier, causing it to exceed it limits quicker. This distortion can easily damage your speakers. So whenever to start to hear it happen (irregardless of where you're at on your unit's volume scale), just back off your volume until it stops plus a little more. This will keep your speakers from being harmed.
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My amp blows it fuse when I hook it up. How do I figure out what's wrong?
First off, we do test amps at the store if you want to bring it in. If you want to try to troubleshoot it yourself, try this process.
If you have your speakers hooked up to it, try unhooking all the speaker leads from the amp and then try powering it up. If it blows a fuse then, your amp is most likely damaged.
If it doesn't blow the fuse when the speaker wires are disconnected from it, check your wire to the speakers and make sure there aren't any shorts (bare wire touching together) between the + and - wires. If the speaker wires looks OK, power the amp off, disconnect the speakers from the speaker wires and hook the speaker wires back up to the amp. Power it back up. If it blows a fuse, there's a short somewhere in the speaker wires. This can sometimes be a result of wires being pinched along the path you chose to run them in your vehicle.
If it didn't blow a fuse when the speaker wires (without speakers attached)
were hooked back up, rehook the speaker to the wires (making sure that there are no stray wire strands touching between the + and - terminals of the speakers and power the amp back up. If it blows the fuse now, it probably is due to damaged speakers.
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