Tuning Your Amplifier
If you have aftermarket amplifier to power your speakers or subwoofer(s), but how do you tune it to reach both your speakers, subwoofer(s) and amplifier's full potential?
CarAudioNow has put together a quick guide to do a basic tune on your amplifier to make your stereo reach it's potential. Use it to tune subwoofers or speakers alike. But before we get into tuning, lets review a few basic and common terminology, features and functions that will help you better understand the tuning process.
Common Tuning Terms
Max (Peak) Vs RMS Power
The difference between "Peak Power" and "RMS Power" is simple, so don't let it confuse you. RMS Power is a measure of the amplifier's continuous power. It's the realistic amount of power that the amplifier is rated for. It's more of an average of the wattage output over a set amount of time. Peak Power can best be described as the "peak" amount of power that the amplifier can generate or handle in a very short amount of time, a burst. It is not the amount of power the amplifier emits on a continuous basis, but more of a quick burst.
Even though the Peak Power ratings are marketed by speaker and amplifier manufacturers to catch the eyes of consumers, it is not the Peak Power, but the RMS Power that you want to use as a tool to match the right speaker with the right amplifier.
Gain is the input sensitivity adjustment necessary that is used to match an amplifier's input to the receiver's output. A properly adjusted gain reduces background noise, distortion and prevents speaker damage.
Frequency is the pitch at which your speakers emit sound at. You will need to know the range of your speakers or subwoofer in order to tune your amplifier properly.
Low-pass (LPF) and high-pass filters (HPF) are filters that pass signals with a frequency lower/higher than a certain maximum/minimum frequency. If you choose the high-pass filter on your amplifier, the corresponding frequency dial will set the minimum frequency that the amplifier will send to the connected speakers/subwoofers (HPF is typically used for smaller sized speakers). Vice versa, if you choose the low-pass filter, the frequency dial will set the maximum frequency that your amplifier will send to its connected speakers/subwoofers (LPF is typically used for larger sized speakers and subwoofers). The optimal setup will have speakers that cover the high range frequencies, while subwoofers will cover the low range frequencies, without any gap in between the frequency coverage.
In addition to low-pass and high-pass filters, there is also a "Full" selection, that does does not filter the frequencies and sends a full range of frequencies to the connected speakers/subwoofers. If you have a system that does not have subwoofers, and the amplifier is being used to power 6.5", 5" x 7"/6" x 8" or 6" x 9" speakers, you can use this option to get a full range of sound.
Bass boost is a feature designed to boost the low range frequencies. It's typically used for subwoofers, however, can be very touchy and dangerous to use. We recommend not using bass boost unless you have to.
Tuning Your Amplifier - Steps
Great, so now that you have an idea of some of the basic terms, lets get to setting up your amplifier:
Step 1: Setting Volume and Gain Control
Turn your stereo off and disconnect the RCA cables that run to your amps. Then turn your system back on, turn the volume on your radio/receiver all the way up to max without any music playing on them. If your speakers are running off of your radio, and you are tuning your amplifier for an additional subwoofer, make sure that you disconnect all speakers before you turn your radio to prevent damaging your speakers.
Now that you have found the maximum volume (many radios denote the maximum by a number), turn back the volume to around 80% of the maximum, and set your radio's Equalizer to 'Flat'. Then turn your amplifier's gain and bass boost to zero and turn the crossover filters to off or full.
Now, plug back in the RCAs into the amplifier channel for which you would like to tune (e.g. if you are separating speakers by channels and have separate RCAs that for each, choose one to tune). With your favorite genre of music, or purchase a test disk for tuning, slowly turn the gain up until you begin to hear distortion in your speakers. Once your speakers start to distort, back of the gain until you no longer hear distortion. This is the base gain that you will use now to tune frequencies.
Step 2: Tuning Frequencies
Now it's time to switch to the built-in cross overs and filters that are built into your amplifier. For subwoofers, select the low-pass filter (LPF) and for speakers (for a system that has a separate subwoofer or speakers to cover the low range frequencies), select the high-pass filter (HPF). If you are using the amplifier to power mid sized speakers that are meant to cover a full range of frequencies, select the full or off position, and disregard this tuning.
Now, find the frequency range of your speakers/subwoofers. If you are tuning for speakers and select the HPF, you will align the frequency dial with the lowest frequency that your speakers are rated for (note that the numbers on the dial may be in 1000s). If you are tuning a subwoofer(s) and select the LPF, you will align the frequency dial with the highest frequency that your subwoofers are rated for.
Step 3: Bass Boost
If you're feeling risky, and don't mind putting loudness in front of longevity, bass boost is a great way to increase how loud your bass is but can be very tricky to use and hard to set properly. If you are going to turn your bass boost up, make sure you turn the gain down. Each subwoofer is different, so finding the right combination of bass boost and gain is up to your ear, but bottom line is to have the highest output without distorting.
Step 4: Back to Gains
Now that frequencies and bass boost have been set, turn back to your gains while your radio is at 80% to max with music playing, and tune the gain again until you hear distortion, tuning back once you hear it.
Step 5: Finish it Up
Last step! Reconnect all amplifiers (if you were tuning channels or amplifiers separately) and turn your radio down to zero. Slowly ramp up the volume until you reach the 80% or distortion, whichever comes first. If everything is set correctly, you will reach the 80% without any distortion in any of your speakers. If not, find the corresponding gains for the speakers/subwoofers that are distorting, and turn the gain down until they no longer distort.
And that's it! Do not exceed the 80% maximum on your radio. Keep in mind that different genres of music might need different tuning to maximize the output. Now you're all set and your amplifiers are tuned!
You could pay someone to install this for you, but it's not a particularly difficult project for anyone even slightly familiar with auto electrics. Why not do it yourself and put the money saved towards new speakers or that subwoofer you've been thinking about?
We're going to talk you through the main steps in installing a car amplifier. Each make and model of car is different, so we can't provide precise instructions for your specific vehicle but we will take you through what you need to do. In doing that we'll address:
- Amplifier types and integration
- What you'll need (tools and parts)
- Installing the amp
- Running power
- Speaker hookups
- Finishing up
1. Amplifier types and integration
If you've done your homework you'll understand how to size your amp for the speakers you intend using. You'll also know that amplifiers come with various numbers of channels and usually two speaker input options. (Our top list will help you find the best car amplifier for your needs.)
Channels and speaker inputs have a large bearing on how long the install will take. A mono channel amp has only one output and that you'll use for driving a subwoofer. A two-channel amp will most likely be hooked to the front speakers, although you could bridge the outputs to drive the subwoofer.
Likewise, a four-channel amp works with either four speakers or the two fronts and a subwoofer. And if you haven't already figured this out, a five channel works with four speakers plus the subwoofer.
The speaker inputs you'll use depends on whether you're sticking with or replacing the factory head unit. Factory units rarely have pre-amp outputs, so you'll be tapping in to the speaker wires and feeding them to the speaker-level inputs on your amplifier. An aftermarket head unit will probably have pre-amp outputs that feed straight into the amplifier inputs.
However many channels on your new amplifier, and however you feed the signals to it, there's one other part of this project to remember: you will also be running wires from the amplifier out to all the speakers.
2. What you'll need (tools and parts)
In addition to the amplifier itself, go out and buy:
- Amplifier wiring kit. (These come in various wire gauges. Check the instructions with your amp for the correct size.)
- T-tap connectors (if that's your preferred wiring connection method.)
- Zip ties or electrical tape.
- As for tools, you should have:
- Pry tools for removing trim pieces.
- Crosshead and flat-bladed screwdrivers.
- Wire strippers
- Soldering iron (if you prefer the security of soldered joins.)
- Electric drill
- Utility knife
- Socket set
3. Installing the amp
Start by deciding where you want this mounted. An important aspect to consider is airflow for cooling. Amplifiers can get warm and heat is no friend of electronics. Bear this in mind when installing an amp.
The most popular places are:
Passenger side firewall (keeps the wire runs short but access may be difficult.)
In the trunk, against one of the side panels (or the back seat, if that's fixed.)
Under one of the front seats. (This will mean taking the seat out. If it has airbags built-in be very careful how you do this.)
Having settled on a location, remove any trim, mark where you want the holes to go, then drill. (Be careful to check what's on the other side of the panel!) Secure the amp with the screws provided. (From here on we will assume you put your amp in the trunk.)
4. Running power
This section covers installing the power, ground and amp turn-on wires. First, disconnect the battery.
The amp draws currently directly from the battery through a large diameter red cable. Connect the wire to the battery, then install an in-line fuse. This is essential to protect your high-value system!
Thread the power cable through the firewall and into the cabin. You may need to drill a hole for this. If so, try to fit an appropriate grommet.
Remove the kick panel and door scuff panels and run the power wire through to the back seat. Lift out the seat cushion and thread the wire into the trunk.
The amp needs a turn-on wire so it powers-up when the head unit is turned on. This joins to the turn-on output at the back of the head unit, so that has to come out of the dash. Every vehicle is different but this generally means removing the trim pieces on each side of the center console, then unbolting and withdrawing the unit itself.
If the head unit doesn't have a turn-on output, connect to the ignition wire running to the head unit. This can lead to an audible thump as the amp turns on, so an alternative is to buy a line turn-on converter.
Run the turn-on wire back to the amplifier.
Connect one end of the ground wire to the amp and the other to a good chassis ground. Then connect the power and turn-on wires to the amp.
5. Speaker hookups
Run speaker wires from the amp out to the front and rear speakers plus any subwoofer. Disconnect the wires coming from the head unit and fit the new wires to the speakers.
If the head unit has pre-amp outputs, (usually RCA connectors,) connect wires to these and run them back to the amp. Run them down the opposite side of the car to the power and turn-on wires so as to avoid interference.
If the head unit lacks pre-amp outputs, which is usually the case with the factory installed system, you'll need to connect to the speaker wires. You can do this at the head unit itself or out at the individual speakers. (The former allows you to keep the wires away from the power.) Connect your wires using either T-taps or by stripping, splicing and soldering the joints.
At the amplifier plug in wires from the pre-amp outputs. If you're using the speaker wires themselves, these go into the speaker level terminals on the amp.
6. Finishing up
Before replacing all the trim you've removed check everything works. Reconnect the battery and turn the system on. Verify you're hearing sound from all the speakers and that the amp only turns on with the head unit. Set up your amp following the instructions supplied.
Re-install the head unit. Before putting trim back use zip ties or electrical tape to secure all the wires. You don't want them tapping or rattling while you drive! Finish by reinstalling all the trim.
Save money by installing a car amplifier yourself!
When upgrading your car audio system you naturally want the best car amplifier you can afford. Why not save some money to put towards the amp by installing it yourself?
Installing an amp is a straightforward job, especially if you've had some previous experience with vehicle electrics. In just a few hours you'll be enjoying deeper, clearer and crisper music from your car's speakers.