Everything Car Audio

Car Audio Wiring

noreply@blogger.com (Anonymous) — Tue, 29 Apr 2014 21:41:00 +0000

Car Audio Power Wire

Power wire is one of the most important parts of an amplifier installation. The proper gauge is the second most important consideration, next to fusing. The proper gauge should be used so that the amplifier is not choked off by the size limitations of the wire. If you use too small of a power wire you can get a large voltage drop between the battery and the amplifier. This voltage drop can cause distortion in the output and even cause the amplifier to shut off if it is equipped with under-voltage protection. When selecting a power wire, be sure to purchase one that has many hundreds or thousands of strands so that it will be easier to install and will not break when passing around sharp corners. Also make sure that the jacket of the wire is of a material that will resist chemicals such as oil and battery acid that it will encounter in the engine compartment.
When running power wire always make sure to cover it in protective wire loom in the engine compartment and to use rubber or plastic grommets when passing through any metal or abrasive surface. Otherwise the power wire can chaff and eventually short out.

Car Audio Speaker Wire
Speaker wire is also important in terms of size and strands for the same reasons but the jacket is not as important because it will not see the same chemicals as the power wire. When shopping for speaker wire, look for oxygen free copper (OFC) wiring. The size of your speaker wiring depends on the amount of power going to your speakers and the length of wire from the amplifier to the speakers. Most systems will need to use 16 gauge to 12 gauge wire.

Car Audio Signal Cables
Signal or RCA cables are also important for their noise rejection properties. Cables range in price from a couple of dollars to over one hundred dollars a pair. Most decently priced cables in the twenty to thirty dollar range (for a twenty foot pair) should be adequate for most listeners and noise situations. Twisted pair cables offer much better noise rejection properties as opposed to coaxial cables (the most common). Twisted pair cables consist of two small gauge wires that are twisted around each other in a helix pattern. Coaxial cables are one small gauge wire jacketed by a braided cable which are then both encased in a plastic jacket. The advantage of the twisted pair cables is in the twist in the cables. By twisting the cables noise picked up by one cable will theoretically be canceled by that same noise in the opposite cable. Twisted pair cables can be difficult to find so ask for them specifically when buying RCA cables.

Features and terms that may be encountered with regard to wiring are:
Butt Terminals: This type of terminal resembles a long barrel and is used to connect small gauge wires together. These type are crimp terminals and considered less desirable than soldering when soldering is an option. These terminals are also sometimes referred to as crimp connectors though that term can apply to many variations of crimp terminal.

Deep Cycle: A battery usually reserved for marine use that can be drained and replenished many times. While popular years ago many installers have relegated this battery to system use only with a traditional car battery for main power.

Farad (F): The base unit of measure for capacitor storage. One farad is very larger and is equivalent to one million microfarads (uF).

Gauge: This refers to the diameter of the wire. The smaller the number, the larger the wire. Sixteen is common for speaker wire, eight is common for average size amplifiers, while four gauge and below is used for large amplifiers. For reference, four gauge wire is about the same diameter as the average male pinky finger.

Gel Cell: A type of battery that uses a gel type acid. These batteries can be desirable because they may be mounted upside down without the danger a standard type battery would pose.

Heat Shrink Tubing: A type of insulating plastic that resembles a drinking straw. A small portion of this tube is cut off and placed on a wire before soldering. After the connection is soldered and cooled, the tube is slid over the joint and shrunk around the wires by means of a heat gun or hot hair dryer.

Microfarads (uF): The more common unit used to measure capacitor storage. One million microfarads is equivalent to one Farad.

OFC: An abbreviation for oxygen free copper. This is the most desirable wire to buy and there is really no reason to buy any other kind. As the name implies it is pure copper that is free from oxygen impurities.

Spade Terminals: A type of terminal used on most speakers. The type found on speakers are male spades while the ones used to connect to these terminals are female spades. These terminals are also referred to as quick disconnects though this name can apply to many different types of terminals that come apart quickly.

Voltage Rating: Referring to the amount of voltage a capacitor is rated to handle. The very least a capacitor used for reinforcement should be rated at is 16 volts while 20 volts is much more desirable and available on the slightly more expensive capacitors.

Car Audio Show Competition Organizations

noreply@blogger.com (Anonymous) — Thu, 18 Oct 2012 21:16:00 +0000

Car audio shows are one of the most exciting things in the car audio hobby. They bring together people of all backgrounds that share a common love for car audio and competition. There are four major car audio show competition organizations. If you think competing is right for you, check them out below. Not all car audio show organizations are available in all areas.

IASCA - The oldest car audio competition organization and also the largest. IASCA has traditionally been associated with sound quality competitions but has more recently added the idBL, an SPL (boom car) category. Their sound quality segment, SQ, has seven categories and only two power classes, 1-600 watts and 601+ watts.

USACi - Once the new kid on the block, USACi has become a major player in the sound off scene. USACi also has two competition formats, SQ (sound quality, basic and advanced categories) and SPL (boom car). USAC was started with the idea of bringing fun back into car audio competitions. There are two power classes in each SQ division (0-600, 600+) and several in the SPL competitions.

dB Drag Racing - Started and led by veteran competitor and soundoff legend Wayne Harris, dB Drag Racing is just what the name implies. Competitors boomin side by side for the title of loudest vehicle. The measurements are displayed on a large drag racing type "tree" and are very exciting to watch. dB Drag is all about SPL. If you want to be a boomer than you need to look into dB Drag Racing. Competitors are classified by the number of woofers in their system and the extent to which their vehicle has been modified.

MECA - MECA classes its SQ competitors by the extent of vehicle modification. Competitors are classed as either Amateur, Street, Modified, Modex or Extreme. MECA also offers SPL classes in similar categories.

Choosing a Quality Amplifier

noreply@blogger.com (Anonymous) — Thu, 18 Oct 2012 21:15:00 +0000

Also keep in mind the quality of the amplifier. A generally good indication of quality build and the power output is the size and the weight of the amplifier itself. Better quality amplifiers will usually have a heavier and larger heatsink versus a low quality amplifier of the same power rating. Do not accept size as a definite indication though. I bought an amplifier at a yard sale for two dollars that was two feet long, eight inches wide and two inches tall that had a five inch square circuit board inside of it. This amplifier was so poorly built that I could actually hear the music I was playing coming from the circuit board itself. However there are many top quality amplifiers that do not follow this rule. The ever growing Class D (and its variants) amplifier is much more efficient and there does not produce as much heat or use as much power. This means a smaller power supply and a smaller heatsink. Because of the high efficiency design of those amplifiers a heavy heatsink is not required.

Also a good indication of an amplifier's true output is the size of the fuse used. True two hundred watt amplifiers do not use a ten amp fuse. Use your head when buying and keep in mind the brand's reputation for quality. A quick and dirty way to check the true power output of an amplifier is to take the fuse value of the amplifier (or the sum for multiple fuses) and multiply it by 6 for class A/B amps or 10 for class D amps (higher efficiency). This is by no means an accurate way to judge power but it will tell you if your amp is even close to it's specifications. For example, if a class A/B "1,200 watt" amplifier has a fuse value of 25 amps then you can take 25*6 and get 150. So this "1,200 watt" amplifier is more in the range of 150 watts.

If you find yourself on a budget or lack space for many components then the economical thing to do is buy a multi-channel amplifier with the built in features and processors that you desire. This can save a lot of room and several hundred dollars in added component and installation cost. The quality will be a little less as compared to outboard processors but will probably not be noticed. Also, by minimizing the number of components the chance of noise entering into the system is lessened.

Some features and aspects of amplifiers to consider are:

Bridgeable: This feature allows a pair of amplifier power channels to be combined into one channel of greater power. This is usually used for driving a subwoofer although it will work with any other type of speaker as well.

Channels: A channel is one power (speaker) output of an amplifier. The more channels an amplifier has the greater the installation flexibility it will have. Especially in terms of options, future add-ons and upgrades.

Class: This refers to the way the amplifier operates. The three types that are most likely to be encountered are A, A/B, and D. Class A amplifiers are the least efficient in terms of power consumption, staying on continually, but also have better sound in general than A/B amplifiers. They are very, very rare in car audio. Some argue non-existent but in any case don't expect to see any. Class A/B amplifiers are more efficient than the class A design and are the most common type. Almost all amplifiers in the car audio market are of the A/B design. Class D amplifiers are usually reserved for high power subwoofer amplifiers and can reach efficiencies in the 80%+ range. This design can therefore be smaller, uses less current and produces less heat than the other classes. However there are some full range Class D amplifiers becoming available.

Connectors: This is the method of attachment used for wires that are connected to the amplifier, including speaker and power wires. The most common kind is the screw terminal strip. This is a series of screw connectors that can be removed and replaced without compromising the amplifier. The other main type of attachment is the "Molex" type connector. This method involves a wire harness that plugs into the amplifier after the power and speaker connections have been made with a crimp or solder connection. If the amplifier is installed in more than one system these wires can get pretty short over time and become more difficult and even dangerous to work with. A variation on the two is a harness that the power and speaker wires screw into. Then the harness plugs into the amplifier. This is probably the most convenient of all connections. Virtually all amplifiers use the screw terminal strip though many older amplifiers used the Molex or straight wire connections.

Crossover/Filter: A built in crossover can be useful, especially if it is many frequencies of adjustment. A filter is a crossover that only affects one channel, not actually splitting frequencies but simply reducing a range of them. Most amplifiers that have built in filters will have the option for either Low Pass (LP) or High Pass (HP). If you see AP on the filter that means "all pass" which basically means the filter is turned off and passes all frequencies.

Distortion: This is often given as T.H.D. or total harmonic distortion. It is the measure of how much an amplifier will change a signal from the input signal it is given. Figures below 0.1% are negligible and will probably not be heard. Usually the figure can be in the 3% range without being heard but virtually all high quality amplifiers will have a T.H.D. below 0.1%.

Efficiency: This is the ratio of of power input (from the battery) to power output (to the speakers). A 100 watt amplifier with an efficiency of 50% would take in 200 watts of power from the battery and output 100 watts of power to the speakers. The other 100 watts of power would be wasted as heat. The higher the efficiency of an amplifier the better. Most class A/B amplifiers are around 50-60% efficient and Class D around 80%. Amplifiers are generally less efficient at low power and more efficient at full power so this number varies in actual use.

Power Output: The rated power output of an amplifier should be given into a four ohm load, all channels driven from twenty to twenty thousand hertz (20Hz-20kHz). Keep in mind that while the low end amplifiers are exaggerated in their power output, many high end amplifiers are under-rated in their power output. These are sometimes called "cheater amps" because they allow a car audio competitor to compete in a lower power class while in reality having a larger amplifier. This under-rating may be three times less than the actual power output. Look for the CEA 2006 standard when comparing amplifier power.

Power Supply: The two most common types are the IC chip and the MOSFET supply. The IC chip is what is used in most source units (head units) and are only capable of producing about eighteen watts per channel. MOSFET is the more common design and has a smoother sound than the chip design.

Pre-amp Inputs: This is a set of jacks (usuallyRCA Jacks) that will accept a low level pre-amp signal from a source or processing unit.

Pre-amp Outputs: This is a set of jacks (usually RCA Jacks) that pass on a low level pre-amp signal to another amplifier or processing unit. These will sometimes be filtered outputs.

Separate Gain Controls: This allows the gain of each channel of the amplifier to be set independently of the other(s). This allows you to more evenly match the amplifiers channels.

Speaker Level Inputs: For source units that do not have pre-amp level RCA outputs this feature may be used to take the signal from the speaker leads of the source unit. The signal will not be as clean as a pre-amp level output but will be adequate for most factory upgrade applications.

Stability: The measure of how low of an impedance load an amplifier can handle (in ohms). Any good quality amplifier will be two ohm stable while a rare few will go as low as a quarter of an ohm. Ideally an amplifier should double its power each time the load is halved. For example, a one hundred watt amplifier (into a four ohm load) should produce two hundred watts into a two ohm load and so on. This is most useful when running multiple speakers off of a single amplifier or in sound off competitions that are classed by total power output.

Tri-Mode Output: This feature is available under different names but is the ability of an amplifier to run a stereo pair of speakers and a mono subwoofer (or center channel) from only two channels of the amplifier. Personally, I would not recommend doing this. Instead buy a good quality four channel amplifier and bridge two of the channels for the subwoofer.

Tube Amplifiers: These are the least common amplifiers and are also the most expensive. Rather than the traditional solid state components they use old fashioned vacuum tubes. They are said to produce a warmer sound and a smoother midrange than solid state designs. For most systems the standard design will be more desirable.

Basic Electrical Upgrades

noreply@blogger.com (Anonymous) — Thu, 18 Oct 2012 21:15:00 +0000

A vehicle's electrical consists of many parts but the ones we're interested in are the battery, the alternator, and the power wiring. A vehicle electrical system is a 12 volt DC system. The primary source of power when the vehicle is NOT running is the battery. The primary source of power when the vehicle IS running is the alternator. This is a very important point so remember it. The primary functions of the battery are to start the vehicle and provide power when the vehicle is not running. Because the battery's stored power is so great it is important to treat it with respect. It's the automotive equivalent of a loaded gun. It has the power to stop your heart and can burn your vehicle up if an unfused power wire is shorted to ground. Always remember to disconnect the negative battery cable before doing any work on a stereo system. NOTE: If your radio has a security feature that requires a secret code to be input after power has been disconnected make sure you know this code before you begin.

Depending on your car's factory electrical system, you may not have enough power to run your aftermarket stereo system. You probably do unless you have a multi-megawatt system or an extremely tiny alternator. If your battery goes dead often after the installation of your new stereo you may have an electrical system problem. Have your battery and electrical system tested by a qualified technician. If everything checks out then you probably are in need of an upgrade. Here are some of the common problems and their likely cures.

Adding a Second Battery
Many people are under the impression that adding a second battery will cure their electrical problems. If one battery is good then two must be better. Right? Wrong. Remember that the function of a battery is to start the vehicle and to provide power when the vehicle is not running. The only thing a second battery will help you with is "parking lot" listening time. Basically it will provide you the additional capacity to run your stereo longer without starting the vehicle. After the vehicle is started the second battery becomes another load on an already overworked alternator. If you do replace your battery I would recommend getting one from Optima or one of the other specialty battery manufacturers such as Stinger or Rockford Fosgate.

Upgrading Your Alternator
Frequent dead batteries are a good indication that your electrical system isn't keeping up and you may need to upgrade your alternator. Doing so will give you more juice to run all of your electrical components, including your stereo system, without looking to the battery for help. The problem is your alternator is undersized for your new electrical requirements and has to look to the battery to provide the extra power, resulting in shortened battery life. Have a qualified technician verify this before investing in a larger alternator. Hopefully you can find a larger alternator from your vehicle's manufacturer that will interface with your existing system. Consult the manufacturer or the local dealer to find out about this. If not then you can look to the aftermarket manufacturers to see what is available. Check with Ohio Generator or Stinger for high output models.

Power Capacitors
Another solution is to add a power or Stiffening™ capacitor. This device acts as an electrical storage "buffer". It stores power until needed for high electrical demands such as heavy bass notes. If your headlights dim when you have you stereo cranked then you MAY benefit from one of these. This is most noticeable when music with a heavy beat is played. Your headlights will dim to the beat. This is being caused by a voltage drop that is being created by the large power demands of your amplifier(s). A power capacitor will help fill in the gaps in the energy required by your amplifiers. Because of their low internal resistance they can deliver a lot of power much more quickly than a battery can and can often prevent this voltage drop.

Types of Audio Power

noreply@blogger.com (Anonymous) — Thu, 18 Oct 2012 21:14:00 +0000

Car Audio Power Capacitors
Power capacitors or Stiffening capacitors are used to assist an automobile that has a problem with dimming lights (voltage sag) or to help tighten up the bass. These capacitors store a large amount of power and then release it very quickly when the demand is the greatest from the amplifier. These capacitors release the current much faster than a battery can and do not force the amplifier's power supply to be at a loss (due to a voltage drop) when bass notes and other transients are greatest. Capacitors should be chosen in the ratio of one Farad per thousand watts. Click Here to see how a power capacitor is wired in a car audio system.

Car Audio Batteries
If extended engine off listening is desired then a second battery can be useful. Keep in mind that this will put a greater strain on your charging system as well as add several hundred dollars for a second battery, dual battery isolator, and installation charges (or headaches for the DIY'er). If you are having problems with your charging system then you might need a new or larger alternator. Have it checked out by a qualified technician.

Features and terms that may be encountered with regard to wiring are:
Butt Terminals: This type of terminal resembles a long barrel and is used to connect small gauge wires together. These type are crimp terminals and considered less desirable than soldering when soldering is an option. These terminals are also sometimes referred to as crimp connectors though that term can apply to many variations of crimp terminal.
Deep Cycle: A battery usually reserved for marine use that can be drained and replenished many times. While popular years ago many installers have relegated this battery to system use only with a traditional car battery for main power.
Farad (F): The base unit of measure for capacitor storage. One farad is very larger and is equivalent to one million microfarads (uF).
Gauge: This refers to the diameter of the wire. The smaller the number, the larger the wire. Sixteen is common for speaker wire, eight is common for average size amplifiers, while four gauge and below is used for large amplifiers. For reference, four gauge wire is about the same diameter as the average male pinky finger.
Gel Cell: A type of battery that uses a gel type acid. These batteries can be desirable because they may be mounted upside down without the danger a standard type battery would pose.
Heat Shrink Tubing: A type of insulating plastic that resembles a drinking straw. A small portion of this tube is cut off and placed on a wire before soldering. After the connection is soldered and cooled, the tube is slid over the joint and shrunk around the wires by means of a heat gun or hot hair dryer.
Microfarads (uF): The more common unit used to measure capacitor storage. One million microfarads is equivalent to one Farad.
OFC: An abbreviation for oxygen free copper. This is the most desirable wire to buy and there is really no reason to buy any other kind. As the name implies it is pure copper that is free from oxygen impurities.
Spade Terminals: A type of terminal used on most speakers. The type found on speakers are male spades while the ones used to connect to these terminals are female spades. These terminals are also referred to as quick disconnects though this name can apply to many different types of terminals that come apart quickly.
Voltage Rating: Referring to the amount of voltage a capacitor is rated to handle. The very least a capacitor used for reinforcement should be rated at is 16 volts while 20 volts is much more desirable and available on the slightly more expensive capacitors.

What Is Sound?

noreply@blogger.com (Anonymous) — Thu, 18 Oct 2012 21:14:00 +0000

Sound?
Webster's dictionary defines sound as:

"The perceived object occasioned by the impulse or vibration of a material substance affecting the ear; a sensation or perception of the mind received through the ear, and produced by the impulse or vibration of the air or other medium with which the ear is in contact; the effect of an impression made on the organs of hearing by an impulse or vibration of the air caused by a collision of bodies, or by other means; noise; report; as, the sound of a drum; the sound of the human voice; a horrid sound; a charming sound; a sharp, high, or shrill sound."

Mmm, fancy. We all know what a sound is. It's a noise, something we sense with our ears. But what is sound? It's the vibration of the air by a moving body. For our purposes in car audio that moving body is our speakers. The movement of the speaker forward and backward causes a vibration in the air that our ear receives and we hear music. Here's what sound looks like as a wave:

A sound wave goes through a cycle of 360 degrees. As the speaker moves forward it goes from rest (0 degrees) through one quarter of its cycle to 90 degrees. As it starts to move back to rest it travels another 90 degrees to the 180 degree mark before moving completely rearward to 270 degrees. As it moves back to the rest position it travels the final 90 degrees to the 360 degree mark. The cycle then repeats itself and we hear the result as music. To summarize, as the speaker moves up and down it travels one cycle which equals 360 degrees. These cycles are measured in Hertz (Hz) with one Hertz being equal to one cycle. The lower the number of Hz the lower the sound we hear. A human can hear, on average, the sounds between 20 Hz and 20,000 Hz (also known as 20 kHz).

We do not hear all of the sounds equally though. Our ears are less sensitive to sounds at the far ends of the scale. This was discovered through research done by Fletcher and Munson and they have given us the "Fletcher-Munson" curve which illustrates this point.

Notice how the curve goes up at both ends of the scale. Also notice how the curve is greater at lower volume levels (sound pressure levels). This is what the loudness circuit on a head unit tries to do. Increase the level of the low and high frequencies at lower volume levels. As the volume goes up the level of boost at these frequencies is reduced. However, some loudness circuits do nothing more than boost the low and high frequencies by a constant amount. If you've seen a vehicle with an in-dash equalizer the chances are very good that the vertical sliders were arranged in a similar fashion to the Fletcher-Munson curve. This is sometimes called "making your EQ smile".

Wiring Diagrams

noreply@blogger.com (Anonymous) — Thu, 18 Oct 2012 21:13:00 +0000

Bridged
Bridging an amplifier is a means of combining the power of two channels to drive one speaker. Typically this will double the power of a single channel (i.e. two 50 watt channels would combine to become one 100 watt channel) although some of the top amplifiers will actually quadruple the power of a single channel (i.e. two 50 watt channels would combine to become one 200 watt channel). This is usually the most desirable and you can plan this into your overall design. For example, if you have two subwoofers in your system and you want to drive each of them with 100 watts you can do one of the following.

Parallel

Parallel wiring involves wiring each speaker positive terminal to the positive speaker output of the amplifier and likewise the negative speaker terminals are wired to the negative speaker output of the amplifier.

Series
Series wiring involves connecting the amplifier's positive terminal to the positive terminal of the first speaker and then connecting the negative terminal of the first speaker to the positive terminal of the second speaker and so on. The final speaker in the chain will have its negative terminal connected to the negative terminal of the amplifier. See the figure below. This wiring scheme is best reserved for multiple subwoofers because any audio artifacts (distortion, frequency attenuation, etc.) caused by the first speaker(s) in the chain will affect the speakers in the chain after it. This is a major problem when mixing multiple speaker types (i.e. woofers with tweeters).

Capacitors

There is often a lot of confusion on how to wire a car audio capacitor (a.k.a. power capacitor or stiffening capacitor). There are two terminals on a car audio capacitor. A positive and a negative. The negative terminal is connected to ground. The positive terminal is connected "in-line" with the car audio amplifier +12 volts terminal. See the diagram below.

Ideally the power capacitor should be as close as possible to the amplifier. Within a couple of feet is acceptable.

Charging

Here's how to wire two capacitors in a system:

NOTE OF CAUTION: Power capacitors store a large amount of energy and they charge very quickly. You must first "charge" your power capacitor using a resistor before connecting it directly to +12 volts. This is done with the a 1k ohm resistor and a voltmeter. The exact value of the resistor is not critical but I would keep it in the 500-1k ohm range. I would recommend getting a 1 watt resistor if possible (your capacitor may have come with a resistor for charging). A lower wattage resistor will heat up too quickly. Also, do not hold the resistor with your bare hand. The current flowing through the resistor will cause the resistor to heat up and you could be burned. A good place to put the resistor is in the main power wire fuse holder. Simply substitute the resistor for the fuse. A diagram for the capacitor charging setup is shown below. You will need to place a voltmeter across the capacitor to monitor the voltage. Once the voltmeter reads 12 volts you can remove the voltmeter and replace the resistor with the power fuse.

Pioneer Video Bypass

noreply@blogger.com (Anonymous) — Fri, 26 Aug 2011 17:27:00 +0000

Since the high demand for the Pioneer parking brake bypass; I have decided to come up with a easy diagram for you to follow which will allow you to play videos while you are in motion.

1. Connect the blue system turn on (Remote) wire to spade #85 (If you have or installing and amplifier connect your amplifier turn on (Remote) wire to this prong also)

2. Connect a grounding wire to spade # 87 which jumps and connects to spade # 86. Then connect the wire to a good ground.

3. Connect the parking brake wire from the head unit (Green Wire) to spade # 30

4. Finish installing your stereo and enjoy your video.

Flared Ports vs. Slot Ports

noreply@blogger.com (Anonymous) — Thu, 04 Aug 2011 00:06:00 +0000

Many people question what the difference is between flared ports and slot ports. There are fairly basic differences between the two, and depending on your situation, one might suit you better than the other. The common purpose of the two ports is that they must be the correct length for the particular subwoofer box to achieve the desired sub box tuning. There are a few differences that may help in your decision between flared and slot ports for your custom subwoofer box.

Flared ports are very good at virtually eliminating port noise. Port noise is the noise created by the friction of air moving through the port. If you have sharp edges on a port (as with standard round ports, which we do not use), you are going to have significantly more port noise than with a flared port. A flared port requires the smallest acceptable port area for a subwoofer box. Since the ends are flared, and the inside of the port is round (no sharp edges), it is unlikely you will be able to notice any port noise from the subwoofer enclosure. However, if you are running a large, high-powered subwoofer, you will want to use two flared ports. A single flared port is still capable of creating port noise when very large amounts of air pass through it.

With a slot port, you can use as much port area as needed for your application, which is especially helpful in SPL applications. A slot port requires more port area than a flared port to minimize port noise. We generally use a rule of 12 square inches of port area per cubic foot of internal volume of the custom sub box. You may go with a larger port area, but this will increase the total volume and length of the port. In turn, a large port area will mean an increase in the total size of your subwoofer box. Slot ports are the standard for our ported custom subwoofer boxes.

If you are not limited on space, we would recommend going with a slot port for your subwoofer box. If space is tight, and you have a few extra bucks, you'll probably want to use a flared port (or two, depending on your subwoofer size and power). It is possible to achieve the same result from both subwoofer boxes, so the decision between flared ports or slot ports depends on your specific needs for your custom subwoofer box.

For Help with Port Sizing go to calculateing port size

Installing a subwoofer in a pre-fabricated enclosure

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:56:00 +0000

This guide will cover the installation of one or more subwoofers in a pre-fabricated enclosure. It will also cover the process of hooking up an amp to power the sub.

The easiest way to add low-end punch to your car’s stereo is to install a subwoofer. This guide will cover the installation of one or more subwoofers in a pre-fabricated enclosure. It will also cover the process of hooking up an amp to power the sub.

The first thing to do is to put the woofer into the box. This should be easy as long as you got the right size enclosure. Before actually screwing down the speaker, be sure to connect the included leads to the terminal in the back of the box. Next, screw the woofer down tight into the front of the box and mount the protective grille directly over the speaker.

Put the box in the trunk. For the best sound, the woofer should be facing the back of the car. To keep it from sliding around, consider using high-strength Velcro strips to secure it to the trunk floor. If this is not possible, L-brackets may be mounted to the cargo floor, but be sure not to put any screws through the side of the box. However you decide to secure it, make sure that it is out of the way of anything you put in the trunk.
Now it is time to install the amplifier. Begin by mounting the unit in the desired location. This should be a flat area with a lot of open space so that the amplifier can cool properly. Do not mount the amplifier on the subwoofer enclosure, as the vibrations from the speaker can damage the internal parts.

The next step is to hook the amp up to power. Before doing this, disconnect the negative terminal from the battery. Hook the long positive power cable for the amp to the positive terminal of the battery. If the cable does not have a fuse, you should install one inline within three feet of the battery connection. Consult the amplifier owner’s manual for the size of the fuse. Run the fused positive cable through the firewall and back into the cabin. Remove any trim panels necessary and pull back the carpet so you can run the cable underneath. Once the cable can reach the amp, trim off any excess, strip the end, and connect it to the positive power terminal of the amplifier. For the negative cable, connect it first to the amplifier, then run it beneath the cargo floor of the trunk and connect it to a ground point on the chassis or floor pan.
Next, you need to connect the amplifier to the head unit. You should do this using the subwoofer pre-amp hookup on your stereo. This can be either a stereo (paired RCA plugs) or mono (single RCA plug) connection. Unless you have a mono subwoofer amp, you will need to use a paired RCA cable to plug into the amp. If your head unit has a mono RCA out, this means you will need to use an RCA mono-to-stereo adapter to plug the stereo cable into the mono jack. Run the RCA cable underneath the carpet on the opposite side of the car from the power lines to avoid interference. When you get the cables back to the amplifier, plug them in at the RCA in terminals. Before putting the carpet and trim back, run a small 16-18 gauge wire from the head unit amp remote connection to the remote control terminal on the amplifier. At this point you can replace the carpet and trim panels to make the installation look clean.

The last step is to plug the subwoofer into the amplifier. To do this, use 12-14 gauge speaker wire. If you have a bridgeable stereo amp, you should bridge the amp by plugging the positive wire into the positive terminal for the left output and the negative wire into the negative terminal of the right output. The actual configuration of the bridge will vary from amp to amp, so read the owners manual for specific instructions. If you have a mono amp, simply connect the positive and negative wires. Finally, plug the wires into the back of the sub. If you have more than one sub, you can run a length of stereo from one sub terminal to the other.
Finally, put the negative terminal back on the battery and fire up your system. You will need to adjust the gain and filters on your amp, if it has them. First, turn on the low pass filter (LPF) option. Then, turn the gain all the way down. Turn up your stereo until the speakers begin to distort, then turn it down just a hair until it no longer distorts. With the stereo playing at this volume, turn up the gain on the amp just until the subwoofer begins to distort. At this point, turn the gain down a bit. That’s it; you’re done, and good luck with your new subwoofer.

2 10" KICKER Solo X

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:52:00 +0000

2 KICKER SOLO X on 5,000 WATTS!!!

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:51:00 +0000

2 10's Flexing Hatch

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:50:00 +0000

2 DD 6.5" subwoofers on Term Lab

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:49:00 +0000

Digital Designs 15's in Ext. Cab Chevy

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:48:00 +0000

SUNDOWN AUDIO SA-8

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:47:00 +0000

2 Sundown SA-8's on 200 WATTS!!

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:46:00 +0000

Window Flex with 2 8's

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:46:00 +0000

Subwoofers Break Iphone

noreply@blogger.com (Anonymous) — Wed, 03 Aug 2011 23:45:00 +0000

PORT DESIGN INFORMATION

noreply@blogger.com (Anonymous) — Thu, 11 Mar 2010 18:41:00 +0000

WHY GO PORTED?
Efficiency is the easiest one word reason for choosing ported over a sealed box. Everything is better with a little efficiency sprinkled on it. Ask any motor builder what they would do to a motor if it were theirs and they'd say turbo charge it! What does turbo charging do for an engine? It raises the efficiency. Why not apply this same thing to your audio system. Making the most out of the air space you have for a subwoofer enclosure, is the first step in raising the efficiency of your system. This means that you will utilize this space in the most efficient manner possible.

Designing a ported a.k.a. vented enclosure will not only give you added output, but can give you more low-frequency extension. This means louder and lower! Since the speaker system is the least efficient part of the whole audio chain, would it not make sense to make it as efficient as possible? Of coarse it does.

MORE SOUND, BETTER BASS
This is why venting is basically free output, and free sound quality. Local shops tell you that a small sealed box is the best way to go? Hit up your local hi-end home audio store and find out how many of those $20,000.00 pairs of speakers are sealed designs. You won't find many. Think efficiency, this will help you clear all of that smoke out of your eyes that most car audio manufacturers have been pumping all along.

HOW DOES A PORT WORK
Think of a box port not as a vent in the terms of a venting path for air to travel into and out of a box, but rather as extra cone area that is propagating acoustic energy from the enclosure to the cabin. The air in a port is fixed; it is trapped within the confines of the port walls. When the cone moves there is a corresponding change to the pressure in the box, that pressure change then causes the trapped air in the port to move either forward or backward. It moves as a solid unit, just like a speaker cone does. When you build a properly vented enclosure, its kind of like a two for one special! Since the port is essentially another woofer!

MORE RADIATING AREA
A passive radiator and a vented port work on the same theory. When a port mass moves back and forth, a pressure wave (sound wave) is sent into the cabin. The larger the port, the larger the radiating area is that creates the pressure. Tuning a port is tuning the mass of the trapped air in the port to the air mass in the box volume.

For all out no holds barred SPL efficiency, rule of thumb is the larger the box, the higher the output. The larger the box, the larger the ports can be for a given frequency tuning range. There is no substitute for cubic inches. Some drivers can achieve high efficiency in moderate sized vented enclosures (3 to 4 cubic feet) but will continue to increase in output with increase in volume and port size. Multiple drivers in such enclosures can yield a frightening amount of output and should be used with caution.

THE RIGHT PORT AREA
Most modeling programs that simulate box responses were written for home audio use. They are not suited for high output systems. The port area defaults are inadequate. The port area must be commensurate with cone area. If the port velocity gets too high, the port no longer functions as a port, you end up with a leaky sealed box, double bad.

Lets say we have a 12 inch speaker in a box, roughly 100 sqin of surface area. Many programs and manufacturer sites will suggest a 4" diameter port for a 12" vented box. A 4" diameter port has about 12 sqin of area. This is about an 8-1 ratio of cone area to port area. If the 12 inch cone moves 0.25", the port must move 2.0". It can handle this, but when the cone is moving 1.0", the port must move 8 inches! Now you've got a leaky sealed box.

You need more port area for a clean sounding, high output system. The perfect port formula is this: 16 sqin of port area per cubic foot of box volume. The port should be 16 inches long. Remember, the port is tuned to the box volume, not the sub(s).

This formula was derived from 1000s of hours of in-car testing and 1000s of installs. It works. It takes into account the need for increasing port area for increasing cone area. When combined with the correct box requirements, you'll end up with the perfect match.

VARIABLE PORT TUNING
The design philosophy of low moving mass, well controlled suspension and strong, linear magnetic systems allow the user many design applications never realized with traditional speakers. The growing popularity of the SPL competitions has led to new engineering requirements for an audio system.The problem lies in the fact that the frequencies where a vehicles peak SPL may occur rarely ever coincide with a tuning frequency that promotes utmost sound quality. The peak SPL frequency is usually somewhat higher that the tuning frequency for sound quality.

The use of a larger than normal port will allow the user to find the cars peak frequency for greatest SPL. Reducing the port opening will lower the box tuning frequency and provide loading to the woofer over a wider bandwidth. This will improve the transient response and impact of the system. The higher tuning frequency redirects the woofers radiating energy into a narrow band which when tuned to coincide with the vehicles peaks can yield dramatic SPL numbers. The focus of attention here should be to tune the system to each application. Although the general box recommendation will yield very satisfying results, competing at the highest levels of SPL or SQ contests, or simply yielding the best possible results are directly related to methodical tuning.

Calculating Port Size

noreply@blogger.com (Anonymous) — Thu, 11 Mar 2010 18:40:00 +0000

Calculate Port Size
The box port can be calculated with a simple formula. Box volume in cubic feet X 16 (the amount of port area in square inches per cubic feet of box volume). For example, 3.4 cuft X 16 sqin= 54.5 square inches of port area. Try to stay within 10% of this number.

The port length should be 16 inches deep. This tunes the boxes to about 40 Hz.

How To Make A Slot Port
The easiest and most effective way to build a port is to use a slot shaped port that uses 3 sides of your enclosure as port walls. If the port is located at one end of the box, only one additional piece of wood is required to complete the port. The additional piece of wood should be spaced off the end of the box.

The port area is in square inches, meaning it takes height times width to calculate total area. A port 4 inches high by 4 inches wide would calculate as 4 X 4= 16 square inches.

In our example box, we have an inside height of 14.5 inches. To calculate the slot width that would make a total area of 54.5 square inches, and we use 14.5 inches as the height: divide 54.5 by 14.5= 3.76. Round that figure to nearest ¼ inch, and you get an offset measurement of 3 ¾ inch wide. The slot port would be 3 ¾ inches wide by 14 ½ inches tall.

You don’t have to get too critical about the box and port volume, a good rule of thumb is that if you stay within 5-10% of calculated volumes, there will be very little if any audible effects.

Port Length Obstructions
Some port lengths do not allow for 16-inch port depths without some sort of modification. The rule of thumb is not to let the end of the port get any closer to the back wall than the width of the port. So back to our example, we have an internal box depth of 12.5 inches. We need a 16-inch deep port. We will have to bend the port along the back wall to get the full port length. To calculate where to make the bend, subtract the port width from the inside box depth. 12.5 – 3.75=8.75. We must bend the port at 8.75 inches, then continue the port parallel to the back wall for an additional 7.25 (8.75+7.25=16).

You now have an L shaped port totaling 16 inches in depth.

WHY GO PORTED?

High Output Sub Enclosures

noreply@blogger.com (Anonymous) — Thu, 11 Mar 2010 15:57:00 +0000

I don’t believe in the tiny sub box theory. If you are looking for tiny sound, get a tiny sub and put it in a tiny box. Be happy. If you are looking for real bass, you need to have a real box.

In order to get true high performance, you have to make the most of the available airspace you have. To do otherwise is wasting your time, energy and money. Don’t try to fit a larger speaker in a box that is better suited for the next size down. The smaller sub in the right space will outperform the larger sub in too small of airspace.

The first step in getting major bass in your vehicle is to allocate the space for your enclosure. If you really want to flex some sheet metal, the old adage applies, “there is no substitute for cubic inches”. The more space you make available, the higher the potential spl.

You don’t have to use a large amount of enclosure space to make a loud system; loud can be done with a single sub. The amount of loud needs to be determined as you figure out what space you plan to give up. Really loud bass, where you have to scream at your passengers, can be done on a single or double woofer setup. Stupid loud bass, where there is no point in trying to communicate in the vehicle, takes more space and bigger/more subs. F@#$ing crazy loud bass, where it is impossible for the car next to you to communicate inside his vehicle, takes even more space, even more subs and a gazillion watts of power.

A few tips on what to pay attention to when determining the box shape:

If you plan to use a rear firing setup in a trunk car, make sure your box doesn’t seal off the trunk from the passenger compartment. You need to leave some space for the waves to pass back into the interior of the car. Either make the box as low as possible so the wave passes over the box and enters the cabin via the seatback and rear deck, or reduce the width of the box so the wave can pass to the side and into the car’s interior. A big, giant box may make your trunk extremely loud, but all you’ll hear is muffled rattle if the box takes up the whole space behind the rear seat and under the rear deck.

If you have a hatchback car, keep the box as far back in the vehicle as possible. Keep the port as far to the rear as possible.

Amplifier Troubleshooting

noreply@blogger.com (Anonymous) — Sun, 30 Aug 2009 07:08:00 +0000

Please try these things before sending in your amplifier. By the numbers, 40% of all amps returned to us work just fine and there is a problem in the wiring or install.
You must have a DMM (Digital Muti Meter) and know how to use it.
If no: take it to someone who does.
If yes: thumb through the following scenarios

Amp will not come on (no lights):

Set DMM to DC voltage and check at the amp. You need to test with both (+ & -) leads on the amplifier Power terminals.

If over 12 volts: check both sides of the fuses in the amp.
If no or low voltage: ground the DMM (-) test lead to a good, clean, metal chassis ground in the vehicle and retest.

If over 12 volts now: problem is in the ground wire or connection (between the amplifier and its chassis ground).

If still no voltage: check both sides of the fuse by the battery.

NOTE: You cannot check a fuse by just looking. Fuses can be “bad” and not blown; especially the larger, cheap-ass, glass ones.

If blown or bad: replace and start beatin’ again!

If all is good with battery voltage, it is now time to check the remote (or turn on) wire. Check voltage at terminal of amp.

If no voltage: check voltage at head unit. You can also make a jumper from the main 12V+ connection to the remote terminal to see if the amp comes on. If it does, the problem is in the head unit remote output or remote wire between the head unit and the amplifier.

If all power wiring tests good, remove the amp from the vehicle and test with short jumper wires directly at the battery, using a jumper wire from amp 12V+ to the remote terminal, just as a “I need to make sure” final test. If it still doesn’t come on, it needs to be sent in.

Amp turns on but goes into protect:

Disconnect RCAs and speakers and try turning the amp on again.

If it still goes into protect with just power, ground and remote; the amp is bad.

If it is now on and not in protect: connect the RCA’s first.
If it goes into protect: the problem is in the cables or headunit. Change and retest.

If still not in protect: reconnect speakers
If it goes into protect: problem is in the speakers or wiring (most likely shorted [or grounded] wiring or burnt coils). Set DMM to 'ohms' and first test by shorting leads together. This number (usually in the .4 range) will be subtracted from any reading you get. Connect DMM leads to each speaker wire pair. If you have a short, reading same as touching the leads together, trace the wiring to find short.

If no short in wiring: test the speakers individually and eliminate problem.

If amp comes on (and not in protect) and has no output:

Check all settings. Turn deck on at low volume.
       Master/Slave switch in master position.
       Gain all the way up.
       Subsonic filter all the way down.
       Boost all the way down.
       X-over all the way up.

If still no sound: you will need to try an alternate input. The best is a signal generator right to the input of the amp. Alternately, you could use another radio wired in with temporary wiring right at the amp with a very short, known-working RCA cord.

If still no sound: try a known-working test speaker with very short wiring right to the amp terminals. If still no sound: amp is bad. This is a very rare failure but it can happen.

Amp has distorted output:

Same test as above. You need to eliminate all the variables.

If you are testing a stereo amp and you have the problem on one channel:

Swap RCA’s: if it changes sides, the problem is in the deck or RCA cables.

If same side: swap speaker outputs at the amp. If it changes sides, the problem is in the amp. If it stays on the same side, the problem is in the wiring or speaker.

Amp plays but has low output:

Check all settings. Turn deck on at low volume.
       Master/Slave switch in master position.
       Gain all the way up.
       Subsonic filter all the way down.
       Boost all the way down.
       X-over all the way up.

Turn up the radio. If problem remains:

Check voltage drop at amp power input terminals. Set your meter to DC voltage with the hold feature activated. If your meter does not have that feature you will need to watch it to see how low the voltage drops when it is trying to play loud. If voltage drops below 11 volts at any time, you need more battery/alternator power and or better wiring.

If voltage remains above 12 the entire time, you need to check the speakers.

Set meter to ohms and check the DC resistance of the speaker load. If it falls within the proper load for the amp, check the amp, hooked to known-working speakers. If new speakers work, the problem is in the speaker system. If it still has low output, you need to check the inputs as described above with a known-working deck and RCAs.

Amp plays but cuts off and on:

Attach volt meter to power and ground terminals at the amplifier.

Set the meter to peak hold (max/min) and display "minimum DC voltage".

Run the system until the amp shuts off and check the voltage. If voltage has dropped below 10 volts at any time, check all wiring.

Leave the meter positive on the battery wire and use a good, clean ground point on the vehicle and test again. If voltage has a higher reading than before, the problem is in the ground connection.

If it has the same voltage, work your way back to the battery; testing at any and all connection points. I.e. distribution blocks, capacitor, fuses, etc.

If at any point voltage goes up, you have found the voltage drop point.

Single vs. Multiple Drivers

noreply@blogger.com (Anonymous) — Wed, 19 Aug 2009 01:49:00 +0000

There are advantages and disadvantages to either approach. For this, let's consider a scenario where the cone area of a single driver is equal to the cumulative cone area of multiple drivers: An example of this would be a single 10" woofer with an Sd of 50in^2 versus a pair of 8" woofers with an Sd of 25in^2 each.

The single driver advantage: Linearity. A single driver system isn't subject to the acoustic or electrical forces countering in phase--even if by a fraction of a degree--which typically occurs when multiple pistons share a common space or when multiple inductors share a common circuit.

The single driver disadvantage: It has been my observation that a single larger driver will typically exhibit higher equivalent air compliance (Vas) than the combined compliance of two smaller drivers. This can translate into higher Vb requirements.

The multiple driver advantage: Assuming that the motor structure is the same on both the 8" and the 10" model, the immediate advantage is twice the motor for every square inch of cone area, twice the power handling, and more end-impedance versatility.

The multiple driver disadvantage: As stated above, using multiple independently actuated pistons increases the risk of the electro-mechanical forces countering one another. This is particularly evident with high Qts drivers.

The Perfect Subwoofer Box

noreply@blogger.com (Anonymous) — Fri, 24 Jul 2009 02:36:00 +0000

We often hear talk (specially in car audio) about certain boxes being RIGHT for certain woofers. Many folks talk like a given woofer wont even play at all if the box size is not exactly perfect!

What is perfect?

Manufacturers often recommend a certain box for their speakers.

Computer box programs can PICK the box size (or tuning) that works best(?) with the woofer if you input the Thiele/Small parameters.

Is the box size the manufacturer recommends perfect? How can it possibly be perfect when they don't even know what kind of car your installing the box into? We all know the car will change the sound (this is called transfer function)! How can they possibly choose the perfect box size? Many times the speaker manufacturers recommendation is chosen not for perfect sound but for an average that might work well in the average car. Many times they might recommend the box that's easiest to build for beginners or small (since many folks like woofs that work in small boxes) or sealed instead of vented because it is less likely for you to blow your speaker in a small sealed box than a large vented box! (if you blow your speaker (a) they might have to replace it. (b) the company might get a reputation for lousy speakers if they blow a lot) Sure, the manufacturers recommendation will probably sound great! But perfect??? Is the manufacturers recommended box size really right for you?

Is the box size provided by computer programs perfect? Again, how can it be unless they take into account the transfer function of the car??? I don't know of a current popular program that does! Most computer programs will calculate a box for you with the lowest response and with the least ripple. In car audio, this many times IS NOT the best! Sometimes (specially in SPL competitions) the ripple the computer program tries to avoid might actually be an SPL or bass boost! Or for an SQ car, a slight ripple (inaudible, an may likely be made up for by the cars transfer function) might get you much deeper bass... Is the computers recommendation the perfect box? Is the computer programs recommended box right for you?

How bout the difference in CUSTOM made boxes vs PREFAB boxes?

Most real car audio enthusiasts would never consider a PREFAB box, we all know the custom built boxes are far superior sounding... BUT ARE THEY REALLY?

From my experience there is a great amount of BADLY BUILT custom boxes being built! Built so badly in fact that for many cases a prefab box would be miles better!

A prefab box could be better than a badly built custom box! I have heard some darned good systems with prefab boxes and some very poor systems with custom built boxes.. It's important if your gonna pay high dollar for an installer to build you a custom box that the installer be good at building boxes or you might just as well have spent your money on a pre-fab and spent the left over money on something else.

PLUS, since we mentioned installers, how many really have any background in speaker design? Many claim to be experts, but in the real world most installers just build the so called custom boxes with no AUDIO PHYSICS in mind. So for a custom box, its important the installer be not only a carpenter but also an expert at loudspeaker box design... Or a pre-fab box might be the better choice! ;-)

And, in reality, there is no PERFECT box, and to really custom build a box to perform as good as possible in a given vehicle it requires huge stacks of expensive test equipment, lots of woodworking tools and saws, and building, testing then rebuilding and retesting, and rebuilding and retesting again and again and again until no more good is achieved. This is done only by a few crazy competition gurus or a few nutty hobbyists, certainly NOT for the average car audio guy, or even the average installer...

So, I think it would be safe to say most so called perfect boxes are no where near perfect, they can all be improved on. And even if they were perfect, putting them in a car will change them, even the direction the box fires in the car can have an effect!

And it makes me laugh when I hear a fellow say something like " the manufacturer recommends 1.5cu ft for this speaker, it wont work in 1.25cu ft!"

Sure it will!
If that's all the space you have,
build it,
play it,
enjoy it!

There are so many variables involved there is a chance the NON-PERFECT box might even sound better than the so called perfect one! Try it ;-)

Enjoy!