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This guide is to aid you in your search for car sub woofers and amplifiers. So many people jump right into car audio without really knowing much about it. These people can get burned by over priced equipment, blown equipment due to improper installation, and purchasing of subs and amplifiers that just do not work together.
So lets start with the basics:
Most people looking for sub woofers and amplifiers are solely looking to add BIG BASS to their vehicles.
Lets talk about the types of sub woofers:
I talk about RMS often, RMS is a technical term referring to the continuous amount of wattage a sub can handle. When shopping for subs, DO NOT look at PEAK power, its a stupid marketing/sales aspect of a sub. Apparently PEAK is how much power a sub can handle if the power peaks, such as a kick drum hitting, etc. Do not factor PEAK power into anything, always know the RMS, if you were to hook up a 1000 watt RMS amp to a 1000 WATT PEAK sub, it would blow after a day, maybe sooner.
8 inch woofer: These subs are best used in the back dash of a car, or maybe in a bazooka tube in a truck. Basically for people that don't really want to take up much space in their vehicle but still get some decent bass. Putting these in a trunk would be a waste of money, you'd barely hear them! An 8 inch woofer will not make the hair on your arms stand up, but will fill the car with a better than factory sound. It really depends on the quality of the sub and the number of them installed, a pair is best I think. Most 8's will not be able to handle low frequencies, 40 Hrtz or below I believe, but can hit higher ranges of bass safely, up to 110 hrtz(see below about crossovers). A good 8 will be able to handle up to 400 watts RMS, some sound good at lower RMS, some expensive ones can handle power higher than 400 watts RMS. The sound of an 8 kinda gets inside your head, some people find this annoying, the frequency is just too high.
10 inch woofer: These subs are good for putting a pair in a trunk and still having some room. Only putting one in a trunk would, in most cases, not produce enough sound unless you bought one that can handle 500 to 1000 watts RMS, then you'd hear some strong bass from the trunk. There are certain 10's that can handle lower frequencies of bass, around 30 Hrtz. Most people get 10's because they produce a better punch and higher frequency, but not annoying like the 8's. 10's seem to be the preferrence of rock music listeners. Rap will sound ok, but for many songs it won't. A 10 should be able to handle having the crossover(see below)
set to 90 Hrtz, though a little lower is always safer.
12 inch woofer: Referred to as the most dynamic woofer. The 12 inch woofer is definately made for the trunk and for producing BIG BASS! Two quality 12's will make your hair stand up. One 12 of good quality, such as 1000 watts RMS, would shake the car and make your hair stand up pretty well. 12's are able to hit bass frequencies from 30 Hrtz up to 80 Hrtz, but its safe to keep the crossover lower around 60 Hrtz, its just not worth possibly blowing the sub for a minimal boost in volume. Fully powered 12's are both punchy for rock songs and can be thunderous for rap songs. Definately the most popular sub around.
15 inch woofer/ 18 inch woofer: These big things will shake the crap out of your vehicle, definately for the BASS maniacs! They can hit really low frequencies to thunderous proportions. The box size required for these subs will definately fill the entire trunk, in some cases may not fit, depends on the vehicle. These subs can hit frequencies 50 Hrtz down to 25 Hrtz for 15's and 20 Hrtz for 18's. Some 18's can go even lower than 20 Hrtz, but thats so low the volume starts to drop off and most songs don't go that low, except for BASS cd's. The best thing about 15's, you can buy 2 of them that can handle only 300 WATTS RMS, and they can sound louder than 2 12's that can handle 600 watts RMS. They are just so big and push so much air. Any kind of 15 or 18 will add some serious bass and take up tons of space.
Crossover: A device that filters out different frequencies from an audio signal. Most good amplifiers come with one built in, though you can get them separate too. They are the best way to protect a sub from blowing out. Crossovers on amplifiers for subs should be LPF or Low Pass Filter, it only allows low frequencies to pass through. If its set to 50, then only frequencies 50 Hrtz and below will go to the sub.
I WILL TELL YOU A SECRET!!! Car audio subwoofers are very different than subwoofers for home audio. They are technically supposed to be able to handle all frequencies, though they really can't. If you ran a car woofer with a full frequency range going to it, the voice coil(which are pathetic in car audio) will overheat and melt, they are just not able to handle high frequencies. I once had a 12 and had set the crossover to what I thought was 60 Hrtz, I later found out after it blew 30 days after the purchase date that I had incorrectly set it to about 90 Hrtz. Only 30 Hrtz higher from a safe setting of 60 Hrtz and it limited my woofer to a 30 day lifespan !
Matching amplifiers to woofers and what the heck does bridging mean: Finding the right amplifier for your subs is very important, the wrong combination can result in a huge waste of money and damaged goods.
You generally want to match the subs RMS power to the amps RMS power, but it can depend on how they are hooked up.
Some info to help select an amp:
bridging an amp: most amps are 2 channel stereo amps, thats a left and right frequency/channel. These are very popular when running 2 subs. Bridging essentially combines the power of both channels into one mono channel, doubling the RMS power in most cases. A MONO amp is a 1 channel amp, thats it, just one channel, though they are designed to run at lower ohms.
Ohms: Ohms are the amount of resistance a speaker is rated as. A speaker is nothing more than a giant resistor of electricity. Most subs are 4 ohm, though they can also come in ohms of 2, 8, 3, and 6.
Most 2 channel amps can run at 4 ohm, but nothing lower. Mono amps can run at lower ohms, 2, 1.333, maybe even 1 ohm.
Calculating ohms and watts of my installation: to calculate the ohms and wattage of an installation, you need to know some things; WATTS RMS of the amp at different ohms, 4 ohm stereo, 4 ohm mono, 2 ohm stereo, etc.
This is where is gets kinda technical, but not difficult to understand:
Subs can have 1 or 2 voice coils on them. Most have one, though you should think of a dual voice coil sub as two in one shell and they will have two sets of terminals on them, one for each voice coil.
There are two ways to run multiple subs; series and parallel. Series is running the subs in a row, so that power has to go through the first one before it gets to the second one. Running subs in series will double the resistance, so 2 subs run in series at 4 ohms a piece will make a total ohm of 8 (4 + 4=8). Parallel is like running the subs side by side with their own path to the amp, the power is split to each sub evenly. Running subs like this puts more work on the amp and results in lower resistance, so 2 subs run in parallel at 4 ohms a piece will make them a total of 2 (4 / 2=2) ohms.
The terminals on a dual voice coil sub should be treated as two individual subs. If you want the whole thing to be parallel, you would wire the terminals positive(coil 1) to positive(coil 2) and negative(coil 1) to negative(coil 2); series is would be positive(coil 1) to negative(coil 2) and negative(coil 1) to positive(coil 2).
As for two separate subs, same principals apply, only instead of connecting their terminals as I just described, you can have them meet at the amplifiers terminals. Most amplifier manuals have crude diagrams showing what I just described.
Now comes the fun part:
So now you know what ohm your sub is; single voice coil, dual in series, dual in parallel, lets talk about the amp hook up. Just remember that a channel is its own functioning device. You could technically blow the right channel of a 2 channel amp and still be able to use the left channel. If its bridged or a mono amp, you only have one channel to work with.
To make this easier, lets look at a simple example and a complex example:
Two 8 ohm subs at 200 WATTS RMS. If the 2 channel amplifier puts out 100 WATTS RMS a channel at 4 ohm stereo, you could hook each sub to a channel, but because each channel is its own device, you'd have 8ohms on one and 8 ohms on another resulting in half the power, so 50 watts RMS to each sub. This is no good. So hooking them to the amplifier bridged(combining the amp into one channel) will double the power, so the amp would put out 200 WATTS RMS at 4 ohm mono. If you hooked the two subs in series as I described above to the amplifiers terminals, you would double the ohms to 16 !! You wouldn't be able to hear anything, maybe even damage stuff!! Instead, run them in parallel, this will divide the ohms 8 by the number of subs 2 to get a 4 ohm circuit! Congrats, you now have 2 subs that can handle 200 WATTS RMS hooked up to an amplifier that is now bridged and putting out 200 WATTS RMS, a perfect match!
Two dual 4 ohm voice coil subs at 200 watts per voice coil, 4 ohms per voice coil. This like working with 4 individual subs. Its simple if you think of the first example, just with one extra step. First wire the voice coilspairs on each sub in series as described earlier. This will turn each sub into a 8 ohm sub. Now you have two 8 ohm subs and can use the steps from the first example to finish the install.
Some other pieces of information:
Wiring is important, any amplifier running from 0 to 500 WATTS RMS can get away with 8 gauge, nothing less, bigger is better though. Note the gauge size is reversed, 4 gauge is bigger than 8 gauge. Any amplifier running more than 500 WATTS RMS should have 4 gauge, anything less could heat the amp up and shut off.
BASS BOOST IS BAD!!! Never turn any bass boost on, or increase the bass on the cd player, all it does is boost the bass frequencies past the normal. This can distort the bass and easily blow a sub out, not worth the extra volume, you should have bought stronger subs/amplifier if you wanted louder BASS.
People in car audio can become name brand selective and brand arrogant, don't listen to anyone like this, they will usually tell you all other brands except their brand are garbage. Now that you have gained some knowledge, you can look at the specs, the Ohms, the RMS power, and make an educated decision. REMEMBER, all car audio companys test their products and figure out the capabilities. A 800 watts RMS sub is an 800 watt RMS sub, brand doesn't matter. Other things do though, like construction quality(a poorly built sub won't last as long), or what the voice coil is made of, different metals handle heat differently. Research, read product reviews, ask around in forums. Good luck in your bidding!
Sincerely,
John Castilano
Car Audio Nut!
So lets start with the basics:
Most people looking for sub woofers and amplifiers are solely looking to add BIG BASS to their vehicles.
Lets talk about the types of sub woofers:
I talk about RMS often, RMS is a technical term referring to the continuous amount of wattage a sub can handle. When shopping for subs, DO NOT look at PEAK power, its a stupid marketing/sales aspect of a sub. Apparently PEAK is how much power a sub can handle if the power peaks, such as a kick drum hitting, etc. Do not factor PEAK power into anything, always know the RMS, if you were to hook up a 1000 watt RMS amp to a 1000 WATT PEAK sub, it would blow after a day, maybe sooner.
8 inch woofer: These subs are best used in the back dash of a car, or maybe in a bazooka tube in a truck. Basically for people that don't really want to take up much space in their vehicle but still get some decent bass. Putting these in a trunk would be a waste of money, you'd barely hear them! An 8 inch woofer will not make the hair on your arms stand up, but will fill the car with a better than factory sound. It really depends on the quality of the sub and the number of them installed, a pair is best I think. Most 8's will not be able to handle low frequencies, 40 Hrtz or below I believe, but can hit higher ranges of bass safely, up to 110 hrtz(see below about crossovers). A good 8 will be able to handle up to 400 watts RMS, some sound good at lower RMS, some expensive ones can handle power higher than 400 watts RMS. The sound of an 8 kinda gets inside your head, some people find this annoying, the frequency is just too high.
10 inch woofer: These subs are good for putting a pair in a trunk and still having some room. Only putting one in a trunk would, in most cases, not produce enough sound unless you bought one that can handle 500 to 1000 watts RMS, then you'd hear some strong bass from the trunk. There are certain 10's that can handle lower frequencies of bass, around 30 Hrtz. Most people get 10's because they produce a better punch and higher frequency, but not annoying like the 8's. 10's seem to be the preferrence of rock music listeners. Rap will sound ok, but for many songs it won't. A 10 should be able to handle having the crossover(see below)
set to 90 Hrtz, though a little lower is always safer.
12 inch woofer: Referred to as the most dynamic woofer. The 12 inch woofer is definately made for the trunk and for producing BIG BASS! Two quality 12's will make your hair stand up. One 12 of good quality, such as 1000 watts RMS, would shake the car and make your hair stand up pretty well. 12's are able to hit bass frequencies from 30 Hrtz up to 80 Hrtz, but its safe to keep the crossover lower around 60 Hrtz, its just not worth possibly blowing the sub for a minimal boost in volume. Fully powered 12's are both punchy for rock songs and can be thunderous for rap songs. Definately the most popular sub around.
15 inch woofer/ 18 inch woofer: These big things will shake the crap out of your vehicle, definately for the BASS maniacs! They can hit really low frequencies to thunderous proportions. The box size required for these subs will definately fill the entire trunk, in some cases may not fit, depends on the vehicle. These subs can hit frequencies 50 Hrtz down to 25 Hrtz for 15's and 20 Hrtz for 18's. Some 18's can go even lower than 20 Hrtz, but thats so low the volume starts to drop off and most songs don't go that low, except for BASS cd's. The best thing about 15's, you can buy 2 of them that can handle only 300 WATTS RMS, and they can sound louder than 2 12's that can handle 600 watts RMS. They are just so big and push so much air. Any kind of 15 or 18 will add some serious bass and take up tons of space.
Crossover: A device that filters out different frequencies from an audio signal. Most good amplifiers come with one built in, though you can get them separate too. They are the best way to protect a sub from blowing out. Crossovers on amplifiers for subs should be LPF or Low Pass Filter, it only allows low frequencies to pass through. If its set to 50, then only frequencies 50 Hrtz and below will go to the sub.
I WILL TELL YOU A SECRET!!! Car audio subwoofers are very different than subwoofers for home audio. They are technically supposed to be able to handle all frequencies, though they really can't. If you ran a car woofer with a full frequency range going to it, the voice coil(which are pathetic in car audio) will overheat and melt, they are just not able to handle high frequencies. I once had a 12 and had set the crossover to what I thought was 60 Hrtz, I later found out after it blew 30 days after the purchase date that I had incorrectly set it to about 90 Hrtz. Only 30 Hrtz higher from a safe setting of 60 Hrtz and it limited my woofer to a 30 day lifespan !
Matching amplifiers to woofers and what the heck does bridging mean: Finding the right amplifier for your subs is very important, the wrong combination can result in a huge waste of money and damaged goods.
You generally want to match the subs RMS power to the amps RMS power, but it can depend on how they are hooked up.
Some info to help select an amp:
bridging an amp: most amps are 2 channel stereo amps, thats a left and right frequency/channel. These are very popular when running 2 subs. Bridging essentially combines the power of both channels into one mono channel, doubling the RMS power in most cases. A MONO amp is a 1 channel amp, thats it, just one channel, though they are designed to run at lower ohms.
Ohms: Ohms are the amount of resistance a speaker is rated as. A speaker is nothing more than a giant resistor of electricity. Most subs are 4 ohm, though they can also come in ohms of 2, 8, 3, and 6.
Most 2 channel amps can run at 4 ohm, but nothing lower. Mono amps can run at lower ohms, 2, 1.333, maybe even 1 ohm.
Calculating ohms and watts of my installation: to calculate the ohms and wattage of an installation, you need to know some things; WATTS RMS of the amp at different ohms, 4 ohm stereo, 4 ohm mono, 2 ohm stereo, etc.
This is where is gets kinda technical, but not difficult to understand:
Subs can have 1 or 2 voice coils on them. Most have one, though you should think of a dual voice coil sub as two in one shell and they will have two sets of terminals on them, one for each voice coil.
There are two ways to run multiple subs; series and parallel. Series is running the subs in a row, so that power has to go through the first one before it gets to the second one. Running subs in series will double the resistance, so 2 subs run in series at 4 ohms a piece will make a total ohm of 8 (4 + 4=8). Parallel is like running the subs side by side with their own path to the amp, the power is split to each sub evenly. Running subs like this puts more work on the amp and results in lower resistance, so 2 subs run in parallel at 4 ohms a piece will make them a total of 2 (4 / 2=2) ohms.
The terminals on a dual voice coil sub should be treated as two individual subs. If you want the whole thing to be parallel, you would wire the terminals positive(coil 1) to positive(coil 2) and negative(coil 1) to negative(coil 2); series is would be positive(coil 1) to negative(coil 2) and negative(coil 1) to positive(coil 2).
As for two separate subs, same principals apply, only instead of connecting their terminals as I just described, you can have them meet at the amplifiers terminals. Most amplifier manuals have crude diagrams showing what I just described.
Now comes the fun part:
So now you know what ohm your sub is; single voice coil, dual in series, dual in parallel, lets talk about the amp hook up. Just remember that a channel is its own functioning device. You could technically blow the right channel of a 2 channel amp and still be able to use the left channel. If its bridged or a mono amp, you only have one channel to work with.
To make this easier, lets look at a simple example and a complex example:
Two 8 ohm subs at 200 WATTS RMS. If the 2 channel amplifier puts out 100 WATTS RMS a channel at 4 ohm stereo, you could hook each sub to a channel, but because each channel is its own device, you'd have 8ohms on one and 8 ohms on another resulting in half the power, so 50 watts RMS to each sub. This is no good. So hooking them to the amplifier bridged(combining the amp into one channel) will double the power, so the amp would put out 200 WATTS RMS at 4 ohm mono. If you hooked the two subs in series as I described above to the amplifiers terminals, you would double the ohms to 16 !! You wouldn't be able to hear anything, maybe even damage stuff!! Instead, run them in parallel, this will divide the ohms 8 by the number of subs 2 to get a 4 ohm circuit! Congrats, you now have 2 subs that can handle 200 WATTS RMS hooked up to an amplifier that is now bridged and putting out 200 WATTS RMS, a perfect match!
Two dual 4 ohm voice coil subs at 200 watts per voice coil, 4 ohms per voice coil. This like working with 4 individual subs. Its simple if you think of the first example, just with one extra step. First wire the voice coilspairs on each sub in series as described earlier. This will turn each sub into a 8 ohm sub. Now you have two 8 ohm subs and can use the steps from the first example to finish the install.
Some other pieces of information:
Wiring is important, any amplifier running from 0 to 500 WATTS RMS can get away with 8 gauge, nothing less, bigger is better though. Note the gauge size is reversed, 4 gauge is bigger than 8 gauge. Any amplifier running more than 500 WATTS RMS should have 4 gauge, anything less could heat the amp up and shut off.
BASS BOOST IS BAD!!! Never turn any bass boost on, or increase the bass on the cd player, all it does is boost the bass frequencies past the normal. This can distort the bass and easily blow a sub out, not worth the extra volume, you should have bought stronger subs/amplifier if you wanted louder BASS.
People in car audio can become name brand selective and brand arrogant, don't listen to anyone like this, they will usually tell you all other brands except their brand are garbage. Now that you have gained some knowledge, you can look at the specs, the Ohms, the RMS power, and make an educated decision. REMEMBER, all car audio companys test their products and figure out the capabilities. A 800 watts RMS sub is an 800 watt RMS sub, brand doesn't matter. Other things do though, like construction quality(a poorly built sub won't last as long), or what the voice coil is made of, different metals handle heat differently. Research, read product reviews, ask around in forums. Good luck in your bidding!
Sincerely,
John Castilano
Car Audio Nut!
Guide created: 08/24/06 (updated 09/06/08)
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