car stereo system 101

well bmlbytes did a beautiful job with his instructable. But i guess its my turn to take a swing at explaining how to buy, install and modify your subwoofers, and audio to perform to their fullest extent. Now remember these are guidelines to help buy equipment. my system is one of the cheapest, but i figure if your in the position to buy decent stuff, these are the guidelines to follow.

Step 1: Buying

Well, there are a few aspect you have to keep into account.
- price/ what your willing to pay
- wattage
- brand
- music listened to
obviously more bass i good. However i doubt a fan of orchestra is going to need a 1000 watt system. thinking of what music you listen to will determine what size system is acquit to what you listen to. And in the end will give you a price range. Obviously Rap, of course is the number one, music type associated with subwoofer systems. i personally listen to NO rap, but Classic rock, and a smiggit of new rock. For my need i really dont need much watts. but i guess "brag rights" got to me. i personally own a 1000w system and LOVE it. I enjoy listening to Godzilla by Blue Oyster Cult, it is one of the best songs with bass. Led Zepplin offers tons of bass and enjoy them as well. But this just demonstrates what is needed and what u might want. next is the idea of brand, brand will offer better sound than others and better warranty. Here is a guide to the goods and bads of subwoofers and amps:

Good brands, including but not limited to: Alpine, Rockford Fosgate, Kicker, JL Audio, Soundstream, ARC Audio, Cadence, Diamond Audio, Focal, Dayton (subs), Precision Power, some MTX, RE audio, Fi car audio, Sundown Audio, Hertz, MB Quart, Zapco, Infinity, Incriminator Audio, Missing Link Audio, JBL, Mach5, Ascendent audio, and DC sound labs, Digital Designs, Pioneer Premier; old school brands: Lanzar, Hifonics, Orion, and Phoenix Gold.

Mediocre brands (brands that are good for the money, but there is better): Quantum Audio, Sony ES line, Memphis (I have heard of lots of problems with their amps), Dual, Infinity (in my opinion), Pioneer, Kenwood (in my opinion).

Junk brands, including, but not limited to: Pyramid, Boss, Profile, Lanzar (except old school Lanzars), HiFonics (again except old school, series VIII and earlier), Legacy, American Pro, Rampage, MA Audio, Alphasonik, Crunch, Lightning Audio, Visionik, Audiovox, Volfenhag, Rockwood, Jensen, American Legacy, Audiobahn, Sony Explod line, VR3, JVC, Pyle. Any thing at Wal-Mart, or an auto parts store.

now some may be labeled as bad, but some actually with the right components will sound good. Good places to check are Ebay, propertyroom.com, and your local craigslist.

Comments

[internethotspot]

Venting is not controlled, whereas porting is considered controlled venting, allowing for tuning. In other words, adjusting the right amount of venting. BOSE is the master or porting, and has incredibly complex methods of folding the air.

You WILL blow your speakers if you send a clipped signal (square wave) through. The MAIN reason people clip their signals is because they are increasing the gain to try to get more from their amplifier, resulting in a clipped signal being sent to an underpowered amp, and on to the drivers where they overheat the magnetic coils. An overpowered amp would also blow the speakers, but in 99% of the cases the reason for clipping is due to people trying to get more from their underpowered amplifier.

"In the case of under-powering, the driver is blown because the amplifier is driven to the point that it can no longer amplify the signal.
The amp tries to generate the amplified version of the input waveform, but runs out of "headroom" before the full wave is generated.
The result is a square wave."

[internethotspot]

Ok gotta clear up some silliness...

First, the only time you would use a non-ported box is when there is a port between two separate chambers, and the drivers are run with reversed polarity. Well, there is another exception - there are drivers designed for any space... self-contained so they can be in a sealed box. Generally more expensive, and a loss of quality.

For every action there is an equal and opposite reaction. If the driver moves in and creates pressure, it WILL push back - and that's going to distort the sound you try to produce next. So the only time you would do this is when your second driver has reversed polarity and is moving IN when the other driver is moving OUT. That way one driver supports the other. Be careful the chambers are not too small or too large, or you will just end up with crappy sound. GOOD REASON TO JUST USE A PORTED BOX. If you aren't a sound engineer, don't try this without a plan designed by an engineer... or you are wasting your money.

There are some drivers designed specifically for non-ported boxes. Use these if you don't have the knowledge or specifications to make a sealed box.

When you use a sealed box with two drivers (one reverse polarity), you don't get to run your amp in bridged mono mode. When you run your drivers in series, it will drop from 4 to 2 Ohm... essentially providing an extra 3db output.

One other little thing, I can't tell if there's a crossover inside the box, and hopefully not. Amplifying all frequencies then throwing away that power would be a shame.

Many amplifiers have built-in crossovers... many passive. Best bet is to ONLY send the frequencies you want to amplify to the amplifier, by using an active (powered) crossover, placed before the amp.

Bunch of considerations... I recommend buying a box at FutureShop, get an active crossover and Bob's yer uncle.

[bsodergren]

I would just like to let you know, that nothing you said in your comment is remotely true or accurate.

1) Ported boxes provide a slight, natural, boost in the subwoofers Fs, which is the resonence frequency. For example, if you have a sub with an Fs of 37, you tune the port to that frequency (by adjusting the volume the port takes up) and when viewed with an RTA, you will see a boost in the 35-40hz range. The Problem with the ported box is that they're more sensitive to distortion and the sound quality is far worse. The boxes are also bigger.

2) Sealed boxes provide superior SQ and almost no distortion (regardless of how many drivers you are using). They also allow for smaller box sizes, which is always a positive thing to have.

You use a ported box when you want volume and don't care about sound quality.
You use a sealed box when you care about sound quality.

That's pretty much the end of that discussion.

Now, if you have two subwoofers, wired out of phase, the sound produced by those drivers would be cancelled out. Google Destructive Interference.

You don't need to be a sound engineer to make a good box, you just need to read the manual that comes with the subwoofer. Every respectable manufacturer includes recommended box sizes (in CuFT) and some even give you a cut list.

Any subwoofer can be used in a seal or ported box. There have been subwoofers that can be used "free air", but those are largely outdated and no longer produced.

I can't even begin to explain how you can't run your amp in bridged mono because you're using more than one driver, but then you say that running your drivers in series will drop the load in half. If you have 2 drivers and you run them in series, you have to use a mono amp (or bridge your 2ch amp).

The extra 3db output comes from using 2 drivers v.s. 1 driver and nothing to do with the load on the amplifier.

[masterba]

oh by the way make sure you separete your power wire and your RCA's because with then running right next to each other like you have pictured you are going to runn inn to the problem of alternator noise or a whine for your speakers.

[internethotspot]

Good reason to run an extra ground wire if system allows. It would filter out such noise and all other noise. There is an animal called balanced RCA (has extra wire). May require some modification...

[ndiller]

my buddys got two "12 subs and a 1500 rockford amp. but the subs are sony xplods : / so idk if i should buy he's offering me 150-170 for all

[pdlbooboo]

 i really want to know why people use capacitors and extra fuses for their systems.

[mcc1angela]

caps store power so that when needed for lots of bass its already there and doesn't take so much form the battery when needed. whole lots of power needed without a cap may cause your headlights to flash or dim at night while cranking up the volume.

[slimguy379]

awh well caps allow the subs to receive the needed amount of power. when the cars running other things use the battery's power so not all 12v can be run. but all in all with experience i realize that if your going to spend money to help you system in the volts department, your better off buying a new alternator to crank out more volts. caps can be used but caps only help the system, were a better alternator help the whole car. but its all about opinion and money. Fuses are used to protect your amp and/or battery. if your 12v hits a ground then your fuse blows instead of messing your amp up. another opinion thing, but its actually a decent and recommended idea. However most amps use extra fuses inside of them so its not all that necessary.

[internethotspot]

Personally I would never use caps on woofers/subwoofer drivers. Caps equate to a passive crossover, and that means you are REMOVING frequencies you have already amplified... basically it's like your amp is the chef, and you are throwing out food before it hits the table because you don't like it. It's best to tell the chef what to cook so you don't waste food.

Also, every connector in between the deck and amp will cause leakage, and result in noise. It's not a big problem if you have an active crossover to get rid of it before you waste power to amplify the noise.

If you can get a deck with balanced output, then you don't have to worry about noise, as it will filter it out. A balanced deck will give you a benefit equal to 2x the size of amp. The reason for this is that for every 3db increase, it requires double the power. A balanced line results in a 3db increase over unbalanced (standard RCA). You can CREATE a balanced line by adding a 3rd wire (ground) from the deck through to an active crossover - and to the amp.

Note an active crossover will give you 3db increase as well (equal to 100% additional power).

Simplified:
RCA from deck to amp - passive crossover/caps - driver is equal to about 9db decrease/loss.

Balanced output from deck to active crossover - to amp - driver will result in 9db increase. AND as your amp is only amplifying frequencies you wish to reproduce, you will essentially gain another 3-6db for an increase in sound level and quality of up to 15db.

Don't worry about getting the biggest amp - instead think about how to get the best quality (balanced) signal through, and narrow the range you amplify so you don't throw away frequencies.

By comparison, a 50w amp that has balanced lines all the way, and uses an active crossover, is going to give you as much bang as you would get with a 400w amp with standard unbalanced RCA, passive crossover.

Quick notes:
- * every increase of 3db requires double the power (eg, 1 - 2 - 4 - 8 - 16...)
- balanced system gives +3db increase
- active crossover gives about +3db increase
- bridged mono series gives about +3db increase (compared to parallel)
- passive crossover/ caps throws away amplified frequencies (waste)

* known as the 3db rule

[Modifier]

all car alternators push the same volts. i think you mean better alternators push more amps

[mcc1angela]

most guys that put a sub box in the trunk of the car is because thats the only place there is enough room for the sub box. but doing this does tend to make the trunk etc... rattle at loud volumes, besides lots of your bass is escaping through the vents in the trunk area of the car. actually whats happening is you are loosing some of your sound and quality. the correct way i think to do this is to make a seal from the box to the rear of the rear seat of the vehicle. and if you are using a sub that is enclosed in the box with only a port where the bass is released...you should run a port from the port of the box directly to the rear dash of the vehicle or to the rear of the back of the seat directly and mount the sub enclosure to the floor of the trunk so that it doesn't slide around. without doing this i beleive that you are not getting all of the true bass because it is roaming around in the trunk of the car instead of towards the interior of the car.

[ph1lt3ch]

 What gauge power wire are you running? Concerned you might pop the wire before your fuse by the looks of it. Do you have a true 1000watt system, or like most of us a 1000watt amp and around 300-500 watt RMS? haha because I'm running a KAC-8104D (1000 watt, 300RMS @4ohm, 500RMS @2ohm) and that feeds my JL 10w0v2-4(ohm). Just all that to say, I'd never run under 4 gauge wiring to a 1000 watt amp :D Maybe I'm just overly concerned. (the system is small because it's in my tiny single cab f-150, and i've already blown one eardrum out earlier in life)

[mcc1angela]

The size wire used for amplifiers are usually in the amp install booklet and depending on the length of the wire the guage of the wire may need to be enlarged if you use a certain amount (feet) of wire. if your amp calls for 8 guage wire up to 20 feet and your using 25 feet of wire you may need a bigger guage wire to get the full potential of power from the amp...

[MIKEPALMA1]

ROCKFORD FOSGATE CAR STEREO RECIEVER, CLARION 7 BAND EQUALIZER WITH BUILT IN CROSS OVERS, 1 ROCKFORD FOSGATE AMPLIFIER, 2 MTX AMPLIFIERS, 2 CLARION 6 INCH BY 9 INCH 3-WAY SPEAKERS, 2 JL AUDIO 12 INCH SUB-WOOFERS AND 2 JBL 12 INCH SUB-WOOFERS ALL OF WHICH I INSTALLED AND CUSTOM BUILT THE SPEAKER BOXES NOT PORTED, AND IT ROCKED!  FIRST, ITS CALLED A BACK DASH NOT A HEADLINER! SECOND, IF YOU ONLY PAID 10 DOLLARS  FOR 25 FOOT RCA CABLES YOU WILL HAVE PROBLEMS...TOO THIN, GETTING RUBBED THROUGH, WIRES BREAKING INTERNALLY WHEN BEING FISHED THROUGH THOSE HARD TO GET AT PLACES FOR THAT PROFESSIONAL/ FACTORY INSTALLATION LOOK! THIRD, THE BLUE WIRE OFF THE BACK OF A NON-FACTORY DECK IS THE REMOTE/POWER ANTENNA  REFERENCE SIGNAL WIRE. IF YOU HOOK THIS UP TO A RED IGNITION WIRE YOU WILL HAVE PROBLEMS. THE REMOTE WIRE FROM THE AMPLIFIER SHOULD GO TO THE BLUE, SOMETIMES BLUE WITH WHITE STRIPE WIRE COMING OUT OF THE BACK OF THE DECK. IF YOU HOOKED THE REMOTE WIRE OFF THE AMPLIFIER TO A RED IGNITON WIRE THIS CAN CAUSE A POWER SURGE TO YOUR AMPLIFIER CAUSING A THUMPING NOISE WHEN THE KEY IS TURNED ON. NOT SURE, DONT KNOW THE STATUS OF YOUR RED WIRE IF IT IS SWITCH POWER OR BATTERY POWER! RUNNING ALL THE WIRES TOGETHER ALONG SIDE EACH OTHER  COULD CAUSE RADIO INTERFERENCE IN THE FORM OF ENGINE NOISE COMING THROUGH THE SPEAKERS. IT COULD GENERATE A MAGNETIC FIELD. THE ONLY WIRES THAT SHOULD BE RAN OPPOSITE OF THE REST WOULD BE THE POSITIVE CABLE AND REMOTE WIRE. BE SURE TO INSTALL  A INLINE 30 AMP FUSE FOR THE POSITIVE CABLE CLOSE TO THE BATTERY! CAR STEREO BASICS 101: DECK POWER WIRES-BLACK IS GROUND, RED IS KEY ON POWER, YELLOW IS EITHER MEMORY OR BATTERY POWER AND BLUE IS REMOTE OR POWER ANTENNA. NOT TO BE MEAN BUT SOMEONE COULD LOSE SOME MONEY IF THEY THOUGHT THAT THEY HAD MADE A MISTAKE!

[pdlbooboo]

YOU LEFT CAPS LOCK ON

[slimguy379]

theres a button called "Caps Lock" push it once and your writing wont be like that LOL

[pdlbooboo]

haha just realized someone else posted it too lol

[renswic]

wow... First off. NEVER run a power wire through a door, that's just begging for a pinched wire. Theres always space to drill through the firewall or find a factory grommet for the wire to go through. Second off. Mounting the amp on top of the sub box honestly works great. The only down side is that you just made it easier for someone to steal it all, subs, box and amp in one deft move

[jayhawk67]

i have a 99 monte too and will try to simulate this at a later time--I don't think you took enough pictures

[noonetrulylives]

If you don't understand how ported boxes work you shouldn't be writing an Instructable. A well made ported box allows pressure relief and causes better bass notes as well as adds to the lifespan of your system. Closed boxes simply don't get the same kind of tonal range.

[Yerboogieman]

Depends a lot of the hertz of the sub-woofers,  what you listen to, and what kind of bass you want to hear.

[staindoutside1]

first off who are you replying to dude...sounds like you don't know much of what your talking about,?think about it for a minute if you had a airtank that had a hole in it and filled it with air, well the pressure would escape that's just like your port and if the airtank was without a hole it would hold pressure,well pressure is how you get your low better bass notes, if your saying  i'm wrong by saying a enclosed box sounds better than a ported well you just turned it around and said the same thing i did, but in your favor, your just stuck on ported boxes, like i said come by my house or we can meet and i'll change your mind when you can't catch your  breath in my ride a ported box allows for higher volume and a enclosed doesn't take as much volume and if your box is tuned right the enclosed will hit harder bottom line

[Hycro]

Non-ported, I've found will give you things like drum beats, and will hit hard. Ported will give you thunder, and is a low rumble kind of box. I ran two 10" subs, one ported, one not for my computer (they had a dedicated amp, though the amp could only pump out 50W/channel, but was a decent amount for the subs, which were 150W RMS, 450W peak) and I had excellent results for music and games. Both subs were given the same power, and I'd shut the ported off, and then I couldn't get low rumbles very well, I'd turn it back on, shut off the non-ported, and then I wouldn't have drum beats very well. If you're able to do it, I'd suggest running BOTH ported and non-ported, wired to both be getting the same signal at the same time, and you probably won't want to go back to using just one or the other.

[noonetrulylives]

By the set up you described yourself as having its obvious that good sound isn't your forte. Put a 1000 watt amp into any speaker that can handle it and it will shake everything around it

[slimguy379]

(removed by author or community request)

[blindsalesman]

it looks like you did insert, that whole blurb, [fail]

[noonetrulylives]

I understand what you're saying but again a lot of the assumption of tonal range depends on it being ported correctly. A properly ported sub will never "bottom out" if used within its proper frequency range. Most of the "distortion" is actually gain caused by the amp. for tight hits use unported for smoother bass tones go ported. Any subwoofer instruction booklet will say the same. Also I think you might be confusing vented boxes for ported boxes. Ported boxes usually have only one or two holes about 2" wide and 3-4" deep. Also I apologize if I came off a little rude, I just think if you are going to talk subs you need to explain your choices and tell why you decided not to go one way or the other.

[internethotspot]

When a driver bottoms out, it is generally a result of clipping - underpowered. But also be careful of BASS killers. Just like there are computer viruses out there, there are driver viruses that will kill the best drivers.

The way they work is they have the driver produce a continuous frequency for an extended period of time, thereby frying the driver. Just a note on that - a sealed box holds more heat, and reduces the driver's ability to reproduce tones.

[bsodergren]

Again, totally inaccurate.

Drivers do not bottom out because they are under-powered. It is a electromagnetic impossibility.

Clipping is a form of waveform distortion that occurs when an amplifier is over-driven and attempts to deliver an output voltage or current beyond its maximum capability. It has nothing to do with speakers.

Speakers have a rating called Xmax, which is the mechanical limits of the suspension (the surround and spider). You obviously will get distortion at the peaks of the Xmax, but you're more likely to get distortion at the amplifier from clipping.

Also, playing a continuous frequency for a period of time is how manufacturers test and break in drivers before shipping them to you. Usually they're played for 8-12 hrs to fully relax the suspension.

While sealed boxes can hold in heat, a properly built subwoofer can handle the excess heat produced by the driver and the little amount of heat that is produced has absolutely NOTHING to do with how a speaker reproduces sound.

[Modifier]

so what's the difference between ported and vented?

[bsodergren]

There is no difference between ported and vented. they're two different words to describe the exact same thing.

[internethotspot]

Ported refers to a hole that allows air to move in and out. The port itself can be tuned. For example, consider an ABS pipe of 1"... 2"... 3"...4"... then a lenght of 1" - 8" long. Depending on the size of the pipe, and length, it will effect the movement of air.

As for vented, I've really no idea but sounds like something to do with cooling ;)

[slimguy379]

nah i understand, just theres only one other instructable about subwoofers etc. why dont you make one?

[staindoutside1]

i have purchased alot of ported box/sub combo's that was made for the port and it does bottom out .no port means better thump, bring your ported box/subs by my house and i will show you how a sytem should hit 140db, and i will shake your ride parked beside me

[slimguy379]

what system do you have love this kinda talk

[staindoutside1]

2 ..1000/1 JL Audio amps 2...JL Audio w6's in a custom box firing face to face 0g wire, big 3 upgrade a big azz cap. in a 00 s10 extreme extended cab

[slimguy379]

sweet any pics?

[cornflaker]

lol no reply 

[Kaosprophet]

A side note on the ground. Make sure your ground is the same size or bigger than your power wire. A smaller ground causes heat in the amplifier and runs the risk of melting something/hurting components. :)