Car audio competition walking dead? Photo By Sam Valliere

This weekend (October 3rd and 4th) marked the 22nd annual USACi World Finals event in Tulsa, OK. Held at the Tulsa Convention Center, this year’s event was a unified World Finals, combining the USACi (United Sates Autosound Competition International)  finals with dB Dragracing finals. Featuring a combined total of 100 competitors (including those registered in multiple events), the competition side of things was smaller than that of previous years. With the receeding economy, traveling to a world finals event becomes increasingly more difficult. It was no surprise that many of the competitors were regional, with the majority of them coming from surrounding states like Texas, Missouri, Louisiana and Arkansas, and several from Oklahoma. There were of course a few coming from further away, such as Chicago.

Where my peoples at? Over at the unemployment office probably

Walking into the convention center, I was shocked and disappointed. Where just three years ago, it was standing room only, this weekend, you were hard pressed to find anybody there that was not a competitor or somehow associated with the event. The spectator level was damn near zero. Even the manufacturers didn’t bother to show up. DB Drive was the major sponsor of the event and their presence was felt by the giant semi-trailer that was next to the stage. Car Toys, one of the biggest car audio shops in Oklahoma (where Gary Biggs, 7-time world champion, got his start) had the next biggest booth, and they footed the bill, not the manufacturers they sell. There were no giveaways, no T-shirts, no swag at all. Not that that is important to me, but handing out free stuff gets people in the doors, and the place was empty. It was very disappointing. I do not expect much in the future from USACi or dB Dragracing. Though the word on the street is that this year’s event was bigger than last year’s, held in Dallas, TX. I spent the day at the event trying to get photo shoots lined up for future feature stories, but that only took about an hour because nobody showed up for the car show. And to think that the Convention Center cost $13,000 for two days.

While it may seem like shameless self-promotion (which it is), my latest book, “How to Design and Install In-Car Entertainment Systems” is finally on the shelves. After months of hard work, late nights and several purpose-built systems, the book is done and on the boat from China. Yeah, they print them in China. Don’t worry, I am sure the paper is lead-free, at least I hope it is.

In case you are wondering, the book covers everything car-audio and then some. The first chapter is all about the fundamentals of car audio and electronics, which is to say a brief primer on automotive acoustics and basic electrical theory. It is presented in a way that is easy to read and understand, so you don’t get bogged down in the mire of technical jargon. The next two chapters are about planning and basic installation tools and techniques.

From there the book gets into the nitty gritty details of installation. Covering all the basics like head units, amps, subs and speakers to MP3 players and GPS. Many of the techniques shown in the book are cutting edge, things you won’t find ANYWHERE else. These are the tips and tricks that make installing car audio much simpler for the novice and may even provide the pro with a few ideas too.

Want to know how to blend a TV into the dash of your ride? It’s in here.

Always wanted to understand how cancellation and reflective waves work inside a car? Read it here.

Need some guidance for GPS navagation systems? Find your answers in the book.

If you are a beginner in car audio, spending $26 bucks on this book can save you hundreds in mistakes and installation costs. You need this book.

Drop us a line if you want one. We will be selling a few through the site as soon as we get our grubby little hands on them.

In retail, chat forums and lunch rooms across the country the single most common questions are “how do I get my system louder” or “how loud will these subs be”. I can personally guarantee you that you ask ten people this question, including the guys at the stereo shop, you will get 13 different answers and none of them will be basing their answers on facts. They simply do not know how it works. There are some basic physics at work here.

Volume, which is measured in decibels (expressed by dB), is a function of power, cone area, enclosure design, and transfer function. Oh, you knew that already? Ok, sure that last statement might seem a little obvious, but undestanding how they interact togethr is critical to calculating volume. That’s right, you can calculate exactly how loud you system will be. Enough BS, here is the worksheet. You won’t find this anywhere else, send your friends.

This formula requires a few specs. First, you need the sensitivity of the sub(s). This listed on the woofer spec sheet in dB. It is sometimes notated as the SPL of the sub. Next, you need to know how much power your amp puts out. An amp birth-sheet (usually included in the box) will have the actual power the amp displayed when it was tested at the factory. Not all amps come with these. If you do not have such a sheet, you can use the power ratings, or even better, you can test it yourself (that is whole other enchilada and we will get into that another time). Other specs you need are more simple- what type of car do you have- truck, hatchback, or sedan; and what kind of box is it installed in. The enclosure will make a big difference, if it is a crappy home-built box with lots of leaks, held together with carpet and liquid nails, it probably won’t function as well as a professionally-built enclosure (like the Q-Logic pre-fab enclosures- shameless plug) and how many woofers you have. Have fun.

Sensitivity =

Every time the cone area doubles, the output of the system increases by 3 dB, which is relative to a doubling of volume. If you have 4 subs, you would add 9 dB to the sensitivity rating of the subwoofers.

add 3 dB per doubling of cone area

i.e. 2 subs, 3 dB, 4 subs, 6 dB

Let’s consider sub sensitivity, with 3 dB per sub added and calculate the SPL. Each time the output power (wattage) of the amplifier doubles, the SPL increases by 3 dB. To figure this, use the following figures.

This represent 3 dB added per doubling of power starting at 1 watt/meter SPL.

1=0

2=3

4=6

8=9

16=12

32=15

64=18

128=21

256=24

512=27

1024=30

2048=33

4096=36

8192=39

Next we add in Transfer Function

add 12 dB for a standard car/truck

add 16 dB for a hatchback car

Now we figure in box type

For a sealed box, 0 dB, sealed offers no dB gain.

For a ported box, 3-9 dB depending on tuning frequency and air ripple. The higher the ripple, the more gain but at a cost of sound quality.

For a bandpass box, 6-12 dB again depending on the tune freq. and ripple.

For example, a 12″ Rockford Fosgate subwoofer has a sensitivity of 86 db at 1 watt/1 meter, and is capable of handling 300 watts.The sub is installed in a ported enclosure, so we are going to use a the lower output rate for the ported box at 3 dB. Powering the subwoofer is a Rockford Fosgate Punch 300-1, which is rated at 300 watts to a single 4-ohm load. All of this is installed in a 2006 Honda Civic Si, which is a hatchback and gets a boost from the 16 dB transfer function. Using the formula, we get the following results-

86+ 24 (at 256 watts, it is close, but you could add in an extra dB if you want) + 16 (trans function) + 3 (box gain) = 129 dB estimated output. This estimation will be within +\- 3 dB of the measured output. This is simple physics, and it works.

The big three refers to the wiring for the charging system; battery to ground (frame or body), alternator to battery, and engine to frame (or body). Contrary to popular belief, electricity flows from negative to positive, not the other way around. The negative cable is just as important as the positive cable; the methodology of transferring that power is just different. Most cars use negative ground systems, and all car audio equipment is designed for negative ground systems. This is where the negative pole of the battery ties to the vehicle’s metal body or frame. The positive pole of the battery is run to each component with individual wires, so each component gets the proper gauge of wire it needs for the length of run and current demands. The negative pole is supplied by the entire chassis of the vehicle, ensuring that the chassis has the best supply feed is critical.

Starting with the battery negative pole to chassis, pull the original wire and replace it with at least 4-gauge wire. It is a good idea to match the amplifier power feed cable gauge, if not use a bigger cable. In my cars, I use 1-ga battery to frame cable. You should clean the frame (or body if a unibody car) where the battery ground attaches. This should be secured with a bolt and not a screw. Any paint, rust, scale or grease should be cleaned away as well, you want a nice clean metal only surface. If the factory location does not allow you to use a bolt, move it. It does not have to be in the same location as the factory cable, but it should be as short as possible. You don’t want a 4-foot ground cable if you can help it, as the shorter the cable, the less resistance you will have.

Along with the battery to chassis, you need to run a ground cable to the engine. Most vehicles come from the factory with a ground strap, which is a braided metal strap that ties the engine to the body or frame. While this is ok, these don’t get replace often and are usually heavily corroded, which inhibits the flow of electricity. I like to tie the engine ground to the same point as the battery ground. This eliminates a connection point and really simplifies the entire process. I also like to add a body ground on full-frame cars and when the battery ground cable is attached to a subframe. The actual initial ground point for the entire vehicle (when running) is the alternator case. This is where the electricity is being generated, the battery is merely a storage device.

Another key point, but not part of the big three, is the ground point used for the amps. On full-frame cars, I mimic the body to frame connection in the rear of the car for the amp ground as well. I bolt the amp ground wire (usually off a distribution block) to the body with a bolt and then run a second wire off the other end of the bolt to the frame, making sure the body and frame are both clear of any paint, rust or grease. This might seem like overkill, but a good ground is the first defender of noise.

The last part of the big three is the alternator to battery upgrade. Using 4-gauge power wire, you simply replace the factory wire that runs from the back of the alternator to the battery. This is usually the large post with a nut and a washer. You do not need to route the wire just like the factory wiring, but it is very important for you to route the wires where they are not in danger of abrasion, burns or any other potential hazard, this goes for all wiring in the car.

One key point- if your system has capacitors, it is important that you disconnect or discharge these before working on the system. Caps stay charged and you can create big sparks and potentially ruin the cap (or other components) if you accidentally arc the terminals during the process.

With the big three in place, your system will charger better, provide more voltage (due to less resistance in the system) and be capable of providing the max output of your alternator to the battery and the rest of the system.

This year marked the 35th annual Mid-America Ford and Shelby Nationals event held at several locations in Tulsa, OK area. The 5-day long event included road racing at Hallett Motor Circuit, drag racing at Tulsa Raceway Park and a car show at the Southern Hills Marriott in Tulsa, OK. This was my third year covering the event, and it was also the best so far.

When I arrived on Wednesday morning, the Shelby Automobiles booth was set up and ready for business. This being the media day, they had several Shelby cars ready to be put to the test on the track by the journalists. I patiently awaited my turn to get behind the wheel of a Shelby, and finally that moment came. They said “Jefferson, why don’t you take out the Terlingua”. I obliged, thinking this would be fun.

The Terlingua Shelby is an aftermarket package assembled by Shelby Automobiles. Basically, you purchase a new 2010 V6 Mustang (yeah, I said V6) and the folks at Shelby bolt on a Paxton supercharger, 6-piston brakes, a new hood, Ford Racing suspension and add the Terlingua graphics kit. The Terlingua Mustang is a continuation of the famed Terlingua Racing Team formed by Shelby in the 1960s to compete in Trans-Am racing. The new version is as race inspired as you can imagine. The car handles incredible, and the Baer brakes will throw you through the windshield. The supercharged V6 has plenty of power, putting out more than the stock 4.6 V8 found in a Mustang GT. If you want a car that will haul ass and take corners like an F1 car, this is it.

The next car I drove I will remember forever. Shelby had brought out a couple of continuation cars, cars that are built just like they were when they were new, a Shelby Daytona coupe and a GT40. While I did not get a chance to drive the GT40, the Daytona was the highlight of the day. This is a full-on race car. Race pedals, mid-engine 427 big block, race tires, harnesses, the whole deal. The interior literally wraps around you, if you are big person (at 6’ I barely fit with a helmet on) it is a little claustrophobic. Oh well, cause when you drop the hammer going around a blind up-hill right-hand turn and the car side-steps a bit then digs in and launches you down the straight-a-way, none of that matters. It was too much fun.

I finished the day driving the new 2010 Shelby Super Snake. This 725 hp machine puts so much power to the ground, triple digit speeds are commonplace on short straight runs on the track, given the opportunity on the street, and this car would be scary fast. Taking hairpins at 60 mph is not a problem with the race-tuned suspension of the Super Snake. While the package may be a little pricey ($33,495 for the 725-hp post-title package version, that’s in addition to the $47k Shelby GT500 price tag) you couldn’t build the same performance in the same car for less.

If you ever have the opportunity to visit the Mid-America Ford and Shelby meet, do it. It will be something you never forget.

The US congress has introduced a bill that will put in place a national vehicle scrappage plan in an attempt to boost domestic auto sales. The plan states that you can take any car that you have owned for one year (and had insurance on) to any car dealership and get a voucher for $3500 to $4500 toward the purchase of a new car that gets better gas mileage. I won’t go into the dirty details, but you can find it on USA TODAY.

The Specialty Equipment Manufacturers Association (SEMA) has been fighting this legislation, knowing full well that with the full weight and support of the President of the United States, they didn’t have much hope of killing it. These programs threaten the very livelihood of the automotive aftermarket industry, as many of the cars that would be scrapped tend to be older cars that don’t get driven, and do not contribute to pollution, but are a much needed resource for parts and projects. In an impressive win, SEMA has managed to get a 25-year exemption worded into the bill. This makes it so that the car must be 1984 or newer to qualify. Not many classics in that time period.

This is still a troubling trend, because while the cars themselves may not be great, the drivetrain and other parts are. The bill states that the car can be resold in parts, like at a salvage yard, but the engine and drivetrain must be destroyed. With the SEMA exemptions, the transmission and rear end can be salvaged, but the engine must be destroyed. You can kiss those fuel-injected 350 chevys and 302 Ford motors good-bye.

The scrappage program will run for a term of one-year, when it will be reevaluated. In the end, the program will cost taxpayers in the neighborhood of 2.5 billion dollars. This program will not generate any significant environmental change, nor will it reduce congestion on the streets. What it will do is significantly raise the price of any used vehicle for sale and make it harder for the rest of America to buy a car. Sure, they will sell more new cars, but those used cars will not move to the used lot, they will go to the salvage yards. Every jackass with a $500 car sitting in the driveway with a “For Sale” sign in the window just went out and added three-grand to the price.

If you need a new used car, you better buy it now before this becomes law, which it will. The measure passed through Congress with a 298-119 vote.