Dual Voice Coil or Single Voice Coil? Which is right for me?
February 28, 2008
As a store owner since 1994, I’ve heard it a million times: “I want a dual voice coil sub.” So I do my job and ask “why is it that you think you need a DVC sub?” The answer every time is the same: “Well they’re louder!”
I guess it is natural to think that. If one coil is loud, 2 coils are louder. Unfortunately, that is not the way it works. All things being equal, an SVC sub and a dvc sub are virtually identical in output.
Why make them if they produce the same output? Simple… To be able to derive the maximum power that an amplifier can safely produce. Let me explain…
For the purpose of this post, we will assume that all individual coils are 4 ohms.
Suppose a customer has a 1 channel (monoblock) amplifier that produces it’s maximum power output of 500 watts when presented with a 1 ohm impedance. If presented with a 2 ohm load, it produces 250 watts and a 4 ohm load produces 125 watts. You have decided that you want 2 12 inch subs.
If you take 2 single voice coil (SVC) subs (4 ohms each) and hook them up in parallel, you end up with a 2 ohm load. You are essentially using half of your amplifier. Not an optimum situation… Read more
Gain Controls… Level Matching Devices, Not Volume Controls
February 26, 2008
I’m sure every contributor to BestCarAudio.com would agree that one of the most common misconceptions in the car audio industry is the purpose of the gain control on an amplifier. We all see it on a weekly, if not daily basis… The custom comes in with a blown sub and complains that “my amp is only 200 watts and the sub can handle 500 watts! What’s up with that?”
Truth is, in the 15 years that I have been doing this, I would say that 90% of the blown subs that I have encountered are due to improperly set gain controls, not big bad amplifiers! The purpose of this post is to explain what a gain control is.
To put it in it’s simplest form, a gain control is a level matching device. Read more
Will an After Market Installation Void My Vehicle’s Warranty?
February 1, 2008
I am sure that most retailers would agreed that a common question we always hear is “Will this installation void my cars warranty.” The car dealer told them that if they had an after market product installed, their warranty would be voided. Nothing is further from the truth! The Magnuson-Moss Warranty Act of 1975 specifically forbids the use of”tie-ins” by any manufactures. One example of a “tie-in” is a vehicle manufacturer requiring that the consumer use a specific brand of motor oil or the warranty will be voided.
Since “tie-ins” are made illegal by federal law, a dealer cannot void a warranty just because you choose not to use their product. The only way that they can require you to use their product is if they are offering it to you at no charge. For an easy to understand translation of the act, click here.
Of course, a dealer or manufacturer cannot be responsible for faulty workmanship or poor quality after market products. If an after market product is found to have caused a defect in the vehicle, the dealer can refuse to warranty that specific problem. To this end, it is even more important that you choose a reputable shop to do your after market installations.
I don’t want to make it sound like all car dealers are bad and out to refuse warranty claims. By far, most dealers try to stick to the law and do the right thing. In most cases, it is a poorly trained service manager who is unfamiliar with the law. Unfortunately, in some instances, your dealer may just be deceptive. These are the cases that deserve some attention. One option is to contact the Federal Trade Commission at (202) 326-3128 or www.ftc.gov
There are endless upgrades available for your vehicle. When properly installed by a professional, you can rest assured that you warranty will be intact and the results will be fantastic.
Posted by Mitchell Schaffer Owner of Mobile Edge in Lehighton, PA Mobile Edge is a leading provide of quality aftermarket accessories and installations in Eastern Pennsylvania www.MobileEdgeOnline.com mitch@mobileedgeonline.com
