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Audio and Electronics

This blog is an attempt to understand everything that is related to audio and electronics. i.e. : cd players : speakers : amplifiers : wiring (including RCA's) : custom car audio installs : car audio installation : car audio video : home audio : car insurance : auto insurance : ... and practically anything that you may need to know to make/decide your audio equipment of home audio or car audio.

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CAR AUDIO

A car audio system can be a sound cure to your traffic jam headaches. However, choosing and buying a quality hi-fi system needs some basic understanding of the subject.

Automobiles are highest on our list of objects of desire - they thrill, excite and get our pulse racing... unless of course you’re cooling your heels in a traffic jam. No set of wheels, no matter how quick, sleek or sexy, is any fun when you’re caged inside, inching forwards at three Ks an hour, be it a Merc, Honda or an Opel. With your eyes on the road and hands resting on the wheel, the only thing to keep the mounting frustration at bay is a quality car audio system.

FACTORY FITTED SYSTEMS

Car manufacturers today have recognised the fact that in-car entertainment constitutes an integral part of a modern car. Customers expect quality and many like Opel and Honda have gone to great lengths to provide quality head units from top-of-the-line audio manufacturers like Alpine, Blaupunkt and Kenwood. Most manufacturers however cut corners due to budgetary constraints, and install much cheaper OE speakers. These poor quality speakers form a weak link in the chain, resulting in a serious deterioration in sound quality despite the good head unit (the system itself). If you have a factory-fitted car audio system, make sure the speakers are the genuine thing, or else don’t hesitate to go out and get the real stuff.

Placement of speakers has a major bearing on sound quality, hence Bose's customized setup and placement for the Cadillac Seville.

SPEAKERS

Car speakers are generally located in doors and rear parcel shelves of a sedan in modern cars. High-end or competition stereo systems often have speakers mounted in "kick panel" enclosures, allowing for larger drivers and better driver placement. Before stereo radio was introduced, the most common speaker location was in the middle of the dashboard pointing through perforations towards the front windshield.

Car speakers come in a range of sizes, most commonly between 4 inch and 12 inch, and also in non circular sizes such as 6 X 9. The most common impedance for car speakers is 4 Ohms. Speaker power rating is usually between 35W (common head unit output) and 250W. High-end audio systems include Component Speakers that consist of a matched tweeter (high frequency), midrange (medium frequency) and woofer (low frequency) set. These component pairs are available in two speaker and three speaker combinations, and include an audio crossover which limits the frequency range that each component speaker must handle. This allows each cone to produce its optimal frequency for maximum sound quality and volume. In addition subwoofer(s) may be installed for bass and sub bass (ultra low frequency), which is felt more than heard depending on the sub frequency. Crossover systems can be active or passive crossover networks. Active electronic crossovers divide the signals before they are sent to the amplifiers giving a dedicated amplifier channel to each individual driver in the component system. Passive crossover networks divide the signal after amplification, making it possible to run multiple speaker component sets using just one channel.

5.1 and even 7.1 channel surround sound systems, as well as THX II Certified, are now being integrated into some cars by both aftermarket enthusiasts and car manufacturers themselves. These systems include the full complement of front left, right and center speakers along with rear right and left surround speakers (7.1 systems include left and right side surround speakers) along with digital surround sound processors. They can allow you to turn your car into a virtual rolling theater. This is becoming increasingly popular with the advent of SACD and DVD Audio which contain music encoded in 5.1.

SUBWOOFER


Subwoofers are larger drivers that are used to create the frequencies around and below 100Hz. Ordinary loudspeakers are unable to effectively produce frequencies in this range due to size limitations of the driver. Subwoofers are generally considered speakers of 8" or larger and will require more amplifier power than coaxial or component loudspeakers due to their larger size. Subwoofers will also require an enclosure to produce these lower frequencies effectively. Sometimes the enclosure can be as simple as the trunk of a sedan or as complex as a isobarically loaded series-tuned dual-reflex band pass enclosure. The cone size and enclosure required will be two very important factors when deciding on a subwoofer for your system.

There are several manufacturers that offer non-typical subwoofer applications. Examples are the tube type subwoofer and the vehicle specific subwoofer system. Tube subwoofers are cylinders (tubes) with one end containing the subwoofer and the other end sealed. These are a fairly common way of adding a subwoofer to a limited space application or a leased vehicle and come in self-amplified varieties as well. The best known and really the pioneer of this type is Bazooka.

Vehicle specific subwoofer systems are usually built from wood and fiberglass and are designed to fit snugly into a factory void or pocket. Because they are specific to one vehicle they are more expensive then either a standard box or tube configuration. However they can’t be beat for fit and use of space.

One final note when purchasing a subwoofer. Determine how much space you are willing to give up and THEN decide what subwoofer you want. You don’t want to decide you want two 15” woofers and then realize they won’t fit in your Mini after you're out of the store. Be realistic about your goals for the system and the space you are willing to sacrifice to achieve those goals. If you want strong bass but have limited space, add more power to your subwoofer system.

Aspects and features that need to be considered when purchasing subwoofers are:

Enclosure Type: This is the type of box or enclosure your subwoofer will be mounted in. The main types are infinite baffle, sealed, vented (ported), and bandpass.

Power Handling: This is the amount of power a speaker can withstand before failing after a given amount of time. The most important number is the speakers continuous or RMS power handling. Peak power handling means virtually nothing.

Sensitivity: This is a reference measure of how loud a speaker will be with a certain amount of power at a certain distance. The standard is one watt at one meter. By halving the distance an increase of six decibels will be realized and doubling the power will increase the output by another three decibels. This is a trick used by some companies to make their speakers appear more efficient than they are. Most loudspeakers will be in the ninety decibel range. Keep in mind that a difference of three decibels is equivalent to a doubling of the amplifier power.

Hertz mille sub

AMPLIFIERS

Car Audio Amplifiers

The purpose of a car audio amplifier is to take a low level signal from the source unit and change it into a high level signal for driving the loudspeakers. Amplifiers range in power from about twenty watts per channel to over one thousand watts per channel. The price range can be anywhere from fifty dollars to several thousand dollars depending on features, power output and quality. An amplifier may have as little as one channel of output to as many as eight channels at the time of this writing. The most common amplifiers are two and four channel models although mono subwoofer amplifiers are also very popular, especially the class D type.
Amplifier Power Ratings

Extra features may also be built into a power amplifier. These features include built-in active crossovers, equalizers, signal processing and speaker level inputs. When shopping for an amplifier consider that all power ratings are not created equal. Some of the low-quality brands will exaggerate or even outright lie about the power output of their amplifiers. This is a good reason to stick with the well known manufacturers. The only true measure of an amplifier's power is its continuous power rating or R.M.S. rating. R.M.S. is an acronym for root mean square and refers to the amplifiers average power output. An even better method is the CEA 2006 standard but not all amplifiers adhere to this testing method. Basically the test is performed at 14.4 volts with a four ohm impedance load. The entire audible frequency range, 20-20kHz is tested with a distortion level of 1% T.H.D.

One thing to note is that doubling the amplifier power does not double the sound output. A doubling of system power adds only 3dB of SPL (volume) to the output. SPL works on a logarithmic scale so it takes 10dB of change for the sound to be "doubled". This works out to a little over three "doublings" of power.

CAPACITORS

Capacitors are used to store energy for the amplifier to draw on demand. They come in many different sizes ranging from .5 Farads to well over 100. Like just about everything in life, capacitors have their place in the car audio world. Sadly, the majority of people who use capacitors would really benefit far more from running a second battery instead of capacitor. Capacitors will not make up for an insufficient electrical system; if you are trying to run a given amount of power, be sure your electrical system can support it. Alternator and battery upgrades are the way to go. For audio applications you want to look into AGM and deep cycle batteries such as PowerMaster, Kinetik, Stinger SPV, Xstatic BatCaps, and Optima batteries.

Keeping your Car Audio System secure : auto insurance

Keep your system discreet.
How? Go for a stealth install. Try and use stock locations and keep things like subs and amps out of view. Speakers installed in parcel trays of small cars are soft targets as they can be removed in an instant.

Thieves know this: Where theres a sub, theres an amp, and maybe an eq or dsp. Try and keep your sub out of sight. A reason why we prefer box installs where the sub box sits in the boot with nothing visible in the parcel shelf. See the spare wheel well install thread for a fully discreet install.

Secure the HU!!
Most installers install the head unit in the standard sleeve that comes with the HU. All thieves have the so called 'keys' required to unlock the HU and in a lot of cars its very easy to forcibly push out the HU by getting one hand behind the dash. If your car has a removable center facia (Getz, Optra etc), you need to ensure your HU is installed from behind the facia and held in place by screws (see the Getz thread). You can also attach a pull contact sensor to your HU and integrate it with your security system. So if someone yanks out your HU, he will set of the alarm. This is especially useful when you hand out your keys to strangers in Valet type situations. Here is what a pull contact sensor looks like:


Be discreet!
When you approach your parking spots, whether its outside your home, office or at the mall: Dont play your system loud. Dont show off. Thieves are hanging around, waiting for you to 'declare' your arrival with loud thumping of your subwoofer... its like taking candy from a kid. Parking attendants are usually involved in thefts. They also have a master key for most common cars like marutis. There is NO exception, they always DO have theys keys. If you have act discreet, have a discreet system, with no speakers or subs visible, and your HUs faceplate is removed, you will reduce 90% possibility of a theft.

Your car is easy to break in: Get Insurance
Whether it takes a ruler, a master key, a blade or just a piece of wire to break into your car, know that your car is very easy to break in. While modern cars like the Getz, Aveo etc are a bit more difficult to break in, its still possible. Make sure you have insured your IEC system. That way even if it does get stolen, you get the money and go out and buy the latest model.

Secure all windows
Secure the quarter glass windows. On some cars it is childs play to remove the beading and glass from outside. If you afford it, use Llumar / 3m kind of security film on all windows. Increases glass strength by 200% in some cases and makes it near impossible to break the glass.

Intrusion Alarm Systems / Central Locking Systems
Most entry level systems are more of central locking systems and less of alarm systems. Spend a couple of thousand more and get a higher model which can have a ultrasonic movement sensor. While all systems cover the doors, boot and dicky, sensors like ultrasonics ensure that theres an alarm even if none of the doors were opened... if the thief entered through a window. Also go for vibration sensors and glassbreak sensors. Your regular installer has NO clue how these things are installed. Most manufacturers offer free installation so make sure your system is installed by the manufacturers OWN installer. Take time to understand the system so you will have zero false alarms. There are newer GSM based systems out there (I have one) which use a standard SIM card to relay all alarm messages via SMS to your cellphone. You can also arm/disarm and immobilise your car via your mobile. This is good if your job keeps you on the move or you travel a lot.

In the end, its all about making things difficult for the thief. He will just go for the softer target. So is your car a soft target?

GOOD AND BAD : BRANDS TO LOOK FOR IN CAR AUDIO

This list is my personal OPINION on what I consider how manufacturers and their products rank. I have used some of the products listed, but most of these brands/models listed is what I have came across from years of research on the subject, and/or from first hand listening.

Amps:

Audiophile

McIntosh
TRU
Audison VRx, LRx series
Brax
Milbert
Butler
Zapco C2K
Genesis Series 3
Sinfoni
Xetec P5 line ( www.xetec.de )
Steg K series
Steg Master Stroke
Focal Power

Audphile but a step down from the above

Genesis Profile Series
U.S. Amps Tube amps
Phass
Linear Power
PPI Art amps
DLS A series
U.S. Amps
Soundstream Reference, Class A
Helix
Xetec Gravity
Zapco Reference
Denon
Adcom
Diamond D7 and D9 amps (D7's can be had cheap right now, good amps)
Esoteric
Arc Audio CXL, XXK
Phoenix Gold Ti, ALso Older MS and Limited Production amps(Anniversary Editions, etc)
ADS
Phase Linear

Quality :

JL Slash amps
PPI Powerclass (Pre DEI)
Elemental Designs (good warranty, underrated power too)
Diamond D5 and D3 (very cheap right now on ebay, good amps, esp. D5's, very flexible crossovers if you need onboard crossovers)
Arc Audio Kar
Phoenix Gold Tantrum
Memphis-Very compact
Alpine
Pioneer PRS (older line)
Orion-Pre DEI
XTant
MB Quart amps
Rockford Fosgate
Avionixx
MTX
Older Mobile ES Sony
Exile Audio, new company founded by former Phoenix Gold employees.
Xetec Xircuit and Vector Series amps

Value :

MTX
Kicker
DEI
Clarion
Pioneer Amplifiers
Coustic
Crossfire
Infinity, and JBL amps (pretty mch same thing)
Hifonics


Poor :

Audiobahn
Dual
Jensen
Boss
Volfenhag
American HiFi
Rockwood
Legacy
Kole
Pyramid
MA Audio
Kingwood
Newer Sony
Pyle
XPlore
Lanzar(Except Opti Drive amps.)
Audiofonics
Rampage
Audiovox
New Soundstream
Phoenix Digital
Formula
Koiker
Nitro
Power Acoustik
Lightning Audio
Niche
Verge
Crunch

Speaker brands to look into

Audiophile

Seas Lotus Reference
Seas Excel
Rainbow
Focal Utopia, K2P
Morel
Dynaudio
Hiquphon tweeters
MB Quart QSD
Scan Speak
Alpine F1 Status (similar to Scan Speak Revelators, but tweaked for Alpine)
Arc ACS
DLS Iridium, UR
Beyma
Image Dynamics HLCD's
RS Audio
AVI
LCY
ACCUTON
Fountek
CDT HD, Eurosports and 07 model lineup.
Boston Z6
Diamond D9

Quality Passive Component systems Keep in mind, all these can be wired active.

MB Quart QSD
MB Quart PCE216 6.5" set Or PCE210 if you need 4" components. (also can be a nice 3 way active set with midbass addon)
JL XR
Alpine Type-X SPX-177R
Image Dynamics Chameleons
CDT EF, HD, they make slim mounting depth variants.
Elemental Designs eDi6500s eDi6000s are ok for the money.
Phoenix Gold TI 6 Elite (Morel)
Boston Pro Series
ADS
Exile Audio
Diamond Hex

DIY Components
Mids: 7"
Seas CA18RNX, G18RNX - 55 each
DAYTON RS180S-8 - 33 each (deep driver though check clearance) Nice mid
Peerless HDS Exclusive
Adire Audio Extremis 6.8
Phaze Audio/PPI Tubedriver mids
Seas Lotus/Excel $ but awesome.




Tweeters:

LPG 25NFA (silk) 26NA(Aluminum) The aluminum is best suited for people that like sharper highs. These are 37 each.
Dayton Neo domes
Dayton RS Tweeters
Seas 27TBFC/G (H1212)
Vifa XT
MB Quart QTC25
Focal TN-51, TN-52
Hiquphon OW2



Midrange:

Domes:
-Usher 9845 3" Textile
LPG 51AT(Aluminum), LPG 50FA(textile)
DLS UR2.5(-+75 bucks each), Iridium 3
DAYTON DC50F-8 2" 28.00 each

Cones:
Seas Excel W15
MB Quart QSD213
Vifa 10BGS aka MG10
Vifa M10
Audax HM100Z0
Vifa PL
Eton 4-300 hex

Remeber to check mounting depths, and plan on using a 1/2" to 3/4" baffle to mount the speaker to the door. That will give you some extra mounting depth. Also check clearance from the speaker to the door panel. Most importantly, do as much research you can before deciding to buy. These are just certain things to get you looking in the right direction. There's alot of other good stuff out there, and there are 10X more bad stuff out there. Research is the key.

WIRING : Recommended Power and Ground Cable Sizes

To calculate the proper power and ground cable sizes, find the distance of the power cable along the top row. If your measurement is between two measurements, use the higher one. Next, find the total RMS power the cable must support on the left. If your measurement is between two measurements, use the higher one. The size listed where your two measurements meet is the recommended cable size

Wiring chart
* Note: These figures have been rounded off for easy reference. Ground cables should be the same size (or larger) as the power cable. ** Current Draw figures are based on RMS Power of the amplifier with a 50% efficiency rating. *** Although wire gauge sizes smaller than 10 gauge may be acceptable for the amount of current draw, we recommend using 10 gauge as the smallest wire size for any amplifier of 100 watts or more. The goal is to provide as much current to the amplifier as it could possibly need for optimal performance.

SUBWOOFER ENCLOSERS

The enclosure is equally as important as the woofer and should be designed for use with the particular woofer you have chosen.

Deciding which enclosure(s) and woofer(s) are best for you can be a task all of it's own, but size constraints of the vehicle, knowledge of Thiele - Small parameters, and understanding the inherent sound characteristics of different enclosure designs will help you decide.

All enclosures should be constructed of at least 5/8'' - 1'' MDF (medium density fiberboard) or material of comparable rigidity or better. Bracing (not shown) should be used throughout the enclosures as needed to prevent any loss of energy due to flexing. For you SPL competitors, I repeat...bracing should be used throughout the enclosures.... Flexing = lost output. With all enclosures, lining the walls with a damping material (fiberglass batting, polyfill, tar based spray, etc.) is recommended to reduce high frequency resonances.

Often the total order of the system is confused with the order of the enclosure. The order of the crossover will add to the total order of the system.

There are many types and variations of woofer enclosures. The following information is intended to provide you with a basic understanding of enclosure types and their respective characteristics, design possibilities, and to help you decide which enclosure may work best for you and/or your customers.

CAR AUDIO INSTALLS

Here are some pics of car audio installs. The car is a Mitsubishi Lancer . the equipment is -

Hertz mille front components
Hertz high energy 8" midbass hv200 X 2 pairs
Hertz spl 15" subwoofers
Audison lrx 1.1k X 2
Audison lrx 2.9k X 2
Audison wiring

The car

Alpine dvd touch scrren unit

Doors damped with damping sheets and egg foam

The component speakers

Components mounted

Amlifiers and subwoofers mounted

Moulds prepared for hv200

Final look !!