The first part of a system that I would purchase is the head unit.
I would look at them all, you never know what you may like best. My favorite
right now is probably the SONY AM/FM/CD w/ CD changer controls.. I have a Sony CD with
10 disc changer, and am very pleased with it. I like it's analog volume, bass, and treble
functions. Also, it has two sets of pre-amp outputs so you can still use the Fade function
when using external amplifiers.
What I would look for in a head unit is detachable face, or other
security device. I would check to see how good the tuner is, try to listen
to lots of stations, even try the AM frequencies.
I would look at the specs, such as the THD(Total Harmonic Distortion)
and the Signal-to-Noise ratio. THD stands for total harmonic distortion, using this factor the lower the perccentage is better. Below .1% is inaudible, even with this there are head units out that that have specs for .005%.
The next spec on a deck is the signal to noise ratio, this ratio is shown in db's (decibals). This is the measurement of the ratio of power put in and the amount used. Always look for the highest number. Cassette players being less efficient will always be lower than CD players.
Another thing that is less important, but should be mentioned, is
the display on the player. Make sure the display matches your dash
lights, some new units are even switchable. It is not a big deal, but it
looks nice.
After getting a head unit, I would figure plan on buying some good
quality coaxial speakers the interiors. Coaxials have the midrange woofer
and the tweeter built together, along with passive crossovers. Many
times the crossovers are built right into the amps, so the sound is
more clear. Also, in most cases the speakers are better quality,
especially noticeable with the tweeters.
There is no general rule for buying speakers. There are many types of
speakers, many which perform well in different areas. I like crisp highs
and relatively flat midrange, while some people don't like the highs as
much. What you like is all based on your personal preference. What
you need to do is to go to a store with a nice display, and listen to
them all.
There are a couple things to look for when purchasing speakers.
The first is the RMS power handling. The difference between RMS and Peak is: RMS is what the speaker can play at, peak is what the speaker can peak at, a peak is a short burst of power, not sustained. You probably would want a
speaker that can handle a good deal of power. The next thing to
look for is the sensitivity. Sensitivity is given in decibals, or
Db's. The higher the number the better. It means the speaker will
play louder with less power. When you put 100 watts into a 94db speaker it will use 94watts of it, there is a 6 watt loss, from the physical design of the speaker. If you see a speaker with a high
sensitivity, say 94db's, and a high power handling of say 100 watts
RMS, you are most likely looking at a good speaker.
There are so many different types of amplifiers on the market
right now that it is very hard to keep up.
I do think a multi-amp system is necessary for people who want a system
that has both crisp highs and hard hitting lows. There are amps that
you can bridge to two channels for mids and highs, and with a
channel for one subwoofer, but if you can have multiple amps in your budget, then
get seperate amps. What amp to get, first depends on what you want. The easiest
way to boost your system quick is to add a sub, and you really can't run a
sub off the head unit, so a subwoofer amp might be the logical choice to
purchase first.
A typical amp that is to be used for a subwoofer is two channels.
This is because four channel amps generally do not have as much power per
channel as a two channel, and subs need LOTS of power. I have found it
is better to give a sub too much power than not enough. A good size amp for
a subwoofer can range anywhere from 75 watts per channel to 250 watts per
channel, maybe even more. If you do find an amp that claims to have more
than 200 watts per channel RMS, you might want to check it out and see if
it's true.
Maybe I should say what RMS is. You've probably noticed ratings
on amps that don't seem to match their prices. Well, some
lower quality amps rate their amps by maximum wattage that the amp can
acheive, like when the bass really hits for that split second. When you
want the rating of what the amp can really handle, look for the RMS
rating.
Crossovers are one of the most commonly overlooked pieces when a
person puts together their first system. I have talked to friends and
other people who are just beggining to get into systems, and when I ask
them what they are using for a crossover, lots of times they will just
look at me funny. I know when I first started, I didn't realize that
every speaker should have a crossover. Now I know that every speaker in
a system should have a crossover. Using a 3 watt factory stereo and full range
speakers is about the only way you can possibly get away without using
one.
There are passive and active crossovers. A passive crossover is
one that does not require a power source. These crossovers are often
times in line with the speaker wires. For the most part they block out
low frequencies to midrange speakers, though they do make low pass
passive crossovers. Another thing about inline passive crossovers is
that you can not adjust the crossover frequency to your needs. A good
thing about in-line passive crossovers is that you can use them on
speakers that are not powered by an external amp, and they are cheaper,
both good attributes for the person on a budget.
Passive crossovers are at a disadvantage because they do not offer
bass boost or treble boosts and basically because they are not adjustable.
Many active crossovers let the user adjust it to any users needs. An active
croossover is almost always in line with the patch cords going to the amps.
They can be simple with one set of inputs-outputs for under $50.00, or I have
seen them with 3 sets of inputs and about 10 sets of outputs with all types of
options for slightly over $500.00.
Active crossovers can have features such as constant variable
frequencies, phase reverse, adjustable bass boost, bass boost frequency
adjustment, and variable crossover slope. Active crossovers are also better
than passive crossovers because the slope of the crossover, denoted in
db's/octave are generally higher, meaning better in most cases. On the higher
end amp (more expensive as well) this item is usually built in, but if it isn't
keep reading.
What to look for when purchasing a crossover is to get the most
flexibility you can afford while still maintaining a quality piece. It
would be foolish to spend lots of money on quality amps and speakers, and
get a cheap quality crossover. Your system is only as good as your
weakest link. The reason you want to get a flexible crossover is so it
can grow and change with your system. Also, changing the crossover
points can somewhat change the sound of your system.
There is a subwoofer out there for everyone, even for those who
listen to Country music. In my opinion a sub is the center point of any system
Every system should have at least one. After having one, I can not say that
I have liked any system that I have heard that has not had one. A sub is
known to be the easiest way to upgrade and make your system sound 100%
better instantly.
But it is not always that easy. What sub you want to buy depends
on your car, your personal preference in bass, your amps, and mostly your
budget. I still don't really understand the art to building boxes. I can
build a sealed enclosure, but I would not even attempt to build a bandpass
enclosure (but box building will come next).
Much like speakers look at the sensitivity, the power handling. Listen to each
one and see what you like. In some cases you may have limited space in you car so box size
is critical. Ask a professional what speaker will work good in your
situation.
Do not go to a chain if it is possible, many times those guys
know by far less about subwoofers than you do.
Try to find a small place that builds their own systems, and competes.
There are many types of enclosures, but basically three. The first, and
definitely my favorite, are sealed enclosures, meaning there is no port in the
box for the pressurized air in the box caused by the subwoofer. This makes a
nice tight bass, but requires more power for the same volume. This
is because you, the listener, only hears the bass made by the front
of the sub, and not the back. Another good thing about sealed enclosures is
that they are simple to design and build, since all you need is the dimensions,
and total air space. Sealed enclosures can take on many shapes.
Ported enclosures are the second easiest to build, but that does
not mean it is easy. By the name, you can figure ported enclosures have ports.
The ports are a means for the air that is pressurized from the back of
the woofers to leave the box in a controlled manner to give the
listener even more bass. The reason is you get bass from both the
front and back of the woofer. Therefore ported enclosures are more
effiecient than sealed enclosures. This is good for your budget because you
can purchase a less expensive amplifier to power the subs. Ported boxes can
be bad for sound quality if the ports aren't designed correctly, or if you push
them too hard, or there is a slight air leak. Also, they can sometimes be
slightly boomy. Ported enclsures are commonly boxes or tubes.
Bandpass enclosures are not at all easy to build, they don't
sound nearly as good as a sealed enclosure, and they beat on the
woofers. But, you get the loudest bass for you buck.
Bandpass makes really incredible bass at some frequencies, but at others it falls
on its face.
