Speakers
There are many types and styles of speaker on the market.
Co-axial
These can be round, oval or even square.
They have a bass diaphragm and one or more tweeters to play the high notes built into the speaker.
Component speakers
These have a separate bass diaphragm speaker and a tweeter which is fed its signal through a crossover, the crossover filters out the lower frequencies. These are considered the best for door speaker applications.
Dual cone
A full range of frequencies are played by these cost effective speakers. Often found as original equipment in cars, they do a decent job but if you want to upgrade them to a co-axial it is usually very easy and worthwhile.
Subwoofers
Usually 8” to 15” in diameter they are designed to play the low bass notes, they need an amplifier which will have filters built in to take out the higher frequencies. They are popular for playing the modern music which has a hard pumping bass note rhythm.
6 by 9s (six by nines)
The most popular speaker to use in a rear parcel shelf. They are co-axial speakers and can have as many as 4 tweeter / midrange speakers built into them.
They fall into two categories- those suitable for amplification and those suitable for operation off the amplifier built into the headunit. I consider these speakers to be the powerhouse of a good audio set up.
When you want to upgrade your speakers the first thing to do is to decide which type you want to use and then take your car apart and see what size you can make fit.
Normal problems can be:
A door speaker is too deep and the window hits it!
The 6x9s are too heavy for the parcel shelf, special shelves are available to get over this one.
The original speakers might have shaped mountings, there are special speaker adapters available for some cars and custom mounting is possible for many others.
When it comes to subwoofers they are usually mounted in a solid wooden box which may or may not have port (a hole which lets sound out and air in). I leave the choice of a port or not to the customer usually as it does make a difference to the sound. Vibe make boxes with a pluggable port – the best of both worlds!
Some enthusiasts like to make the boot, and sometimes the rear passenger area a solid custom-made speaker mounting with many speakers, these are referred to as “Boot Builds” and have to be made very well to withstand the pounding the subs give out. I don’t make them myself as I do not have the carpentry and fibreglass skills required. I have seen many very good boot builds but also many bad ones which vibrated, cracked and did not give as good a sound as you would have received with a simple twin sub box!