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errr, back to the topic of "Function of crossover?"
Putting it as simple as i can, "Crossover" is a device (or u can treat it as a filter, frequency-filter of course) that will only allowed a pre-determined range of frequency to reach the specific driver(speaker).
An analogy to it: Sunlight (audio source), white in colour (20Hz - 20k Hz). If u wear a red sunglasses (crossover set at eg: 80Hz-500Hz), u will only see red light (the driver only receive 80Hz-500Hz).
Crossover is only a device/filter. It is not a magic tool to make your sound system suddenly becomes "better sounding" by just adding it into your system! However, properly tuned crossover AND properly installed drivers can optimise your system to its best performance (note clearly, optimised to YOUR SYSTEM's best performance, not optimised to the best performance system!!) And as the saying goes..a tool is only as good as the person using it. Same goes to Crossovers, it is only as good as the person tuning it(active crossover) or building it (passive crossover). (Let's not go into technically superior xovers vs xyz xovers)
Now, to understand more about Crossover and why it exist, probably you have to understand a little bit more about drivers. Generally there are: 1) Full Range Driver 2) Tweeter 3) Mid Range 4) Mid Bass 5) Subwoofer
Full Range Driver, as the name says, is able to receive the full spectrum of frequency without distortion [up to certain level of dB (volume) design by the manufacture]. Thus, no crossover is required. [to avoid confusion, able to receive full spectrum frequency doesn't mean it can REPRODUCE the full frequency spectrum. Because of its physical limitation, it may not be able to reproduce lower/higher frequencies at all, or as accurate as subwoofer/tweeter respectively, well, unless we are using very HIGH END full range drivers, that might cost..i don't know..maybe a car?]
For the rest of the drivers, because of its physical limitation, they can only handle specific range of frequency up to certain level of dB without distortion. For example: generally tweeters are able to play from frequency 2000 Hz and above without distortion up to certain level of dB. (note: not all tweeters are built equal, there are some that can play slightly below 2000 Hz without distortion, and some only able to play 3000 Hz and above without distortion) Hence, crossover is needed here!! The crossover has to be set to play above those frequency! Let's say there is NO crossover in you system at all, playing music at normal listening dB (volume), be ready to buy another pair of tweeter. If u just swap in the new tweeter and play again, then, be ready to buy another pair of tweeter again!! =p
That being said, unless your car is using Full Range drivers, there will be crossover in your system!! Be it very simple crossover consists of only basic capacitor and inductor, manufacturer supplied passive crossovers that came with your speaker set, properly built passive crossovers, or active crossover.
There are a lot more about Crossovers from technical point of view...google it..
Alot of the points above have been mentioned by our sifus here, as there are common knowledge, hope you guys don't mind me repeating it..=X
Its just my little experience collected throughout my ICE journey..if there's any misleading points, pls do correct me! thx..
Added on September 10, 2012, 6:46 amAllow me to share a little on Passive Crossover vs Active Crossover.
Passive Crossover is build from electronic parts consist of capacitors and inductors to set a range of frequency that will go through its output -> reaching to the driver. Normally, the frequency range cannot be changed after it is built, so you have to calculate and design it to the desired frequency before building it.
An analogy to it: Lets say I want to sell TV to america, and I know they are using 120V, so I have to calculate and design the TV into 120V, and build it.
With Active Crossovers, things are more convenient as we are able to change the desired frequency range anytime we want.
When you purchase a new component set (I believe this is the one that refers to a separate tweeter and midbass driver, correct me if i'm wrong >.<), almost all will contain the following: 1) 1 pair of tweeter 2) 1 pair of midbass 3) 1 pair of device - this is the crossover (passive crossover) supplied by the manufacturer specifically for your drivers. They come in various shape, colour and design.
This passive crossover supplied together with the new set of speaker generally will be design primarily to be very safe when playing at the range of dB (volume) specified by the manufacturer without distortion and the risk of blowing off the drivers. Secondly, the power input, ie, the ratio of the volume receive by tweeter and the midbass has been set! You are unable to tune your tweeter to sound louder than your midbass, vice versa. (again, exceptions....there are passive crossovers supplied together with the drivers that can let you adjust the difference in volume between tweeter and midbass, however, I believe it is a very limited adjustment in few dB steps...)
This doesn't mean the original passive crossovers will not sound good. In fact, they are designed to match the speakers. A good component system will always comes with a very well designed crossover.
However, always remember that sound, is a very subjective, personal, matter! What sounds good to me may not sounds good to you; what sounds good to the manufacturer may not sounds good to me!!
When I think the sound reproduce by the drivers are not optimised to my taste, this is one of the example where the need arises for active crossover. Do remember that, right after removing the passive crossover and installing the active crossover, you have to tune it. It's more of trial and error to achieve the best SWEET SPOT from there on. How fast you are able to tuned it depends on your experience, time spent, and perseverance, keep in mind you have to know the limit of each drivers as tuning it beyond what the driver can handle will ultimately blow your lovely driver...=)
For those who just started your ICE journey, stick with the supplied passive crossover. Enjoy your new speakers. Don't stress yourself worrying whether it will sound better if you change to active crossover. The reason you bought that set of speakers is because it sounded a lot better than what you had in your car! So, enjoy the improvement.. Well, unless you are guided by sifus and you SPECIFICALLY KNOW WHAT YOU want to achieve, then go ahead...
Things that you can tune with active crossover(depends on model): 1) Full range, high-pass, low-pass, band-pass 2) Crossover frequency 3) Order of Crossover (or known as the slope of the crossover) 4) Types of Filter/Crossover (Butterworth, Linkwitz-Riley, etc..) 5) dB of each driver
[this is my personal opinion/experience: PROPERLY built passive crossover does sound better to my ears compared to Active Crossover.]
I'm using Active Crossover...reasons..1) I don't know how to build a passive crossover and I don't have the financial capability to ask a professional to build one specifically to suit my system; 2) I'm using raw drivers..no crossover supplied! =.=
If there's any misleading points, pls correct me! thx...=)
This post has been edited by hyy87: Sep 10 2012, 06:46 AM
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