Can someone explain a little about crossovers please. What they are, what they do, are they standard with some speakers or not. Any help will be a help, as i have no idea about them.
I have had great help in the past and i don't think i will be let down now.

I'll leave this one for Chris, but in simple terms it directs the sound to the part of the speaker/or directly to the correct speaker. i.e bass under a certain frequency would be sent to the bass bins whilst the rest would go to the mids and tops.

Did I do alright Chris ?

A crossover is basically a coil and capacitor combination - basically a filter which filters out certain frequencies and passes them to the relative drivers. A Professional 3 way crossover will accept a signal of say 20hz - 25khz and spilt it three ways:-

40hz - 1khz - Bass Driver
1khz - 6 khz - Mid range
6khz - 20khz - Treble

Although frequencies below 60 hz or above 18khz cannot be heard by humans!

Some cheaper Loudspeakers don't even have a crossover, they just use a capacitor and resistor combination soldered in line to the horn. This is called a High Pass Filter (It just passes high frequencies) .

Most Speakers will have some form of crossover in them.

That's what I meant

Chris I thought it was 20hz- 20khz that human could hear ?

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Chris I thought it was 20hz- 20khz that human could hear ?

If you had 4 legs, fleas and were called Rover

When you are younger the frequency range will be more wider - hence why toddlers and young children are the first to put their hands over their ears at a gig!. If you ever done school disco's you'll see the very young kids running around with hands over ears and frowning at you - even if you are playing at very low levels!.

As you get older the upper range falls away, even in your teens your hearing isn't as good as when you were 7 for example. (A good excuse to tell your parents when they moan at you for having your music too loud!).

When you reach 50 your upper hearing threshold is around 3khz below what it was when you were 13 for example

Lesson learnt, thanks Chris. Can't remember what I must have learnt in my sound engineering qualifications then

Yea they say it makes you deaf

Below 40Hz, is that what make's you feel the bass???

As we can't hear it, we feel it!!

Well, one of the nice things about forums is that you sometimes hear the same information from different people, just explained in different ways.

So heres my version...

Crossovers. Put simply, the split a "Full range" signal (a signal which has normal Bass, Midrange and Treble in it), and split it either 2 (rare), 3 (common), or 4(fairly rare) ways.

Firstly, there are "Passive crossovers." These have no mains supply, and are mainly just a few coiled components mounted on a circuit board. These are commonly found inside speaker cabinets and take the full range signal from your amplifier and send the deep, low, bass notes to the woofer in the cabinet, and send the high, treble, top end sounds to the cabinets tweeters, and the middle frequencies go through to the midrange driver in the cabinet (This would be a 3-way crossover then)

Secondly, theres Active Crossovers. These are most commonly seen in 19inch wide, rackmount units. These again can be found in 3way or sometimes 4way versions. The BIG difference is that these normally work on the signal coming from your mixer, NOT the powerful signals coming out of you amps... 3 way Active Crossovers still split the mixer level signals into 3 mixer level outputs, which you then connect to your 3 amplifiers respectively. So, you'll have a Bass Amp, a Midrange Amp, and a high Amp. The amps dont have to be special, they can be 3 identical amps.

Rackmount active crossovers nearly always have front panel controls, but occasionally internal controls to adjust which groups of frequencies the unit should send to the BASS output, the Midrange output, and the Treble outputs respectively.

Some Crossovers may also incorporate additional features such as Compressor, or limiter circuits.

It is critical NOT to feed an active crossover with SPEAKER LEVEL signals from the REAR of an amp...unless you want to add pyrotechnics to your show.

(There is the slightest possibility that I've got Passive and Active around the wrong way... but the descriptions are valid...I think)

I just call mine "The crossover".

A rare, third type of crossover is also seen occasionally.
Some speaker systems offer a dedicated crossover, made by the same company who makes the speakers, which they often call a System Controller, or Black Box. These are commonly a 2 way active crossover, which works specifically with certain models of their cabinets.
The famous Bose 802 speakers often had their bass enhanced by a the Bose 402 Bass cabinets, and a little black box device (Bose System Controller) split the signals accordingly.

My own Ramsa speaker system (made by Panasonic/Technics) uses a similar amp level device to split the full range signal from mixer, into Bass (mono) and then Midrange/top(combined) Left and Midrange/top(combined) right respectively. Those 3 outputs go to the BASS amp (mono) and the left and rights of my stereo amp.

Thanks Chris and Gary, your post's have cleared up my questions on the subject so well done guys

Maybe we could have called Gary's post - "Crossover 2 - The Sequel", or "Crossover 2 - Revenge of the Crossover"

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"Crossover 2 - The Sequel", or "Crossover 2 - Revenge of the Crossover"

Yeah! Why not, after all Edward Woodward was "The Equaliser"