crossovers

[flacopower]

this may be a really dumb question, but i have been trying to figure out what purpose crossovers serve and i was wondering if someone could enlighten me

[too.slow.CB7]

no clue.....-justin-

[pwrusr]

I think I can help you both out a bit
simply put crossovers send the frequencies you want to the speakers/amps you want.

example:
bass freq: 80hz and below the speaker will get a signal and it will cut off the rest above 80Hz

mids: 80-2,000hz (2KHz for short) the mid speaker will only recive these frequencies and cut the rest out

highs: 2KHz and above the tweeter will only get these and no other frequencies

I could go much more in depth but I need sleep

[flacopower]

if i am getting an amp for the speakers are crossovers necessary? are they really necessary at all?? will they increase the sound or quality?

[GrayCar]

There are three kinds of crossovers, low-pass, high-pass and band-pass.

Low-pass cuts off all the frequencies above a set point and lets the frequencies below that point pass through. Cuts off the highs, passes the lows

High-pass cuts off all the frequencies below a set point and lets the frequencies above that point pass through. Cuts off the lows, passes the highs.

Band-pass is a combination of high- and low-pass, but it only passes frequencies between two set points. Cuts off the high and the lows, passes the mids.

So, what use are they?

Well, say you get a set of two- or three-way speakers, you wouldn't want to send your really low bass signals to the speaker. Generally the larger cone (woofer) in these speakers will have to work too hard and will distort the sound. So, you cut the lows and get nice, clean mids and highs.

Same goes for a dedicated tweeter. It doesn't like the mids and lows, so you cut those out with a high-pass crossover and let the speaker do the job it was designed for.

And again, you do the same for a subwoofer. Why make it work on the mids and highs when it wasn't designed too?

On the amp side, if you have an amp powering tweeters, mids or two/three-ways, it has to work to pump the low frequencies out and has less power available for the mids and highs. So, you would want a high-pass crossover to cut the lows out of the signal before it gets to the amp.

Fortunately, any good quality amp these days has a crossover built in, which is your best way to go for a simple set up. You could get a signal processor, which is a fancy, multi-channel crossover network, but they're expensive.

Some amps for dedicated subs will only have a low-pass, some will have both high- and low-pass and some will have all three.

Either way, buy good amps and you'll be alright.

[pwrusr]

Nice job explaining that graycar, couldn't have said it any better myself.

[GrayCar]

Aw shucks, I'm blushing...

[alb_accord]

shit i need that. i wanna conect everything tomy 4 chanel amp and i am gona need those things for the 2 10s and the car speakers.
what they look like lol?

[DRAGGEN]

they look like resistors and coils.

i have a whole box full of stillwater designs passive crossovers in my garage. got them for doing the work on my buds SI.

[alb_accord]

i don't know jack about electronic but how do u put them to the speakers/wires or whatever.
lol do u guys have a diy or whatever i can read more so i can learn more.

[DRAGGEN]

give me a day ill show your a picture DIY with some of the old ones i have. going to borrow a digi cam tommorow from my bud since i cant buy myself one before xmas by order of my wife.

[alb_accord]

that would be so owesome man. that would be like a manual to me to learn about systems and all.

[GrayCar]

Here's what a passive, inline crossover looks like:


Goes on your line outputs between the HU and the amp.

Generally you don't want to use these. First off you can't adjust them at all, when you buy them they cut off at one frequency and one frequency only. So if you ever want to mess with your system you can't.

Secondly, I've heard that they can hurt the sound a bit. Is it a difference that only an audiophile would notice or is it something everybody would notice? I dunno, I've never used them.

Anyway, I've always bought amps that had the crossovers on them, simpler design and less junk flapping about the car.

[DRAGGEN]

those are modulating passive crossovers..junk pretty much. the kind i am talking about are more stable, and im at work so when i get home in about 2 1/2 hours ill get those pics up for alb

[DRAGGEN]

here are some pics of passive crossovers as you can see they are the older style Kicker brand
the Low pass

the range limit is 350Hz which is high by todays low Hz standards but great for a well balanced system

The Midrange

Of course starts from 350Hz and up to 2000Hz again not by todays standards but used in my system for years and was very balanced

The Tweeter


4500 Hz and up 12 db octave cut little harsh but old school