Crossover Question

Early B.

What does it mean? -- 1st order crossover; 3rd order crossover?, etc.

madmax

That is the slope of the crossover. A first order has much less slope than say a 3rd order. This means the first order is 3db less sound level per octave below the crossover point whereas higher order might be 6db or 12db or 18db less sound per octave. It is essentially how steep the rolloff is.
madmax

Early B.

OK, I kinda understand, but a practical example would help.

Let's say I have two nearly identical speakers, except one of them is a 1st order crossover and the other is a 3rd order crossover. How will they sound compared to one another?

gatemplin

Originally posted by Early B.
OK, I kinda understand, but a practical example would help.

Let's say I have two nearly identical speakers, except one of them is a 1st order crossover and the other is a 3rd order crossover. How will they sound compared to one another?

First order is 6 dB attenuation per octave, second order is 12 dB etc. My speakers are 8th order .

There are also two attenuation rates, the acoustic and the electric.

It is hard to say how they will differ sonically because there are too many variables. The Q of the filters, baffle layout and slope, cone modes, BSC etc. But keep in mind that the higher the attenuation rate, the more expensive the crossover.

Pick up The Loudspeaker Design Cookbook by Vance Dickason. He describes most common filters.

unc2701

With low order crossovers you might notice some weirdness in the area of the crossover frequency- you might get much louder (two speakers playing the same freq) or softer (speakers out of phase & cancel each other)... In either case, it'll create a harder load for your amp since there will be a wide impedence dip at the crossover freq (as opposed to a narrower one with a high order crossover).

billbillw

You tend to find steeper (higher order) crossovers between midrange and bass. That keeps the low frequencies in the larger drivers where they can be produced more efficiently and keeps the midrange from distorting. Many speaker designers prefer to have a lower order crossover between the tweeter and the midrange so they blend better.

madmax

If the different orders sound different then they were not implemented properly.
madmax

Early B.

Thanks, fellas.

I take from the responses that the order of the crossover is basically a technical issue and doesn't necessarily determine SQ or the quality of the crossover itself. As Max indicated, if a crossover is designed well, there shouldn't be any "weirdness" at the frequency crossover regardless of its order.

Is that correct?

ND13

Yeah...what they said:D

unc2701

Originally posted by Early B.
As Max indicated, if a crossover is designed well, there shouldn't be any "weirdness" at the frequency crossover regardless of its order.

Is that correct?

Yep, but if you crack open a cheap pair of 2 way speakers, you'll almost always see one inductor, one capacitor... which means a first order crossover. So while a first order crossover doesn't necessarily imply cheap & bad, a lot of cheap and bad speakers use them.