Are you building an SQ car or have knowlage on active crossovers?

if not i wouldnt really reccomend them, there very hard to get right and you need external crossover box's in most case's so it wouuld be cheeper running passive bridged

I am going to be putting an active front stage in my next car, I know it's going to be harder to tune but I see car audio SQ as a hobby and the more things to fiddle with the better.

I can also add a 9.5inch Dynaudio for a 3-way front stage using my active crossover when I go insane.

just remember with an active crossover the signal is processed before it is amplified, and therefore has no resistance to the speaker

Actually, this brings up a point.. When you are building a custom front stage, it is much easier to use active filters rather than passive filters. - Since speakers are a reactive load, if you assume the impedance is at is nominal amount, when designing the crossover, it will end up making the speakers sound horrible..

the passive crossover insertion loss rule of thumb was 0.6 decibels per step, or per 6db per octave, so 1.2 db for 12 db/oct, 1.8 db for 18 db/oct etc.
remember what damon said, that this is just a rule of thumb, approx value only as the end result really depends in components and design of the passive cross over.

the arguement of the passive cross over was designed for the speaker so its the best thing to use doesnt work.
the truth is that the manufacturer wants to seel the product complete. so that you, the buyer can un box them, hook up to a single amp and start listening. its also a warranty issue as well. if you used the supplied x-over, then the speakers where "protected" from the wrong freqs for the speakers.
if the manufacturer supplied the speakers "as is", with out any x-over, they would open them selves to potential waranty issues from dumb bunnies who didnt read the instructions, and wired them straight up to an amp.

supplied x-overs with speakers does not mean that they are the best thing to use with them.

better quality speakers have cross overs with them that are good, being designed to match the speakers characteristics but the fact remains that they are still a compromise no matter how good they are because a speakers characteristics changes over time and while they are working.
speakers impedance is only nominal. they may be 4 ohms while sitting in you hand, but while they are playing, can go anywhere from 1 - 40 ohms.

actives ignore the speakers characteristics totally. the right signal is going to the speaker in the first place so it does not need to be modified, in theory. as long as the active is set up properly.

disadvantages with active? where do i start? expensive, complicated, bulky, rca cables everywhere, in efficiency.
lets say you have three speakers per side up front. each had a 50 watt amp, so you got 3 50 watt stereo amps. in a sense, you have 50 watts total power. because the tweeter amp is only working at high freqs and the potential 50 watts of power below 3-5 kay is sitting there wasted.
what you are doing is splitting the load of one amp over 3 amps.

so, after all that bull crud, which one sounds better? now that is hard to answer. both have flaws, compromises. it really depends which compromise is better than the other. personally, there is a lot that can go wrong with 3 sets of amps, rca's and a extra powered item (the x over) in the signal path that can all introduce noise.
set a active up right, and i think it owns, but there is so much that can go wrong with active.
not to mention the complexity and expense.

get your hands on a decent set of passives and take the easy known quantity path. i reckon its worth while. passive is just not worth the hassles for what is a arguable benefit.

Audiable:
How can the x-overs in a set of slpits not be any good? Why do you think that for some reason you know that speakers change over time but the people who build them don't??
Why would they not set speakers up correctly??
Now if the speakers changed over time, wouln't you have to adjust your active setup as well??

So your saying that when your bandpassing the active fronts that you can put it within a 3-5hz gap on all six channels?
Now wouldn't the amps x-overs have to be as good OR better then the x-overs supplied or their would be no gain?

I am definatly NOT SAYING that I am right, this is my understanding and pls feel fre to correct me.
Mick

I have a fully active system, every speaker has it's own channel on an amplifier, the only exception being my subs as they're mono to the Soundstream amp.

I band pass all speakers except for the four tweeters- two in front and two up back.

Previously I have used a number of combinations of passive and active, I liked the Hart two way passives as well as the two sets of Clarion three way passive crossovers I tried. The system lacked real power in SQ terms, not volume terms.

I have not completed my rear stage, but the front is in and it's as per my system explanation below.

I now believe that if you are serious about SQ at a decent volume level, active is the way.

People who know me, know that what I've changed and how often I change it is stupid and expensive, but having done so, take it from me...

ACTIVE SOUNDS BETTER !!!

[ July 03, 2003, 09:18: Message edited by: R ]

It is difficult to manufacture high Q(low loss)inductors which gives rise to the insertion loss of passive filters. Components such as inductors and capacitors also introduce phase variations.

By using active filters you don't need to use inductors, only capacitors and resistors. This means high power handling, low loss filters can easily be built. Infact these filters can have an insertion gain.

Also lot of speakers are limited in power handling because of the inductors in their crossovers.

While a lot more effort I definately think active filters are superior.

Whats even better is digital crossovers. These allow infinite cutoff slopes and no phase distortion but are even more expensive.