What Does this Mean????

[backtofront001 10+ year member]

I read the sticky but I still dont get it. Could someone explain it to me. With a pair of Rainbow SLC comps. and a Pioneer P880PRS headunit, I believe I can use an active crossover system. What are the advantages of using an active over a passive and what does using an active crossever do?

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[bimma85 5,000+ posts]

There are way too many people asking ?s that can be found all over //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif//content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

http://www.caraudio.com/forum/showthread.php?t=90412

 

[backtofront001 10+ year member]

I read that and I dont get it, thats why i was asking if someone could please give me newbie rundown of what it would do, i would really appreciate it.

 

[backtofront001 10+ year member]

Anyone...

 

[helotaxi 5,000+ posts]

With the time an effort you can usually get the active setup to sound better. The passive is much easier. If you don't have the time, patience and/or knowhow, trying to do an active setup can be frustrating and if you realy don't know what you are doing, it can be hazardous to your speakers. You will also need a four channel amp to go active and it will be larger an more expensive than a similarly powered 2 channel. You would need 100x4 to get the same power as 100x2 with passive.

 

[dogears 10+ year member]

helotaxi I think you got that a little mixed up . Passive crossovers rob about 15% of the power sent to it as it splits the signal to the mid and tweet. That 15% gets used up as heat in the crossover, with active you dont lose that power. If you are running 100 x 2 on passives you could use 40 x 4 and get approx the same power to all four speakers running active.

 

[backtofront001 10+ year member]

If 15% of the power is robbed, and if I have a 150 X 2 Amp then i'd still be giving the SLC's 128 clean watts...am i right?

 

[helotaxi 5,000+ posts]

15% is inaudible.

My point is that a 300w 4 channel amp on an active setup is not going to be as loud as a 300w 2 channel running to the same speakers with a passive network dividing the freqs to them. In the first situation, the mids and the tweets are getting 75W each. In the second, the mids and tweets are getting ~150W each, except above and below the crossover freq respecitvely where the filter begins to act like a resistor in series with the driver and attenuates the signal but at the same time the other driver is wired in parallel and begins getting more power in this freq range and the net result is nearly the same power level all the way across the frequency range. An increase of roughly 100% in power is going to be clearly audible.

Even if you only need the 75W from the original active example to get the volume that you want, having the extra power available will add to the quality of the sound by allowing for some headroom and keeping the amp from being taxed and starting to distort.

 

[squeak9798 5,000+ posts]

helotaxi I think you got that a little mixed up . Passive crossovers rob about 15% of the power sent to it as it splits the signal to the mid and tweet. That 15% gets used up as heat in the crossover, with active you dont lose that power. If you are running 100 x 2 on passives you could use 40 x 4 and get approx the same power to all four speakers running active.

I think you are the one who's a little mixed up.

Assuming you are running 100w x 2 on passives (and 15w of that is lost as heat), and 40w per speaker running active, the passives would still be over 3db louder (10*log(85/40) = 3.27db). Remember that passives don't split power, they split the frequencies. A 100w x 2 amp driving a component set will allow each speaker to receive full 100w of power (less any possible loss in power due to the passives) within the passband (assuming the mid & tweet are the same impedance), whereas each speaker in that active setup would only receive 40w of power.

Also, as helotaxi mentioned, 15% difference in power is inaudible.

To answer the original question; Neither is really better nor worse. It's all application, install and skill level dependent. If you are new, you're likely better off sticking with the passive setup for now. With the right knowledge and skill level, it is possible to improve the sound of your system by going active. But likewise, without that skill level or knowledge, it's really easy to make the active setup sound worse.

 

[squeak9798 5,000+ posts]

If 15% of the power is robbed, and if I have a 150 X 2 Amp then i'd still be giving the SLC's 128 clean watts...am i right?

Close enough for government work......

You won't hear a difference with a difference of 15% in power levels.

 

[backtofront001 10+ year member]

Thanks Sqeak, I'll probably go passive

 

[dogears 10+ year member]

Quote from an article about crossovers:

What's The Difference?

From a technical standpoint, crossovers simply divvy up frequencies. So which one does it better? Well, a passive crossover is in the signal path after your amplification. Since it is modifying a signal that has already been amplified, the signal contains wasted amplified frequencies with the passive crossover is going to kill. And due to the complex interaction between musical frequencies and electricity, the crossover point varies with speaker impedance because the crossover limits frequencies by reacting to the speaker load.

Active crossovers, on the other hand, are in the signal path before the amplifier. This position allows the amps to receive and amplify the correct frequencies for the speakers attached to it. It's unaffected by speaker impedance and makes your system far more efficient. As I stated before, an active crossover lets your amp concentrate its full power solely on those frequencies it passes to your speakers. For this reason, active crossovers are better. Excellent!

Squeak how will each speaker see 100w, each pair will see 100w. There will be loads that the mid will see 70 and the tweet will see 30 and vice versa. The amount of power each speaker will see will vary constantly depending on the reactive load of the speaker in the frequency range. There will be times when each speaker will each see 50watts per but will never see 100w each at the same time according to what i have learned. 100 watts is 100 watts no matter how you look at it right? Saying that passives using 200 watts total ( minus approx 15% 170 watts ) will be 3db louder than an active setup using 160w with no loss of power from the crossover doesnt seem correct (active is more efficient according to that article). More than doubling the power would in fact make it over 3db louder, comparing 85w to 40w but each speaker will not see 85w all the time in the passive setup. I know that you are probably the most knowledgable person on this board, educate me on how this works. If that is the case couldnt I use 1 200 watt amp for my sub and midbass and passively cross them over and see the same 200 watts to both in there used frequency range? Once again I am not wanting to start an argument but learn how this is done and if thats the case maybe design a passive setup for myself.

 

[SilverSquared 10+ year member]

I got an Orion 225 HCCA on a set of Punch 162s components. It was in a set of powerbass ones, but I locked up the left speaker, so I went with Punch. I had to cut the gain down to MAYBE 10%. At 25% it was WAY too loud for me. Anyway...being I am using the crossover that came with the components, does that mean 15% of my 25 watts per side is being lost? That ***** because I am running a midbass and 2 tweeters per door. OMG....I am losing 3.75 watts per side, ****. 21.25 watts divided per a midbass, and 2 tweeters. WOW...

I listen to them daily, and I am far surprised how nice they sound as how I am told they would.

the **** is dam with n at the end.

 

[dogears 10+ year member]

Thats correct, approx 15% loss through the crossover and your speakers are sharing the power , they do not each get the same 21 watts per speaker.

 

[SilverSquared 10+ year member]

My stuff is LOUD for only getting 7 watts each.