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View Full Version : Active vs. Passive



logan963
03-12-2013, 09:57 PM
Why does everyone prefer running active vs. passive? I know the difference, but what are the real benefits of running active instead of passive?

ciaonzo
03-12-2013, 10:07 PM
On-the-fly control of crossover points/slopes, level adjustment, time delay, equalization. Much better control over driver behavior without all the lossy components in the circuit. Massive gains in headroom because high frequency waveforms are not riding on low frequency waveforms (similar to what is seen here).

https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQ6S8GwNW69J40TdAuQrylt82qABsesR 2WWZvrYooqkyQlP7u3sYg

http://sound.westhost.com/biamp-f3b.gif

gckless
03-12-2013, 10:08 PM
You can usually run a bit more power to each, biggest reason is to be able to choose your crossover points to suit your install/equipment/ears and T/A.


Edit: Ciaonzo said it better. As usual lol.

ciaonzo
03-12-2013, 10:18 PM
You can usually run a bit more power to each, biggest reason is to be able to choose your crossover points to suit your install/equipment/ears and T/A.


Edit: Ciaonzo said it better. As usual lol.Hey, we're on the same track buddy. :graduate:

keep_hope_alive will roll through here and really lay it down, lol.

logan963
03-12-2013, 10:31 PM
On-the-fly control of crossover points/slopes, level adjustment, time delay, equalization. Much better control over driver behavior without all the lossy components in the circuit. Massive gains in headroom because high frequency waveforms are not riding on low frequency waveforms (similar to what is seen here).

https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQ6S8GwNW69J40TdAuQrylt82qABsesR 2WWZvrYooqkyQlP7u3sYg


http://sound.westhost.com/biamp-f3b.gif
Alright, so I have an MS-8, so if I run everything through that and leave out the mechanical crossovers I will be running active right?

Vecticus
03-12-2013, 11:33 PM
What about building custom cross overs and mounting the tweeter close to the midbass and just using the TA and EQ the 2-way HU has? Other than changing cross over points on the fly. Seems like you could achieve just as good SQ that way.

zako
03-12-2013, 11:52 PM
Adjust crossover frequency and slopes. Adjust the level of each individual driver. Passive crossovers can't do this. Passive crossovers are always a trade off since each car has its own peculiarities with respect to woofer and tweeter placement (degrees off axis, path lenth differences) and internal reflections. With a good DSP you can also adjust time delay for each driver involved.

zako
03-12-2013, 11:56 PM
What about building custom cross overs and mounting the tweeter close to the midbass and just using the TA and EQ the 2-way HU has? Other than changing cross over points on the fly. Seems like you could achieve just as good SQ that way.

You could. This seems like a lot of work though. Crossover design is not trivial, or at least not as simple as adjusting it on the fly on the DSP.