Why Active is better than Passive..

[gstokes]

Maximum Damping Factor.. in a "normal" system with passive crossovers and multiple speakers per channel the amplifier must work very hard to control each driver, not only does it have to control more than one speaker per channel but it has to do so through an unpowered or passive crossover network containing capacitors inductors and resistors, this passive network between the amplifier and the speaker makes the job of controlling the speaker/s that much harder for the amplifier. Going active is simply eliminating or bypassing the passive crossover networks and using each individual channel to drive only 1 speaker, now the amplifiers job of controlling the speaker is very easy because not only is the passive LCR network out of the way but the single channel has only a single driver to control, the amplifier now has maximum control over each speaker or Maximum Damping Factor.

In a passive system the only component\s the amplifier can "see" is the crossover, it can't see the speaker/s, when we remove that passive network we remove the blinders off the amplifier and allow it to "see" the speaker, now the amplifier has a clear view of the speaker without obstruction and is able to easier control it, hopefully this makes it easier for the layman to understand why active is better than passive. There are many reasons to go active but i would think that maximum damping factor would be the most prominent reason and would make sense why active systems have the potential to sound so much better than passive systems.

Just my $.02

Click to read more...

 

[big scott]

can all, say 4 channel amp run active ? if not what do you look for ??

i have been thinking about this but have no idea..

 

[Jeffdachef 5,000+ posts]

can all, say 4 channel amp run active ? if not what do you look for ??i have been thinking about this but have no idea..

No, there are 4 channels for pure power and 4 channels that have passbands you can set to cross over the mids and highs.

These are a comparison between a non active capable amp vs an active capable amp

going active is fairly easy if you just focus on the front stage. However that luxury isn't for me since i have an 8 passenger van with heavy bass, I need front, middle and rear mids and highs or else everyone behind me will just hear basslines. Rear fill on head unit power doesnt do jack lol.

also to point out another advantage to active vs passive. Some of these passive crossover networks do a poor job of balancing power between the tweeter and the mids which can cause one or the other to be harsh or muddy.

vs

 

[akillj 10+ year member]

You can take it a step further and get an active processor, I know there's more but the first thing that comes to mind is the 3SIXTY.3. That way you can set your crossover points and slopes way more accurately than just a knob. That's one of my pet peves. Like, say I wanted to have a high-pass at 3.5khz on that amp mentioned above, where would I set the knob? It's somewhere in between 500-5000hz on that knob lol.

EDIT: Also another thing that comes to mind when using only the amp's options to go active, is that you can't change the slope of the crossover point. It's going to be set at 12db/octave or something.

 

[Jeffdachef 5,000+ posts]

You can take it a step further and get an active processor, I know there's more but the first thing that comes to mind is the 3SIXTY.3. That way you can set your crossover points and slopes way more accurately than just a knob. That's one of my pet peves. Like, say I wanted to have a high-pass at 3.5khz on that amp mentioned above, where would I set the knob? It's somewhere in between 500-5000hz on that knob lol.
EDIT: Also another thing that comes to mind when using only the amp's options to go active, is that you can't change the slope of the crossover point. It's going to be set at 12db/octave or something.

you can actually generate a tone via audacity for 3500 hz, put it on a cd, usb, phone or w/e music source, you turn the knob until it starts cutting out then thats when you know your in the right ballpark. Its not going to be exact but should be within 50hz give or take depending on how good your ears are. There's always meade's CC-1 thing but thats still has at least a 20 hz margin of error. Many ways to get around not having an expensive sound processor. SQ with loads of money dumped all over it is fine, but I really like it when you can achieve SQ on a small but healthy budget.

 

[akillj 10+ year member]

you can actually generate a tone via audacity for 3500 hz, put it on a cd, usb, phone or w/e music source, you turn the knob until it starts cutting out then thats when you know your in the right ballpark. Its not going to be exact but should be within 50hz give or take depending on how good your ears are. There's always meade's CC-1 thing but thats still has at least a 20 hz margin of error. Many ways to get around not having an expensive sound processor. SQ with loads of money dumped all over it is fine, but I really like it when you can achieve SQ on a small but healthy budget.

Yeah I completely agree, that's a perfectly legitimate way to do it. A few hz too high or low won't make a difference. Personally never been a fan of SMD products. Yes they function fine but there's plenty of well accepted and cheaper ways to do what they do. Way overpriced imo.

 

[yogegoy]

Because you are not limited to the specified wattage that goes through your passive xover, while in active the signal has been filtered before it goes in your amp. The xover (passive is placed after the amplified signal while in active the filter is before the amplifier (or xover is placed before the input stage).

 

[gstokes]

can all, say 4 channel amp run active ? if not what do you look for ??i have been thinking about this but have no idea..

A 5-channel works or you could use a 4-channel plus a sub amp or you could use a 6-channel plus sub amp, i am using 5-channel amplifier with tweeters woofers and a pair of 12's in bridged mono off channel 5, if i ever do it over i would use a 6-channel amp driving tweeters with channels 1 & 2 (Xover @ HighPass), 4" mid-range drivers for channels 3 & 4 (Xover @ BandPass) then a pair of 6.5" woofers for channels 5 & 6 (Xover @ LowPass) then another amplifier for the 12's, that would be my dream system..

 

[AAAAAAA 10+ year member]

Maximum Damping Factor.. in a "normal" system with passive crossovers and multiple speakers per channel the amplifier must work very hard to control each driver, not only does it have to control more than one speaker per channel but it has to do so through an unpowered or passive crossover network containing capacitors inductors and resistors, this passive network between the amplifier and the speaker makes the job of controlling the speaker/s that much harder for the amplifier. Going active is simply eliminating or bypassing the passive crossover networks and using each individual channel to drive only 1 speaker, now the amplifiers job of controlling the speaker is very easy because not only is the passive LCR network out of the way but the single channel has only a single driver to control, the amplifier now has maximum control over each speaker or Maximum Damping Factor.In a passive system the only component\s the amplifier can "see" is the crossover, it can't see the speaker/s, when we remove that passive network we remove the blinders off the amplifier and allow it to "see" the speaker, now the amplifier has a clear view of the speaker without obstruction and is able to easier control it, hopefully this makes it easier for the layman to understand why active is better than passive. There are many reasons to go active but i would think that maximum damping factor would be the most prominent reason and would make sense why active systems have the potential to sound so much better than passive systems.

Just my $.02

Doesn't really work like that. The amp actually just controls one speaker at a time even with two or 3 way passive.

 

[whitedragon551 5,000+ posts]

can all, say 4 channel amp run active ? if not what do you look for ??i have been thinking about this but have no idea..

The easiest way to do it is to have an amp that allows full crossovers instead of LPF or HPF and control everything from an active capable HU.

 

[whitedragon551 5,000+ posts]

A 5-channel works or you could use a 4-channel plus a sub amp or you could use a 6-channel plus sub amp, i am using 5-channel amplifier with tweeters woofers and a pair of 12's in bridged mono off channel 5, if i ever do it over i would use a 6-channel amp driving tweeters with channels 1 & 2 (Xover @ HighPass), 4" mid-range drivers for channels 3 & 4 (Xover @ BandPass) then a pair of 6.5" woofers for channels 5 & 6 (Xover @ LowPass) then another amplifier for the 12's, that would be my dream system..

Could run a 6 channel with no sub amp. Same for a 5 channel. Typically 5 channel amps will do the same power 1-4 ohms and the 5th channel will be staggered and have a higher output. 6 channels typically do the same power output on all 6 channels, but some are staggered, and some have channels 5/6 where they are 2 ohm stable for higher output on a sub.

My old Audiosystem Twister amp was 2 ohm stable on channels 5 and 6.

 

[gstokes]

The easiest way to do it is to have an amp that allows full crossovers instead of LPF or HPF and control everything from an active capable HU.

Wouldn't that require a 6-channel pre-out on the head unit or can you get away with 2-channel ?

 

[whitedragon551 5,000+ posts]

Wouldn't that require a 6-channel pre-out on the head unit or can you get away with 2-channel ?

If your running active with a 4 channel amp you need atleast 4 preouts at the HU. Most if not all active capable headunits have 3 sets of preouts.

 

[big scott]

ok would my alpine me good for active ?

cda-7874

Alpine CDA-7894 CD/MP3 Receiver with Ai-NET CD Changer Controls at Crutchfield.com

 

[whitedragon551 5,000+ posts]

ok would my alpine me good for active ?cda-7874

Alpine CDA-7894 CD/MP3 Receiver with Ai-NET CD Changer Controls at Crutchfield.com

I dont believe it is.