35 replies to this topic

[1point21gigawatts]

Is it better to run speakers active or passive, for instance having a 4 channel amp to either run woofers and tweeters seperately off their own channel, or bridging the amp and then running them through the xover that comes with the speakers for passive use. Because it seems alot of technology goes into the xovers to just shove them aside.
The particular amp i am using puts out the same power in 4ohm and 2ohm so the main question is just running passive or active for sound qaulity. I suppose component qaulity would be a factor, the gear i have is a Alpine PDX4.150 and dynaudio system 240.

[~Spyne~]

try it with both...with $1000 speakers, there is a lot of r&d that goes into the xovers so they should sound very good ran passive.
there are advantages to running active - you can control the amount of power sent to the woofers and tweeters separately, you can play with not only crossover points, but also the slope steepness (6/12/18/24db)

this can allow you to play the woofers and tweeters lower.

all you can do is try both and see which one you like best. but give active a few weeks and a few tries before dismissing it - making tuning changes yourself takes practice to get right

[1point21gigawatts]

That makes perfect sense spyne, thanks for the tip

[Juls]

Having spent alot of time doing both passive and active,
I've come to my own conclusion.

for cheaper speakers, under $500, active can make a dramatic improvement,

however once you go past that bracket, the quality of the x/over improves and the differences between
active and passive become less, almost to the point that they reverse.

personally I love to build budget systems around a good headunit with active x/overs,
since I can make the $1500 systems sound like $3000 systems quite easily.

however with more expensive setups, I found that a passive crossover is generally quite alot nicer when done properly for midranges and tweeters. however for midbass, sub bass, Active all the way.

For this reason I run a active/passive arrangement on my 3 ways.

Juls

[ProClass]

Passive.
Thats all I can say about that!

[jas]

passive it + bridge the amp

try that first see how you like it

[Juls]

Does your X/over have Bi Wire input?
if so, then you can run actively to gain separated control, in terms of EQ, Time alignment and Attenuation,
(depending on the processor) but still maintain the SQ of the Passive crossover.

that is probably the ultimate in my mind.

Juls

[abmolech]

Active.

The advantages are numerous, not the least of which is to use digital.

Sure passive can control impedance, but the losses are large for a car environment.

The loss in power to the driver for starters (Remember the passive filter cannot add, but taketh away)
Loss in damping control is extreme, and should be corrected with a sealed enclosure.


Active crossovers can notch, brick-wall, invert a specified band-phase, correct a specified phase and to some extent, replace an enclosure (still require a baffle)
Flexibility should not be under appreciated either. (including parallel time alignment)

For a car these are advantages are too useful.

(since your talking about "high end" passive networks, I took the liberty of using high end active networks)

If you want to use "every day" passives against actives, apart from cost active win every time

Edited by abmolech, 22 September 2006 - 06:52 PM.

[zion187reigneth]

tyroneair, on Sep 22 2006, 01:38 PM, said:

Is it better to run speakers active or passive, for instance having a 4 channel amp to either run woofers and tweeters seperately off their own channel, or bridging the amp and then running them through the xover that comes with the speakers for passive use. Because it seems alot of technology goes into the xovers to just shove them aside.
The particular amp i am using puts out the same power in 4ohm and 2ohm so the main question is just running passive or active for sound qaulity. I suppose component qaulity would be a factor, the gear i have is a Alpine PDX4.150 and dynaudio system 240.

tell us your thoughts on the PDX4x150, is it making your tweeters more sounding?........zion

[~thematt~]

I wont contribute too much to this discussion, as I think my thoughts are well known.

Try passive first, and if you want more, then go active. Unless you have a lot of money, custom passive is out of your league. They are expensive.

Whilst I believe in the science, which states actives are better, I have NEVER heard a system beat the custom passives I have listened to. The passives have such beauty and musicality to them, whilst it may be worse theoretically, my ears dont care.

Edited by ~thematt~, 22 September 2006 - 07:09 PM.

[muzzy66]

My opinion is active - no two ways about it.

Passive's in my opinion are just far too limiting.

Sure a passive crossover is designed for a particular speaker set, but what the speaker manufacturer cannot take into consideration is the environment that the speakers are being used in, or the listening tastes of the listener. In an actuve setup you can completely tune the system to suit your speaker positioning, the vehicle environment, and your own personal listening tastes. To me, a typical passive crossover (even a high quality one) simply lacks the precise tuning control. Every tuning option you have tends to be stepped, and limited.

A couple of common car audio scenarios:

Scenario
You have tweeter attenuation settings of -3dB, 0dB and +3dB. You find 0dB is abit bright, and -3dB is a tad too lacking.

Passive solution:
Pray that you have a reasonable EQ to play band-aid with, or fork out big $$ on a custom built passive crossover.

Active solution:
Fine-tune the level on your tweeter amp until you are satisfied with the tweeter-midrange transition.


Scenario 2:
You decide you aren't happy with your standard 4ohm tweeter, and want to upgrade it to a higher end 6ohm tweeter.

Passive solution:
Replace the tweeter, and build new expensive custom passive crossover to fix the issues caused by the change in impedances.

Active solution:
Replace the tweeter.


Scenario 3:
You decide you want to add a seperate midrange into your current 2 way front stage.

Passive solution:
Add in the midrange, and spend big $$ on having a complex three way custom passive built up.

Active solution:
Add the midrange of your choice, apply amplification, set crossovers.

Starting to notice a theme here?

That nice new passive crossover may in theory work perfectly for your speakers, but what if you put it in the car and it's off? Build a new one, or re-modify the existing ones! Sounds like a seriously annoying scenario to me...

Run active, and you can alter your crossover points with almost infinite accuracy, anytime, instantly. You can often run several different crossover slope options and see the results on the spot, and many active crossover units give you completely variable 180 degree phase control. And let's be honest - who has their tweeter, mid and midbass all identical distances from the listener? I bet not many... running active allows specific time correction of every individual speaker in your system (if your source unit is up to the tast). Finally, there are no passive crossovers to soak up all that power from your shiny new amplifier

From memory my brother was telilng me also of some proven major technical downfalls of passive crossover networks, but I'm not sure enough on this to really comment on it. I'm sure he hapilly will though I'll try to get him to add some input.

The only thing that would ever lead me to go passive over active is availability of resources. I.e. not having the amplification or source features to support it. This is why I will be running passive until (and only until) I can upgrade my source and add a four channel amp to run the mids and tweeters.

Edited by muzzy66, 25 September 2006 - 08:05 PM.

[1point21gigawatts]

After playing around with the amps settings for half an hour, i got the dyns to live up to their name ... The gains were set far to high, so any adjustments before on the high pass filter below 100hz made the speakers starting distorting heavily.
I thought the audio shop had set the gains in relation to the preouts voltage rating of the head unit. Now the gain is set to nominal (nom.) and the hp filter is down to 50hz, sounds pretty fresh, would like some more midbass, but dont we all.
Zion about the PDX on the tweets, to me they sound insane, clean sounding and far louder than i could have imagined, except they are actually running off the crossovers, not the woofers though. I found when i switched the amp setting from running the channels 3/4 only to 1/2+3/4 they came to life a little more, im just unsure if i should have that setting on with the tweets running off the crossovers.
All in all, one happy dynaudio listener i am

[Domza]

That's good to hear tyroneair: I will also be going active this week, I only have Type R splits but I also think that having the flexibility of control allows greater fine tunning and overall balance of sound, and as a reliable source said it takes time to perfect but the result is better staging and greater dynamics. And as muzzy66 said the active set up allows you to change speakers when ever you want, because there's no way I'm sticking with the Type R's (for SQ)!

[~thematt~]

As to Muzzy's post, every single one of those points can be done for passives as well.

Time delay/EQ correction etc can all be done on biwire/tri-wire systems.

All the rest of it, including 'customising for a car' AND changing drivers, can be done on passives as well. Just at a higher price then active.

[muzzy66]

They can, but how many passive three way crossovers are 'tri-ampable' and how many two way crossovers are 'bi-ampable' ?

And how much more of a pain in the butt is it to have to physically replace compenents just to make those changes, as compared to an active crossover where all you need to do is press a button, or turn a knob.

Let's say you wan't to experiment with a different crossover setting, then find you dont like it. You will have to modify the crossovers once to see how it sounds, them screw around and modify them again to put it back the way it was when you dont like the changes.

With the active, you change your settings - if you dont like it you just set it straight back. Easy.

IMO most people would be pretty limited with how accurate they can get with a passive crossover, because few people would have the patience to build up custom crossovers, then mofify them time after time after time until you get it pretty much right? Even fewer people would have the money to pay a person to spend so much time building them.

The only downside I can see to active crossovers is that you need to run more channels of amplification which means more cabling, more power draw, and more cost. However, Bi-amping / Tri-amping will also face the same dillema, so I just wonder - what's the point?

It's possible that there may be something I'm not aware of, but I don't see any way for a passive crossover to be superior to active...