Active or Passive

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Hello, I am finish the construction phase of my loudspeaker system, (3 way, 10" woofer, 4" Vifa midrange, Fountek tweeter). I was wondering what the recommendation to go active or not would be.

I designed a preliminary passive crossover, and the cost was in the 120-130's for quality components, and installation.

I designed my loudspeaker for an outboard crossover, with the plan of going active down the road. Would it be cost prohibitive to go active with my speakers, assuming I already have the amplifiers (I have a 300wrms x 2 @ 4ohm amp, for the woofers, an old 40wrms x 2 @ 4 ohm reciever, and I'd need another amplifier), but how much would an active crossover cost. The closest I have seen is a behringer 3 way x-over, (but I'd rather have the digital one), but what would the DIY approach be, assuming I have very little electronics experiance, or is there another commerical approach I should look at.
 
The Marchand XM1 modules with Burr Brown OPA2134 is very good. I've had a Behringer and it wasn't even close.

It won't cost much more than your passive network even with a good power supply.




http://www.marchandelec.com/
xm1.jpg
 
The H.E.L. crossover is similar to the Marchand, being 24db LR crossover. It consists of a stereo crossover with on board regulated power supply, which would simplify things a bit. Cost is about the same, or maybe cheaper, depending on what you do to power the Marchand. Parts on the H.E.L. are better, I think, using 2% polypropylene caps instead on polyester types, and resistors are MIL spec Dale/Vishay. I doubt you would hear much difference between the two, however.
The crossover kits on the online store only list 3 frequencies, however, it is easy to set the board for any crossover frequency by changing resistor values. Contact them, they are very helpful.
Going to an active crossover is highly recommended, and actually cheaper than building a good passive one (as you have found out), providing you already have the power amps needed.

http://www.highefficiencyloudspeakers.com/
 
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bjackson said:
Hello, I am finish the construction phase of my loudspeaker system, (3 way, 10" woofer, 4" Vifa midrange, Fountek tweeter). I was wondering what the recommendation to go active or not would be.

I will always recommend an active XO over a passive equivalent - everytime. I'm biased but the results I've had speak for themselves. In fact I've given up on passives for all but the most simple designs.

The disadvantage, well actually its one of its strongest advantages if you look at it from another perspective, is that you will need an amp for each driver, 2-way means bi-amp, 3-way tri-amp etc. Obviously costly but it really shows in the sound, words like effortless, dynamic and transparent best describe an active tri-amped 3-way :)

If you start to look at LR XO's then you've also got perfect phase alignment and stable gain over the XO point. This of course doesn't mean sqat in the real world but electronically its the perfect XO, which means you are that bit closer to making your life and the sound better.
Another nice bonus is the fact that removing the passive network means that there is absolutely nothing between your amplifier and speaker, no distortion or noise is added and the amp can more effectively control the loudspeaker since its not acting through an intermediary(the passive XO).

If it wasn't for the fact that you need multiple amps in an active setup, I think that passive networks would be something that we'd all look at in the local museum and say 'I can remember those!'.

There's nothing that can't be done with an active XO that a passive XO acheives. Actually there's plenty off stuff that you do with active that's simply impossible, impractical or expensive with passive ie. PEQ, LT, high orders, notch filters etc.

No technology is perfect but for me active offers less compromises and more flexibility.
 
An active is the best choice, in every way. Just make sure the crosses are phase linear. You can do that with standard opamp or discreet designs. This G. Randy Sloane book shows how: The Audiophile's Project Sourcebook
DSP is a more elegant way, frequency & phase agile. Costly, though & the golden ears frown upon the binary music thingy.
This is not hard, I started in the late ‘70s; it was so obvious that it sounded better! Give it a try.

Also check:
Walter G. Jung
Don Lancaster
Do a search @ Amazon for active filters.
Good luck.
 
The Marchand XM1 modules with Burr Brown OPA2134 is very good. I've had a Behringer and it wasn't even close.

I switched from marchand to behringer dcx - and do not regret it.
1st. - no difference in sound
2nd. a lot more flexibility
3rd. with time delay auto adjusted through the dcx, marchand cannot even start to compete with the dcx - and I had marchands 12 & 48 db in two and three way configs. Sold my latest one last year.

It's hard for me to justify actively crossing between the mid and tweeter.

I guess thats your problem, nobody elses, and I am not trying to convince anybody.

Tried the sub active/ mid-high passiv config. and then switched. Sounds better to my ears.
 
audio-kraut said:


I switched from marchand to behringer dcx - and do not regret it.
1st. - no difference in sound
2nd. a lot more flexibility
3rd. with time delay auto adjusted through the dcx, marchand cannot even start to compete with the dcx - and I had marchands 12 & 48 db in two and three way configs. Sold my latest one last year.

I was referring to the CX3400 - not the digital Behringer.

I don't need the delay with this rib but it could be handdy with my horns - maybe I'll borrow the digital unit someday and see how I like it.
 
I don't know if we will get anybody posting hear in favour of the passive option!

I converted my two-way kit speakers to active and the improvement was not small.

You don't have to spend a lot of money on active crossovers either. The simple DIY crossover that I use is shown here

In fact I am currently 'renovating' my active system using Gainclone amplification. Gainclones remove the only argument against going active, ie, the high cost of the extra amplification! ;)
 
Somebody hand me a baseball bat.

Tsk tsk, a little agressive, aren't we?

The only argument ever for me against aktiv - and I have persued that route in the diy ls building mode since 1989 - was the cost of the amps.

For diy amps - internet makes it easy now to get the parts, but at that time living close to the middle of nowwhere, diy electronics was a pain in the butt. So I stuck with diy ls building and started out with nad, eventually switching to brystons.

Very satisfied with compound loaded subs, and d'appolito sattellites, i am torn between the thor and the orion as my next projects - aktively amped of course; the orion requires that in any case.
 
Bill Fitzpatrick said:
It's hard for me to justify actively crossing between the mid and tweeter.

But I am eager to learn the error of my ways if someone wants to educate me.

I suppose there is no substitute for entirely active, but it does depend on the design. Im sure you will always be able to tell the difference between semi active and fully active but the amount by which one is better could easily be different from one design to the next.

If you have a three way with a dome mid crossed at say 600hz and 4000hz then it will not handle anywhere near as much information as a mid covering 150-3000hz. In the first instance I bet the change from passive to active would not be as noticeable as the second. In the second, amp clipping is going to be an issue much more then the first, stopping this clipping reaching the tweeter would be audible. This going on a cross at 300hz is like giving half the music to the bass and half to the rest up. The midrange 150-3000 is probably going to have the hardest job in the entire system.
 
why use active crossovers i dont see them having benefits over passive ones and

ahh - you're here now. Leaving Mr. Pass alone, aren't you?
Maybe you check with your countryman who very clearly describes what the problems are with passive xovers.

http://sound.westhost.com/bi-amp.htm
http://sound.westhost.com/biamp-vs-passive.htm
re: time alignment:
http://sound.westhost.com/ptd.htm

There are more studies on the benefits of active xovers if you know how to google, but I guess this will be good enough for a starter.
 
catapult said:
Don't forget all the little "extras" that the commercial analog active XOs don't supply, like the all-important baffle-step compensation and driver time alignment. Designing an active XO is just as hard as designing a passive one. You either need a DSP solution or an analog active customized just for your particular speakers.

http://www.linkwitzlab.com/filters.htm

Im glad you mentioned that, I have seen so many times people writing as if plonking a 4th order linkwitz electrical active on both the woofer and tweeter are going to produce a super speaker. Yes the results of a textbook active xover is more predictable then a passive version. But that is where it ends.

Passive xovers and active xovers require specifically designing to the speaker they are going to be used with. Infact passive and active xovers are neither easier or harder then each other to design with. Both require measuring the drivers in the box they are going to be used in and some sort of software to simulate whats going to happen.

The main advantage of the active xover is the flexability it offers you, most of the time with passives you are stuck with a couple of frequencies and slopes that will keep good phase & frequency response. But with an active xover, mainly because of the time delay circuit, you open up whatever frequency or slope you want to use, but still all of this has to be designed for each individual louspeaker.
 
Another who is firmly on the active bandwagon, but in addition to the cost of amps, I have heard of only one other drawback.

Once calibrated moving the speakers even slightly can necessitate a recalibration.

Hey Bill, those Elliot articles that audio-kraut (nice call on the Thor and Orion, BTW) referenced are pretty persuasive regarding the benefits of actives.

Here's a couple of other proponents:
http://www.linkwitzlab.com/crossovers.htm
http://www.soundandvisionmag.com/idealbb/view.asp?mode=viewtopic&topicID=27324&num=20&pageNo=1
 
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