Active Crossovers what can't they do?

[stephenmarklay]

The more I think about different projects and tweaking crossovers points and filtering etc I started to think active is the way to go.

It seems like you get a lot for the $200-300 price range which is pretty cheap since passive components add up so fast.

It seems as though trying out different drivers would be so much faster and easier? I guess once you nail a design you can build a passive so you can free up your active for the next project or whatever.

So what am I missing? Is the sound quality worse?

Can I do everything I would normally do passive? Can you do notch filters with the parametric eq functions? Driver attenuation to for level matching etc...

It looks like the BBE DS26 or the Behringer DCX2496 could be used.

Any help would be appreciated.

Thanks

[navin]

Active advantages:
1. if the bass amp overloads the effects are not felt in the midrnage or tweeter
2. since there are fewer apssive elements between the amp and the driver the damping/couipling between the amp and driver is better
3. very low crossover frequencies (read as big inductors and capacitor) are easily implemented using active where as with passive crossovers these can get expensive.
4. DSP and other processing (time alignment - ladder networks) can be more easily implemented using active XO. Other adjustments like baffle step might be easier to implement using passive.
5. Amps specific to a driver (for example a 200-400W Class D or Class AB solid state for the woofer, 20-50W Class A solid state or Ultralinear tube for the mid bass, 5-15W Triode class A tube for the tweeter etc...) can be used

Active Disadvantages:
1. You need multiple amplifiers and that means cost and space especially if you are using tube amps.
2. whole lot of wires from the amps to the speaker
3. Primarily used by DIYers as it is very diffcult to bypass the crossover and design an active crossover that exactly replicates the effects of a passive crossover.

[Charles Darwin]

Active Crossovers Vs. Passive Crossovers

The sound quality of actives is vastly superior to anything possible using passives.
They are also a LOT easier to implement. You will need more amps but even when using fairly cheap amps actives have the advantage over passives using the highest quality (and highest priced!) amps. There is simply no contest at all.

[MaVo]

The best speakers out there (gedlees summa or the danley sound labs synergy horns) use passive crossovers, so one should think that the usage of passive components is good enough. The main advantage of active speakers is that you can play with the settings for free. If you know what you do, passive is perfectly fine. If you are a DIY and still learning stuff, buying active components might save money in the long run, since you wont have to rebuy the whole crossover every time you change something.

[Pano]

Active crossovers are faster and more fun for most of us. The DCX is a very handy tool. But you still have to know what you are doing!

Don't dismiss passive crossovers out of hand. Some of the best systems I've ever heard used passive crossovers - 2, 3 and even 4 way.

Active of passive, the results will depend on your skills. Crossovers are not easy. But they do teach you a lot about speakers.

[Charles Darwin]

I've converted a number of speakers from passive to active in my time and the resulting improvement varied between staggering and downright shocking.
I have no doubt that both speakers you mentioned would be vastly improved by using active xovers. Especially if there is an inductor anywhere directly in the signal path as there usually is, at least in the lp.

[5th element]

Originally Posted by panomaniac

Crossovers are not easy.

This.

Active crossovers are no panacea, you still need to know what you're doing. But besides that I highly advocate their use.

Can I do everything I would normally do passive?

You can do that and more with the active filters. Because active filters have gain elements you can add to the response rather then just take away like with passives. In other words a passive can take away what's already there (such as notching out a peak), but if there's a dip you can't do anything about it. With active you can put a peak there to compensate.

Active Filters

Has examples of different things you can do with active.

[Pano]

Originally Posted by Charles Darwin

I have no doubt that both speakers you mentioned would be vastly improved by using active xovers.

However - I DO doubt this. Sure, I used to be an active crossover snob but then I heard and learned what a well designed passive crossover can do.

I believe that getting things right is just easier with active crossovers. And that fact is not to be taken lightly, it's important. That may be the main reason why so many folks think they are superior sounding - they are just easier to get right. Ease of use is why I like them!

Digital crossovers like the DCX are so flexible it's amazing.

[Sheldon]

Originally Posted by panomaniac

However - I DO doubt this. Sure, I used to be an active crossover snob but then I heard and learned what a well designed passive crossover can do.

I believe that getting things right is just easier with active crossovers. And that fact is not to be taken lightly, it's important. That may be the main reason why so many folks think they are superior sounding - they are just easier to get right. Ease of use is why I like them!

Digital crossovers like the DCX are so flexible it's amazing.

Ah, but even Earl's speaker systems are not completely passive. For the full range, he uses multiple subs, which are separately powered. Yes, a good passive design, in its range can sound very fine. But, for full bandwidth, its asking a lot of the amp.

I do want to do some work on my system with passives for at least some of it. The final design frontier for me. I started with a speaker project that was intended to be passive and got sidetracked for several years now, building amps and such. Time to quit procrastinating and do some passive design work. The barrier for me, is that the software measuring and design systems, at least for me, suck up inordinate amounts of time just to learn. Speaker workshop, for instance, is very comprehensive, but also very time consuming to learn. The file system alone mystifies me.

I use a DEQX now, and it's easy to get started with, but still takes a long time to really understand the subtleties of measurement and design. It does make it easier for the DIYer to get excellent sound. Much harder, is to do a design like Earl's and really get it right. It may not be rocket science, but it's close.

Sheldon

[MikeHunt79]

They can't make a cup of tea!