Crossover ? Passive Vs. Active


How many use active crossovers. Would it not be better to crossover before amplifing the signal, or am I missing something? Why waste all that energy just to filter it out. Plus why can't they separate the highs, mids, and lows during the recording and then the processor/preamp sends it to the correct driver and do away with a crossover?
kash1
Bob, I agree with what you say. Yes, many things audiophile will seem irrational to the masses, and many actually are, but since this is a web site devoted to all things audiophile I don't think it irrational to bring up those ideas. I suppose it is silly to debate a term like economical in the first place since that means very different things to different people.

Most people would say spending $2k for any piece of stereo equipment would be insane yet you describe the ATI as being economical. To me economical in high end means what I can afford that gives me what I perceive to be the best sound for the money. I have not heard an ATI amp, but having tried various other solid state amps in that and even higher price ranges in my system I doubt it would perform as I wish, which not only makes it uneconomical for me.
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the amplifiers will be much smaller in power rating and will be economical.

Not really. If you have say a 100 watt amp for a three way speaker, you are still going to need an amp very close to that level for the woofer, and you will need 2 more amps to boot. Yes, the midrange and especially the tweeter will not need as much power but the quality still has to be there. Even if you could get by with 3 amps that had 1/3 the power it would still cost more than a single higher powered amp. Going up the power chain of a power amp line doesn't double the cost when you double the power . It is a fraction of that.

I agree that a well executed system with an active crossover has many advantages for the reasons listed, but saving money is not one of them. Quality amps of any power level are not "economical."
I'm running my two-way Apogee Duetta Signatures with a Marchand XM9 active crossover. One thing you always have to be concerned with when going to an active crossover is that you can smoke a tweeter or midrange driver fast. Remember, once you go active, you have by-passed any and all filter capacitors connecting to the tweeter and(or) midrange drivers - any frequency can pass to these drivers now. For this reason, it is imperative that your amps powering your mid-ranges and(or) tweeters must not pass any DC, and must not have any power-on "tumps" as well. You would be surprised how may good amps pass a little too much DC to be used for bi-amping.

Anyway with that being said, since I have gone active, I'll never go back to passive - at least with this set of speakers.
With an active xover, one can pick and choose xover points, levels, and even the Q on some models. I think the amp choice is less of an issue when you have such flexibility in the xover. Bob's comment is right on.

Losing an inductor [in a conventional woofer xover] with yards and yards of nondescipt wire is a huge advantage in an active system. But 4, 6 or more amps just isn't in the cards for most of us. Perhaps active monitors are a way to go, but I always wondered about the quality of those amps, and how they are subjected to the vibrations of the spkr cabinet. And most are geared to the pro market, for "accuracy" and not necessarily hi-fi.
I'm with Undertow and Tim196. Active is definitely better from a technical perspective but less flexible than passive for tailoring the sound to individual taste (particularly if you like added harmonics from tube power amps to warm or sweeten the sound).
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Active in general is better and more control to end up with the best resolution and adjustments.. And yes of course active will rob far less power, up to 60 % less from what I understand.... No crossovers are very good to using full range drivers.
In theory, I think that active speakers make a lot more sense than passive ones if the goal is getting maximum performance out of a speaker from a technical standpoint.

However, when you go active, you lose the ability to play around with amps and tailor the sound to your liking. I guess it depends on your goals. If you like a sweeter or warmer sonud than active designs such as those from ATC, PMC, or Genelec are not going to be your cup of tea. Most active designs are intended to be used in recording and therefore are designed to be as accurate as possible.

I believe that DSP speaker and room correction is and will continue to be a great way to tweak the sound of a system to ones preference.
Would it not be better to crossover before amplifing the signal, or am I missing something?

better is up for debate but for an active one you need 3 amplifiers per channel for a 3 way system vs only one for passive. Good amps aren't cheap.

Speakers evolved as full range devices so you would have to change the whole culture of high end. Few speakers are designed so you can easily bypass the internal crossover.

Plus why can't they separate the highs, mids, and lows during the recording
they could but what medium would you use and where is the market? Up until the dawn of 5.1 surround and hi-rez recordings nothing could handle 6 channels. The average consumer won't accept SACD and wants mp3. Do you think they will buy such an elaborate system?

what frequencies would you choose as cutoffs? And why 3? Maybe I want a 2 way or 4 way system, and every speaker designer would want a different cutoff for their drivers of choice.

I think you are going to have to make your own recordings and build your own speakers.