Passive Crossovers ...

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If I could be assured of low noise, low distortion and a lotto win to fund the quality of amps I require, I may just abandon passive.
Good active design makes anps even less important than in a passive. Go and look at the Z curves of many multi way passives as measured by Sphile etc, especially in the critical high current band under 500Hz or so. My drivers in this area have a low Q peak at Fb, then are Re with 0.3mH Le until the steep 400Hz xover. Such an easy load, cheap amps work wonderfully. But then they don't have the names or price tags to impress others.
 
i think i like passives best, less complicated then actives and more reliable, less costly and better sound quality

Oh, wow.
I really don't know about that, I'd say for many smaller speaker setups with lower sensitivity rating you can get away with a cheaper slightly noisier DSP solution. And using that cheap DSP you can make something that will, in the majority of cases, vastly outperform any passive solution for the same money. Strictly because DSP can do so much more than mere filters, and you can get something like the ADAU1701 for less than the cost of some passive 1st order components, pending on what the desired xo frequency will be.

You're saying passive filters are less complicated? I honestly do not believe you've ever designed and measured a well implemented second order filter, it takes a lot of work to get it just right, even with good drivers and boxes. And passive filters are not cheap, they frequently require bigger value components that cost more money than what it costs to get a finished DSP circuit board with all components needed.

That said, some of the very best speakers I've heard utilized passive xo's, but they are not cheap! And they are not that easy to get right!

You guys using active crossovers, do yo construct your own actives and optimize transfer functions to your actual drivers or do you use pre-made products like dbx? Or do you use dsp’s?

I think it is safe to say that not many of us use analog active filters any more.
Some purchase ready made DSP boards to make integrated solutions (pre, DSP and Power stages in one box), some purchase ready made solutions like the offerings from DBX, Minidsp, Behringer etc.
And some very few cook up their own boards in the kitchen oven.

Passive filters are great, but they are not cheap, and they are not easy to get 100% just so.
A DSP solution is much more flexible and forgiving, if you make a mistake you do not have to order and wait for new components etc.
 
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You guys using active crossovers, do yo construct your own actives and optimize transfer functions to your actual drivers or do you use pre-made products like dbx? Or do you use dsp’s?
Yes, sort of, and no. In the process.

When you do a side-by-side comparison of active vs passive, you may hear the difference. Many of the long term DIYers have active setups.
 
i think i like passives best,
Great. I don't.

less complicated then actives
Not really. Some passive xovers use lots of components;

and more reliable,
Hardly. I've run PAs for years with inexpensive xovers, carted in and out of venues night after night, rattled around in trucks and trailers etc, and never had a failure. At home, never had a failure.

less costly
Not always, especially with complicated passive designs especially with overpriced booootique parts. I knew someone recently that wanted to do the recent Troels HE design, until he priced the passive xover. I can do it with DSP and second hand amps for much less.

and better sound quality
My experience disagrees completely. Plus I can do a lot of stuff with a DSP, you could never do passively. Kii Three for example.

You guys using active crossovers, do yo construct your own actives and optimize transfer functions to your actual drivers
Yes, mostly. I used custom analogs for years before going DSP.

or do you use pre-made products like dbx?
Depends. I did for my PA, and I used I/O modified DCXs for many years, These may get used in the new surrounds as they're good enough for that application. However, I don't try to wring all the BW possible out of each driver as I think it generally sounds worse. In the surrounds the MB can play about 2 octaves above xover and the MR about the same below. Using LR8 out of band rubbish is not as much of an issue.

Or do you use dsp’s?
Yes, completely now. I have MDs, DCXs a DEQX and a custom PC built to do noting other than be a DSP xover.

And basically a +1 to Kaffi's post 23.
 
Caution, rambling ahead:
The responses to the OP have covered everything pretty well so far, just as in any other thread on the topic.
When building a box type speaker with a single baffle I would go active if only for the sake of time aligning the drivers. With horns physical alignment isn't a big deal, but unfortunately 'everything else' is.
Earlier this year I built a subwoofer (4 slot loaded 15" drivers, placed in room corner) powered by a Crown amp with built in DSP. Considering the corrections needed to make it integrate acceptably doing it passive would have moved me to discard the project.
 
Besides this, a first order is cheaper and easier.
I'd be interested to hear any input you folks have.
JT

Putting things in perspective, first order filters are best suited to individuals hoping to design a loudspeaker by listening method only. The outcome can be rewarding in the sense of personal satisfaction. The SQ may be whatever between bad and not so bad.
 
Putting things in perspective, first order filters are best suited to individuals hoping to design a loudspeaker by listening method only. The outcome can be rewarding in the sense of personal satisfaction. The SQ may be whatever between bad and not so bad.

I disagree with that

If properly implemented (compatable driver pairing) the results can be quite impressive in a two way.

This of course puts serious limitations on driver choice but it’s not impossible.
 
Hi,
two high-pass 6dB / oct in series, produce a 12dB / oct attenuation without constituting a resonant system?
Will the transfer function, attenuation, phase be the sum of the two independents?
 

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What are you trying to say? 5' is 8 ms delay.
That you were saying that the much, much smaller delay between the acoustic centres of cone drivers on a baffle was important, but that the much longer delays in large horn systems wasn't. My experience, let alone the physics, says that's rubbish.

What was your crossover frequency that it didn't matter?
I said it DID matter.

You went from midbass to hf leaving out mids???
Of course not. The point was that it's important to get the drivers time aligned and this was the largest path length, and obviously time delay between elements in the system.
 
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