What do you think of passive crossovers?

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Let's try an experiment. I'll put together a cap, an inductor and a resistor. You breadboard an op-amp, build it a dual supply, design a notch filtering feedback loop and ensure its stability. Then while we tune them, see how long between listening tests for each kind.

I can tell you now that you will be listening months before me ;) I did a RLC notch filter last week and it has improved the sound of my speakers substantially. I tuned it using speaker workshop to arive at the final values, I don't even know how I would do that with active ;)

Tony.
 
Passives and actives each have advantages and drawbacks just as active analog and active digital, and digital IIR and digital FIR all have strengths and weaknesses. However, any done correctly can produce excellent results.

I would caution that I watch the Stuart video and you must realize that it is marketing. Many of the points made are easily contradicted: direct connection to the amplifier, energy storage in passive elements... His opening statements are crafted to put passive in a bad light..."We use active because of everything wrong with passive... " Passives are primitive", with the idea that primitive = bad.

A poorly designed active crossover will sound just as bad as a poorly designed passive x-o. :(
 
I've flirted with the idea of going active for a while, but that's mostly because I spend lots of time trying different drivers and prototype boxes. I've got a garage full of scraps from constantly changing cabinets and driver cutouts.

If you're going to do lots of messing around, active would probably be the way to go if you're like me. It can be a pain to manage a a ton of passive parts, plus you can only solder caps so many times before you start running out of lead to trim. I've seriously got some older caps that have been in and out of crossovers so many times the leads are down to little nubs that I have to attach with gator clips.

I'd vote active for tinkering. If you're going to make one set of speakers and have them around un-disturbed for several years, I'd go passive, especially if there are any plans for home theater, I could imagine a 7.1 DTS-HD rig with all active speakers and 18+ channels of amplification would probably warm up your listening area and spin your electricity meter so fast you couldn't see the numbers anymore.
 
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What does the 96k miniDSP cost once you add PS, case, and all the plug-ins you need?

dave

$10 for a 12-15v laptop brick supply and the plugin is another $10. I'd skip the case and integrate the unit into the speaker along with the amps if cost is the main concern. But if you must have a case it could cost anything from virtually nothing(if you build it yourself with stock you already have) all the way up to few hundred dollars for something fancy.
 
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Let's try an experiment. I'll put together a cap, an inductor and a resistor. You breadboard an op-amp, build it a dual supply, design a notch filtering feedback loop and ensure its stability. Then while we tune them, see how long between listening tests for each kind.

These days analogue active is about as appealing as getting shot in the face. Forget about these types, they're mostly dead in DIY circles. The DSP based systems are much more flexible with parameter changes taking a few clicks of a mouse button.
 
I once saw a 21 component passive 3 way XO that begs to differ. :)

I like the ease and versatility of an active unit, the expensive part is having an amp on hand for each pair of drivers. If you have that then...

I don't know where you guys buy your crossover parts, but a quote of $800 for a crossover is ridiculous. And 8 channel amps for $100. How do you argue with people who make up numbers like that!

Cal - your last comment is like me saying that passive crossovers are free because I already have all the parts.
 
A flat amplitude response with uniform group delay.

If this is your desired end goal for a loudspeaker then perhaps passive isn't for you. But then so aren't the vast majority of active filters. This doesn't make them bad, just not suited to your purpose.

You can jog up and down a dead end street and you end up at the same spot.

Again this is just about your personal preference for what you want a crossover to do. Akin to Linkwitz saying passive crossovers are bad because they can't do what he needs them to do. An apple doesn't taste like an orange, if you want an orange you eat an orange, it doesn't make the apple bad just because you don't want an apple.


What, no provision for the outhouse? :nownow:

:D I think this is the bane of most DIYers, more ideas for loudspeakers then you have place to put them!
 
IMO the reason most folks rave about the advantages of active crossovers is simply because they are easier to get right. That's a huge advantage for the DIY guy. His chances of success are far greater.

:D

On my horn loudspeaker system project, I've run into a problem designing a passive crossover. It's just the first step to making the crossover also. The problem is that the midrange (Dynaudio D54 + Edgar 500Hz tractrix horn) didn't respond as I thought it would to a Zobel network. The rising impedance curve turned into a sine wave instead of a flat line as expected. I'm still scratching my head with that one. Then there's the compression driver tweeter. The last time I did a passive crossover on a compression driver, I got a lot of help from AllenB on this message board. Thanks again Allen. So, this new tweeter also needs 2 notch filters and an L pad in addition to the actual crossover filter. I have yet to figure out how to design notch filters for compression drivers. I don't see any online calculators, for example. So, the upshot of what I'm saying is that for me and my limited ability at designing a passive crossover, going active may be a better choice.
 
I once saw a 21 component passive 3 way XO that begs to differ. :)

I like the ease and versatility of an active unit, the expensive part is having an amp on hand for each pair of drivers. If you have that then...

My passive crossover component count for simple two way system is 14 per channel. If it was a 3 way, depending on the type of midrange, it could be more than 21. It's still cheaper than buying all those amps and active crossovers.

I wanted to keep my Musical Fidelity integrated amp, so I needed a loudspeaker with a passive crossover. I'm not saying one type of crossover is better than another.
 
Indeed, Heath Robinson is only good for laughs.

I could rephrase that as maybe 99% of active filters aren't for you either. Are they a Heath Robinson affair too?

Rather then discussing how appropriate passive or certain active filters are to certain applications, you're simply restating your own personal philosophy. This doesn't automatically mean it is the right philosophy to follow for all applications.
 
diyAudio Member
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I don't know where you guys buy your crossover parts, but a quote of $800 for a crossover is ridiculous. And 8 channel amps for $100. How do you argue with people who make up numbers like that!

Its possible to spend $800 on a single passive component if you look around. For example take a look at the larger values of these Dueland caps, $2,749.84 for a 40uf. So a situation where someone spends $800 for a couple of dozen branded passive components is easy to imagine.

And yes it is possible to get lots of channels of amplification without spending a fortune too. $100 for 8 channels doesn't sound far out if you start considering these:

6 X 100Watt Class-D Audio Amplifier Board ? TDA7498 | eBay

And a suitable SMPS would be around $40.
 
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