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bifcake
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Active vs passive Xover

Are active crossovers better than built-in speaker crossovers as a matter of course regardless of implementation? In other words are you better off with an active crossover no matter how good your built-in speaker crossover may be and one should consider an external active crossover and bi-amping if the speaker design and funds allow it? Aside from the flexibility that an active, external crossover allows, what makes a crossover good or bad from a sound quality perspective? How does one decide which is a good xover (active or passive) and which isn't?

Thanks

CECE
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Re: Active vs passive Xover

eVERYTHING YA NEED TO KNOW ABOUT CROSSOVERS FROM TEH PROS AT rane. mOSTLY COMMERCIAL PRO APPS NEEDS ACTIVE NOT AT HOME IN SMALLER AREAS. http://www.rane.com/note134.html

Elk
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Re: Active vs passive Xover

Great question, Alex.

I know at least a few speakers with huge external active crossovers - with lots of big caps - such as VMPS. Here the designer clearly thinks that the active external is better. But I have no idea if he is right.

CECE
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Re: Active vs passive Xover

Read what RANE says, that in large areas, with multiple speakers needed, not in your home small enviorments. When speakers get into large spaces, and you are trying to balance everything volume wise, and each speaker is in a different acoustic space in a large room or hall, the only way to control it is with active electronics. Which is where active crossovers where developed for, large commerical venues, not home hi fi. Unless you have a 12,000 sq ft house, then you might need em.

Elk
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Re: Active vs passive Xover

Apples and canoes, DUP.

CECE
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Re: Active vs passive Xover

How so? they address active and electronic crossovers. Comparing why and when to apply the active ones. Couldn't be any planer, or clear. You should also get their excellent Audio Reference book You will realize all the myths and fantasys that exist in audiophile consumer stuff.

Elk
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Re: Active vs passive Xover

Because Rane's only concern is PA sound reinforcement. Nothing wrong with this, but it has little to do with home audio.

Merely because passive X-overs have their limitations in sound reinforcement and active X-overs are generally better for PAs installed in large venues (which is true) does not mean that active X-overs are not good for certain home HiFi applications.

Ergo, apples and canoes. Both handy but not interchangeable.

CECE
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Re: Active vs passive Xover

Since Rane explains why it's needed in large applications, with speakers placed far apart, why is it needed in a home enviroment? What case in a home enviroment would they make an improvement? Please explain. Cus' I think Rane is right, and if you read their Reference book, it explains in more detail, why. Why do you think they are incorrect?

mrlowry
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Re: Active vs passive Xover

Elk-

"Apples and canoes?" You got a chuckle and a smile over here. Are you going for Stephen's quote of the week?

AlexO-

This is a bit of an oversimplification but passive crossovers equalize the volume between drivers by padding down the more efficient drivers to match the less efficient drivers, and set a crossover area too. One of the reasons that horn speakers are so efficient is they do the exact opposite. They increase the efficiency of the least efficient driver to match that of the most efficient. The horn changes the way that the driver couples to air it is driving, effectively the air "sees" a driver the size of the opening of the horn (plus some horn coloration of course.) Contrary to popular belief most horns are NOT acting as megaphones, but as an impedance matching device between the driver and the air. Again everything in the above paragraph is simplified for clarity.

Personally the idea of active crossovers in the average person's hands scare me to death. I can't help but picture flaming drivers launched into the listener's lap. Second guessing the person who designed the speaker (if the were good) is never an advisable path. It's almost a sure thing that they know many, many things that the you don't. There are only a handful of good uses for active crossovers. The only two that spring immediately to mind are integrating sub(s) seamlessly and replacing a passive crossover with an active one but making sure to use the speaker designers crossover frequencies and slopes. I've talked to people that actively bi-amp Magnepan MG20.1 using two Bryston amps with Bryston's active crossover and swear by it but he consulted Magnepan and followed their recommendations TO THE LETTER, and was a really advanced user.

andy19191
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Re: Active vs passive Xover

> Are active crossovers better than built-in speaker crossovers as a matter
> of course regardless of implementation?

Obviously implementation matters. Active crossovers have a number of small advantages compared with passive crossovers that add up to a modest but real advantage if the cost of the extra electronics can be borne. Some of the advantages discussed here:

http://sound.westhost.com/bi-amp.htm

It is why almost all loudspeakers that strongly weight accurate reproduction (e.g. studio monitors) use active crossovers.

> In other words are you better off with an active crossover no matter how
> good your built-in speaker crossover may be and one should consider an
> external active crossover and bi-amping if the speaker design and funds
> allow it?

With the possible exception of things like Magnepan panels are there home loudspeakers designed to have their crossovers bypassed? If a home user did this how would they know what the passive crossover did in order to reproduce it? This does not seem a particularly sensible thing for a home user to do unless they are interested in DIY loudspeaker projects.

> Aside from the flexibility that an active, external crossover allows,
> what makes a crossover good or bad from a sound quality perspective?

It depends what you mean by sound quality. Audiophiles as a group have a rather different notion of sound quality compared with, say, sound engineers and this is reflected in audiophile products.

> How does one decide which is a good xover (active or passive) and which
> isn't?

Whether the target audience buys it. This is why professional speakers are active and audiophile speakers are usually passive.

bifcake
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Re: Active vs passive Xover

Thanks Andy. What makes one active crossover cost $100 and the other $5000? Are they all pretty much the same or is there a real difference among active xovers? If I were to replace the manufacturer's passive Xover on a speaker with an active one, keeping the same curves, would my sound quality improve simply due to the use of an active xover?

KBK
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Re: Active vs passive Xover

We've had many a discussion on the subject over the years at DIY audio.

The consensus among those who have the ability to look clearly and debate without heat is that the answer is:

Inconclusive.

When it comes to the 'best of the best' One is not necessarily better than the other.

For example, if active was inherently better than passive...then the big name speaker companies, MBL, Magico, Wilson, Martin Logan, Revel, Verity, Sonus Faber, etc, etc, etc.. would all have an obvious over-abunance of active systems offered at the top of their ranges.

Note that they do not.

The best systems... come out of the hands of the given designers of said systems..be they active or passive designs.

One of the big bugaboos of such Active systems with multiple settings and multiple amplifiers...is that giving the user even the choice of choosing a single amplifier, is like allowing a 'guy on the street' to choose features and conditions of a formula one race vehicle, with it comes to wining the race of 'the highest fidelity'.

There's a near 100% certainty he's going to fuck it up.

And that can make the company's efforts look bad, in a situation that is completely out of their control, quite potentially due to customer ignorance, and customer desire to make the primo speaker system 'go faster.' The customer will resort to standard human considerations, in that they can't possibly be to blame, so the speaker manufacturer must be at fault for making such a shitty system, so bad that it can't be matched, played with, toyed with, and 'fiddled with.' Audiophilia nervosa at it's finest.

So, most companies, with all reasonable precaution and common sense..tend to avoid such possibilities.

CECE
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Re: Active vs passive Xover

Legacy HELIX uses all electronic DSP for it's "crossover" A speaekr SYSTEM capable of 120dB full range. Not your single driver nonsense. But real Hi fi. And then some. I thought they where using a Klark-Tecnik but maybe they switched units...all electronic, all the time. The facotry settings are stored, so if ya mess it up, it can be corrected http://legacyaudio.com/manuals/helix.pdf

CECE
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Re: Active vs passive Xover

Please also note that the mfg. uses the term SLAMINNG bass line tight and controlled. SLAM is what(bottom pg. 6) it's all about, anyone who doubts it, doesn't get it!!! Live has teh SLAM factor, when trying to reproduce that's what ya need. No SLAM, not REAL. SLAM FACTOR,(bottom of page 6) controlled tight bassline. Those who get it, know what it is. And it's not from a single driver, 40W 3% tube crap

bifcake
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Re: Active vs passive Xover

DUP, let's stick to the topic please. Are you saying that an active Crossover is superior to passive as a matter of course? Let's not confuse the subject at hand by infusing unrelated topics and technologies to the discussion.

Thanks

Elk
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Re: Active vs passive Xover


Quote:
Personally the idea of active crossovers in the average person's hands scare me to death. I can't help but picture flaming drivers launched into the listener's lap.


There's an image.

Great info, guys! Thanks!

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Re: Active vs passive Xover

There are the obvious additional complexities that Active Xovers bring -- and the fact that they shouldnt be in the hands of the untrained.

Additional complexity in system design - cabling and tweakage. Also the users interpretation of what the Xover is doing in comparision to the speakers -3dB response and making certain they dont exceed limits -- otherwise unfiltered - unharnessed Watts can go throbbing headlong into a sensitive HF unit and spit the titanium diaphragm all over your sandwiches.

Another lovely benefit of Active Xovers is their ability to go wrong in ways passives dont.

Knowing then, that the gain component is before the passive Xover -- and with an active system, the gain component is after the Xover -- I ask this fundamental qweschun....

What do you think happens if a wire loses it's shield or the HF circuit runs unstable in RF due to a fault? ....say 150Khz at say, the full 70 watts of a HF amplifier into coils barely capable of handling a trickle of power, as most are?

Yeeeehaww

....prepare for bills exceeding your monthly mortgage

Even in the world of sound reinforcement, life here gets complex for the user. I watched $15000 worth of compression drivers, made by JBL Professional, throw their titanuim everywhere due to a DJ removing the suppression on the Formula Sound limiters, once.

His boss wasnt very jubilant -- but he was somewhat excited I seem to remember that the door wasnt given time to open whilst the DJ was shown the egress.

In the hi-fi world - actives would terrify me -- with all due respect -- the users would have too many opportunities to mess up and empty their capacious wallets even more.

rvance
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Re: Active vs passive Xover

As much as I believe in the "shortest signal path, the better" approach to purist systems, Boothroyd Stuart Meridian's line of active digital crossover DSP speakers gets very enthusiastic press from many reviewers.

andy19191
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Re: Active vs passive Xover

> What makes one active crossover cost $100 and the other $5000?

How do you know the price of the active crossovers in a loudspeaker? Or are you looking at the price of PA boxes with lots of knobs, channels and adjustments?

At the upper end, audiophile prices are rather divorced from component costs. This is partly because of small volume numbers in a luxury market and partly because high prices are part of what makes the equipment attractive to audiophiles.

> Are they all pretty much the same or is there a real difference among
> active xovers?

Active crossovers in $10000 studio monitors are probably going to cost the manufacturer around your $100, possibly less. It is straightforward to make such circuits cheaply and audibly neutral unlike some other bits in an active loudspeaker. So for active crossovers where the designer is seeking accuracy to the input signal (e.g. studio monitors but not necessarily audiophile loudspeakers) then all competent examples of crossover circuits are not in themselves going to colour the sound beyond what is intended.

Active crossovers made to appeal to audiophiles perhaps by using valves, wooden knobs or similar are likely to be something else.

> If I were to replace the manufacturer's passive Xover on a speaker with
> an active one, keeping the same curves, would my sound quality improve
> simply due to the use of an active xover?

It depends what keeping the same curves means and what sound quality means to you.

Passive crossovers require more powerful amplifiers and so the transients may be clipping with passive crossovers and not with active. The components in passive crossovers are not always linear or of constant value under load which is much less the case with the line level components in active crossovers. Amplifiers with non negligible output impedances (e.g. many valve amplifiers) will be audibly different on the borders of the passband but this depends what same curves means. And anyway, many audiophiles are going to prefer the valve sound. Etc...

It depends on a range of factors but a competent active arrangement is almost certain to shift things towards being more accurate to the input signal. Whether the shift is enough to be audible or sounds better to an audiophile will depend.

SAS Audio
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Re: Active vs passive Xover

Of course the active crossover utilizes many more passive components, such as resistors, variable controls, capacitors, power supply components, solder connections etc. As such, this may introduce alot of colorations, especially where electrolytic capacitors are used.

It is much more difficult to realize a "transparent/neutral" sound of an active xover than most believe. Virtually none are actually "transparent/neutral".

Another advantage using a passive crossover is the ease of changing out parts when tweeking. It is fairly easy (assuming one can get at the parts) to remove a quarter turn off a choke, if need be.

I believe the negatives of the passive xover has already been discussed.

Cheers.
Steve

bifcake
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Re: Active vs passive Xover

Hi Andy,

Thank you so much for that painstakingly detailed response. This is exactly the kind of information and opinion that I was looking for. I appreciate the time you took and the effort in crafting that response.

cyclebrain
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Re: Active vs passive Xover


Quote:
Thanks Andy. What makes one active crossover cost $100 and the other $5000? Are they all pretty much the same or is there a real difference among active xovers? If I were to replace the manufacturer's passive Xover on a speaker with an active one, keeping the same curves, would my sound quality improve simply due to the use of an active xover?

To be sure about what it is that you are asking, can you be more specific about how you plan to replace a speakers passive crossover with an active one and what active crossovers you are refering to with your $100/$5000 question?
Not trying to be critical, but think that there is some kind of disconnect here.

bifcake
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Re: Active vs passive Xover

I read a lot of posts about people wanting to change the passive crossover that comes with the magnepans in exchange for an active one with bi-amping. There's talk about behringer crossover at around 200 vs some others at many times the price with stuff in between. That's what prompted my question. I wanted to understand what makes an active crossover such an attractive option for many people.

mrlowry
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Re: Active vs passive Xover

AlexO-

As I said in my previous post "This is a bit of an oversimplification but passive crossovers equalize the volume between drivers by padding down the more efficient drivers to match the less efficient drivers." Many people feel that this is a waste of amplifier power. Which is true in some respects. So they figure that getting rid of the passive and using an active lets them buy smaller amps and save money. I'm not really sure that it works out that way because the user is buying two amps, instead of one, twice as many interconnects and twice as many speaker cables. If a user would double their investment to do this that would be one thing but most people just cut their budget in half. Thus they end up with amps that are half as good, interconnects that are half as good, and speaker cables that are half a good. It's hard to end up with a better system by cutting the quality of everything in half if you ask me. For some forum members none of this would be a problem because they believe that "watts are watts" and "cable is cable" but of course most of us don't feel that way.

SAS Audio
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Re: Active vs passive Xover

May I also add that the drivers that are generally the most efficient are the higher frequency drivers, which require much much less power than woofers. Hence not as much power is lost as maybe generally believed.

Take care.

KBK
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Re: Active vs passive Xover


Quote:
I read a lot of posts about people wanting to change the passive crossover that comes with the magnepans in exchange for an active one with bi-amping. There's talk about behringer crossover at around 200 vs some others at many times the price with stuff in between. That's what prompted my question. I wanted to understand what makes an active crossover such an attractive option for many people.

If it is the Behringer DCX24/96, in stock form? The answer is a flat, loud, and resounding NO!. Toss in visual of the derisive arm thrown out with the hand held flat for the extra flourish on that, if need be.

Major suck.

Stay away.

The only way you could like it is if cloudy, screechy, dirty, muddy, flat-out digital hash was your preferred way of listening to 'sonic refinement'.

I've owned and rebuilt two of the DCX24/96 units. In stock form they are pretty primitive at best. A one-trick-pony, if you will. Nice phase integration at the crossover point. Other than that? >>not worth a fart.

A $50 brandless "pro" (no-name) 12/db per octave active unit off ebay's going to blow it out of the water, IMHO.

On the other hand, if you find the sound of bad digital exciting - then go for it.

Elk
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Re: Active vs passive Xover


Quote:
The only way you could like it is if cloudy, screechy, dirty, muddy, flat-out digital hash was your preferred way of listening to 'sonic refinement'.


This pretty much describes the sound of all Behringer pieces - including their all analog units, such as their mixers. Behringer equipment is deservedly cheap.

On a positive note, Marchand has good stuff for the price.

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