[Quiet Earth]

Davey,
I would like to learn more about a line level crossover that uses no active components, no power supply, and retains the coherency of the original signal. I assume it plays nice with the pre amp, the cables, and power amps too. Do you have a link?

Tyson,
If money is no object (or you accept the greater cost), why would you buy an amp that requires the help of a bandwidth limited signal in the first place? And why is the filter so evil at the speaker level but friendly at line level voltages (with the money not an issue)? I think what you are really saying is that at a certain price point, active makes more sense to you. I would never argue with that.

Everyone else,
I heard two really good examples of  active speakers at ces2012. I was actually blown away by one pair, but I think they were more than $20k per pair. Since i have been blown away by passive designs too, it did not make it a universal truth that active is inherently better. That's all I meant to say.

Jtwrace,
Sorry for derailing your thread. I don't think this is what you had in mind when you posted. 

[JohnR]

Davey,
I would like to learn more about a line level crossover that uses no active components, no power supply, and retains the coherency of the original signal. I assume it plays nice with the pre amp, the cables, and power amps too. Do you have a link?

This might help:

http://www.t-linespeakers.org/tech/filters/passiveHLxo.html

You'd need to know about the circuits on either end of it to get the best results, and that article there is not very specific about that. Please remember, though, that this discussion is in "The Lab"

[jimdgoulding]

The full range guys are right.  The best crossover is no crossover.  The 2nd best crossover is active, and the 3rd best is passive, all other things being equal.

Same goes for rooms - a well treated, acoustically ideal room is best.  2nd best is a well treated, non-ideal room, and worst is a non-ideal room with no treatment.

Doesn't mean a system in an untreated room can't sound good, but it will never sound as good as it possibly could in a better room.  Same with crossovers - lots of good speakers out there with passive crossovers, but they would probably sound even better still if active.

I mean, think about it - a single amp driving a full range speaker with a passive crossover is seeing a very complex load with very large demands on it to do bass, mids, and treble simultaneously.  Now imagine that same amp only having to drive a tweeter.  Much easier load.  Do you think the highs will sound better?  Oh yeah.  Same applies for the mids and bass, only more so IMO.

With a passive setup, you need a single amp that has both delicate highs and an iron grip on the bass.  That's a tall order, and it's expensive to get one that can do it.  On the other hand, with active, you can use a bass amp that's a monster, and you don't have to worry how it sounds on the mids or the highs, and that's a lot cheaper/easier to do.  Same with the mids and highs - you can use amps that have delicate highs and that "midrange magic" without having to worry about either of them having an iron grip on the bass.

Good info and nicely put, Ty.  Cheers.

[Tyson]

Davey,
I would like to learn more about a line level crossover that uses no active components, no power supply, and retains the coherency of the original signal. I assume it plays nice with the pre amp, the cables, and power amps too. Do you have a link?

Tyson,
If money is no object (or you accept the greater cost), why would you buy an amp that requires the help of a bandwidth limited signal in the first place? And why is the filter so evil at the speaker level but friendly at line level voltages (with the money not an issue)? I think what you are really saying is that at a certain price point, active makes more sense to you. I would never argue with that.

Everyone else,
I heard two really good examples of  active speakers at ces2012. I was actually blown away by one pair, but I think they were more than $20k per pair. Since i have been blown away by passive designs too, it did not make it a universal truth that active is inherently better. That's all I meant to say.

Jtwrace,
Sorry for derailing your thread. I don't think this is what you had in mind when you posted. 

No, I'm saying that active beats passive at any given price point, all other things being equal.  For a technical explanation of why this is true, see http://sound.westhost.com/bi-amp.htm

[Davey]

This might help:

http://www.t-linespeakers.org/tech/filters/passiveHLxo.html

You'd need to know about the circuits on either end of it to get the best results, and that article there is not very specific about that. Please remember, though, that this discussion is in "The Lab"

John,

Are you saying a discussion of this topic is not appropriate for "The Lab"?  (I'm confused.)

Quiet Earth,

John posted a good link.  Line-level passive crossovers are certainly an option.  They have their own set of variables (just like anything else) that need to be understood, but they can achieve excellent results in the right application.  They utilize no active components, need no power supply, and can retain all the coherency of the original signal.  "Coherent" is a subjective term however. 

Cheers,

Dave.

[Quiet Earth]

Yes, that is a good link. It looks more like the beginning of something, and not necessarily what most people would end up with in the end - I mean depending on their insertion losses, etc. But point proven. I guess you could make it that simple.

Tyson,
Thanks for the link. 

[brj]

My earlier reference to "active analog" crossovers was a generalized label that includes both the passive line-level crossovers and those that have a small gain stage to counter the insertion losses.  Examples would include the Marchand crossovers, the Bryston 10b, the Pass Labs XVR-1 (or almost-available First Watt B4), etc.  Very often these will have adjustable gain, so you can take it out of the circuit if you don't need it.  Be aware that higher order slopes can have advantages in certain situations, but will tend to have higher insertion losses.

(I'd love to play with a pair of XVR-1 crossovers, though even used the price adds up quickly.  The B4 is less painfully priced, and while not quite as flexible as the XVR-1, it still has quite a few options and the gain stage follows the typical class A, no-feedback philosophy.)

Just be aware that most line-level crossovers, whether possessing a gain stage or no, are just crossovers.  If you need a notch filter to deal with some odd driver behavior or need to implement baffle-step compensation, you might need a separate mechanism.

[JohnR]

John,

Are you saying a discussion of this topic is not appropriate for "The Lab"?  (I'm confused.)

No, sorry, I meant the opposite... saying that you can't just put the line-level passive crossover in circuit without considering what's connected to it, it's not "plug and play"

With regard to some comments on interconnects, something like these could readily be built into your amps.

[Steve]

No, I'm saying that active beats passive at any given price point, all other things being equal.  For a technical explanation of why this is true, see http://sound.westhost.com/bi-amp.htm

I have some serious reservations after reading the article and the above general statement for the following reasons.

 The quality of sound of a powered active crossover just as variable as any electronic component manufactured these days, which covers a wide spectrum. The article assumes "all sounds the same" electronics. However, sound can be altered by:

1) Power supply design,

2) Parts quality, including DA and DF problems

3) Grounding scheme, which also includes finite resistances and inductances

4) Active devices used and their individual distortion problems,

5) negative feedback, if used, and its inherent time delay and loop problems,

So is there really that much difference between active and passive xovers, besides the power requirements?

Cheers.

[cheap-Jack]

Hi.

I would like to learn more about a line level crossover that uses no active components, no power supply, and retains the coherency of the original signal.

The simple R/C corner frequency roll-off network as per the link, indeed complies the above description.

BUT, but the simple R/C "line-level passive X-over" cannot work alone as it needs a voltage amp to boost up the hi/li pass signals. It is the line amplifier that follows this passive x-over may screw up the sound, ruining the "coherency" of the signals that pass thru the line level filter.

We have to look at any active or passive line-level filters or so called "X-overs"
together with the line amplifiers that receive the filtered signals. It is a combined function.

When compared to any passive X-over networks inside a loudspeaker, the latter being already the end of the audio chain is a better choice as any damage to the music signals due to distortion etc is limited. Unlike active or passive line-level filters or X-overs located at the middle of the audio chain, any distortions generated by them will be  further magnified.

Which is the better evil? Passive X-over networking of course inside the loudspeaekrs.


c-J

[Davey]

There is no line amplifier (voltage amp) requirement.  (Otherwise the crossover would not be passive.)  I'm not sure where you fellas are getting some of this information. 

A line-level passive network would/may have some insertion loss, yes.  But the existing preamplifier (in most cases) can easily make up for this.  These days, most of our systems have excess voltage gain anyways.

Cheers,

Dave.

[Rclark]

I like the minidsp solution. Wouldn't want to replace my $350 in Jupiter's and Mundord Sio's with some Behringer crap.

But as I would be replacing very expensive passives, active had better rock the joint. Davey I'm coming over. If it's minor to nill I'll just keep it passive.

[sts9fan]

I think the bandwidth limiting is the number one benifit of active. Otherwise if the curves are the same then it will sound the same.  So I would figure line level passives would be as good as actives.

Also, why is the $120 mini OK but the Beringer is cheap crap?

[Rclark]

Oh I didn't see they are $120.

I just have an aversion to Behringer.

And that will make for an interesting comparison then STS. Davey and I have the same speakers, his are active, and he seems to know how to do it right.

[Trismos]

Oh I didn't see they are $120.

I just have an aversion to Behringer.

And that will make for an interesting comparison then STS. Davey and I have the same speakers, his are active, and he seems to know how to do it right.

VERY INTERESTED. Please keep us posted Rclark.

[cheap-Jack]

Hi.

No, sorry, I meant the opposite... saying that you can't just put the line-level passive crossover in circuit without considering what's connected to it, it's not "plug and play"

Yes, it is exactly what I pointed out above. But someone here just fails to get it.

There is no line amplifier (voltage amp) requirement.  (Otherwise the crossover would not be passive.)  I'm not sure where you fellas are getting some of this information. 

A line-level passive network would/may have some insertion loss, yes.  But the existing preamplifier (in most cases) can easily make up for this.  These days, most of our systems have excess voltage gain anyways.
 

Here is the Lab. Please tell us how you will insert the C/R line filter or so called "line-level passive X-over" in the audio chain assuming you got a preamp & a poewr amp there.

FYI, I want to know as I am an audio designer/builder, not only an audiophile.

c-J

[jtwrace]

FYI, I want to know as I am an audio designer/builder, not only an audiophile.

c-J

For which company?

[cheap-Jack]

Hi.

The full range guys are right.  The best crossover is no crossover.  The 2nd best crossover is active, and the 3rd best is passive, all other things being equal.

Sorry I don't think the order is correct.

What is yr scientific explanation of above order, or what is yr logic of yr such choice? Here being the Lab, please define "Best" - "best" of what???

IMO, the order should read: Best no cross-over, 2nd best passive, & worst active.

WhY?  No X-over means no passive reactive components in the signal path for the music signal to go thru.  Just like a straignt wire.

2nd best being passive means the harmonic & phase distortions are confined to a fixed predicable amount as no active devices around to enlarge them.

Worst being active means the amount of harmonic & phase distortions generated by active X-overs onto the complex music signals will be getting magnified by the active electronics down the audio . Getting worse & worse.

c-J

[cheap-Jack]

Hi.

For which company?

For myself only as a DIYer & a devoted music lover/audiophile. I build virtually anything audio from phonostages down to loudspeakers. I doubt any audio firms can afford to hire me.

c-J

[JohnR]

Here is the Lab. Please tell us how you will insert the C/R line filter or so called "line-level passive X-over" in the audio chain assuming you got a preamp & a poewr amp there.

It goes between the preamp and the power amp. If you're concerned about the cables from the passive crossover to the power amp, then build the circuit into the power amps.

Whether this is an "active" system is I suppose a matter of definition.