The Crossover - Brain of your Loudspeaker System

[admin]

Have you ever wondered how the tweeter and woofer have their responses combined in a speaker system, or what the crossover network is and how it works? This article sheds some light on the least seen and perhaps most undervalued part of the speaker system, the crossover network. While passive crossover components and materials and construction have changed over time, the underlying theory and practice has not. In the real world, capacitors, inductors and resistors exhibit behavior which is neither ideal or perfect. In this article, we considered the importance of real loudspeaker impedance, and how it acts as a monkey wrench to complicate and frustrate the function of constant resistance type crossover networks.

Discuss " The Crossover - Brain of your Loudspeaker System" here. Read the article.

 

[bandphan]

Nice article Gene

 

[majorloser]

I still think the Emotiva ERT-8.3 crossover was designed by somebody who's a little anal.
Everything is perfectly lined up.

 

[croseiv]

It's interesting to me the apparent quality of the crossover in the ERM speakers that Emotiva is producing. I noticed a huge difference between the crossover build quality comparing my CSi30 vs. the ERM-6.2 monitor. While the "claimed" low freq response of the CSi30 is lower than the ERM-6.2, it seems that the ERM actually goes deeper to me even though it begins rolling off at 80 Hz. It also considerably has better dispersion IMO. Does the crossover affect the SQ that much? I know driver design also plays a large role here too.

 

[jostenmeat]

Does the crossover affect the SQ that much? I know driver design also plays a large role here too.

I sure can't tell you much the xover is affecting what you are perceiving, but I do know that a Speaker = Drivers + Crossover + Cabinet.

Some people go so far to say that when you listen to a speaker, you are really listening to the crossover. I think they're implying that the greatest variations (and/or chances to screw up) are here.

 

[Loren42]

Does the crossover affect the SQ that much? I know driver design also plays a large role here too.

As long as even a fair job is done with driver selection and cabinet design, the crossover is the single most important element of the system.

So, yes, crossover design and execution is going to make a difference.

Curiously, the crossover pictured by MajorLoser appears to use iron core inductors, which are the worst component you can build with if they are in series with the driver. I don't think it matters as much if they are used as shunts.

 

[croseiv]

As long as even a fair job is done with driver selection and cabinet design, the crossover is the single most important element of the system.

So, yes, crossover design and execution is going to make a difference.

Curiously, the crossover pictured by MajorLoser appears to use iron core inductors, which are the worst component you can build with if they are in series with the driver. I don't think it matters as much if they are used as shunts.

The website says low DCR air core inductors. Does that make a difference?

 

[Loren42]

The website says low DCR air core inductors. Does that make a difference?

Yes it does!

 

[croseiv]

Yes it does!

I'm learning about this, and finding crossovers very interesting really. So are the air core inductors better due to lower distortion?

 

[walter duque]

These are some of the components used in my crossovers would you say they are pretty decend?

State of the art premium internal components include Mundorf Supreme™ silver oil capacitors, HQ Jantzen ™ air core inductors, interior resonance suppressant coatings, and proprietary multi-composite main assembly. Ideal for Home Theater or Stereo it is especially well suited for large rooms

 

[bandphan]

Does the crossover affect the SQ that much? I know driver design also plays a large role here too.

Yes it does and is the single most important component in a speaker. Driver design means nothing without the right crossover.
A prime example..
http://forums.audioholics.com/forums/showthread.php?t=52630

 

[R-Carpenter]

Yaaauzaaa. I just looked at the first crossover before Mark redid it and my eyes rolled.
Mark, is there a strong advantage in compensating driver's impedance pick at the FS? I mean, the parts end up costing a bit of green with the large inductor in the compensation circuit?

On the topic. Speaker system is the integration between the driver, box and the crossover. Even if the driver and the box are calculated well, bad crossover can make the speaker sound horrible. Crossover network can alter most of the aspects of the sound including base response on and off axis response and so on. Crossovers are designed based on the driver frequency responses, distortion and impedance. More drivers, more complicated it gets.

 

[croseiv]

Yes it does and is the single most important component in a speaker. Driver design means nothing without the right crossover.
A prime example..
http://forums.audioholics.com/forums/showthread.php?t=52630

Wow! That's plain awesome!

 

[Seth=L]

It's interesting to me the apparent quality of the crossover in the ERM speakers that Emotiva is producing. I noticed a huge difference between the crossover build quality comparing my CSi30 vs. the ERM-6.2 monitor. While the "claimed" low freq response of the CSi30 is lower than the ERM-6.2, it seems that the ERM actually goes deeper to me even though it begins rolling off at 80 Hz. It also considerably has better dispersion IMO. Does the crossover affect the SQ that much? I know driver design also plays a large role here too.

Unfortunately you can't really compare the two speakers in such a cut and dry method. As stated already other factors are definitely at play when comparing two speakers of different make, design, and parts. A good speaker is the sum of it's parts. A great cabinet with great drivers and a mediocre x-over will likely have less than outstanding performance. On the other hand putting an excellent x-over with bad/good drivers in a good/bad (role reversal) will result in poor performance again.

It's very tough to say that one part takes prescedence over the other because each component is very crucial to the end performance the product creates. So I would argue that the x-over, cabinet, and drivers are all of equal importance with none making the bigger difference, since if one is faulty it's all faulty.

 

[Paul_Apollonio]

Not Really, but not simple either

I sure can't tell you much the xover is affecting what you are perceiving, but I do know that a Speaker = Drivers + Crossover + Cabinet.

Some people go so far to say that when you listen to a speaker, you are really listening to the crossover. I think they're implying that the greatest variations (and/or chances to screw up) are here.

Why would you listen to "some people" on the subject when an expert is available? It is quite unlikely that the largest variation from speaker to speaker is in the crossover, but you unfortunately cannot attribute variation to the crossover ALONE or the speaker ALONE because IF the speaker varies (and they always do) its impedance will change. If the speakers impedance changes, then the crossover (which interacts with the speakers impedance) will in combination with the speaker have a different frequency and phase response (sometimes called the transfer function). It is a simple matter to specify component tolerance on a bill of materials, needed before you go to purchase a crossover for production. Parts with 10, 5 and 2 percent tolerance are always available (at a price). Getting speakers to vary by 2% or less on the other hand, is considerably more difficult, and speaker variations are more difficult to control than crossover variations.

When your head hurts, do you seek medical advice or just ask "some people"

 

[Paul_Apollonio]

As long as even a fair job is done with driver selection and cabinet design, the crossover is the single most important element of the system.

Nope. Sorry. Not even close. This is not to say you cannot take good drivers, and a good box and screw it all up by building your own crossover without measurement equipment and a clue as to what you are doing. What is does mean is that designing a good high quality driver is both far more difficult and far more expensive to do than designing a good crossover. I have 34 years experience building crossovers, and only 26 years experience designing drivers and systems, but yeah, I am sure about this.

 

[Paul_Apollonio]

Unfortunately you can't really compare the two speakers in such a cut and dry method. As stated already other factors are definitely at play when comparing two speakers of different make, design, and parts. A good speaker is the sum of it's parts. A great cabinet with great drivers and a mediocre x-over will likely have less than outstanding performance. On the other hand putting an excellent x-over with bad/good drivers in a good/bad (role reversal) will result in poor performance again.

It's very tough to say that one part takes prescedence over the other because each component is very crucial to the end performance the product creates. So I would argue that the x-over, cabinet, and drivers are all of equal importance with none making the bigger difference, since if one is faulty it's all faulty.

The fact your end quote is "you still have a lot to learn" is a pretty good indication you already know more than most of us. Arrogance and pride about what we know is usually a good indication we do not know all that much. Your point that it is easy to screw up an otherwise good system by using a mediocre crossover is taken. That said, driver design is a more difficult and time consuming task than crossover design. I have seen hundreds upon hundreds of bad drivers and crossovers, and I think driver expertise is more uncommon than crossover expertise. What you may be amazed to learn is how often you can conceal and minimize driver and system flaws with a sophisticated crossover. I learned how to do this by building crossovers for very cheap speakers. I do this once per week for one of my clients. I did it today. I designed 7 crossovers in 6 hours. I refer to it as "making Chicken Soup out of Chicken feathers". I keep looking for white meat, and the client keeps bringing me tails....

 

[Boerd]

I sure can't tell you much the xover is affecting what you are perceiving, but I do know that a Speaker = Drivers + Crossover + Cabinet.

Some people go so far to say that when you listen to a speaker, you are really listening to the crossover. I think they're implying that the greatest variations (and/or chances to screw up) are here.

That is not far away from the truth. I used to own Vienna Acoustics Beethoven and REL R 505. One day I see on the net NHT XD - active crossover system and I order them.
Now I own only the NHT XD 2.2 active crossover system
Active crossover was a shock for me. And I have listened to a few speakers so far... More important - I went to a few concerts/operas...

 

[jostenmeat]

Why would you listen to "some people" on the subject when an expert is available?

It was not intended to be mutually exclusive, though I can see how you might believe this to be fact, regardless if your chicken feather soup could or could not be recreated with a poor crossover coupled with good drivers.

When your head hurts, do you seek medical advice or just ask "some people"

I not only refuse to answer this question due to the rhetorical implication, but because I do not intend to continue with what I find to be both a contentious, and most of all, presumptuous disposition.

I could explain myself further, much further in fact, but it would be a disservice to this forum in my eyes, if not downright annoying, and hence my wish to discontinue.

EDIT: I wanted to add that there are a number of times that I do direct questions to experts, and I do not always get a reply. I've even directly asked the author of this article, Gene, questions for which I've never received a reply. There are other examples, even just at this forum, for which I did not receive a reply from one who is widely accepted to be an expert. I assume no reason for the lack of response, nor am I offended. I am not presumptuous.

 

[bandphan]

Nope. Sorry. Not even close.

I think the context is, what does it matter without the latter. Everyone assumes cabniet and speaker/s, but not the crossover.