The Loudspeaker Crossover Part II: The Brains of your System

[admin]

Ever wonder why some higher end manufacturers utilize top notch parts in their crossovers? This article explores the differences between capacitor and inductor types utilized in the crossovers of your loudspeakers and how the use of a non-linear materials can affect the sound of the music we hear. If we are looking to improve our systems, and purchasing upgrade crossovers, we need not only be informed about the specifications of the parts used in them, we also need to consider the PCB layout as well. While perhaps the simplest electrical circuits in use in audio today, crossovers can play a major role in the sound we hear coming from our speakers, and our speakers are the most important link in the audio chain in the vast majority of systems in use today.

Discuss "The Loudspeaker Crossover Part II: The Brains of your System " here. Read the article.

 

[highfigh]

The resistor(s) could be rotated 45 degrees so one of the long edges is on the PCB to allow better cooling if height is a big problem. Not only can the resistor fail but heat can damage the PCB or whatever material it's mounted on, like the charred floor joist in a house I worked in after another local store had installed the original system and used wire-wound ceramic resistors to decrease the level of some of the whole-house speakers. Not an L-pad, just a resistor in series, dissipating all kinds of heat and causing a 3" charred circle.

This leads to another caution- don't mount capacitors right next to these resistors, either. This can lead to their failure and possibly cause damage to the amp/speaker.

 

[DJKen]

Excellently worded! I'm sending links to several tech geek buddies as we speak! Thanks!

 

[skers_54]

Paul, you did a great job of demonstrating inductor saturation at high drive levels. How would the effect look when the amplifier is providing power on the order of 1 watt? Is it possible to extrapolate or is there too much variance between different magnetic core inductors to generalize when they begin to saturate?

 

[audioantique]

Bypass inductor resistances

Paul,
Very informative and straight to the point, thanks. I suggest that a way to bypass the inductor series losses is to build a series crossover, where there are no components in series with the drivers. One exception to this would be a padding network for a tweeter, but that is only series and parallel resistors. I realize that this solution isn't for everyone, but I've had great success lately with Zeta .7 quasi-second order crossovers. A 3-way is only two caps and two chokes all parallel to the drivers, and the, for me, essential Zobel for the midrange is also parallel to the driver. Of course just like with a parallel crossover, it's essential to use drivers in their usable range and not push their envelopes. I'm not a series crossover zealot, but extensive listening seems to validate my efforts, at least to my ears.
Good luck, all.

 

[highfigh]

Paul,
Very informative and straight to the point, thanks. I suggest that a way to bypass the inductor series losses is to build a series crossover, where there are no components in series with the drivers. One exception to this would be a padding network for a tweeter, but that is only series and parallel resistors. I realize that this solution isn't for everyone, but I've had great success lately with Zeta .7 quasi-second order crossovers. A 3-way is only two caps and two chokes all parallel to the drivers, and the, for me, essential Zobel for the midrange is also parallel to the driver. Of course just like with a parallel crossover, it's essential to use drivers in their usable range and not push their envelopes. I'm not a series crossover zealot, but extensive listening seems to validate my efforts, at least to my ears.
Good luck, all.

Do you have any links to info on these Zeta crossovers?

 

[TLS Guy]

Do you have any links to info on these Zeta crossovers?

Here is a circuit of a series crossover.

Series crossovers present a lot of formidable problems, as both sections of the crossover interact.

My rear backs, use series crossover in the passive part of the crossover. These speakers started in 1984, but the crossover did not get to its final form until 1994!

They are very difficult to perfect.

This was a good article, and reiterates points I have made many times over. The sad fact is most commercial designs do use miserable chokes with iron cores and wire of too thin a gauge, and electrolytic caps abound. A speaker is then severely compromised right out of the stating gate then, and I mean severely compromised. A speaker with decent components in the crossover will not be cheap. This leaves money on the table, for active speakers, which I believe with modern production methods, could give much better performance per dollar.

I really believe it is the receiver obsession that is so limiting. If you think about it, it is absurd that a pre pro generally cost more than a receiver. The only reason is production numbers. Burying the receiver is long, long over due now.

 

[audioantique]

More series crossover

Paul,

I wasn't able to post my series links because my post count is only one since I just joined. Too bad. I've got better things to do than be malicious. Let me know and I'll email them to you if you'd like.
Quite frankly with my latest project the crossover sounded great first try. After experimenting with parallel designs for decades, I find the series much easier to implement and test, with only four components for a three-way and two for a two-way. I've even mixed Zeta .5 and Zeta .7 with good results. I personally shy away from Zeta 1 or lower for the same reason as a parallel slow slope, too much overlap, and most drivers don't have that wide a response to handle it. All my testing is by ear with difficult program material, voice, piano, instrumental combos and percussion, mainly classical and jazz. I just forge ahead right or wrong. It all started when I inherited a pair of Dahlquist DQ-10s. One look at that crossover schematic convinced me that almost anything goes, and they sound great. It works for me, and after all, serendipity rules. Shed those prejudices! Hope this is all helpful.