Depends... Anything with a ferrite core will saturate at some point. Should we not use transformers because a use they have ferrite cores that will saturate? Of course not. We simply use transformers that are designed such that they will properly perform within their specified parameters. There is nothing wrong with using ferrite core inductors, which is why they make them. Like any other component, it is a question of where and how they are used.
Is maintaining a constant inductance value under all conditions an important parameter in a transformer? No. Thus, this is a rather poor example to use. In a passive speaker crossover, the inductance value is expected to stay the same, no matter what. If the core saturates, this can lead to harsh or shouty or otherwise annoying sound at high volume.
Okay, I get it you're not a fan of bi-amping. I've noted that. But you should also note that as I wrote above, I'm pretty intent on dipping my toe in and learning for myself. Cause you can't learn much in life by only considering the experiences of others. You gotta do some of it yourself.
It sounds like you're saying two things: 1) Ditch the passive crossovers at the speaker (or if you can't do that then apply rules 2-4 to improve them.) 2) If you're doing line-level crossovers, go with active not passive. Correct?
First interpretation is correct. Second, not so much. All my personal experience is with active crossovers, but a passive crossover before the amps is probably a great place to start - I'm not biased against that.
Thanks for clarifying. Also sounds like your advice would be to apply rules 2-4 on a line-level crossover whether active or passive.
Good question. My assumption was that no one would use an electrolytic at line levels, but it's my error to assume. Line level circuits are of such high impedance, and the currents are so low, that Rule 4 really doesn't apply. That leaves Rule 3. Again, the currents are so miniscule at line level it probably doesn't matter. But if I had a choice, I'd opt for air cores. Most likely wind my own. I've done this using a small screwdriver as a former and wrap 30ga wire around it. Pull the screwdriver out to measure it, and (hopefully) remove wraps to get to the desired inductance.
As I have pointed out, all ferrous (iron) core inductors will saturate at one point. The concept involves not reaching that point. There are reasons for using iron core inductors in crossovers it depends where and why you are using them.
Yes, it's a good point, which I mentioned earlier. There is a reason to use iron core inductors in passive crossovers, to save money. Back at the beginning of the thread I made a point about choices and how these choices are based on values. It's a choice to go with a compromised component to save money, just as it is choice to go with uncompromising components that hurt in the wallet. Neither is a wrong choice, it just highlights what people's values are.
Don't quite agree... First, I have nothing against bi-amping, just not in a home audio environment. But the title of the thread is bi-amping with active crossovers. You might note, that since I don't happen to think that active crossovers are a good idea in home audio, then we wouldn't be bi-amping with them either. In my previous post, I am simply pointing out that you are choosing to start with an assumption that is not correct. So, nothing is being gained by starting with an incorrect assumption. Pointing this important fact out is the reason why passive crossovers are not the best choice in home audio. The purpose for posing your question on an audio forum is so that you can garner information from other members who might provide some insite. Why else would you start such a thread?
You're not a fan of bi-amping in a home audio environment. But this is a thread about bi-amping in a home audio environment. So you don't really need to keep pointing out how you're not a fan of bi-amping in a home audio environment. Of course the reason I'm posting in a forum is for feedback. And I've received some wonderful feedback. And yes, it's useful to hear that some folks don't like bi-amping in a home audio environment and why. I've decided I'm going to bi-amp in my home audio environment and I want to do it well, which is why I want feedback. Then I'll apply the feedback and take my lumps in the real world. And maybe I'll hate bi-amping when it's all said and done. Then I can post about how I'm not a fan about bi-amping in home audio environments! I probably should have titled this "Bi-Amping with Line-Level Crossovers - Pros and Cons." I had incorrectly assumed that passive crossovers weren't a consideration at line level.
Here is a visual representation of what's in my head. Tell me what I got wrong? I'm sure there's something. Maybe a few things.
There is nothing wrong with saving money, that is what producing commercial products in an open marketplace is all about. The idea is to do this in a proper context that saves money and makes sense in a way that does not degrade the circuit. Remember that I stated it is all about how and why we might do this. For the mutual benefit of those who might be reading this, I will provide a more in depth explaination. Inductors and capacitors in an AC circuit do several things. They store up energy. A capacitor stores this energy in the form of an electric charge. An inductor stores this energy by a magnetic charge. The next thing capacitors and inductors do in an AC circuit, is to oppose changes in electricity that flow through them. This opposition is referred to explanation. This reactance changes with frequency. An inductor that is used with higher frequencies can be physically small. When you use an inductor with lower bass frequencies, this inductor must be physically larger. The lower the frequency, the larger the inductor. Here is where a ferrite core inductor comes in and why they exist. A ferrite core will absorb and store up this magnetic energy. This means that a much smaller physical coil may be used, making it more practical in a small space. Now, the last thing that capacitors and inductors must do in an AC circuit is, that they must also release the energy they have stored up and stop opposing the flow of electricity in one direction, so that they repeat this process in the other direction. The drawback to a ferrite core is that it wants to hold on to that magnetic charge and not let it go as fast a pure air core inductor. It is easy to understand that this is a problem at high frequencies, where the electric current must change directions rapidly. This is where you would not use a ferrite core inductor. At lower frequencies where the inductor is being used for the bass in the crossover, is not a problem. The reason is that at these lower frequencies, the ferrite core has enough time to release the magnetic energy it has stored, in time for the signal to reverse. This means that a ferrite core does not negatively impact the circuit when used at low frequencies. This is one of the custom AP12-500 ALK crossovers designed for the Klipsch K a Scalas, which cross over at 500-Hz. that I use in my Altec Lansing A7's. Notice the fairly large air core inductor, just right of center. There is also a small iron core inductor slightly behind and to the right. Also note the custom crossover in the rear. It has small air core inductors and is used to crossover the signal and send everything above 6-kHz to the super-tweeter.
This sort of thing was very popular with British audiophiles in the 1980s. If a second power supply is the source of the improvement, then you could get the same thing with monoblocks. Two identical amps vs one amp that costs twice as much, or a pair of mono amps, I know how I'd spend my money.
Looks like good clean thoughts there. That's the road map to your destination, you just now need to figure out the details that will meet your needs. In addition to the questions you list next to the crossover, what crossover frequency, what slope, what alignment? Active/passive & analog/digital choices greatly play into the amount of flexibility you'll have. Good luck!
The answer to these questions lies in the design of the AR-3a crossovers, I suppose. Also, instead of getting a tunable crossover I'm leaning towards one in which the circuitry can be modified as needed. Fewer dials, knobs, pots, doo-dads, etc. equals cleaner signal, I figure. But I wonder if that means a pretty sizable number of swaps to get things right. More research...
Thank you for taking the time to so eloquently explain your preference for compromised components. Really, it's your choice to opt for the low cost solution. There's nothing wrong with that, and there's no shame in it. But really, you're spending a lot of cycles discussing passive speaker crossovers in an active crossover thread. By the way, that picture is a good example of violating my Rule 3 & 4. Thanks for sharing!
As a note, "home environment" is not part of the thread title. Bi-Amping with Active Crossovers - Pros and Cons Where Pros and Cons does happen to be a part of the thread title. You might also note, that my response were both to your posts and as a response to you quoting me. In a forum, it is common for someone who is quoted to reply and should be expected. True, my responses do state my position, which is just a comment, nothing more. What my posts contain are reasons why active passovers are not best used in a home environment. Active or passive crossovers at line level is a personal preference. Your use of active crossovers implies use at line level. Just F.Y.I. I'll call your attention to the 19" audio rack on the far left (this is behind the TV). At the bottom are two Crown class "D" amplifiers. Directly above them is a processor to restore phase (with red faceplate) and a Behringer stereo passive electronic crossover.
By the time that iron core inductor on SandAndGlass's crossover is saturating, the db are uncomfortably high, bordering on hearing damage. There is absolutely nothing wrong with iron core, provided the designer accounts for their limitations.
