I found plenty of asymmetrical crossover designs in active crossover world. It’s defined the low-pass and high-pass have different slope rate, e.g., low-pass = 24dB/octave and high-pass = 12dB/octave, and vice versa. First, I thought it might occur coincidentally from the crossover tweaking. However, I rethink and realize that a number of them were constructed by the electronic or active crossovers. Therefore, it could be interpreted that my first understanding was wrong—they should be intentionally created because those crossovers have adjustable frequencies but with fixed asymmetrical slopes, as described above. I’m curious to know what are benefits or purposes of the asymmetrical crossover configuration?
The responses are different before adding the crossover. The crossover must be asymmetrical if it is to make the responses the same.. or are you talking about something else?
I have a query about the design of a speaker, ADS L1590. It might be done the other way around.
They have a mid-to-low section with a second-order crossover configuration—high-pass for the midrange and low-pass for the woofers. Furthermore, the crossover point is written as 350Hz. They use 2-inch dome for the midranges. As a result, I feel the midrange should have its high-pass filter response combined with its natural roll-off in order to go to that low frequency; I don't believe the 2-inch dome midrange could go as low as 350Hz itself, as opposed to the woofers, which can effortlessly meet the 350Hz.
If this is the case, the woofer's acoustical slope would be 12dB/octave as is typical, BUT, for the midrange, its high-pass section should be 24dB/octave! Therefore, this led me to start this topic.
If you did that, phase wouldn't work together under normal circumstances and the response wouldn't add to flat.
There is also delay to consider, though probably not significant around 350Hz?
One reason that an asymmetrical cross might be used is to influence the phase matching at the crossover point. Phase and delay are related, so adding more phase rotation can increase the amount of delay through the crossover point, and this might improve the relationship between the two drivers in that region.
I’ve found their crossover schematic. So now I got the component’s values. The high-pass for the midrange is indeed a typical second-order configuration, only consisting of a 33uF capacitor and a 2.6mH inductor. I, then, put the values in the calculator and it returned that this filter has cut-off frequency at 540Hz! with Butterworth characteristic, Q is around 0.6-0.7. So, would this become more closer to my assumption—this crossover had asymmetrical design; 12 for woofer and 24dB/octave for midrange?
No. It means little without combining it with the midrange response.