Translating Crossover Width (1 octave, 2 octave, etc.) to common DB/octave Parlance

[mccarty350]

Anyone have a guideline or a reference to be able to translate the nomenclature that we use in audiolense for crossover width into something more conventional like DB/octave for easier mental consumption and consumption of DIY audio reference materials on crossover designs using more common terminology?

 

[Omid]

AFAIK, Audiolense’s crossovers do not follow the conventional slopes. If you look at the graph you’ll see that it’s not a straight line with a slope of 6, 12, 18 or 24 dB / octave, but a curve.

 

[mccarty350]

I noticed that but the bell didn't go off until you said it, thanks for pointing it out.

 

[Omid]

I noticed that but the bell didn't go off until you said it, thanks for pointing it out.

I guess there is no need to follow regular crossover rules when you can ensure perfect summation and timing between drivers ;-)
The other advantage of the steeper cutoffs is that you suppress woofer resonances above the Xover freq very well. Regular crossovers don’t always attenuate them well enough to be inaudible.

 

[mccarty350]

I know it! Why follow analog limitations? I find that when I have a steeper crossover I get an increase in dynamics/immediacy but once you get down to 1 octave or below you start having scenarios where it starts to sound processed or at least that has been my observation. As you start to go up past 2 octaves it starts feeling 'thinner' and 'more diffuse' is my other.

 

[kevinzoe]

McCarty350 - I asked myself the exact same question and did some experimentation and came up with the following which should answer your question (or mostly answer it . . .)
> 1st order (6dB) = 6.5 - 7.5 AL width
> 2nd order (12dB) = 3.8 - 4.3 AL width
> 3rd order (18dB) = 3.0 AL width
> 4th order (24dB) = 2.6 AL width
These values will align with the conventional analog type filters 1 octave beyond the xover frequency but the shape of the AL curve deviates away from the straight line curve so they won't align 2+ octaves out from the Xover point.

 

[mccarty350]

Kevin, you rock. I'm so glad to see at least some type of close analogy to what our slopes are. Getting an idea at least helps.

I very very often find out that two octaves is the sweet spot for many of my speakers and configurations (I'm constantly swapping drivers and enclosures).