How to improve step response

[mark100]

My comments were actually directed at the OP...not the "FIR filter enthusiasts" that seem to have seized upon this thread (for reasons unknown).

IIRC, the OP mentioned nothing about digital filtering at all--merely posting a schematic of his passive crossover filters, asking how to achieve better step response.

I'd actually recommend to those that consistently want to talk about FIR filters to the exclusion of passive crossover filters and their real-world implementation to move to another thread more suited to those needs to elaborate on those type of filters. I think the OP would probably appreciate it...

Chris

What thread doesn't wander some?

The times I've addressed you have totally applied to passive crossovers.
Specifically, time alignment and phase rotation.....which sure as heck shape a step response.
Even more specifically... constant group delay (time delay) vs varying group delay (phase growth....which you still haven't been courteous enough to define despite being asked politely twice)
they are not interchangeable.....was I off topic to question your post intimating they are?



To Merlin: sorry for the above, and any unrelated posts to your topic...

If you would like to, post your crossover types, order and freq, and I will be happy to generate what would be an ideal step response for that setup, given proper time alignment and perfect drivers.
(I can't glean what your crossovers are from the files you've posted)

That would provide you with a best-case step response target.

 

[merlin el mago]

A step response is just another way of looking at frequency magnitude and phase. It requires a relatively flat phase to look decent, or another way of saying the same thing, is it requires as little phase rotation as possible. That's why 1st order crossovers have a nice looking step....they minimize rotation. And also why a 2-way will look better than a 3-way, a 3-way better than a 4, etc...because each crossover will add at least 90 degrees rotation.

Any crossover than minimizes rotation will help step response. Someone dimensiones

to look at harsch. I'm not familiar with harsch but I know bessel imparts lower rotation than others.

The best looking step and flattest phase we can achieve, comes from using complementary linear phase crossovers. They also allow virtually whatever order you want to use.

I'm not trying to say step is a function of crossover. It is of course the acoustic flat frequency magnitude and phase that makes a good step. I'm just saying we will never get a good looking step response with much crossover phase rotation, no matter how well behaved our drivers are.

The good news about step IMO, is that we can pretty much ignore it. Because there are only two ways to address it: a. work on acoustic phase and magnitude via measurement, which improves any and all measurements b. choose crossovers that rotate less

I say ignore step response, because

We do a. anyway..... in continuous fashion, and b. is a discrete decision that simply defines what kinda step response is achievable (similar to what Juhazi posted for the 3-way LR2) Unless we are using linear phase, first order, or maybe 2nd order crossovers, the theoretically best step response possible with higher orders gets too squirrily looking to try to replicate.

Post 4

 

[Lojzek]

The problem with this loudspeaker design is, if my initial presumption is correct, that Merlin is not sure what to believe is essential to a good crossover design. It is not important how the step response appears. What matters is how does this loudspeaker sounds at all. Does is sound similar to a good commercial design, regardless of price, or does it fail more or less significantly in comparison?