Future (active?) recommendations please, for a noob

[jostenmeat]

Thanks for the tenth time, Swerd. I appreciate that the measured response should be the one to go by, but could you tell me what the xover might be "on paper"? Thanks, just curious is all.

Assuming that "on paper" it is totally different than LR4, how does a speaker end up having a significantly different result, audibly? I'm sure that's too complex to answer, hm, feel free to say so. Is it something about the nature of how the drivers themselves react, or is more the cabinet, or probably both?

Cheers, and have a good evening.

 

[GranteedEV]

Thanks for the tenth time, Swerd. I appreciate that the measured response should be the one to go by, but could you tell me what the xover might be "on paper"? Thanks, just curious is all.

Assuming that "on paper" it is totally different than LR4, how does a speaker end up having a significantly different result, audibly? I'm sure that's too complex to answer, hm, feel free to say so. Is it something about the nature of how the drivers themselves react, or is more the cabinet, or probably both?

Cheers, and have a good evening.

Drivers have a natural acoustic rolloff, usually 2nd order off the top of my head. So using a 2nd order electrical filter at the right point cascading with the natural rolloff of a driver will give you your fourth order rolloff. You don't need to hard-wire a steep rolloff curve. The electrical filter can usually do enough to protect a driver from over excursion and the natural rolloff can shape the sound.

 

[jostenmeat]

Drivers have a natural acoustic rolloff, usually 2nd order off the top of my head. So using a 2nd order electrical filter at the right point cascading with the natural rolloff of a driver will give you your fourth order rolloff. You don't need to hard-wire a steep rolloff curve. The electrical filter can usually do enough to protect a driver from over excursion and the natural rolloff can shape the sound.

Ah makes perfect sense. I have a feeling that I read something at some point about this kind of thing. Thanks much.

 

[Swerd]

Ah makes perfect sense. I have a feeling that I read something at some point about this kind of thing. Thanks much.

GranteedEV has it right.

Just by eyeball (no measurements of voltage), those crossovers look like they are electrically 2nd order for the woofers, and 3rd order for the tweeter. But if you combine the electrical roll-off slopes of the crossover filters with the natural roll-off slopes of the drivers, you get 4th order slopes if you measure them acoustically. And the acoustic behavior of the crossover network combined with the drivers is what matters.

 

[jostenmeat]

Neat. Maybe one day I can figure electrical/xover stuff out (hopefully explained in the Alder book?). Now I recall some old receivers, I think one was a Yammy, where the high pass of the internal bass mgmt was only 1st order, with the presumption that the satellite would have some natural roll off, so that the overall acoustic effect could be 2nd order. Not nearly as precise, but interesting nevertheless.