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Pensil design using quad Alpair 10.2's...

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chops

chops

Member
Joined 2003
charlest.zenfolio.com/
This is something somewhat in the lines of what I'm thinking. I'm a little rusty in using this SketchUp software, and I'm extremely tired right now as well, so please excuse the crudeness of the drawing. And I have no idea why Stan Lee is the model...

p934066138-5.jpg


p662908728-5.jpg
 
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chops

chops

Member
Joined 2003
charlest.zenfolio.com/
Just a little info on those enclosures...

They would be roughly 40" high, 20" wide and 12" deep at the center of the baffle. At 20" wide, BS is around 230 Hz. Of course, none of this is set in stone and I can adjust all dimensions as needed to dial in the system.

Now as far as playing around with these online x-over calculators, they ask for HP and LP impedance. I'm assuming this should be the actual Re of the drivers and not the nominal impedance of 8 ohms. IWO, 7.2 ohms for the Alpair, 5.7 ohms for the Scanspeak.

How close to being "in the ballpark" do these calculators get you? Being 1st order, they will have a 90 degree phase swing. Is there any way of correcting that or is it even worth it?

I notice the inductors are around the 3.5mH mark which isn't too bad, but those caps! Upwards of 85uF! :eek:
 
chops

chops

Member
Joined 2003
charlest.zenfolio.com/
chrisb said:
But seriously, it might be time to migrate this chain of exchange to the general FR or even Multi-way forums?
Click to expand...

Yeah, that has proven useless. I started a thread yesterday morning and it's gotten nowhere, though several threads have started since mine, even one this afternoon and they already have multiple replies. I guess I'm not well liked on this forum.
 
chops

chops

Member
Joined 2003
charlest.zenfolio.com/
planet10 said:
No. That is the REAL part of the impedance at DC. A starting point is the impedance at the XO point.

dave
Click to expand...

planet10 said:
No. You look at the impedance curve at the point where you XO as a starting point. Iy is just a starting point, the calculator assumes the impedance is REAL, when it is really COMPLEX. And it assumes the drivers have flat response.

dave
Click to expand...

Thank you, Dave.
 
C

chrisb

Member
Joined 2002
chops said:
Yeah, that has proven useless. I started a thread yesterday morning and it's gotten nowhere, though several threads have started since mine, even one this afternoon and they already have multiple replies. I guess I'm not well liked on this forum
Click to expand...

Not at all - but note how quickly the conversation turned towards discussion of XO methodology, not just topology?

There must be reasons for that

I wish you success with the project
 
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