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Resistor values to take the 2123 down 6, please [message #41323]

Tue, 13 May 2003 10:41

DRC
Messages: 169
Registered: May 2009

Master

Wayne,

I've misplaced the e-mail in which you told me what resistors to apply where in my crossover to take the JBL2123 down 6dB. Would you repeat the advice here, please.

Received the decals today, btw. Thanks!

Keep your ears and your mind open.

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Re: Resistor values to take the 2123 down 6, please [message #41326 is a reply to message #41323]

Tue, 13 May 2003 12:27

Wayne Parham
Messages: 18791
Registered: January 2001

Illuminati (33rd Degree)

If the speaker were a purely resistive 8 ohm load, then an 8 ohm resistor in series would be perfect. It's simple and it would pad the speaker 6dB. But since the speaker is not purely resistive and has reactive properties, a series resistor will change the characteristics. If there is series capacitance, it will change the Q of the crossover filter and tend towards peaking. So you might want to include some shunt resistance to counteract this tendency. One could check it all out in Spice, but I think you would be safe with the general-purpose values of 4 ohms in series, followed by 8 ohms in shunt, across the midrange.

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Re: Resistor values to take the 2123 down 6, please [message #41329 is a reply to message #41326]

Tue, 13 May 2003 12:37

DRC
Messages: 169
Registered: May 2009

Master

Hi Wayne!

The mid in question is the 16ohm version. Should I make that 8 and 8?

Keep your ears and your mind open.

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Re: Resistor values to take the 2123 down 6, please [message #41331 is a reply to message #41329]

Tue, 13 May 2003 12:40

Wayne Parham
Messages: 18791
Registered: January 2001

Illuminati (33rd Degree)

Oh, I see, your driver is the 16 ohm version. I assumed it was 8. So for a 16 ohm driver, make the attenuation network be 8 ohms in series and a 16 in shunt.

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Re: Resistor values to take the 2123 down 6, please [message #41334 is a reply to message #41331]

Tue, 13 May 2003 12:45

DRC
Messages: 169
Registered: May 2009

Master

Thanks!

Gotta get this balance really right for the NE Bots Saturday do.

I'd mention Steve's proposed menu, but it would create a stampede . . . . ;-)

Guys - Go out and BUY Hugh Masekela's "Hope". Don't ask why; just DO it! (Someday I'll find a copy on vinyl, but for now CD will do.)

Keep your ears and your mind open.

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Re: The Truck is Packed [message #41339 is a reply to message #41334]

Tue, 13 May 2003 15:42

bmar
Messages: 346
Registered: May 2009

Grand Master

Hi Dave,

I'm all packed and ready to roll! I'll leave at 6am, take a nap and Chris should have us rolling in around 1pm!

Bill

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Re: The Truck is Packed [message #41361 is a reply to message #41339]

Wed, 14 May 2003 04:43

DRC
Messages: 169
Registered: May 2009

Master

Man, you are dedicated. I can't believe you're makin' the haul. Steve C. keeps asking me, are you sure he's coming? Does he know how long a drive it is? ;-)

3 days and counting. I'll be runnin' the speaks pretty heard for the next couple days trying to break 'em in. (I may have to sit outside while this is going on. Either that or pretend I'm at a concert for 3 days! Woodstock at Glastonbury!

See ya there!

Keep your ears and your mind open.

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Re: The Truck is Packed [message #41368 is a reply to message #41361]

Wed, 14 May 2003 11:26

bmar
Messages: 346
Registered: May 2009

Grand Master

There was a post on hug by Bill suggesting for a louder break in volume level. Try facing the speakers face to face and wire one unit oposite phase from the other. sounds like it could work. Sure wont hurt to try. I just through a couple moving blanket over them

Being a native Rhode Islander I feel a deep draw to a New England bottle head meet!

Bill

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