AudioNervosa

Self Medicating => General DIY => Topic started by: richidoo on March 24, 2012, 06:11:50 PM

Title: Resistor math
Post by: richidoo on March 24, 2012, 06:11:50 PM
My speakers have a fixed LPad (R1 & R2) followed by an adjustable rheostat Lpad (R3 & R4) to attenuate the tweeter. I want to replace these two Lpads with a single pad with fixed resistors. I will measure the value of the adjustable Lpad to determine R3 and R4. How do I add the two pads together to determine the replacement resistor values? I'm looking for a single series and single shunt resistor values.  Thank yoU!
Rich
Title: Re: Resistor math
Post by: richidoo on March 24, 2012, 06:19:42 PM
Is it as simple as adding up the series resistors
R1+R3

and adding up the parallel resistors

1/(1/R2 + 1/R4)

as normal?
Title: Re: Resistor math
Post by: richidoo on March 29, 2012, 01:13:17 PM
bump

Can someone confirm if the above post is correct?
Thanks!!
Rich
Title: Re: Resistor math
Post by: Barry (NJ) on March 29, 2012, 01:49:38 PM
Wish I could really help Rich. I saw this when you first posted it, and my gut is telling me you can't just do some math to replace these 4 with 1, because they are in different locations on the circuit, but I'm not really knowledgeable on this stuff, so I sat on my hands ;)
Title: Re: Resistor math
Post by: _Scotty_ on March 29, 2012, 02:53:34 PM
Rich, being the lazy person that I am the first thing I would do is remove the first Lpad resistor network and then measure the resistance needed for the fixed Lpad network directly from the adjustable Lpad.
Scotty
Title: Re: Resistor math
Post by: richidoo on March 29, 2012, 03:00:17 PM
That's OK Barry, thanks for replying!

Dang-NABBIT Scotty you are so clever!  Who needs engineering when you have common sense?  Thanks!