Please help - DIY 7 band 1/3 oct parametic EQ

[David_D]

Hi everyone,
I'm hoping for some help with a sanity check.
I have been looking at ESP's Parametric eq and thought I might be able to taylor one specifically for my sub.
Project details can be found here:

http://sound.westhost.com/project28.htm

Attached is a proposed diagram of what I am thinking. I hope someone may have the time & inclination to see if I am on the right track.
This is my first venture into this area and looking for some sage advice.

[Saurav]

Are those the fixed frequencies you'll be equalizing? That looks like the standard 1/3 octave center frequencies, which isn't bad, but you might benefit from finer-grained control. I noticed that the original had pots on the bottom to adjust frequency as well. Look into Room EQ Wizard, at hometheatershack.com. That's free software, it can measure your room and output the exact settings needed for a PEQ like the Behringer Feedback Destroyer, and I think it uses a higher resolution than 1/3 octave. Since you can use something like that to calculate your EQ center frequencies, you might want the ability to match them more closely.

You might have to think about component tolerances. For instance, the first leg uses 2.7M + 150K to get to 2.85M. If you get +/-5% resistors, then the upper resistor could be anything between 2.5M and 2.9M. So you may need something other than 150K to hit 2.85M accurately. You won't know until you buy the resistors and measure them.

Disclaimer: I'm not an expert at any of this, so take this with a big grain of salt

[ThomasW]

Sorry but I'm not sure why someone would choose this over the $99 Behringer DSP1124P?

[David_D]

You might have to think about component tolerances. For instance, the first leg uses 2.7M + 150K to get to 2.85M. If you get +/-5% resistors, then the upper resistor could be anything between 2.5M and 2.9M. So you may need something other than 150K to hit 2.85M accurately. You won't know until you buy the resistors and measure them.

Disclaimer: I'm not an expert at any of this, so take this with a big grain of salt

Thank you very much for your input. That is definately a consideration.

Sorry but I'm not sure why someone would choose this over the $99 Behringer DSP1124P?

Thanks for your input Thomas. It's just the DIY'er in me keeping me awake tonight. Thought I may try to intregrate this into an amp build, and axe a piece of equipment.