# Am I correct?



## Lendanear (Sep 22, 2012)

Hello. 
My system is 2:1 as in 2 channel and sub. My source Openelec on a Raspberry Pi, analogue out to my amp, a Technics unit, amplifier SU-5A, a 12 Channel SH-E4 graphic eq driving a pair of book shelf speakers SB-F41. oldies but goldies passed down from my mum.
I take a speaker level output and feed it to a stereo low-pass filter crossed 80hz-12db slope. Because i take one channel, the output from my crossover is fed back in to the second crossover channel to give 80hz-24db slope. 
Next in this chain, a Behringer Ultracurve DEQ2496, a 450Wrms BK Electronics amp module and 2x15" Fusion car subs in a manifold doing an IB thing with the adjacent room. 
I watched a Youtube video showing how to Auto EQ and have tweaked the 12 channel Technics eq. I'm happy with its limited control and my Bookshelves sound good.
its my Sub I can't grasp!
I ran Auto eq on it, saw the peaks and troughs and eq'ed it accordingly. It thumps horribly and I'm tempted to use PEQ's to pull the upper bass out.

I need to purchase a USB Sound card for my PC and install REW and measure properly.
I am I correct in that you measure the sub via no low-pass. Then apply filters to tame just the peaks, setting PEQ's in the Ultracurve, then plug the low-pass back into the chain, and finnish off with a House-curve where my ears perceive 100hz to sound the same as 30hz by playing test tones and setting a slope on the GEQ to get that?

I understand its good to measure with various mic positions and get an average, not seeing a complete video on You-tube is disheartening, everyone gets you up and running with sub measuring, but no-one sets up a House-curve.


I also have the digital SPL meter from radioshack and ECM8000 omni-mic.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Welcome to the Forum, Mike!

It’s best to equalize with the sub’s crossover in place; that way any phase-induced response issues around the crossover frequency can be addressed. You can use boost or cut filters to eliminate peaks and depressions in response; just keep in mind that nulls (deep, narrow depressions) can’t be addressed.

As for the house curve, the slope is best set with REW using a house curve file (based on the 100 and 30 Hz tones you mentioned) to generate a target curve. Then equalize the sub’s response to the target curve. This is best accomplished with parametric filters.

Regards, 
Wayne


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