First time with rew and eq - how'd I go?

[oldmatee]

Measurements were taken using umik-1, listening distance is approx 2.5m, speakers are Ascilab C6B. Measurement procedure was as follows:
1. Measure L and R in 6 positions forming a grid in and around my seating position (about 40cm x 15cm rectangle).
2. Take the average of L and R separately.
3. Use the rew eq tool, generate a PEQ and load them into minidsp flex. eq was applied up to 600hz
4. Repeat step 1.

It sounds much, much better which is nice! A few questions for y'all knowledgeable folks:
1. I tried boosting the 120hz dip on the right speaker by about 4db, which against my expectations looks to have succeeded? Is there a way of divining when boosting a null will work how much and headroom can I sacrifice? I don't want to spend days fiddling with eq and measuring, are there good rules of thumb?
2. My pre and post eq measurements diverge a fair bit in the 1khz-1.6khz region. I only applied eq up to 600hz, so have I made a mistake in the measurement process? The post eq measurements have a dip in this region, if it is not a measurement error, what would cause this dip
3. I am considering adding a subwoofer, but as most of my nulls are at >100hz will I get much benefit?
4. Any other feedback/suggestions!

 

[Keith_W]

Show some respect to the people you are asking for help. Rename the graphs. Don't make us look at your key and rename it ourselves. I have some tolerance for people who make mistakes in REW, but this is just inconsiderate.

When displaying graphs: ONLY display the graphs you are trying to compare. It's much clearer. Like this:

Left (pre-EQ in blue) vs. Left (post-EQ in red). Your left PRE EQ graph (blue) looks better than the post-EQ. There is a huge bass peak at 50Hz.

Same for the right. Pre-EQ looks better. It's flatter and does not have that bass peak at 55Hz. Just looking at the measurements, I think that your key is wrong.

As for what caused that dip between 1kHz - 1.6kHz, it is very likely a measurement artefact. Without having access to the individual measurements that made up that vector sum, I can't prove it. And I would bloody hope that you used a timing reference before you did that vector sum.

Subs won't address nulls > 100Hz.

 

[oldmatee]

Hi Keith, many thanks for taking a look. I have updated the post to address your feedback re formatting and presentation. TIL you have to click "expand" for the measurement names to be editable . The original measurement set is 30mb zipped so too large to upload. All the point measurements were taken using the acoustic timing reference. The measurements with the enormous 50hz peak are pre-eq.

Do you have advice on avoiding measurement artefacts? Is the answer just to make more measurements?

 

[Keith_W]

So your colour key was wrong, then.

Re: measurement artefacts. Take a look at the eBook in my signature on how to take measurements and evaluate them for quality. I don't know how you took your measurements, and without access to at least a couple of the non-vector summed measurements I can't tell what went wrong.