REW Graphs: Which Is Better?

[ttocs]

What makes for a better choice when viewing and comparing measurements of subwoofers?

I've been experimenting this week with separated and colocated twin subs. For now I've settled on a spot that works the best for stacking one on top of the other. So far everything I've done has been without using miniDSP, and using REW for the quick measurements.

Without having had much experience with REW until late last year, I'm still new at using it. I have a miniDSP HD 2x4 but haven't used it. So the question for now is, what kind of graph makes for a better result after being corrected?

Here's an example. The two curves represent locations about 10 feet apart along the same wall, the only wall in fact that produces the least lumpy curves. Which one is the better choice and why? I know which one I would pick and have what I think is a good reason, but I'd like to hear first from others. Thanks in advance.

I don't know what kind of smoothing is involved, it's whatever REW starts with I guess. The measurements involve Focusrite 2i4 with CSL UMIK-1, REW, one VSUB-1 transmitter transmitting to receivers attached to each sub, both subs on and stacked.

edit: I checked and no smoothing is applied.

[millst]

The green has significantly more output, which should be easier to EQ flat. I'd speculate those deep spikes are just room modes that EQ can't do anything about. They are probably less audible than that trough from 30-60 on the red.

The biggest advantage of the red would be the extra extension, but that is probably not as important unless your more concerned with movie effects and organ music.

[audiobill]

Ttocs, you prob don’t want to “eq flat”. Most listeners like a “target curve” from 1-2.5 db/octave from 200-30 hz.

[ttocs]

Aug 7, 2020 13:01:39 GMT -5 millst said:

The green has significantly more output, which should be easier to EQ flat. I'd speculate those deep spikes are just room modes that EQ can't do anything about. They are probably less audible than that trough from 30-60 on the red.

The biggest advantage of the red would be the extra extension, but that is probably not as important unless your more concerned with movie effects and organ music.

As a calibration novice, what I was looking at with these two examples are those two dips. The way I figure, regardless of whether there's a slope or some "lumps" as I call them, I would think it's more beneficial to have as few dips as possible, no?

Full disclosure, I left out one piece of info because I wanted to get unbiased opinions, and that is the fact that my small speakers don't do well below 90Hz, so I set the crossover at 100Hz. As such, that green curve would be a problem, but I wanted to use it as an example because it has other features which I would think are benefits, such as the increased energy you point out.

Since making these measurements I've added a third sub to the mix to play with. That one dip below 70Hz is less wide and a lot less deep with the third sub.

I'm still interested in all opinions for what makes for better choices in what we see in the curves. So many things to consider. Thanks.

[ttocs]

Aug 7, 2020 18:25:15 GMT -5 audiobill said:

Ttocs, you prob don’t want to “eq flat”. Most listeners like a “target curve” from 1-2.5 db/octave from 200-30 hz.

Good to know, thanks Bill!  I was not aware of the actual target number per octave with all the talk about bass boost, house curves, Harman curves, etc. But it goes up to 200Hz? Seems higher than I would've imagined.

So, is it better if the raw curve starts with a natural slope such as the red one above? 

Also, this week I've done a lot of testing in my great room and was really trying to see if I could use any combination of the subs I have as a compliment to my main speakers for 2 channel music. So far that's been a bust. The ARC calibrated woofers in the Left/Right speakers simply work much better than when subs are added to the equation. I'm not finished trying because I am hoping to have a more enveloped feel without being inaccurate.

[audiobill]

The overall slope of your curves looks pretty good, a lithle fine tuning by ear and call it a day.

[millst]

Crossovers aren't brick walls. You'd just be trading one dip for another. The human ear/brain is better at ignoring very narrow gaps versus broader ones. One way to confirm whether something is a room mode is to try applying some boost. A true null won't respond. For the final EQ, you should generally be sticking to cuts, though.

It's a bit art and a bit science. As audiobill said, you need to involve your ears and flat isn't ideal. Even if you could make it flat, you'd have to lock your head in place since any movement changes things.

The Harman curve is just a composite of the measures from a bunch of speakers that most people in the studies thought sounded the best. It follows that if you have good speakers, you'll probably have something close to that. Beating bad speakers into something that looks like the curve probably won't sound good. The takeaway is to not equalize that out. Sometimes, people take it the wrong way and turn room EQ into an overly complicated [fixed] bass tone control.