First posting (here) of REW graphs...

[boarder1995]

Ok, I posted some initial graps at another forum, but I've adjusted these for the requested requirements of HTS for axis spreads - except I went down to 12Hz, since I thought it revealed a bit more information with the subs. These are Outlaw Audio LFM1-EX's set in 16Hz tune (one port plugged).

Room details: 15wx17dx10h with ceramic tile flooring and a rear that opens up to a double vaulted ceiling great room. Mirage 895i mains and a Denon receiver. Here's a photo...


Here's the first...
Graph1:
The red is my current best pick with one front right, other left rear, both about 3 feet from the corners along the side walls, front crossover off (just receiver's, don't remember what it's supposed to be - 100Hz?), rear using internal crossover at 80Hz and phase set opposite of front.


Graph2:
For comparison, here's the above dual setup (red) versus a single front (blue) versus a single rear (green). This shows how in my room the dual setup helps smooth the response.


Graph3:
Here's the initial dual setup while sitting in the main chair in the middle of the room (red) versus another seating position along the wall (blue).


Graph4:
Yet another graph with minor tweaks...the standard (for me) dual setup, front right: crossover off, phase normal, left rear: crossover on, phase opposiste. (red) VERSUS having the rear with the same phase setting (blue) - make a fairly substantial change in response.


Graph5:
Another minor tweak...the standard (red) VERSUS having both crossovers on and phase opposite (blue)


Hope these aren't too many graphs, but I find it very intersting that once you think you have or do not have ideal locations for subs, just some minor changes with internal crossovers and phase can make huge differences. My personal opinion is that I don't need a parametric EQ - what's y'alls thoughts? With my preferred setup, there doesn't appear any place I need to tone down, and I know I can't really boost a spot (not recommended).

[boarder1995]

Anther thought with Graph4...
Would the extra boost below 20Hz with slight additional dip just above 40Hz (blue line) be more desirable? I know the additional dip isn't good, but thought the deeper and extra boost below 20Hz would be good for new movies for a bit more visceral experience, or would that be emphasizing too much sub-sonic feeling and get annoying to most others? Just wondering what the concensus is. Fortunately, this change only requires a quick switch on one sub, so it's easy to do.

[brucek]

what's y'alls thoughts?

Yeah, I think you can get away without any equalization. The response looks fairly good.

would the extra boost below 20Hz with slight additional dip just above 40Hz (blue line) be more desirable?

I think that's a matter of taste. I would probably go with the red line myself.

BTW, normally we set the Measure end frequency to 200Hz - not 100Hz. There is still influence from the crossover after 100Hz.

brucek

[Wayne A. Pflughaupt]

The graphs seem to be unrealistically "pretty." Are they smoothed?

Regards,
Wayne

[boarder1995]

Wayne,
I've looked around in REW to see if I have/had on any smoothing or something. Some of my other graphs are a bit more jagged. Anything in the software I should look for? I'll re-read the help files and online guide. I also ran the sweep fairly slow (512k length). Perhaps, I've got the perfect setup in the perfect room! Ok, maybe not...but I like to be optimistic. Thanks for the help.

BruceK,
Yep, I noticed all my measurements stopped at 100Hz, not 200Hz. I'll start taking them up to 200 (with mains off/unplugged?) for better upper end info. I played a bit with the two settings (graph4) I inquired about yesterday. In the mid range of the sub there is a very slight change in output during a sweep, but the lower end down to 15Hz zis definitely more visceral. I kind of like it, but will take further measurements around the room to see if it remains good elsewhere. Otherwise, I've got a good setup with the red line.

[boarder1995]

Ok, another graph...

I shifted some things and changed some receiver settings and got the best (deep) looking graph I've seen so far (blue line). Then I decided to compare the single front Outlaw Audio sub (green) with my original (paradigm 12" PW1200) in it's original location (red). The best line is the blue with dual outlaw audios. But with just a single OA in its ideal location I get major dips, etc. It seems to take duals in my room to even things out. Now the single Paradigm doesn't seem to have this issue. Granted it doesn't go nearly as deep (only 30Hz before rolloff), but above that it looks better single than the OA single. Another thing I'v noted is the big lack of mid bass out of the outlaw audios. Still tweaking. I guess I'm just wondering if I spent $1000+ for a more depth versus my admirably performing Paradigm unit.

[brucek]

Your comparison makes it difficult to come to the conclusions that you are offering.

Simply look at the green and red line. If you are going to compare two subs you have to test at approximately the same level. You haven't done this. At the very least use the trace offset feature to overlay them.

Once measured at the same level, you have to overlay the graphs to get a better look. You can easily see the identical dips and peaks in the red and green lines, except the green sub extends to a much lower frequency than the challenged red. Yes, there's a large room peak at ~17Hz that the green sub reveals, that the red one cannot hope to reach. The green sub appears to be the better one.

brucek

[boarder1995]

Ahhh, thanks very much. I'll have to play with the trace offset feature to get a better comparison. Perhaps tonight I'll redo some of these to get the levels similar. That's a good point about the red and green having the same peaks and valleys.

[Wayne A. Pflughaupt]

Then I decided to compare the single front Outlaw Audio sub (green) with my original (paradigm 12" PW1200) in it's original location (red).

If you want to do a valid comparison of two subs, they must be measured from the same location.

Regards,
Wayne