First run at REW and I love it; graphs posted

[Rambo4]

Hey, just setup my REW, following the instructions, and have results that look like an actual response curve. Just can't really say I am happier from getting the software setup properly or sadder from seeing my actual response curve. haha

Here are the curves. These are all taken in a 14 x 18 x 8 room with two AS-F2 speakers and a Velodyne DLS 5000R in front corner powered by an HK 635 receiver.

(Edited out the first graphs posted as they included the mains in them, which is not my primary concern. Still learning...)

1) HK Flat response (darker purple) mains at full range + sub VS Ezset/Eq mains 60Hz + sub (pink)

2) Full range right main response curve (blue) with no sub - tone flat no ezset/eq

3) Full range left main response curve (red) with no sub - tone flat no ezset/eq

4) Subwoofer only mains disconnected (aqua) - tone flat


Any ideas of where to go from here whether a BFD is useful with so many nulls, position my subwoofer somewhere else, any help I'll welcome!

Thanks!

[Wayne A. Pflughaupt]

I’d try first moving the sub some. Try moving it out of the corner a few feet down the wall. Sometimes that can take care of things like the 40 Hz problem and still be close enough to the corner to retain the benefits of corner loading.

Regards,
Wayne

[brucek]

Why do your two mains plots look like there is no crossover set?

brucek

[Rambo4]

Hi brucek, thats a good question. I was experimenting to see how far down my two towers would go. From what I could tell each will go down to a good 35 Hz. I was trying it to see if having a two speakers going down that low would help my nulls in the 40 Hz and 70 Hz range. If that was the case I would have assigned my receiver to set speakers as small and crossover at 40 Hz, which is as low as it can go. As you can see, it didn't go so well.

Also, as an update to my previous post, the measurements were taken with a tripod, with an RS meter (.cal loaded in REW), at ear height, at main seating position 11 feet back from front wall.

[Rambo4]

Tried a few different positions for the sub. Out of the available spots, the corner behind the seating yielded this result. Crossing my fingers for no sound localization from that area though. It's as close as I can get to a flat response curve before doing any EQing.

I don't understand why I don't have more volume from the 15 to 30 Hz range though. The 15" Velo is plenty powerful. Anyway it is likely a simple explanation for it.

[Wayne A. Pflughaupt]

Wow, that is scary-good! Anyway you can turn the room around? I take it that moving the sub down the wall from the corner used in the first graphs didn't do much for you?

I don't understand why I don't have more volume from the 15 to 30 Hz range though. The 15" Velo is plenty powerful. Anyway it is likely a simple explanation for it.

Judging from this Sound and Vision review, it looks like your sub is pretty much done at ~32 Hz. Note that they showed output to be 19 dB down at 25 Hz. Amazingly, their info corresponds to your own graph pretty much dead-on – 25 Hz looks to be about 18 dB down compared to ~32 Hz.

Regards,
Wayne

[Rambo4]

Hi Wayne, thanks for the link. Explains a lot.

Regarding the placement, I placed the sub up the wall incrementally to the sides of the seating, but kept getting a serious null moving from 40 to 60 hz. Until I placed the sub in the corner location behind, perhaps it sitting on the riser at that point, with the elevation was enough to flatten the frequency out a bit more.

Any suggestions on whether it would be more advantageous to keep settings on receiver as flat, and pick up a BFD 1124 or use an overall room correction device (ezset/eq) that exists in the Harman? Or maybe both together.

On a side note, being relatively new to the field, I really appreciate any time experienced members, like yourself, take to help out guys like me, who would be quite lost without a bit of helping hand in the right direction. Thanks for the patience!

[Wayne A. Pflughaupt]

Happy to help George!

By all means, take what you already have at your disposal as far as you can. You never know, it may be enough.

It looks like I spoke too soon about your last graph – I just noticed it’s scaled differently than the others. Can you re-do it in our standard 45-105 scale?

Regards,
Wayne

[Rambo4]

oops! Ok, fixed now. Thanks for the tip! Not quite as smooth as before...

This is the original response curve, I have used REW to plot the peaks for me, and where to smooth it out if I purchase a BFD. This graph is a result of my sub at 12 volume and it goes to 80! My receiver sub level at 0 and receiver volume at -35...

[brucek]

I have a tip for you rambo. There's a button on the filter panel that has an up down arrow icon. Press it and you can sort your filters from low to high at any time..............

brucek

[Rambo4]

Thanks brucek, I'll check that out. I was wondering if there was a methodology to the default plot order.

Of course now that I am getting a handle on the audio end, my IN76 projector just died this morning after about 1200 hrs of use. Thankfully it's still within the two year warranty. Likely the onboard fuse. I wanted the guys at Infocus to check my M1 port anyway. Ah well that's life.

[Rambo4]

New update to my subwoofer room response. This measurement was taken at my seat after I set all my crossovers from 60 to 80 on the mains, and ran the HK's Ezset/EQ on manual. Quite a difference!

Here is the new response:

[Rambo4]

And the waterfall graph, if anyone can decipher it...

[brucek]

Looks real good now.

The waterfall plot should be changed to LOG rather than LIN mode (click the log/lin axis button) bcause there is a small bug in REW, then you'll get the full plot. It's better to observe waterfall in LOG anyway, since it will match the frequency response graph. Pull the waterfall slider back to 1 slice and you'll see the frequency response graph. Then move the slider slowly up to 30 slices and you see how the sound rings away in your room.

brucek