Room EQ \ Treatment Suggestions

[Skipper53]

Any suggestions on some first steps to take with room treatment, Sub, sub eq, room eq, etc? Here are the two room graphs that I've gotten so far with Room EQ (great program BTW). I was planning up upgrading my sub, and that caused me to take a look at my room before I invested in a new sub. I think a new sub will help with the 20hz area, but any suggestions on the larger hole in the 2khz range?

Equipment:
Bryston SP1.7 Pro/Pro
Bryston 9BSST Amp
Tanburg 2ch for rears
Mirage OM-9 L - R, OM-C2 Center, OM-R2 Side and rear surround. Main and center are omni-polar speakers.

12" 90w Mirage Sub (14 years old)

All speakrs set to small, Crossover set to 80hz

Room dimensions: 28' L X 11' W X 6'2" Drop ceiling in basement with studs and drywall over cinder block. Opening on the right side about 10ft long. two layers of rug down in the main listing area, two couches, 1st is in main listing posting, 2nd is behind. Directly behind that is a floor to ceiling book case filled with DVD's and books, that is about 20' from the front wall.

There are no other room treatments or EQ systems in place.

My plan was to replace my sub, maybe with a passive SVS tube, or a custom JL 12W7 enclosure with external amp; Add a sub EQ system, and possibly a room EQ system for the mains. Does anyone have any suggestions or comments? Is the dip in the 1khz to 2khz area fixable? Is that caused by too many soft surfaces?

test1.jpg

This has a 1/3 octave smoothing curve applied
test2.jpg

Tested with a Digital Radio Shack SPL with d/led calibration file

[Skipper53]

I forgot to add my LF Waterfall graph, looks like I have a room node at 40hz and 120hz. I heard a rattle during the test (door or something), I wonder if that could of affected it.


test3.jpg

[Wayne A. Pflughaupt]

Welcome to the Forum, Brian!

but any suggestions on the larger hole in the 2khz range?

Most receivers these days have on-board EQs flexible enough to help with that problem, but I’m not sure if your Bryston will be in that category.

Is that caused by too many soft surfaces?

From what I know about acoustics, soft surfaces generally affect higher frequencies than that. AFAIK, it takes special treatments to affect down that low.

By the way, your waterfall looks amazingly good for having no bass traps.

Regards,
Wayne

[Skipper53]

Thanks for the reply Wayne! I've been doing a lot of reading here and keep learning more and more. I appreciate your comments.

My Bryston doesn't have any EQ (auto or otherwise), those units are built on the less is more idea, it doesn't even have video switching! I've been thinking about a few of the Berhinger EQ's although I've read a lot of material that would lead me to think that doing any EQ is harmful (in the higher freq anyway for the mains, not referring to sub woofer EQ). How bad is my overall 20hz-20khz room response? I'm not sure what kind of real world readings are acceptable.

I think I also need a better microphone then my Radio Shack SPL meeter.

[brucek]

I think your overall response is very good, although I wouldn't trust an RS meter above 5Khz.

You do indeed need a better sub, and some EQ down low (never in the mains).

brucek

[Skipper53]

I just upgraded to a SVS PC-Ultra 13. I Posted some new graphs in the SVS forum. I would say there are some profound differences!

http://www.hometheatershack.com/foru...-response.html

Brian

[DrWho]

I think Bass traps would certainly help with that 120Hz ringing (which shows up on your SVS measurement too)

[Skipper53]

Good point, I didn't consider that a bass trap could help out above 80hz (My X-Over setting). I'll start to look into my options for 100-200hz traps.

Brian

[OvalNut]

I'll start to look into my options for 100-200hz traps.

Look into the Tri-Traps from GIK Acoustics. Great performing products at a very reasonable cost. And Glenn and Bryan there are great to work with too.
www.gikacoustics.com


Tim

[bpape]

If you really want to see what the room is doing, set the scale at log for the horizontal instead of linear and also make sure you can see a full 60db down from the average level of the frequency response. Right now, your waterfalls are showing barely 40db - but it still gives the basic idea of what's up. The 120Hz is only down 30db after 1 full second. We should be looking at around 0.5 seconds to be down close to 60db.

Bryan

[DrWho]

bpape wrote:

If you really want to see what the room is doing, set the scale at log for the horizontal instead of linear and also make sure you can see a full 60db down from the average level of the frequency response.

Changing the scale on the graph really doesn't change what the room is doing...

I also just wanted to mention that RT60 is meaningless in a small acoustical environment (which is true of anything home audio). Heyser and a few other guys have written quite a bit about it - I would be willing to provide some references for anyone interested in exploring it a bit more.

[bpape]

Hi Mike.

You're right - it doesn't change what the room is doing. But, looking at a linear vs log scale can distort human perception of what the measurements are telling you.

As for RT60, you're correct, it is more useful in large spaces. However, it is still useful in making relative judgements for small space acoustics. I've used it for years in this manner and I think my customers are very pleased with the results using it for planning and eval purposes. I haven't had anyone complain yet

Bryan

[Skipper53]

I have a LF Waterfall with a log scale in the SVS thread.

http://www.hometheatershack.com/foru...-response.html

Thanks for the help, I hope this graph give a better idea of what is going on. I just have to readjust the DB scale when I get home.

Brian

[bpape]

Yup - saw that after I posted here. It doesn't look too bad but does definitely need some damping.

Bryan