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Done treatment - Room EQ Wizard Results
Old 7th October 2010
Done treatment - Room EQ Wizard Results

OK so this has been a long time coming. I've been building the traps for about 2 months. Everything is done and hung - 40+ trips to home depot, lowes, joann's and a ****ed up thumb from pulling all the fabric. Upon the general consensus I covered every corner I could with bass traps - wall and ceiling. I did early reflection and a few other spots. Firstly, it's dead in here and I'm not too happy but I will deal with that later because I have no facing on any of my traps and maybe if I add some it will help. My room is only 10' x 15' and the ceiling is only 7'. The back wall has 2 doors that I really could not cover but I covered everything around them.. So again I realize the room is not optimal. That being said here's are some specifics of what I did:

4 Corners - 6' tall, 6" deep bass traps

Ceiling/ Wall corners - 7, 4" bass traps hanging. They are everywhere I could put them with the exception of the doors.

6" 2x4 panel in the middle of the back wall

I have a bookcase that is filled with records that I cannot move but I did put 2, 4" basstraps on the wall parallel to it.

Clouds - 3, 4" clouds spanning the whole ceiling. 1 4'x4' above my desk and 2, 2'x4's extending the rest of the room. I was not originally going to have the extra 2 but I was having modal ringing issues and these fixed them.

Early reflection:
2, 2" 2'x4's on each side.

I had 3 more 2" 2x4's in the room, 2 behind the speakers an one on a spot behind the early reflection but it was so dead in here I removed them.
Done treatment - Room EQ Wizard Results-front.jpg
Done treatment - Room EQ Wizard Results-back.jpg

It took me some time to grasp the room eq wizard program and get the levels right but I think I figured it out here are some results:
Done treatment - Room EQ Wizard Results-average.jpg
Done treatment - Room EQ Wizard Results-waterfall1.jpg
Done treatment - Room EQ Wizard Results-waterfall2.jpg
Here are the Room EQ Wizard files to go with it:

So overall what do you guys think? It's not too bad is it? I do notice the dip at around 85 and 140. I played a tone at 85 and it vanishes at certain spots and is really loud at others... Is this common for a room with my dimensions and what can be done? I make bass heavy music and that 85 dip concerns me the most, but you guys tell me what's up.

Old 7th October 2010
Lives for gear
thetalkinghead's Avatar

one thing you want to do is change the parameters so we can really see the most important areas. for example, the waterfall graph... we wanna see the end of the decay. and the freq response chart... zero in on 20-500 hz
Old 7th October 2010 | Show parent
Old 7th October 2010 | Show parent
Lives for gear
Nordenstam's Avatar

Had a look at the measurement file. Is this a single speaker or both? If both, can you repost with a set of single speaker measurements?
Old 7th October 2010 | Show parent
Thanks for responding.
This was done with a pair. Should I just play through one and leave the other off or should I remove one speaker from the room and center it then retest?
Old 7th October 2010 | Show parent
Gear Maniac
Xavier L's Avatar
I'm doing the same thing now, can you post your results with no smoothing and just the 10-1k scale ? I'd like to compare. mine is here and updating every day to get close to perfect..:Splayed Walls in Control Room

Old 8th October 2010
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Jens Eklund's Avatar

Originally Posted by kingrhythm View Post
So overall what do you guys think?
A quick say based on the REW-file:

Your room locks very dead; short decay times (apart from the lowest region, e.g. 43 Hz) and little energy after the strong reflection (from the desk I guess). Quite a rollercoaster in the lower range (looks better with a 240 dB scale heh). The dip at 1 kHz is probably due to the desk reflection. The comb filter effect in the highs is most likely due to dual speaker measurement with off centered position of the mic.


EDIT: Oh, and I’m guessing SBIR on the 85 Hz dip and modal null for the 140 Hz dip.
Old 8th October 2010 | Show parent
Jens - Yes, it is really dead in here. I would like it somewhat dead cause I record in here but this is a little too much. Is there anything I can do other than add facing to the panels?

Do people ever cover their desk to stop reflection?

Here's some updated measurements with individual speakers:
Done treatment - Room EQ Wizard Results-overlays.jpg
Done treatment - Room EQ Wizard Results-lftwater.jpg
Done treatment - Room EQ Wizard Results-rtwater.jpg

Roomeqwiz ffuts:

Thoughts from anybody else would be greatly appreciated!

Old 8th October 2010 | Show parent
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Jens Eklund's Avatar

Originally Posted by kingrhythm View Post
Jens - Yes, it is really dead in here. I would like it somewhat dead cause I record in here but this is a little too much. Is there anything I can do other than add facing to the panels?

Do people ever cover their desk to stop reflection?
Covering some of the panels with a thin (approx 3mm) panel or perforated panel (< 15 % perforation) will help to regain some HF to the room but it probably won’t do much about the longer decay in the lows unless the devices function as membrane absorbers (sealed back). I haven’t seen a covered desk. The normal approach is to make it as small as possible.

Old 9th October 2010 | Show parent
Lives for gear
Nordenstam's Avatar

The first thing that strikes me when looking at the measurement is the level of distortion:
Done treatment - Room EQ Wizard Results-kingrythm1.png

The measurement method employed means that the distortion products are pushed ahead of the main impulse. The "pre-blips" of energy are the harmonic distortions. Can't recall seeing such amounts of distortion before. You could try running the soundcard at a bit lower level (say 12dB lower) and see if the level of the distortion products are changing. Then try running the amps a bit softer and see if that helps. It doesn't change the acoustics, but it may be worth looking into in itself.

The room certainly looks dead! Covering as much of the traps with reflecting surfaces as you can manage to do will help in that regard. Keep an eye on the ETC plot:
Done treatment - Room EQ Wizard Results-kingrythm2.png

If you didn't use this plot while treating the room, you can use it now to check the effect of each particular piece of treatment. Do a measurement, remove the panel and measure again. Do measure each speaker, one by one. Looking at the response from both speakers is difficult at best, as it will show a mess of constructive and destructive interference from the dual mono signal. If the absorbing panel is not effectively adressing an early reflection in either of the plots, it doesn't need to be there. In other words: if removing the panel doesn't introduce a disturbance in the early reflection pattern, it can safely be removed. It may, however, be that it does some good to the modal response. If that's the case, the absorber can be dressed with a facing that reflects from mids and up as Jens suggests. It looks like something like half of the absorbers in your room can be made reflective without hurting the early reflection response.

The 60Hz "problem" in the low end seems to be hum from the mains:
Done treatment - Room EQ Wizard Results-kingrythm3.png

It would be pretty hard for a resonance to start before the excitation energy. As is typical, it can also be seen that porous absorbers aren't particularly effective below 100Hz. Though I bet it's a lot better down there too, compared to the before result.

Looking at the waterfall can be a bit confusing at first. Try using various observation and window lengths in the "controls" panels and make sure you get friendly with the "slice" slider. A lot of things are easier to see when using that slider. The 33Hz main mode is obvious. There's also some junk in the 60-80Hz area. And, to my suprise, there's something going on between 200 and 400 Hz. Those are not loud resonances, but I was a bit surprised to find them as they are typically easily dealt with using porous absorbers. I don't think it's unrealistic to assume that you can get rid of those by moving the absorbers around a bit.
Done treatment - Room EQ Wizard Results-kingrythm4.png

Dunno if this helps or was more confusing...? Don't hesitate to ask questions if needed!
Old 10th October 2010 | Show parent
Gear Head

Lupo - Interesting walkthrough of the measurements for us noobs. Thank you for taking the time to do that.
Old 12th October 2010 | Show parent
Ok first and foremost thank you Lupo for taking the time to respond so completely!
A lot of what you have written is going over my head but the more I read it the more I'm starting to grasp it.

I do have a huge bookcase (filled with records) in there plus the desk, 2 equipment racks and a case for the computer. I wonder how different the room will be if I remove them/ move them to different locations (they are all reflective surfaces)... I now realize this is going to be an ongoing project and a lot more time needs to be spent trying things out.

After knowing that I should have done this differently (trying one thing out at a time instead of just throwing it all in) I'm just wondering how I would deal with trying ceiling/ wall/ corner/ general placement out. Punch holes in the walls, use anchors to hang, find out the positioning/ spacing is bad, take them out, punch more holes 2" down, again find another spot and again and end up with a room full of holes to patch? I know this may be trivial but I'm just wondering if this is what people do.

Would you suggest a good way to attack this would be to run the real time mode in REW, play the suspect frequencies charted and start moving things around and see what happens? Or does it not work like that and I should just keep working with freq sweeps?

Also, Could you give me some specific examples of products that I can use for facing? Links to something would be the best, everybody says just get something __" thick but I would like to see something specific. I think I'll apply the facing to 4 or so at a time and see how it sounds. Surprisingly enough I'm getting use to it being so dead, still I can't help but feel like I'm Hal in 2001

Thanks again!
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