Thanks guys... I look to this as a new beginning. Starting fresh with a clean slate and now will be getting help from the designer and the speaker manufacturer.
Speaker/Room calibration
- Thread starter Bruce B
- Start date
I also have questions about nulls
Hello, this is my noob attempt at a post, I recently built Ethan style panel traps one 1/4" and one 1/8" in each corner and a 6 x 7 cloud in my 11X16 bedroom (project studio) and took some measurements using Fuzzmeasure. This graph shows the left Focal CMS 50 speaker only (6" woofer), no sub. I tried moving the speaker around quite a bit, but still have null issues.
The mic was placed at ear level pointing straight up about a foot back from my current listening position which is 38% back in the room. That's where the null seemed to be its least awful. The room has an arch about 2/3 of the way back that opens into a area that has a much higher ceiling. It was at one time an outdoor space, that has been roofed over. It sounds real nice in here, but then I'm not sure what to expect. I can say it sounds worlds better than the last room I had. The arch makes putting superchunks in difficult. The room also has the dreaded door in the corner also making super chunks next to impossible. I was thinking of adding some membrane type traps, but I'm not sure how to make them yet.
Hello, this is my noob attempt at a post, I recently built Ethan style panel traps one 1/4" and one 1/8" in each corner and a 6 x 7 cloud in my 11X16 bedroom (project studio) and took some measurements using Fuzzmeasure. This graph shows the left Focal CMS 50 speaker only (6" woofer), no sub. I tried moving the speaker around quite a bit, but still have null issues.
The mic was placed at ear level pointing straight up about a foot back from my current listening position which is 38% back in the room. That's where the null seemed to be its least awful. The room has an arch about 2/3 of the way back that opens into a area that has a much higher ceiling. It was at one time an outdoor space, that has been roofed over. It sounds real nice in here, but then I'm not sure what to expect. I can say it sounds worlds better than the last room I had. The arch makes putting superchunks in difficult. The room also has the dreaded door in the corner also making super chunks next to impossible. I was thinking of adding some membrane type traps, but I'm not sure how to make them yet.
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roomscan_4_7_12..jpg
Another great looking graph, I do find these interesting. A couple of peaks that look like they are less than Bruce's. You dont have the extension that he has though. His is down to 5hz! But it should be adequate as it appears to be around 30hz, which for music is more than enough. Congratulations, how does it sound?
Wendell
Wendell
I do have a sub connected, but I didn't run it for the graph. I was afraid of getting phase cancellations and confusing myself even further. It sounds real nice, but there is some fluctuations when running a low freq sweep. Most noticeable is the 300hz ring. Thanks! This is my project studio. I have ARC room correction software, but I'm trying to use that as icing on the cake.
Yes, looks good! You certainly are on the right path. Does your mic have a calibration file for 90 degrees?
I wrote a speaker to room calibration walkthrough that may have a few tips and tricks that may be useful. http://www.computeraudiophile.com/blogs/Speaker-Room-Calibration-Walkthrough
One of the tips from the article is to use 1/6 octave smoothing as that more closely resembles how our ears interpolate the peaks/dips (reference in the article). I am not sure if the software you are using can measure Energy Time Curves (ETC). If it does, it is typically used for measuring room (early) reflections and allows you to pinpoint these and take care of them with either absorption or diffusion (I prefer diffusion as I don't like the sound of dead rooms). Aside from that, if you really zoom in on the time scale, you can "time align" your sub with your mains so that the sound arrives at the listening position in sync sorta to speak.
Hope that helps.
Cheers!
Mitch
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1/6 smoothing
Great info in that link. Will take some time to absorb it all. I didn't calibrate the mic. I think one of my issues could be the monitors are almost exactly 1/2 way between the floor and ceiling. Where they're sitting is halfway, the peak is 10 feet at the center. Of course with this giant cloud in here, it's hard to say where the ceiling is! They monitors need to be high enough to shoot over my racks w/o picking up a whole lot of reflection off the top of them. I will try raising them up another six inches and angle down from there to see if that helps. ...here is the 1/6 smoothing. Thanks guys!
Great info in that link. Will take some time to absorb it all. I didn't calibrate the mic. I think one of my issues could be the monitors are almost exactly 1/2 way between the floor and ceiling. Where they're sitting is halfway, the peak is 10 feet at the center. Of course with this giant cloud in here, it's hard to say where the ceiling is! They monitors need to be high enough to shoot over my racks w/o picking up a whole lot of reflection off the top of them. I will try raising them up another six inches and angle down from there to see if that helps. ...here is the 1/6 smoothing. Thanks guys!
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1:6 smooth..jpg
LF room nulls are a pain. Ideally, a primary peak can only double (3 dB) the power, though other factors can easily raise it to 6 dB or so, but a null can go to 0 (-infinity dB).
progress
Well, hopefully I never get to infinity, or beyond! Here's a shot of my progress so far, taken with a hand-held wide angle lens in front of my iPhone. I came up with a neat design for some speaker stands, I should have them built by Monday. I'll post pics then. Thanks again.
Well, hopefully I never get to infinity, or beyond! Here's a shot of my progress so far, taken with a hand-held wide angle lens in front of my iPhone. I came up with a neat design for some speaker stands, I should have them built by Monday. I'll post pics then. Thanks again.
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smlprogress..jpg
blurry stand photo
Finally finished the stands, they are adjustable, using shelf brackets counter-sunk in slots on the front of the stands, I installed wooden plates to hide the shelf brackets. There are braces to keep the shelves from wobbling mounted on the column just under the shelf on each side. But, they are still adjustable. This allowed me to get the speakers out of the half way point between the ceiling and floor. The speakers are sitting on the supplied Focal rubber pads on top of cement blocks. I think I can hear the bass, everything actually, being smoother. I will shoot the room again and see what it did to the null.
I might even fill the bases of the stands with concrete, that would stiffen them up even more. Hard to see from this photo, but there are four allen bolts on the bottom plate that I ground to a point, they can be used for leveling.
Finally finished the stands, they are adjustable, using shelf brackets counter-sunk in slots on the front of the stands, I installed wooden plates to hide the shelf brackets. There are braces to keep the shelves from wobbling mounted on the column just under the shelf on each side. But, they are still adjustable. This allowed me to get the speakers out of the half way point between the ceiling and floor. The speakers are sitting on the supplied Focal rubber pads on top of cement blocks. I think I can hear the bass, everything actually, being smoother. I will shoot the room again and see what it did to the null.
I might even fill the bases of the stands with concrete, that would stiffen them up even more. Hard to see from this photo, but there are four allen bolts on the bottom plate that I ground to a point, they can be used for leveling.
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standsinstalled..jpg -
stand..jpg
Damn I love my wife. I tilted the speakers and she took out the Wave Kinetics footers, spikes and then put furniture sliders under them. They move pretty easily now.
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speakers..jpg
No I haven't. If I were to add subs to the room, I would look into JL Audio or something.
The top subs are connected to a speakon umbillical and doesn't have its own controls. Both top and bottom subs are controlled by one set of adjustments.
Helmholtz resonator
Bruce, Another option to address that 40 hz null is using a helmholtz resonator. There is a Italian company that makes adjustable helmholtz resonators that can address that problem. Their web site is acousticaaplicata.com . They have two different ones. The Polifemo and Phemo. I believe these are pretty pricy but are an alternative to additional subs. A cheap way would be to build your own. I am contemplating doing that myself.
Sean
Bruce, Another option to address that 40 hz null is using a helmholtz resonator. There is a Italian company that makes adjustable helmholtz resonators that can address that problem. Their web site is acousticaaplicata.com . They have two different ones. The Polifemo and Phemo. I believe these are pretty pricy but are an alternative to additional subs. A cheap way would be to build your own. I am contemplating doing that myself.
Sean
Hi Bruce, It has been a while since you last posted a graph and moved your speakers. Any updates yet?
I am curious as to how can the response change in a rectangular room, since you are just "swapping ends" when moving your speakers from one end to the other. The room is still the exact same dimension so the room modes stay exactly the same.
What are you expecting to change?
Also I am curious was not the room designed by your acoustic designer to work with the speakers on the end you originally had them? Won't moving the speakers to the other end destroy this balance?
Thanks,
Wendell
I am curious as to how can the response change in a rectangular room, since you are just "swapping ends" when moving your speakers from one end to the other. The room is still the exact same dimension so the room modes stay exactly the same.
What are you expecting to change?
Also I am curious was not the room designed by your acoustic designer to work with the speakers on the end you originally had them? Won't moving the speakers to the other end destroy this balance?
Thanks,
Wendell
the "damage" of going analog to digital then back again is far less than the damage of running through all the extra circuitry of an analog eq - especially if you try something like the z system rdp1 - which will accept a digital signal and output a digital signal - you would insert id between your digital source and your d to a converter. Also, the digital eq can do things so much more precisely than an analog unit.
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