jared
Junior Member
Posts: 57
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Post by jared on Aug 20, 2020 13:00:26 GMT
Thanks Pasim. Ive tried on the SPL Meter and also the calibrated microphone from sonarworks, and the results are identical.
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Post by Hexspa on Aug 20, 2020 18:41:05 GMT
Frequency to wavelength in centimeters. Wavelength x 1, 0,5 and 2 = contributing dimensions. You have ringing at 100Hz.
Please let me know exactly what is unclear. I'd like to be as transparent as possible but it takes me the better part of an hour to do a full analysis and I'm trying to do other things.
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jared
Junior Member
Posts: 57
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Post by jared on Aug 21, 2020 8:35:28 GMT
Thanks Hexspa, I went through your tutorial again and think i have figured it out. My length is 5m, width 3.4m, heigh 2.8m. I found a site that automatically shows you the null and peak frequencies (im sure you have seen it). amcoustics.com/tools/amroc?l=600&w=300&h=270&r60=0.6My peak wavelengths: 1. Length - 500cm (69HZ), 250cm (138 HZ), 1000cm (33HZ) 2. Width - 340cm (100HZ), 170cm (200HZ), 680cm (50HZ) 3. Height - 280cm (124HZ), 140cm (245HZ), 560cm (62HZ) My null wavelengths: 1. Length - 125cm (278HZ), 375cm (93HZ), 625cm (55HZ) 2. Width - 85cm (400HZ), 255cm (138HZ), 425cm (85HZ) 3. Height - 70cm (494HZ), 210cm (165HZ), 350cm (99HZ) I now know where in the room there is frequency problems. The problem is that I already have acoustic treatment in these places..... For example; 124HZ I have a large peak. This is the ceiling. However, I have 2 large panels already on the ceiling with one in my mix position. I am not sure what do to now.... If there is much more to this calculation, and i have to redesign my room, please be in touch via private message and we can discuss further.
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Post by Hexspa on Aug 21, 2020 18:44:49 GMT
I'm glad you found amroc. Personally, I prefer to do my calculations manually but your space looks perfectly rectangle so any calculator should do.
The ceiling is a pretty large surface, wouldn't you agree? Your cloud is large, yes, but maybe not large enough nor thick enough. The 6dB peak at 124Hz is not as much a problem as the sharp 100Hz ringing. Try to find which dimension relates to 100Hz.
Remember that other dimension which are 1/2 and 2x the wavelength of these frequencies also contribute. I call that modal bunching. You may be able to find one or two dimensions which counteract those and I call that balancing.
The ringing can only be solved with absorption - positioning won't help much unless you place the speaker in a null but then you still have some ringing and much less SPL. Positioning is probably your best bet with SPL which means you may want your speakers a little higher. Also, stubborn bass peaks can be tamed with subtractive EQ. The secret is to measure your listening position in a reasonable radius to ensure you're not overcompensating and creating a null near your dead center producer spot.
One of these days, I'll offer analysis services but for now I'm chopping the Amen break. I'm happy to help so long as the person I'm helping makes use of the plethora of great info on this site. Since I've already published everything I know, no more free custom deep dives.
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Deleted
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Post by Deleted on Aug 21, 2020 19:11:32 GMT
Thanks Hexspa, I went through your tutorial again and think i have figured it out. My length is 5m, width 3.4m, heigh 2.8m. I found a site that automatically shows you the null and peak frequencies (im sure you have seen it). amcoustics.com/tools/amroc?l=600&w=300&h=270&r60=0.6My peak wavelengths: 1. Length - 500cm (69HZ), 250cm (138 HZ), 1000cm (33HZ) 2. Width - 340cm (100HZ), 170cm (200HZ), 680cm (50HZ) 3. Height - 280cm (124HZ), 140cm (245HZ), 560cm (62HZ) My null wavelengths: 1. Length - 125cm (278HZ), 375cm (93HZ), 625cm (55HZ) 2. Width - 85cm (400HZ), 255cm (138HZ), 425cm (85HZ) 3. Height - 70cm (494HZ), 210cm (165HZ), 350cm (99HZ) I now know where in the room there is frequency problems. The problem is that I already have acoustic treatment in these places..... For example; 124HZ I have a large peak. This is the ceiling. However, I have 2 large panels already on the ceiling with one in my mix position. I am not sure what do to now.... If there is much more to this calculation, and i have to redesign my room, please be in touch via private message and we can discuss further. I would just build two huge traps and place them, where I mentioned earlier. Probably will get bass energy back on that null area and reduce ringing on upper bass. BTW if its possible, can you take measurements with sonarwork microphone? Im quite interested about that "phasey sound" because I didn't really see any early reflections that high on your ETC.
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jared
Junior Member
Posts: 57
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Post by jared on Aug 22, 2020 17:25:14 GMT
Thank you both Hexspa and @pasim. I appreciate all your help and assistance. I have a company coming in on Monday to quote on some thicker bass traps. Out of interest, on the Amroc Room Mode calculator, I tried to get my room into the "Bolt-Area". It appears that if I reduce my ceiling height from 2.8 meters to 2.5 meters, then many of these issues will dissapear. Would you recommend reducing the height of my ceiling (my builder can do this)? Or should I rather just put in treatment? And Why? Thank you!
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Post by Hexspa on Aug 22, 2020 19:40:12 GMT
I've never altered a room's dimensions so I don't know. Lowering the ceiling might help. Whether the issues will 'disappear' is another story. Acoustic response is complex and, for all we know, new issues may arise.
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Deleted
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Post by Deleted on Aug 22, 2020 19:45:42 GMT
Thank you both Hexspa and @pasim . I appreciate all your help and assistance. I have a company coming in on Monday to quote on some thicker bass traps. Out of interest, on the Amroc Room Mode calculator, I tried to get my room into the "Bolt-Area". It appears that if I reduce my ceiling height from 2.8 meters to 2.5 meters, then many of these issues will dissapear. Would you recommend reducing the height of my ceiling (my builder can do this)? Or should I rather just put in treatment? And Why? Thank you! NO! Never make already small room even smaller. It makes only sense to hit that bolt area if you can make it bigger or have already big room and you're building into two or more rooms. The only way to lose room volume is by absorption(thats what they do in planned studio builds, you'd be suprised how much room is lost to treatment), like doing the whole ceiling 50-60cm covered in absorption, it would be one big bass trap.
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jared
Junior Member
Posts: 57
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Post by jared on Aug 22, 2020 20:46:51 GMT
thanks Pasim! makes sense
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Post by Hexspa on Aug 23, 2020 4:17:52 GMT
For some reason, I thought this room was bigger. I agree with Pasim.
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jared
Junior Member
Posts: 57
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Post by jared on Sept 4, 2020 15:30:14 GMT
Sorry to bring this question up again guys - just need to clarify.
1. My roof is currently 2.8 meters high, but with treatment on the ceiling which I am about to do, it will drop to 2.6 meters high. According to the amroc acoustic calculator (https://amcoustics.com/tools/amroc?l=500&w=340&h=250&r60=0.6), if I reduce the ceiling by a mere 10cm to 2.5 meters (i.e. drop the ceiling panels by 10cm), my room will now in the "bolt-area” and be a much more ideal dimension than if it was 2.6m. I know you said I should never reduce the size, but is 10cm a material difference?
2. One more question: If I hang my acoustic panels slightly away from the walls e.g. 8cm, will this be equivalent or similar to adding another 8cm of treatment to that panel? For example, if my acoustic panel is 8cm thick and is flush against the wall, if I use a mechanism to hang the acoustic panel a little away from the way, say 8cm away frm the wall, will this be the equivalent of hanging a 16cm acoustic panel on the wall? If not, how beneficial will this be?
Thanks for your help!
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Post by rock on Sept 4, 2020 20:26:07 GMT
I'll chime in to mention that your absorbers don't reduce your room dimensions when calculating room modes. The hard, rigid boundaries are what determine your room modes etc. so don't worry about absorbers too thick or spaced away from a wall or ceiling.
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Post by rock on Sept 5, 2020 13:43:39 GMT
Jared, for #2, yes.
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Deleted
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Post by Deleted on Sept 5, 2020 14:33:01 GMT
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Post by Hexspa on Sept 5, 2020 16:25:50 GMT
As per Ethan's book, adding absorption actually makes your room appear larger to the sound. He gave examples of before and after heavy absorption and, indeed, the peak frequencies were lowered on the pitch axis.
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