Did a ceiling cloud just make my room worse?
Posted: Fri Mar 27, 2020 1:45 pm
Greetings all. This is my first acoustics post and I'd love your collective wisdom on the below...
I've just built and installed a bunch of broadband traps and have seen a significant improvement in my room response. However, I finally installed my cloud and can't help but think that in some respects it's made things worse. Here's the background information:
My room dimensions are 4260mm (L) x 3665mm (W) x 3020mm (H). My speakers are on the 3665mm (W) wall, firing down the length. The house is old with a timber frame and weatherboards with no in-wall insulation. There is a large window at the front of the room. In other words, sound can readily enter (and escape) my room.
I have so far installed:
- Large floor-to-ceiling superchunks in each of the front corners (~83cm across the face)
- Two 600mm x 1200mm x 300mm thick RFZ panels on both the L and R side walls at the first reflection points (ie a total of 1200mm x 1200mm x 300mm on both sides)
- 200mm thick corner straddling panels (600mm width) spanning both the front-wall / ceiling corner, rear-wall / ceiling corner
The insulation I've used is polyester and has a published GFR of 7994 Mks rayl/m.
The room is sounding good and shows marked improvements on REW (however I am likely to cover some of the corner traps with plastic to bring a little life back into the room).
So far so good.
However, I've just installed the cloud which is 1800mm x 1200mm x 300mm with a 200mm gap from the ceiling. I used a local equivalent of pink fluffy (fibreglass - published GFR of 5840).
And here's where things get confusing. I'm no expert with REW but any improvements after adding the cloud appear to be marginal at best. In fact, the right speaker now seems to have a null at around 134Hz. I'm not sure if the cloud is making things better or worse. I even swapped out the pink fluffy for the 7994 Mks rayl/m polyester to see if that made a difference but I'm struggling to see any even though at that depth the lower GFR fluffy is theoretically marginally better at absorbing at lower frequencies. I've even tried moving the speakers about a little, including right up against the front wall but if anything this exacerbates the frequency swings.
Can anyone analyse my mdat file to see if I'm going crazy? Have I fixed one problem only to reveal another?
My primary question is: Would you stick with the fibreglass or the polyester or ditch the cloud entirely?
Any suggestions would be most welcome as I'm feeling a little deflated after all the effort of building and mounting the cloud. Perhaps there are improvements overall in some of the other graphs I'm less familiar with.
Here is the Dropbox link to the Mdat file which displays L, R and L+R with no cloud, fibreglass cloud, and polyester cloud.
The attached images are from the right speaker only. The brown frequency response curve is with no cloud, and the green curve with the fibreglass cloud.
The low end tails on the waterfalls seem to change between measurements and across the day (same treatment and same mic and speaker positions) so I suspect some of these tails are noise pollution - traffic rumble etc - from outside but can't be sure.
I'm aware there are other problems in the room, especially the lack of L and R symmetry. Any advice across the board would be gratefully received!
ps - I've also posted this call for assistance on another well known forum. I hope that's OK.
I've just built and installed a bunch of broadband traps and have seen a significant improvement in my room response. However, I finally installed my cloud and can't help but think that in some respects it's made things worse. Here's the background information:
My room dimensions are 4260mm (L) x 3665mm (W) x 3020mm (H). My speakers are on the 3665mm (W) wall, firing down the length. The house is old with a timber frame and weatherboards with no in-wall insulation. There is a large window at the front of the room. In other words, sound can readily enter (and escape) my room.
I have so far installed:
- Large floor-to-ceiling superchunks in each of the front corners (~83cm across the face)
- Two 600mm x 1200mm x 300mm thick RFZ panels on both the L and R side walls at the first reflection points (ie a total of 1200mm x 1200mm x 300mm on both sides)
- 200mm thick corner straddling panels (600mm width) spanning both the front-wall / ceiling corner, rear-wall / ceiling corner
The insulation I've used is polyester and has a published GFR of 7994 Mks rayl/m.
The room is sounding good and shows marked improvements on REW (however I am likely to cover some of the corner traps with plastic to bring a little life back into the room).
So far so good.
However, I've just installed the cloud which is 1800mm x 1200mm x 300mm with a 200mm gap from the ceiling. I used a local equivalent of pink fluffy (fibreglass - published GFR of 5840).
And here's where things get confusing. I'm no expert with REW but any improvements after adding the cloud appear to be marginal at best. In fact, the right speaker now seems to have a null at around 134Hz. I'm not sure if the cloud is making things better or worse. I even swapped out the pink fluffy for the 7994 Mks rayl/m polyester to see if that made a difference but I'm struggling to see any even though at that depth the lower GFR fluffy is theoretically marginally better at absorbing at lower frequencies. I've even tried moving the speakers about a little, including right up against the front wall but if anything this exacerbates the frequency swings.
Can anyone analyse my mdat file to see if I'm going crazy? Have I fixed one problem only to reveal another?
My primary question is: Would you stick with the fibreglass or the polyester or ditch the cloud entirely?
Any suggestions would be most welcome as I'm feeling a little deflated after all the effort of building and mounting the cloud. Perhaps there are improvements overall in some of the other graphs I'm less familiar with.
Here is the Dropbox link to the Mdat file which displays L, R and L+R with no cloud, fibreglass cloud, and polyester cloud.
The attached images are from the right speaker only. The brown frequency response curve is with no cloud, and the green curve with the fibreglass cloud.
The low end tails on the waterfalls seem to change between measurements and across the day (same treatment and same mic and speaker positions) so I suspect some of these tails are noise pollution - traffic rumble etc - from outside but can't be sure.
I'm aware there are other problems in the room, especially the lack of L and R symmetry. Any advice across the board would be gratefully received!
ps - I've also posted this call for assistance on another well known forum. I hope that's OK.