Saldog's Basement Build Thread
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saldog
Active Member
I realized over the weekend that I hadn't updated this thread in awhile. I did end up getting an actual screen. It's an Elite Screen 125" (diag) 2.35:1, with the CineWhite material. View Size: 48.9" H x 115.2" W. It seems quite good for the money. It's definitely brighter than when we were just projecting on a white primed wall. It also just seems to finish the space aesthetically.
I'd still like to hang some velvet curtains mounted under the screen to hide all the wires and wall plates.
From second row:
From just behind 1st row:
You can see clearly in this one where we painted the ceiling black near the screen:
I'd still like to hang some velvet curtains mounted under the screen to hide all the wires and wall plates.
From second row:
From just behind 1st row:
You can see clearly in this one where we painted the ceiling black near the screen:
saldog
Active Member
So you can see by the bare side wall in the last picture above, I have not done the whole acoustic panel thing yet. I am still deciding whether i want to DIY or buy them, but either way, i'd like to come up with a treatment plan. My initial thought is to treat 3 places:
1) Primary early reflection points on side walls
2) Ceiling reflection points (as much as i can due to the soffit. i am not going to reduce ceiling height more by putting panels on the soffit itself)
3) Behind the front L&R speakers
Thoughts? Are the ones behind the L&R speakers worthwhile? I keep hearing about the Allison Effect, etc.
So here is the plan schematically. The grey rectangles are the proposed acoustic panels.
1) Primary early reflection points on side walls
2) Ceiling reflection points (as much as i can due to the soffit. i am not going to reduce ceiling height more by putting panels on the soffit itself)
3) Behind the front L&R speakers
Thoughts? Are the ones behind the L&R speakers worthwhile? I keep hearing about the Allison Effect, etc.
So here is the plan schematically. The grey rectangles are the proposed acoustic panels.
For the most impressive stereo performance, you should focus on Symmetry - it is the Lord God Master of stereo imaging.
So, if the ceiling panels cannot be centered, you may be better off making them smaller so they are balanced between left and right.
Also, for the Soffit, a thin 3/4" panel mounted directly to the ceiling is better than nothing. You do lose a little height, but it isn't the end of the world. You could get some thin compressed fiberglass panels and mount them flush against the ceiling where the soffit is then let them extend out into the room where they are separated from the higher ceiling. You could even place some other panels on top of the ones which extend from the soffit to get the most of the opportunity.
As for the side panels, that may be more than you need. I would look into using some geometry to specifically address first order reflections for each seating location and nothing else. Then, spend the rest of your acoustics budget on bass traps.
So, if the ceiling panels cannot be centered, you may be better off making them smaller so they are balanced between left and right.
Also, for the Soffit, a thin 3/4" panel mounted directly to the ceiling is better than nothing. You do lose a little height, but it isn't the end of the world. You could get some thin compressed fiberglass panels and mount them flush against the ceiling where the soffit is then let them extend out into the room where they are separated from the higher ceiling. You could even place some other panels on top of the ones which extend from the soffit to get the most of the opportunity.
As for the side panels, that may be more than you need. I would look into using some geometry to specifically address first order reflections for each seating location and nothing else. Then, spend the rest of your acoustics budget on bass traps.
saldog
Active Member
Thanks for the compliments, guys, and the suggestions, Flint. You are right, i could do a 1" on the soffit.
How's this look? Green dashed line is the room centerline. The tan rectangle is the trim between black/white ceiling, so a panel can't go across that.
I did a little geometry and that covers all 1st reflection points for the front row, and most of the second row. The cloud covers all 1st reflections for the 1st row couch. And it's symmetrical!
Are the ones behind the speakers less important? Those seem to be recommended often on AVS.
How's this look? Green dashed line is the room centerline. The tan rectangle is the trim between black/white ceiling, so a panel can't go across that.
I did a little geometry and that covers all 1st reflection points for the front row, and most of the second row. The cloud covers all 1st reflections for the 1st row couch. And it's symmetrical!
Are the ones behind the speakers less important? Those seem to be recommended often on AVS.
I like the new acoustic panel layout quite a bit.
Behind the speakers is, indeed, important, but it needs to be the sort of acoustic technology which can absorb down to below the step response null frequency. There are a ton of step response null calculators out there, so if the null is at something like 210Hz, you need a panel which can absorb 50% or more of the energy down to 175Hz or so, which is a really thick piece of fiberglass or a proper bass trap. It gets complicated, eh?
However, smaller panels behind the speakers are still good because they generally soften the room in a part of the room where reflections can smear the sound from the speakers. So, if you cannot put a large, thick and bass effective panel behind the speakers to address the baffle step null, then move the panels from directly behind the speaker and put them to the inside of the speaker and around the screen.
Behind the speakers is, indeed, important, but it needs to be the sort of acoustic technology which can absorb down to below the step response null frequency. There are a ton of step response null calculators out there, so if the null is at something like 210Hz, you need a panel which can absorb 50% or more of the energy down to 175Hz or so, which is a really thick piece of fiberglass or a proper bass trap. It gets complicated, eh?
However, smaller panels behind the speakers are still good because they generally soften the room in a part of the room where reflections can smear the sound from the speakers. So, if you cannot put a large, thick and bass effective panel behind the speakers to address the baffle step null, then move the panels from directly behind the speaker and put them to the inside of the speaker and around the screen.
saldog said:Thanks for the compliments, guys, and the suggestions, Flint. You are right, i could do a 1" on the soffit.
How's this look? Green dashed line is the room centerline. The tan rectangle is the trim between black/white ceiling, so a panel can't go across that.
I did a little geometry and that covers all 1st reflection points for the front row, and most of the second row. The cloud covers all 1st reflections for the 1st row couch. And it's symmetrical!
Are the ones behind the speakers less important? Those seem to be recommended often on AVS.
Mike, What is the Gold Colored Bar just behind the ceiling panels? Keith
D
Deleted member 133
Guest
When I treated my HT, I used sixteen (16) black 24" x 48" x 2" Acoustic Ceiling panels from Audiotec USA.
I'm no good at CAD drawings so I'll describe where they went.
I used six (6) panels on the ceiling, covering pretty much every reflection point from all speakers.
I used two (2) panels on the front wall - positioned vertically, pretty much in the space between the left and right stacks - and the centre stack of speakers. Almost all of the front wall is also draped in lightweight black fabric - but that's not for acoustic purposes; rather it's to absorb light that passes through the screen that could get reflected off the wall and back onto the screen. (It's an acoustically-transparent material, and somewhat light transparent as well, hung far enough in front of the front wall to allow a full stack of speakers to sit behind it.) First noticed this as an issue with the end credits of Battlestar Galactica - scrolling white lettering on black background.
I used four (4) panels along each side wall - again covering all the reflection points.
The treatments are all symmetrically placed. They were easily put in place with liquid nails - both on flat and stippled surfaces.
The rear of the HT is open to the rest of the house and acts as a giant bass trap. No treatments - except that the opening is covered with two layers of thick drapes (primarily to ensure a dark HT). Bass passes through; everything else: there's no reflection and a lot of absorption.
The floor has a large area rug and underpad. All of the stacks sit on concrete slab.
My modus operandi has been to over, rather than under, treat. Given the size and proximity of the speakers stacks, both to the walls and the listener, and very small size of the room itself (relative to most members' rooms that I've been in - with the exception of Zing's, which is comparable in overall size) I thought it necessary to do so.
I can no longer find Adiotec's web site, however I see them for sale here http://www.hometheaterplus.com/auusa48accep.html. The asking price per panel is almost twice what I paid for mine. But I bought direct from AudiotecUSA, way back when.
Jeff
I'm no good at CAD drawings so I'll describe where they went.
I used six (6) panels on the ceiling, covering pretty much every reflection point from all speakers.
I used two (2) panels on the front wall - positioned vertically, pretty much in the space between the left and right stacks - and the centre stack of speakers. Almost all of the front wall is also draped in lightweight black fabric - but that's not for acoustic purposes; rather it's to absorb light that passes through the screen that could get reflected off the wall and back onto the screen. (It's an acoustically-transparent material, and somewhat light transparent as well, hung far enough in front of the front wall to allow a full stack of speakers to sit behind it.) First noticed this as an issue with the end credits of Battlestar Galactica - scrolling white lettering on black background.
I used four (4) panels along each side wall - again covering all the reflection points.
The treatments are all symmetrically placed. They were easily put in place with liquid nails - both on flat and stippled surfaces.
The rear of the HT is open to the rest of the house and acts as a giant bass trap. No treatments - except that the opening is covered with two layers of thick drapes (primarily to ensure a dark HT). Bass passes through; everything else: there's no reflection and a lot of absorption.
The floor has a large area rug and underpad. All of the stacks sit on concrete slab.
My modus operandi has been to over, rather than under, treat. Given the size and proximity of the speakers stacks, both to the walls and the listener, and very small size of the room itself (relative to most members' rooms that I've been in - with the exception of Zing's, which is comparable in overall size) I thought it necessary to do so.
I can no longer find Adiotec's web site, however I see them for sale here http://www.hometheaterplus.com/auusa48accep.html. The asking price per panel is almost twice what I paid for mine. But I bought direct from AudiotecUSA, way back when.
Jeff
saldog
Active Member
I ended up deciding to do the acoustic panels in 2 phases. Phase 1: the essentials, and they'd be most visible, so I wanted to get pre-made ones. So i ordered 9x 4'x2' (3.6" thick) panels from GIK Acoustics for the side walls and one for the ceiling. Phase 2 will be DIY'ing the others for the ceiling. The more i thought about the ones behind the speakers (and referencing Flint's primer on first reflection points), i realized the proper placement would be blocking the screen, so i'll reevlauate those later.
For now, this is what i'll look like in ~ a week when they get here.
Stay tuned after this weekend, though, as there may be another important upgrade to the theater...
For now, this is what i'll look like in ~ a week when they get here.
Stay tuned after this weekend, though, as there may be another important upgrade to the theater...