Need qualified room acoustician

[Andrew Steele]

Audioguy, can I clarify that the ceiling is 9' at the edge of the room? It then opens up into the front absorptive and rear diffusive areas? Can you also tell me the width of the soffit around the edges.

Thanks,

Andrew

 

[audioguy]

Audioguy, can I clarify that the ceiling is 9' at the edge of the room? It then opens up into the front absorptive and rear diffusive areas? Can you also tell me the width of the soffit around the edges.

Thanks,

Andrew

The ceiling is 9 feet in the middle but the outside area is all soffited. The soffit is 21 inches deep (measured from the wall toward the center of the room) and hangs down about a foot. Please note that the front part of the room may be 8'11' and the back part (see earlier photos) is really open so it goes up to the floor above. So the height in the rear of the room is more like 9'9".

 

[Andrew Steele]

Thanks for that - can you tell me current location and models of your LCR speakers and the distance of your head from the front wall.

Can you also take a photo that captures the new front wall & ceiling treatments, when possible.

 

[audioguy]

Thanks for that - can you tell me current location and models of your LCR speakers and the distance of your head from the front wall.

Can you also take a photo that captures the new front wall & ceiling treatments, when possible.

I'm curious where we are going with this. I have no issue with taking the photos and posting them (the front wall is all black except the screen so won't show much) but I guess I'd like to know why. As for the speakers and distances, the "glare issue" I am having has occurred with 5 very different speakers (Dunlavy SC-IV-A, Theil 3.5, Seaton Catalysts, Some Radio Shack speaker the model number of which escapes me and one other small speaker) all placed at distances from right up next to the front wall to about 7 feet from the front wall and right up next to the side wall and about 3 feet from it and listening positions that varied equally as much. Furthermore, I switched the speakers to the other end of the room (180 degrees) and have tried multiple amps, preamps, power cords, DAC's, CD players, etc. NONE of these changes eliminated the "glare".

To eliminate the back wall, last night I had a 4 inch thick wall of acoustic panels 5 feet high and 5 feet wide placed right behind my listening position. Did nothing for the "glare". I have covered the front of the room (the floor) in about 6 inches of OC703 and that did nothing. I have covered the entire front wall of the room with 2 inches of OC703 and that did nothing.

Since I have tried so many different things for the past 3 years (all unsuccessfully) to try to locate the source of the problem, I'm just curious of where you might be going with your requests.

 

[Andrew Steele]

I'm building a model

I've already run it through one of my available raytracing packages, the room models nicely with a EDT and T30 that sits right on 260ms across all frequencies. There are no obvious issues being thrown up looking at the other metrics available. Which is inline with what I thought I'd see using a raytracing package, If the source of your upper midrange glare problem is what I think it could be - no raytracing package is going to pick it up. I don't want to get you excited just yet, I'd like to adjust the model first based on your current layout and treatments.

 

[audioguy]

Tweeter is about 43 inches from side wall and 60 inches from "screen wall". The "screen wall" is actually 1 inch RPG BAD panels on the left and right of the screen and 1 inch 703 above and below the screen. These sit about 5 inches off the real wall, which is covered with 2 inch OC703.

I tried taking a photo of the speaker but a black speaker against a black wall doesn't photograph very well. I edited it a bit (adjusted the contrast and brightness) so that at least you can see it. I also took a photo of my "ceiling cloud" located in the front part of the room.

 

[Andrew Steele]

Thanks for that - Just for you information, I'm on holiday this week (snowboarding in the alps) but I'll take a look at it on one of my no-ski days, most probably Wednesday.

 

[audioguy]

I'm on holiday this week (snowboarding in the alps)

That's disgusting

 

[Andrew Steele]

Audioguy,

Long time no see, apologies for the delay - I've been a busy, busy man.


You mentioned that you had a quantity of 2" & 4" 703 you've been using to troubleshoot what you're hearing.

If you're interested, I've included below two investigations to get an idea what you hear change when absorptive material is placed in these locations.

The locations suggested have been fine-tuned with raytracing studies that were conducted based on your latest information.

I understand gravity makes this a task, let me know when you have success temporarily propping/mounting the panels. Have a good listen to each investigation and share your observations.

Regards,

Andrew

 

[audioguy]

Thanks for the recommendations. I had already thought of the first two spots and had panels built but they were too thick (a mistake by GIK) and blocked the light from the PJ. I will have them remade.

Your recommendations do make some sense since those are the only non treated surfaces in the room!

I will keep you posted.

Thanks again,

 

[zootallures]

Acoustic design

I just saw this thread and I am surprised no one mentioned Acoustic Sciences Corp. I had them do a room for me and also a recording studio and it tested wonderfully and they are great to work with.
Check out www.acousticsciences.com

 

[Steve Williams]

My entire room was done by Art Noxon at Acoustic Sciences. In fact there is a picture of my room on their home page

http://www.asc-home-theater.com/

Welcome to the forum

 

[audioguy]

In the first iteration of my listening room in my other home, I used ASC products (ceiling, corners, side wall, et al) but I re-did that room and wanted all of the stuff "built in/integrated". Same with this room. Which is why I did not use ASC.

 

[audioguy]

The locations suggested have been fine-tuned with raytracing studies that were conducted based on your latest information.

I understand gravity makes this a task, let me know when you have success temporarily propping/mounting the panels. Have a good listen to each investigation and share your observations.

Regards,

Andrew

You were right about gravity!! I tried using Duct tape but it did not do well as the piece of 703 fell after about 5 to 10 minutes . I went ahead and ordered from GIK two more of the panels that are already on the ceiling. I should get them (permanently) installed some time next week and will do some listening (which may not be until the week after that). I have repurchased my Dunlavy SC VI's (550 pounds each) and they are to be delivered this Friday. Once they are in place, I can do some serious listening and evaluating.

Depending on the results of the listening, I will try to figure out a better way to hold up some 703 for the second iteration (maybe screws with washers).

Thank you again for your efforts. Would you be willing to share with me on the forum or in a PM what your tracing results looked like so I can get a better feel for how you came to your recommendations?

 

[AudioNMe]

I hope you don't mind me suggesting a different approach. It won't cost you anything but an afternoon.

Instead of patching (adding more absorption), have you tried to identify the source of the problem? Try the less is more approach. Maybe you have so much absorption in the room that it is sucking the life out of the midrange - hence the glare. Have you tried moving the furniture out and removing the treatment that is not built in? You could even go as far as temporarily covering the built in stuff with plywood borrowed from Home Depot. The ceiling would be hard to cover but the built in wall stuff you could just lean plywood panels against it. Now if that removes the glare you then slowly bring stuff back in and listen for the changes.
Forget about measurements for this test. Use you ears.

 

[audioguy]

I hope you don't mind me suggesting a different approach. It won't cost you anything but an afternoon.

Instead of patching (adding more absorption), have you tried to identify the source of the problem? Try the less is more approach. Maybe you have so much absorption in the room that it is sucking the life out of the midrange - hence the glare. Have you tried moving the furniture out and removing the treatment that is not built in? You could even go as far as temporarily covering the built in stuff with plywood borrowed from Home Depot. The ceiling would be hard to cover but the built in wall stuff you could just lean plywood panels against it. Now if that removes the glare you then slowly bring stuff back in and listen for the changes.
Forget about measurements for this test. Use you ears.

Interesting thought but it would be more than a bit difficult. And the room has diffusion or reflection in the front third (except the front ceiling which I just replaced diffusive with absorptive and made a huge positive difference). The front wall is diffusion; the front side walls are diffusion and some absorption and it has hardwood floors. The only real absorption is 3 panels on the back third of the side wall and the front of all of the bass traps. The rear wall is all diffusion.

Measuring has NEVER indicated I had a glare problem but anyone who listened could hear it.

I am making considerable progress following the current path and should this run into a dead end, I will give your idea a try, although there is very little that I can change short of removing the rear side wall absorptive panels.

I do appreciate the idea.

 

[Nyal Mellor]

Interesting thought but it would be more than a bit difficult. And the room has diffusion or reflection in the front third (except the front ceiling which I just replaced diffusive with absorptive and made a huge positive difference). The front wall is diffusion; the front side walls are diffusion and some absorption and it has hardwood floors. The only real absorption is 3 panels on the back third of the side wall and the front of all of the bass traps. The rear wall is all diffusion.

Measuring has NEVER indicated I had a glare problem but anyone who listened could hear it.

I am making considerable progress following the current path and should this run into a dead end, I will give your idea a try, although there is very little that I can change short of removing the rear side wall absorptive panels.

I do appreciate the idea.

Do you have an ETC of the room you could post?

 

[audioguy]

Do you have an ETC of the room you could post?

And ETC would stand for?

 

[Nyal Mellor]

And ETC would stand for?

Energy time curve

 

[Andrew Steele]

I went ahead and ordered from GIK two more of the panels that are already on the ceiling. I should get them (permanently) installed some time next week and will do some listening... Once they are in place, I can do some serious listening and evaluating.

I should reiterate that the purpose of the suggested investigation locations is to identify via the use of 'band-aid' treatments and that the panel layout is by no means a suggestion for the permanent solution. If listening tests show tangible improvements, we can then look at moving forward to a permanent treatment solution that maintains your room performance/aesthetic goals.

Depending on the results of the listening, I will try to figure out a better way to hold up some 703 for the second iteration (maybe screws with washers).

If investigation A provides a large improvement (or no improvement at all), I recommend you still continue with Investigation B.

I have some suggestions for non-invasive temporary mounting options:
1. Propping up with 1"x1" lumber or similar, I imagine the stiffness of 703 would only require a single piece/strut per 24"x48" panel.
2. 3M Command strips - may work depending on how well it adheres to the 703...?

Would you be willing to share with me on the forum or in a PM what your tracing results looked like so I can get a better feel for how you came to your recommendations?

I ran a full test on the model of your room. Results came back as expected - nothing out of the ordinary. Which is what I was hoping for based on the limits of all acoustic prediction software.

I'll PM you with more info. I might post something here later.