Any benefit of Bass Trappings not in corners? - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #1 of 16 Old 12-11-06, 01:40 PM
steve shisler
Inactive
 
Posts: n/a
Any benefit of Bass Trappings not in corners?

I've thought about adding bass trappings for quite some time in my Home Theater. Actually my room is somewhat of a multipurpose room in that it also doubles as a billiards room in the back half of my theater area, and a nice adult beverage area off to one side.

So the wife isn't really into large pieces of anything placed in any of the corners. It dawned on me this weekend that I could hide some owens corning panels underneath the 4' x 8' billiard table and could also hide some behind my 55" mits rear projection unit, and no one but me would even know anything was there.

But neither of these places is in a corner, so I'm thinking that it would be of little to no value.

Expert (and even non-expert) opinions welcomed.
Sponsored Links
Advertisement
 
post #2 of 16 Old 12-11-06, 02:03 PM
Elite Shackster
brucek
 
Join Date: Apr 2006
Posts: 7,514
Re: Any benefit of Bass Trappings not in corners?

Quote:
and even non-expert) opinions welcomed
That's me for sure. I would think that in the same way if you hung curtains on all the walls, the sound would be damped because of the loss of reflective surfaces, the corning panels would provide the same result. This would be more for higher frequencies would it not?

brucek
brucek is offline  
post #3 of 16 Old 12-11-06, 06:48 PM
Senior Shackster
 
Bob_99's Avatar
Bob_99
 
Join Date: May 2006
Location: New York
Posts: 649
Re: Any benefit of Bass Trappings not in corners?

Steve,

I'm not an expert but I just treated my listening area and unfortunately you can't change the physics of sound. For bass trapping, you need to get as much of the wall/wall corners and wall/ceiling corners. Then, deal with the first reflections points. I understand the dilemma of making it look good but unless you want to tear the room apart and build it to hide the treatment, then you just have to try and find something acceptable. My wife has been really outstanding in letting me put panels up and I only had to let her paint whatever she wanted. I may have to pee in a purple bathroom but my listening area sounds pretty good.

Bob
Bob_99 is offline  
 
post #4 of 16 Old 12-11-06, 08:10 PM
steve shisler
Inactive
 
Posts: n/a
Re: Any benefit of Bass Trappings not in corners?

Quote:
Bob_99 wrote: View Post
For bass trapping, you need to get as much of the wall/wall corners and wall/ceiling corners.
This is what I figured to be the case. Particularly since in my room there are 2 corners where I can hear a substantial loudness increase. It sounds as if the bass accumulates in these corners, must be that physics thing.

So with that in mind, I have an HVAC soffit, boxed out in drywall, that runs down the middle of the room, dropped about 9 inches below the height of my drop ceiling and about 14-16 feet long. I wondering if a small base trap at this soffit/ceiling junction would be of value? I think if I did it properly it could blend into the environment fairly easily, but I'm also thinking this small of an area may not be too much of a problem area for bass accumulating.

One of my challenges is that the room sounds pretty good as is. I have a pad and carpet over the concrete floor, an Armtrong acoustic tile drop ceiling and some pretty thick drapes on the 2 windows. So I'm not displeased with the sound quality at all, just trying to tweak it to be even better. Of course my wife thinks I'm nuts as is, so trying to convince her "bass traps" are essential is fighting an uphill battle.
post #5 of 16 Old 12-12-06, 06:58 AM
Senior Shackster
 
Bob_99's Avatar
Bob_99
 
Join Date: May 2006
Location: New York
Posts: 649
Re: Any benefit of Bass Trappings not in corners?

Steve,

The soffit down the middle probably won't do much for the bass but, if I understand your layout correctly, I think that it gives you a great opportunity by considering running fake soffits down the left and right side of the wall/ceiling corner. If you fill the fake soffits with OC703 or equivalent, you should get some really good bass trapping. It will also make the the room look symmetrical and not look out of place (if done correctly). For the front corners, have you considered something like GIK tri-corner traps? They look nice and can easily fit in without being too intrusive. You should also consider measuring the room to see what your decay time looks like. The bottom line though, is this: whatever sounds good to you, is what you are trying to achieve . Do the treatment if it's something that you will enjoy. Personally, I was totally impressed with my results. After I first installed my system, my wife told me that she couldn't tell the difference between my new surround system and a fifteen year old Technique stereo system . Then one day after I treated the room and while we were watching a movie, she told me that the system really sounded good . This totally came out of the blue and I practically soiled myself when she said it :holycow: .

Bob
Bob_99 is offline  
post #6 of 16 Old 12-12-06, 08:44 AM
Shackster
 
yphs_mst's Avatar
Hadi
 
Join Date: Nov 2006
Location: Philadelphia
Posts: 16
Re: Any benefit of Bass Trappings not in corners?

Hello Steve,

If half back of the area is used for other thing, I don't think we need to worry that much on that area (if I understand it correctly). The point between the home theater and the billiard area can be separated be .. say draperies ? I guess putting bass trap like doubling the wall with thin gypsum board near the listening area would work if that's possible. If bass is really a big problem at the listening spot, trapping can be made by cutting PVC at certain length if you know what frequencies the problems are.

Hadi


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
yphs_mst is offline  
post #7 of 16 Old 12-12-06, 08:51 AM
Elite Shackster
brucek
 
Join Date: Apr 2006
Posts: 7,514
Re: Any benefit of Bass Trappings not in corners?

Quote:
trapping can be made by cutting PVC at certain length if you know what frequencies the problems are.
Can you explain this further?

brucek
brucek is offline  
post #8 of 16 Old 12-12-06, 12:44 PM
HTS Senior Moderator
 
bpape's Avatar
Bryan Pape
 
Join Date: Sep 2006
Location: Wildwood, MO (St. Loui
Posts: 5,288
Send a message via AIM to bpape Send a message via Skype™ to bpape
Re: Any benefit of Bass Trappings not in corners?

The absorbtion behind the TV is in the wall/floor corner. It's not a lot but better than nothing. Under the pool table will give you a little but but again, not a lot and will actually filter somewhat as it's in the center of the room. It will be more effective at the 2nd, 4th, etc. harmonics of the mode for the dimension it's centered in.

Would the significant other allow something that looked like Wainscoat on the bottoms of the walls? If so, you could build some wood faced membrane absorbers that would work over a couple of octaves in the bottom end and be pretty effective.

Bryan

I am serious... and don't call me Shirley.

Bryan Pape
Lead Acoustician/Owner
Sensible Sound Solutions
bpape is offline  
post #9 of 16 Old 12-13-06, 03:58 PM
Senior Shackster
 
scott's Avatar
ratchet
 
Join Date: Dec 2006
Location: southern indiana
Posts: 100
Re: Any benefit of Bass Trappings not in corners?

i have read that you can take a concrete form (sonno tube) plug it and fill it with sand for base trapping. of courase it would work in the corners where your wife doesn't want anything, but you could turn it into a kind of pillar to display something of hers! like...baby i want to build you a place to show off your angle figures. that stuff works for me all the time,it's months before she figures out that i somehow benefited from it!
scott is offline  
post #10 of 16 Old 12-14-06, 08:51 AM
Shackster
 
yphs_mst's Avatar
Hadi
 
Join Date: Nov 2006
Location: Philadelphia
Posts: 16
Re: Any benefit of Bass Trappings not in corners?

Quote:
trapping can be made by cutting PVC at certain length if you know what frequencies the problems are.

Can you explain this further?
It's bassically taking the principle of an open-closed tube, match the resonance with a certain frequency and putting it on the node.

by using L=1130/4f (where L is the length of the PVC in feet), and f is the frequency (the diameter of the PVC shouldnt be bigger than 7 inches) we can get the PVC length. Put fiberglass near the opening of the PVC (not on the close end). By putting that on the node (where the frequency is the problem), you'll trap that frequency.

The more fiberglass you put (filling it until the closed end), you'll have a wider bandwidth.

Does that make sense ? My friends have tried this. It works well to trap low frequency, it's just the PVC rings a little bit (around 2-4KHz), it has to be damped at the end.

Hadi


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
yphs_mst is offline  
Reply

Bookmarks

Tags
bass , benefit , corners , trappings

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome