Sub Room Placement Story and Question - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 4 Old 01-05-2004, 10:15 AM - Thread Starter
Member
 
kendenton's Avatar
 
Join Date: Dec 2002
Location: Elmer, NJ
Posts: 171
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
First the story...

I recently replaced a Velodyne CT-80 sub with an HSU VTF-2. Put the new sub in the same location where the old sub was, front of the room left corner. Sounds a lot better, more than just the one-note performer I felt the CT-80 was. Still not that impressed with the 'feel' of the bass. Time to take out the new SPL meter and see what's going on.

Nothing is going on below 35hz from my listening position. I'm down 6db (corrected for meter) at 40hz, and 35 and below don't even move the needle. Before I ordered the sub, I had sent HSU a layout of the room, and of course they suggested placing the sub directly behind the listening position. So I drag the sub over there, frankenstein some cables together to reach the new location, and re-test. Holy rumble batman! I'm level at 40, 31.5, and only down 1db at 25.

So I throw in the Hulk and settle down to check out the new setup. After waiting what seems like an hour for some kind of LFE scene, Bruce finally transforms and wrecks the lab. Oh. My. God. So that's what I've been missing! After the movie, I turn on the lights, and notice that 3 of the hi-hats have dropped about 2" from the drop ceiling. Hee Hee.


Now the question...

The room is 22 feet by 10'4", with a 7.5'x7.5' opening on the front right side for a 'snack bar' area (picture the room as an upside down L). After trying the sub in about 10 locations, the most even response is indeed right behind the sofa (about 16 feet from the front wall), nearly adjacent to the side wall. However, there is one little problem with this location. From my sweet spot (about midway L-R in the room), I'm down almost 10db at 50hz. From the other prime listening spot (next to me on the couch, almost adjacent to the wall the sub is on), that same 50hz is UP almost 10db. Every other frequency is about the same. FWIW, I didn't notice a huge difference while listening to Toy Story 2 and Hulk from either location. Thoughts?

Here's the layout of the room:
http://www.kendenton.org/theaterlayout.jpg
kendenton is offline  
Sponsored Links
Advertisement
 
post #2 of 4 Old 01-05-2004, 12:35 PM
Member
 
Chris A H's Avatar
 
Join Date: Nov 2003
Posts: 19
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Based upon your room width you have will have standing wave issues at 55Hz and room length the secondary wave is at 51hz, so it is the room and not the sub. The fact that you can move around the room and get differing readings confirms this. Also the worst place for standing waves is the in middle of the width of the room (where you primary listening position is) and the middle of the length.

You might try the placing method wherein you put the sub in your listening position then crawl around the room listening for the best bass response. When you find that spot that is where you place the sub.

See this thread for more info on room placement.
Chris A H is offline  
post #3 of 4 Old 01-05-2004, 03:47 PM
AVS Special Member
 
Larry Fine's Avatar
 
Join Date: Sep 2002
Location: Richmond, VA
Posts: 3,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
As an aside, to me, your seating is much too far back. If it were my room, I'd try the sofa where the ceiling description is, place the side speakers directly to the sides, and place the rears on stands (or hang them) about where the sides are now, except about six feet apart.

Maybe it's only me, but I like a big image and near soundfield. My room is 25.5' long by 16' wide, picture is about 10' diag., and seating places heads about 12' from the screen. Nobody has ever said the image is too large.

To me, your room, at more than twice as long as wide (not including the "snack bar"), is too long to use the entire length for sound.

Larry
www.fineelectricco.com
My system (new larger pix!)
Larry Fine is offline  
post #4 of 4 Old 01-05-2004, 04:08 PM - Thread Starter
Member
 
kendenton's Avatar
 
Join Date: Dec 2002
Location: Elmer, NJ
Posts: 171
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Larry,
Quote:
As an aside, to me, your seating is much too far back. If it were my room, I'd try the sofa where the ceiling description is, place the side speakers directly to the sides, and place the rears on stands (or hang them) about where the sides are now, except about six feet apart.
My biggest obstacle to that is the projected image from the Matinee 1HD - anything much closer than where I am now and SDI becomes a larger issue.

When I made the drawing I had guessed at the location of the couch, but now I've had a chance to actually measure it (all other dimensions are accurate). The back of the sofa (ear position?) is 13' from the screen, so the sofa is actually more towards the center of the room.

I agree that the length of the room is not ideal, but I'm kinda stuck with it. Thanks for the advice, though.
kendenton is offline  
Closed Thread Subwoofers, Bass, and Transducers

User Tag List

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


Forum Jump: 

Posting Rules  
You may not post new threads
You may not 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 code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off