Home Theater Forum and Systems banner

1 - 14 of 14 Posts

·
Moderator Emeritus
Joined
·
606 Posts
Discussion Starter · #1 ·
In my pre-BFD days, I moved my sub around the room and found the spot that sounded best to me was directly behind my listening position. When I got the BFD, I did not move the sub, I just EQed it where it was and was very impressed by the improvement. Later I started to wonder if moving the sub into the corner would give me more headroom, but it sounded good enough that I didn't bother to try it for a while.

I recently read an article that discussed the benefits of corner loading the sub especially with respect to phase and cancellations from the reflections off the walls and floor. The one disadvantage of corner loading is that you will excite all of the room resonances, but thats what the BFD is designed to correct, right?

Well, my wife was out all Sunday afternoon, so I took the opportunity to move the sub and re-EQ. Moral of the story? I gained 4dB!

Not only that, but the new location is in a corner close to my TV and mains. (My TV is in the corner and the sub won;t fit behind it.) I pointed the sub toward the TV so that at least the first reflection is coming from the direction of the mains. The percived directionality of the bass is now much more rooted to the front, instead of the more directionless bass that i had before. It's really great.

I just bought my first floorstanders and was listening to them full-range. I decided to put my pride down and objectively compare them set to "large" and then to "small" with an 80 Hz crossover. Well, you know what I'm going to say. I'm leaving them crossed over. The sub-bass makes so much difference.

BTW, your crossover muct be at least 80 Hz for watching movies with LFE. I recently learned that almost every receiver adds the "small" channels to the LFE before it low-pass filters the sum. If you set the crossover frequency below 80 hZ, you're going to truncate your LFE. (The LFE does extend up to 120 hZ, but it almost never contains much information above 80 hZ.)
 

·
Premium Member
Joined
·
960 Posts
Corner loading was a no-brainer in my situation. I've got a sealed subwoofer so I knew placing it away from all bounderies wouldn't help boost the lower frequencies that roll off much sooner with sealed subs. In my listening room I am flat to ~18hz as a result of corner loading, with output down to 10hz! W/O EQ

Here's my FR


My current mains are rated down to 51hz, and are faithful to this spec. So I also happily crossover at 80hz with great results.
 

·
Registered
Joined
·
2,398 Posts
BTW, your crossover muct be at least 80 Hz for watching movies with LFE. I recently learned that almost every receiver adds the "small" channels to the LFE before it low-pass filters the sum. If you set the crossover frequency below 80 hZ, you're going to truncate your LFE. (The LFE does extend up to 120 hZ, but it almost never contains much information above 80 hZ.)
This would have been the case a few years ago, but most modern receivers don't actually do that anymore. If they don't give you the option of manually setting the LFE crossover independent from the speaker crossover points, most will keep the LFE channel full range (3-120hz).
 

·
Moderator Emeritus
Joined
·
606 Posts
Discussion Starter · #5 ·
Steve - Thanks, I hate to pass off misinformation. Maybe people should at least check to see how their pre-pro or receiver handles the low pass before they set a low crossover for their small channels. I know my Denon manual is not very detailed and doesn't say.

Exocer - Thats a nice in-room response without EQ! Corner loading in my room excited more problematic modes than that, but I handled them with the BFD.
 

·
Registered
Joined
·
472 Posts
Naut
I'm curious,when you moved your sub into the corner did you find that you needed to use more or less bands of EQ to flatten the response.Or did you have mainly one large mode to deal with.
 

·
Moderator Emeritus
Joined
·
606 Posts
Discussion Starter · #7 ·
I was pleased with the added output, but I found that even after EQ the sound was still "boomier" than before. I have since concluded that its important to minimize excitation of the room modes by moving the sub out to the quarter point of my room. I don't get as much LF output, but the quality of the sound is better to me. (I am building an IB sub to solve the output problem.)
 

·
Premium Member
Joined
·
960 Posts
Sounds like a plan...Those IB people are always smiling from ear to ear :D Keep us up to date with that. Have you decided on which drivers you're using yet?
 

·
Moderator Emeritus
Joined
·
606 Posts
Discussion Starter · #9 ·
Yeah, they're in transit. Four MJ-18s from Mach 5 Audio. Check my thread here.
 

·
Registered
Joined
·
472 Posts
Im jealous,I would really like to be able to do an IB like you are but WAF is an issue for me.
Those MJ's look like a great deal
 

·
Moderator Emeritus
Joined
·
606 Posts
Discussion Starter · #11 ·
Use the "Wouldn't it be great to get rid of that box?" angle. Then explain how the built-in sub is completely hidden by a grille!
 

·
Registered
Joined
·
472 Posts
Use the "Wouldn't it be great to get rid of that box?" angle. Then explain how the built-in sub is completely hidden by a grille!
Thats probably the only argument that would get the slightest consideration.Maybe I should move my negotiations in that direction.:R
 

·
Registered
Joined
·
1,585 Posts
Add that the "grille" doesn't have to be the typical black "foam". I've seen pics of IB's with air vents and such as a grill. Now, how much that affects the actual sound is beyond my knowledge to even guess, but, well, it's been done.. as seen here:


or



Or, something like this should be pretty high on the WAF..


or..




Good luck..

JCD
 

·
Registered
Joined
·
472 Posts
I like the white ceiling vent Idea but because our cold winter climate (temp sometime below 20 deg C) I would'nt want to compromise my ceiling insulation.The floor vent would be the only option as long as It did not have to have a large square area .I could fit drivers up into the floor joists underneth.hummmmm.
 
1 - 14 of 14 Posts
Top