Help with Nulls - Blu-ray Forum

DjGuinness · 03-09-2010, 01:07 AM

So I did a subwoofer crawl, placing my sub at my seating position and going around the room, staying low and looking for peaks.

For the most part, the front 2 corners did well, with the right corner being slightly smoother. Smooth all the way down to below 40 Hz. Playing a 30 Hz tone was near inaudible in both front corners, and as is 30 Hz cannot be heard where I sit. I can push it till it sounds like the windows are going to break, but can't hear anything.

However in the back two corners, 30hz is heard deep and clear, while 40hz doesn't seem to have the same smoothness as the front corners.

Is it normal to have a peak for a certain frequency range in one area, while another range is completely nulled?

Is that the big advantage of having two subs? Would you all suggest I look into getting another sub for the back corner as well? As it stands right now with one sub, where should be it's permanent spot, front or back corner?

erict · 03-09-2010, 01:20 AM

Quote:

Originally Posted by DjGuinness

So I did a subwoofer crawl, placing my sub at my seating position and going around the room, staying low and looking for peaks.

For the most part, the front 2 corners did well, with the right corner being slightly smoother. Smooth all the way down to below 40 Hz. Playing a 30 Hz tone was near inaudible in both front corners, and as is 30 Hz cannot be heard where I sit. I can push it till it sounds like the windows are going to break, but can't hear anything.

However in the back two corners, 30hz is heard deep and clear, while 40hz doesn't seem to have the same smoothness as the front corners.

Is it normal to have a peak for a certain frequency range in one area, while another range is completely nulled?

Is that the big advantage of having two subs? Would you all suggest I look into getting another sub for the back corner as well? As it stands right now with one sub, where should be it's permanent spot, front or back corner?

Yes. I would try building a riser and see if it changes anything. Get something temporary to raise the sub up 8 to 12 inches and retest.

DjGuinness · 03-09-2010, 01:27 AM

Quote:

Originally Posted by erict

Yes. I would try building a riser and see if it changes anything. Get something temporary to raise the sub up 8 to 12 inches and retest.

I tired raising the sub, it was on a cardboard box, though it was sturdy with a perfectly fit brick of styrofoam in it, the box was about eight inches high. That would be OK right?

Well I had the sub raised and I did notice the sub was louder and cleaner, but I still had the null at 30 Hz in the front corners.

Big Daddy · 03-09-2010, 01:59 AM

Yes, two or four subwoofers can help. Read A Guide to Subwoofers (Part II): Standing Waves & Room Modes.

Driver_King · 03-09-2010, 02:12 AM

Have you recently run your automatic calibration on your receiver? If so, have you adjusted the phase on the subwoofer to see what sorts of results you get? By the way, you should try experimenting with different heights all the way up to 24" off the ground. Dual subwoofers would certainly help. It is also possible that at your seating position, you simply have a null.

crazyBLUE · 03-09-2010, 02:17 AM

Quote:

Originally Posted by Big Daddy

Yes, two or four subwoofers can help. Read A Guide to Subwoofers (Part II): Standing Waves & Room Modes.

Is 3 kinda in between working & not working

Driver_King · 03-09-2010, 02:20 AM

Crazy, it's more like in-between nearly ideal and ideal.

You're on the right track. Add one more and you'll be in the ideal range.

crazyBLUE · 03-09-2010, 02:25 AM

Quote:

Originally Posted by Driver_King

Crazy, it's more like in-between nearly ideal and ideal.

You're on the right track. Add one more and you'll be in the ideal range.

Now all I need to do is figure out where to put it . Maybe on the ceiling in the center of the room facing down

Big Daddy · 03-09-2010, 02:34 AM

Quote:

Originally Posted by crazyBLUE

Now all I need to do is figure out where to put it . Maybe on the ceiling in the center of the room facing down

Don't forget on the sofa next to you. Nothing is better than cuddling with a subwoofer. No woman can match the vibrations.

crazyBLUE · 03-09-2010, 02:48 AM

Quote:

Originally Posted by Big Daddy

Don't forget on the sofa next to you. Nothing is better than cuddling with a subwoofer. No woman can match the vibrations.

That was good Big Daddy

You are right too

The center ceiling idea is starting to sound good . I wonder what that would do with the bass in the room . I am sitting here trying to imagine having it come from the front & sides & from above

DjGuinness · 03-09-2010, 02:51 AM

Quote:

Originally Posted by Big Daddy

Don't forget on the sofa next to you. Nothing is better than cuddling with a subwoofer. No woman can match the vibrations.

I'm sure this sub will be quite nice to cuddle with.

http://www.techeblog.com/index.php/t...inch-subwoofer

Big Daddy · 03-09-2010, 03:20 AM

Quote:

Originally Posted by DjGuinness

I'm sure this sub will be quite nice to cuddle with.

http://www.techeblog.com/index.php/t...inch-subwoofer

No, that subwoofer is too mucho. I prefer to cuddle with THIS SUBWOOFER.

crazyBLUE · 03-09-2010, 03:33 AM

Quote:

Originally Posted by Big Daddy

No, that subwoofer is too mucho. I prefer to cuddle with THIS SUBWOOFER.

Can you make that pic any BIGGER !

Big Daddy · 03-09-2010, 03:35 AM

Quote:

Originally Posted by crazyBLUE

Can you make that pic any BIGGER !

Be honest. You want me to remove her arms and thigh so that you can check her low-end performance.

DjGuinness · 03-09-2010, 03:39 AM

Quote:

Originally Posted by Big Daddy

No, that subwoofer is too mucho. I prefer to cuddle with THIS SUBWOOFER.

Even better

By the way it seems like forever I last seen Jensen speakers.

crazyBLUE · 03-09-2010, 03:41 AM

Quote:

Originally Posted by Big Daddy

Be honest. You want me to remove her arms and thigh so that you can check her low-end performance.

Priceless ~ Big Daddy

03-09-2010, 01:07 AM	#1
DjGuinness Active Member Member since:Nov 2009 Location:FLooRI.D.A	Help with Nulls So I did a subwoofer crawl, placing my sub at my seating position and going around the room, staying low and looking for peaks. For the most part, the front 2 corners did well, with the right corner being slightly smoother. Smooth all the way down to below 40 Hz. Playing a 30 Hz tone was near inaudible in both front corners, and as is 30 Hz cannot be heard where I sit. I can push it till it sounds like the windows are going to break, but can't hear anything. However in the back two corners, 30hz is heard deep and clear, while 40hz doesn't seem to have the same smoothness as the front corners. Is it normal to have a peak for a certain frequency range in one area, while another range is completely nulled? Is that the big advantage of having two subs? Would you all suggest I look into getting another sub for the back corner as well? As it stands right now with one sub, where should be it's permanent spot, front or back corner?

03-09-2010, 02:12 AM	#5
Driver_King Blu-ray Ninja Top contributor Member since:Jan 2008 Location:Tampa Bay, Florida Home Theater Gallery:96 Blu-ray collection:28 Trading Score:10	Have you recently run your automatic calibration on your receiver? If so, have you adjusted the phase on the subwoofer to see what sorts of results you get? By the way, you should try experimenting with different heights all the way up to 24" off the ground. Dual subwoofers would certainly help. It is also possible that at your seating position, you simply have a null. Last edited by Driver_King; 03-09-2010 at 02:17 AM.

03-09-2010, 01:59 AM	#4
Big Daddy Blu-ray Champion Top ranked HT gallery Member since:Jan 2008 Location:Southern California Home Theater Gallery:79 Blu-ray collection:122 Trading Score:1	Yes, two or four subwoofers can help. Read A Guide to Subwoofers (Part II): Standing Waves & Room Modes.

03-09-2010, 02:20 AM	#7
Driver_King Blu-ray Ninja Top contributor Member since:Jan 2008 Location:Tampa Bay, Florida Home Theater Gallery:96 Blu-ray collection:28 Trading Score:10	Crazy, it's more like in-between nearly ideal and ideal. You're on the right track. Add one more and you'll be in the ideal range.

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