Sub driver faces the wall- Do I need treatments? - AVS Forum
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Sub driver faces the wall- Do I need treatments?

My room is 21ft deep and 17 feet wide. In the right front corner of my room I will have the sub placed. It is an Epic Empire which has the dual side firing 15" drivers. Since its in the corner. 1 driver will be about 12-24" away from the wall facing the drywall. Do I need any sort of treatment on the wall or in the corner for this since it is so close to the drywall?
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post #2 of 8 Unread Yesterday, 04:22 PM
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You are fine as is (even 6-inches is fine), provided you did the subwoofer crawl test and that test told you to put it there.

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post #3 of 8 Unread Yesterday, 04:25 PM - Thread Starter
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Quote:
Originally Posted by dsrussell View Post
You are fine as is (even 6-inches is fine), provided you did the subwoofer crawl test and that test told you to put it there.

I did not do the subwoofer crawl test nor do I even know what it is.

EDIT: I just google searched it. I can try it but the room is already wired up for the sub in the corner of the room. Only issue is this sub is 120#s so getting it up on the seating to do this test is not going to happen

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Well, that's not good. I suspect you just thought your sub would look best in the corner . Because bass frequencies have such long wavelengths, standing waves play havoc in the room (nulls and peaks). All rooms have this problem. Just walk around your room right now and you will find areas where you can't hear the bass and where it sounds bloated.

A subwoofer crawl test is used to find the optimum location of your subwoofer so that it gives you the best, cleanest, smoothest and loudest bass at your listening position. You set the subwoofer on top of your listening position (couch or chair) and run some test frequencies (free downloads from the net), or use music with low, sustained bass notes. You then crawl around the perimeter of the room and note where the sub sounds the best. You'll find null areas (can't hear the bass), peak areas (where the bass is bloated or boomy), and hopefully areas that really sound great. It is in that best spot where you should place your subwoofer.

Of course, for all I know, you accidentally found the best place .
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Yep, 120 pounds is a 2-man lift. Just move the chair or couch out of the way and locate it there.

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Quote:
Originally Posted by Juiced46 View Post
Only issue is this sub is 120#s so getting it up on the seating to do this test is not going to happen
You don't need to lift it onto the seating, just place it on the floor. You may think of it being 120lbs, but in reality a sub is more akin to an 800lb. gorilla. It doesn't go where you want it to go, it goes where it wants to go.
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post #7 of 8 Unread Today, 10:11 AM - Thread Starter
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Quote:
Originally Posted by dsrussell View Post
Well, that's not good. I suspect you just thought your sub would look best in the corner . Because bass frequencies have such long wavelengths, standing waves play havoc in the room (nulls and peaks). All rooms have this problem. Just walk around your room right now and you will find areas where you can't hear the bass and where it sounds bloated.

A subwoofer crawl test is used to find the optimum location of your subwoofer so that it gives you the best, cleanest, smoothest and loudest bass at your listening position. You set the subwoofer on top of your listening position (couch or chair) and run some test frequencies (free downloads from the net), or use music with low, sustained bass notes. You then crawl around the perimeter of the room and note where the sub sounds the best. You'll find null areas (can't hear the bass), peak areas (where the bass is bloated or boomy), and hopefully areas that really sound great. It is in that best spot where you should place your subwoofer.

Of course, for all I know, you accidentally found the best place .
I hope I accidentally found the right spot! I am still building the room so I pre wired it where I thought it would be best for the layout. One is in the front right and I added a 2nd subwoofer hookup to the rear left of the room. I will try the crawl test as soon as everything is hooked up. Worst case I can find a way to hide the wiring if the right front corner is not optimal.

Quote:
Originally Posted by dsrussell View Post
Yep, 120 pounds is a 2-man lift. Just move the chair or couch out of the way and locate it there.
Perfect. Since its a row of 4 chairs I think I will move all of them. Also since the sub has dual drivers in it I am assuming I should face them towards the sides of the room instead of the front and back when I put it where the seating is?

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Originally Posted by Bill Fitzmaurice View Post
You don't need to lift it onto the seating, just place it on the floor. You may think of it being 120lbs, but in reality a sub is more akin to an 800lb. gorilla. It doesn't go where you want it to go, it goes where it wants to go.
Good news. Putting this thing up on seating would be a big pain in the ass!

Also another question. The sub will be on top of carpet. Should I use any sort of rubber isolation pads underneath it? The Epik sub enclosure seems to be made pretty well. In my old setup I could place a glass of water on it and it would not move or vibrate the glass at all. Just not sure if any vibration will transfer through the floor. This is in a basement so its concrete, then the padding for the carpet then the carpet obviously.
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Once you've found the right spot for your sub, you can rotate the sub however you like (a sub is a point source that radiates outward). And there is no need to move anything but your main listening position chair (unless you want to rearrange them anyway).

You won't have to worry about vibrations, especially on concrete. First, your sub has dual-opposing drivers so that cancels vibration. Even if you had a front-facing or down-facing driver, you need not worry.

Adding a second sub (located as you described) is always a good idea.

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