Woofer placement in uneven room + 1 vs 2 subs for 1 listening position - AVS Forum
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post #1 of 7 Old 07-30-2014, 12:58 PM - Thread Starter
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Woofer placement in uneven room + 1 vs 2 subs for 1 listening position

Due to the uneven nature of my theater room I am unsure where to place my subwoofer(s). In the attached .jpg I labeled the possible sub woofer placements. Any help as to where to place them and which way to face them would be greatly appreciated. My main concern is the problematic wall area where I'm sure sound will reflect off of unevenly to the listeners on the couch.

I was thinking placement 2 and 7 but they are uneven distances to the listener and I hear you are not supposed to put a sub in the center of the room... What do you guys think?

Also, are there major benefits to having dual sub woofers if I always sit in the same spot in the room and don't need the bass uniform throughout the room? I've heard dual subs have greater DB's but does that matter if you need to keep the Subs at a similar level as the speakers? The room is 400 square feet with 8 ft high ceilings. The woofer(s) I'm looking at are identical ascend acoustics FV15HP.

I was thinking I could do Ascend Acoustics 340SE Fronts and 170 Surrounds with two subs or Sierra-2 fronts and 170 surrounds with one sub. The content is 100 percent movies.

Sorry one last question. With identical subwoofers would I be benefited by Audyssey Sub EQ HT? I'm trying to decide between the Denon x3000 and x4000 and that is the only feature I can really see that I may need in the x4000.

Any help greatly appreciated as I'm ordering speakers as soon as I have this answered.
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post #2 of 7 Old 07-30-2014, 02:08 PM
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The only definitive method of getting the best placement is to measure the in-room response. It's very much an exercise in trial and error. Measuring response at the LP you find the spot where one sub alone works best. You then try different placements with the second sub until you find where it provides the best smoothing of response.
You may find one sub is adequate with a fairly small LP area, but the only way to be sure is to measure.
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post #3 of 7 Old 07-30-2014, 04:34 PM - Thread Starter
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Quote:
Originally Posted by Bill Fitzmaurice View Post
The only definitive method of getting the best placement is to measure the in-room response. It's very much an exercise in trial and error. Measuring response at the LP you find the spot where one sub alone works best. You then try different placements with the second sub until you find where it provides the best smoothing of response.
You may find one sub is adequate with a fairly small LP area, but the only way to be sure is to measure.
Hmmm... I don't really want to have to pay for return shipping on a giant sub if dual subs didn't make a difference, and it would also influence which fronts, receiver and center I order. With a narrow listening position are the odds for or against two subs making a significant difference in the experience? Or is it a coin toss? Thanks!

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post #4 of 7 Old 07-31-2014, 12:28 AM
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1 or 5 plus 7 will give you the most SPL and tactile bass . might not be smoothest response. Depends upon you priorities.
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post #5 of 7 Old 07-31-2014, 06:28 AM
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Quote:
Originally Posted by pulp25 View Post
it would also influence which fronts, receiver and center I order.
It shouldn't.
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With a narrow listening position are the odds for or against two subs making a significant difference in the experience?
The size of the LP doesn't eliminate cancellation modes, it just makes it easier to account for them. There's a prevailing myth that you can't EQ out cancellation sourced response dips. You can. The problem is that when you use EQ to fill a dip at one location in the room it will cause a bump in other locations. If you only listen from one small location that may not be a problem. The benefit of using multiple subs versus EQ alone is that the smoothing of response occurs over a wider area. Personally I'd go with one medium sized sub to start, one that will provide the extension and output that you've calculated will meet your needs without spending more than you have to. If it turns out you can get acceptable response with just the one all well and good. If not add another later on, the 6dB of additional headroom will only enhance the overall experience, especially if you ever do decide on sharing it with others.
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post #6 of 7 Old 07-31-2014, 07:43 AM - Thread Starter
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Originally Posted by Bill Fitzmaurice View Post
It shouldn't.
The size of the LP doesn't eliminate cancellation modes, it just makes it easier to account for them. There's a prevailing myth that you can't EQ out cancellation sourced response dips. You can. The problem is that when you use EQ to fill a dip at one location in the room it will cause a bump in other locations. If you only listen from one small location that may not be a problem. The benefit of using multiple subs versus EQ alone is that the smoothing of response occurs over a wider area. Personally I'd go with one medium sized sub to start, one that will provide the extension and output that you've calculated will meet your needs without spending more than you have to. If it turns out you can get acceptable response with just the one all well and good. If not add another later on, the 6dB of additional headroom will only enhance the overall experience, especially if you ever do decide on sharing it with others.
Thanks so much for the advice. Ill do that.
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post #7 of 7 Old 07-31-2014, 03:26 PM
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Bill has given you great advice, and he is correct that the only way to know for sure which sub placement is the best is with measuring gear....but, until you get said gear, the sub crawl is a very reliable way to determine where to put your sub.

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