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If you are using only one subwoofer, it is not uncommon to have more bass in certain parts of the room based on room modes.
 

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Quote:
Originally Posted by KyoceraFan  /t/1524295/bass-increases-when-standing-up#post_24529213


Why does base level increase when I stand up?

It sounds like, (pun intended), that you probably have a null... when you sit you are in it... when you stand up your ears move higher and out of the null.


Try repositioning your sub.
 

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Quote:
Originally Posted by KyoceraFan  /t/1524295/bass-increases-when-standing-up#post_24529213


Why does base level increase when I stand up?
Because you have a null at the seating position caused by ceiling bounce. Did you do the sub crawl to determine where to place the sub?
 

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Discussion Starter · #6 ·
Thanks for all the replies.


Due to WAF and furniture layout I am limited on placement, so can't really deploy subwoofer crawl because chances are I won't be able to move them much anyway (maybe a few inches...)


I have two (2) Rythmik F15s located equal distance from either side of MLP on couch located on back wall. Any other location(s) would result in unequal distances of subs from MLP. Would minor acoustical treatments on walls and/or ceiling help to offset null?
 

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Quote:
Originally Posted by Bill Fitzmaurice  /t/1524295/bass-increases-when-standing-up#post_24530253


Because you have a null at the seating position caused by ceiling bounce. Did you do the sub crawl to determine where to place the sub?

Will facing the driver in a different direction eliminate those nulls?
 

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Quote:
Originally Posted by KyoceraFan  /t/1524295/bass-increases-when-standing-up#post_24530692


I have two (2) Rythmik F15s located equal distance from either side of MLP on couch located on back wall. Any other location(s) would result in unequal distances of subs from MLP.
That could be the problem. Subs should seldom, if ever, be placed that way. Symmetry with respect to the LP promotes deep nulls.
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Would minor acoustical treatments on walls and/or ceiling help to offset null?
Minor acoustical treatments work with very short wavelengths. Subwoofers project very long wavelengths.
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Due to WAF and furniture layout I am limited on placement, so can't really deploy subwoofer crawl because chances are I won't be able to move them much anyway (maybe a few inches...)
To be blunt, screw WAF. What about HAF? The point of having two F15s is to have the best sound you can get. 99% of the time you can put subs where they sound the best, or where they work the best, but only 1% of the time the twain shall meet.
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Will facing the driver in a different direction eliminate those nulls?
Perhaps, but not likely. You need to shift the driver position by a significant portion of a wavelength, say 1/8, to have much effect. 1/8 wavelength at 80Hz is 1.8 feet, 1/8 wavelength at 40Hz is 3.6 feet.
 

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If I spent close to $2K on subs I would be making dang sure that they were in the optimum position for sound quality - screw WAF!
 

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Discussion Starter · #10 ·

Quote:
Subs should seldom, if ever, be placed that way. Symmetry with respect to the LP promotes deep nulls.


???

Notwithstanding the goal is to reduce the null, I thought Audessey (and Rythmik as well as Audioholics) specify that subs should be equidistant because bass management only sees "one sub" so treats the two as one? (AVR, Marantz SR6006), does not have XT32).
 

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^^ Time to upgrade to xt32 with subeq HT where it will calibrate both subs independently? That way, you can place your subs unsymmetrically.

How about trying raising your subs up a foot or so and see if you get that bass sitting down?
 

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Quote:
Originally Posted by KyoceraFan  /t/1524295/bass-increases-when-standing-up#post_24534188


Notwithstanding the goal is to reduce the null, I thought Audessey (and Rythmik as well as Audioholics) specify that subs should be equidistant .
In most cases with two subs you'll get best results when they're on opposite ends of the room. That way whatever nulls that are created by one won't be created by the other. They'll both still create nulls, but at different frequencies, so the effect is to smooth the overall response over a wider listening area.
 
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Quote:
Originally Posted by KyoceraFan  /t/1524295/bass-increases-when-standing-up#post_24534188


???

Notwithstanding the goal is to reduce the null, I thought Audessey (and Rythmik as well as Audioholics) specify that subs should be equidistant because bass management only sees "one sub" so treats the two as one? (AVR, Marantz SR6006), does not have XT32).

The Rythmik subs have a delay/phase knob. With measuring equipment you can integrate two subs quite easily using this control. If you don't have measuring equipment you can play an 80hz tone through your system with both the speakers and one sub engaged (before you run YPAO/Audyssey/MCCAC) and turn the delay/phase knob slowly while someone at the listening position indicates at which point the tone sounds the loudest. Set the knob to where the tone is loudest. Repeat this process with the other sub and then run your AutoEQ. I would note that this is pretty rough and our ears are not precision mics.
 

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^^ I should note that the delay/phase knob is defeated with LFE input. He can try your method using the line in.
 

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Discussion Starter · #16 ·
Assuming I level match the 2 subs to 72dB before running Audessy, how much of a truly audible difference would it make if one were 6ft away and the other 12ft away from MLP? I know this would be 'measurable' with equipment , but would it really be that audible of a difference in the room? (I know it depends on the unique characteristics of my room, but just generally speaking?)
 

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Quote:
Originally Posted by KyoceraFan  /t/1524295/bass-increases-when-standing-up#post_24549081


Assuming I level match the 2 subs to 72dB before running Audessy, how much of a truly audible difference would it make if one were 6ft away and the other 12ft away from MLP?
Probably none. Whatever phase differential is there would easily be fixed by the twitch of a knob, and even that might not be necessary. But you'll need measuring software to know the effect of phase correction, and for that matter if it's required.
 
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