GR SUB positioning

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jimbones

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GR SUB positioning
« on: 26 Aug 2019, 03:28 pm »
I have my subs "facing" me with my  toppers sitting on the subs. The subs are 2x12. They are crossed over 80/24db oct. I recently put the Toppers on stands. That free me up to position the subs for optimal SQ. Question: I assume with a low enough XO frequency they dont have to face me. Are there any guidelines (like lenghtwise along a long wall in the room?) Thanks for the advice.

mlundy57

Re: GR SUB positioning
« Reply #1 on: 26 Aug 2019, 03:41 pm »
Which tops are you using? For monitors that cross up around 200Hz like the Wedgies, Super Mini, and Super 7, the monitors need to be right next to the subs so you might as well just leave them on top of the subs. If the monitors cross around 100Hz you can have them a little further away from the subs. I’m not sure exactly what that distance is.

This is because the higher up the subs play, the more they localize. You want all the sound from the subs to sound like it is coming from where the monitors are. If you move them too far away, it’s going to sound like the music is coming from different locations.

Mike

Captainhemo

Re: GR SUB positioning
« Reply #2 on: 26 Aug 2019, 04:27 pm »
I am assuming they  are    Ob pair  of  2x 12  each  side ?
If so,  they  need to   basically face you as  there will be nulls  to the side of each 
As Mike said, where  eactly are you   crossing ?  If you  are using he  80/24  c/o slope, you're basically   dropping 24/db ocstarting with 12 db at  80hz then anothe r 12 at whatever you  have the  dial set to.  Remember too,  those numbers are electronic quides,   they are  likely  playing up higher  than  what's indicated by the slope / dial. .

The higher  you  cross, the   more  you  want to keep   those subs    as close to the  mains as possible.


jay

Early B.

Re: GR SUB positioning
« Reply #3 on: 26 Aug 2019, 04:34 pm »
I recently put the Toppers on stands.

I did that once for a couple of weeks for the same reason you indicated until I realized they sounded better sitting on top of the woofers, and I reclaimed some floor space. 

jimbones

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Re: GR SUB positioning
« Reply #4 on: 26 Aug 2019, 05:11 pm »
I did that once for a couple of weeks for the same reason you indicated until I realized they sounded better sitting on top of the woofers, and I reclaimed some floor space.

Not for me They were up too high on the subs. i sue 24 inch stands.

jimbones

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Re: GR SUB positioning
« Reply #5 on: 26 Aug 2019, 05:13 pm »
I am assuming they  are    Ob pair  of  2x 12  each  side ?
If so,  they  need to   basically face you as  there will be nulls  to the side of each 
As Mike said, where  eactly are you   crossing ?  If you  are using he  80/24  c/o slope, you're basically   dropping 24/db ocstarting with 12 db at  80hz then anothe r 12 at whatever you  have the  dial set to.  Remember too,  those numbers are electronic quides,   they are  likely  playing up higher  than  what's indicated by the slope / dial. .

The higher  you  cross, the   more  you  want to keep   those subs    as close to the  mains as possible.


jay

Yes OB Subs. The toppers are my DIY MMT they start rolling of about 60 hz. Its a Vented design with 2 Satori MW16P and a TN29R.

jimbones

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Re: GR SUB positioning
« Reply #6 on: 26 Aug 2019, 05:15 pm »
Which tops are you using? For monitors that cross up around 200Hz like the Wedgies, Super Mini, and Super 7, the monitors need to be right next to the subs so you might as well just leave them on top of the subs. If the monitors cross around 100Hz you can have them a little further away from the subs. I’m not sure exactly what that distance is.

This is because the higher up the subs play, the more they localize. You want all the sound from the subs to sound like it is coming from where the monitors are. If you move them too far away, it’s going to sound like the music is coming from different locations.

Mike
My own DIY see my other post. Yea I am thinking since I am crossing over at 80 hz it is "non directional"

mlundy57

Re: GR SUB positioning
« Reply #7 on: 26 Aug 2019, 05:32 pm »
My own DIY see my other post. Yea I am thinking since I am crossing over at 80 hz it is "non directional"

Since they are rolling off at 60Hz you can move the sub farther away. Keep in mind what Jay said about orientation pointing straight into the room in front of the LP. Since they have nulls to the sides you can get them pretty close to side walls but you still need at least 3' from the front wall. If you are thinking about putting them on the back wall behind the listening position, they need to be 3' off the back wall and pointing straight toward the LP.

You're going to have to experiment to find the best position. If you can tell where the sub is, it needs to move closer to the mains.

Mike

Captainhemo

Re: GR SUB positioning
« Reply #8 on: 26 Aug 2019, 06:26 pm »
If the uppers are begining to roll off at 60hz, yo  likely have a  ton of overlap  between them and the subs.... unless you've got that  c/o dial  set   really  low.
You  should try crossing them   at   the -6db point of both the   uppers and  the  subs, or at least  close to it.   If you cross at that  -6db point and the sub woofers and upper  speaker woofers are in phase with each other, it shold  raise the    response  in  the cross over  area back to "flat".  Right now, if your mains are  beginning to roll off at  60, depending on how  steep that  roll off its,  yo  should  actually    be crossing  somewhere   below   60.
If you  want to cross   higher up and have the subs do a bit more work, run a small inline  cap on  each   of  the amps input, cap value will vary  upon  amp inut impedence.  This will  also take some of the   work  load off your  main amp  and your   upper section

jay

jimbones

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Re: GR SUB positioning
« Reply #9 on: 26 Aug 2019, 07:38 pm »
I am not actively crossing over Hi Pass to the main amp. I will measure what the acoustic roll off is.

Danny Richie

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Re: GR SUB positioning
« Reply #10 on: 27 Aug 2019, 03:08 pm »
Man, the regulars here in my circle are sharp guys. What a great community. I couldn't have helped him any better myself.