Sub Crawl Question - AVS Forum
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Old 10-30-2013, 09:14 AM - Thread Starter
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I asked this question at the end of a different post but it was a little OT and I didn't get any response. I hope it's okay if I ask it again in its own thread, I'm just trying to learn as much as I can from you guys.

 

If I do the sub crawl with my current subwoofer and find its best position will I have to repeat the process when I buy new a subwoofer to replace the old one?  The new sub will be larger and much more powerful. 

 

It seems to me that it would not be necessary but I read in a post where someone replaced their old sub with something more powerful and since they had already done "the crawl" for the old sub they just assumed the new sub would go in the same spot. But the new sub never sounded as good. Finally they did "the crawl" again and found the new stronger subwoofer sounded better in a different location than the old weaker subwoofer. I believe both were ported subs (if that makes a difference).

 

Does anyone have any knowledge about this? I don't mind crawling around my room more than once if need be but I do find this curious and would like to learn about why bass waves between two different subwoofers would vary to the point of there being different sweet spots for their placement in a room.

 

I hope I wrote this in a way that made sense. Thanks for any help.

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Old 10-30-2013, 09:18 AM
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Originally Posted by Hopinater View Post

If I do the sub crawl with my current subwoofer and find its best position will I have to repeat the process when I buy new a subwoofer to replace the old one?
No. The best spot for the sub is based on the room dimensions and listening position, not the sub itself.

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Old 10-30-2013, 09:27 AM
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Bill, wouldn't a difference between two subs' in-room FR curves affect perceived output at a given location, making a location that is good for Sub A different / not as good for Sub B? (Or even, possibly, different / better for Sub B?)
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Old 10-30-2013, 10:00 AM
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I'm not trying to say anyone is right or wrong, but this is my experience. I tried this with a front firing, front ported older Sony sub and with a down firing front ported POS Onkyo sub. Did sub crawl and found best spot which just happened to be a corner a dual outside wall corner. I placed the sub in the corner and tried 4 different orientations: (1. with the driver and port and on the other sub just the port facing straight forward, (2. then firing forward at a 45degree angle with the corner, (3. then firing sideways toward the TV not the wall, (4. then at a 45degree angle with the driver and or port firing into the apex of the corner. Using a Radio Shack SPL meter I measured each sub to 75db at the MLP with the driver and or port facing forward so at position 1. Position 2 I read 76db, Position 3 I read 74db, and Position 4 I read 78 db.

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Old 10-30-2013, 10:02 AM
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Originally Posted by eljaycanuck View Post

Bill, wouldn't a difference between two subs' in-room FR curves affect perceived output at a given location, making a location that is good for Sub A different / not as good for Sub B? (Or even, possibly, different / better for Sub B?)
The response wouldn't be the same, but the room modes that cause peaks and dips would be. There would have to be major differences in the sub responses for it alone to result in the need to move it.

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Old 10-30-2013, 10:05 AM
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Old 10-30-2013, 10:08 AM - Thread Starter
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Ok, thanks Bill. It's what I assumed to be the case but I wanted to make sure. 

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Old 10-30-2013, 10:28 AM
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Just did the Sub Crawl 2 weeks ago, Sunfire HRS-12 front firing. A little note, if your in your 60's and have hardwood floors, use knee pads eek.gif I muted my 7 speakers and only listened to LFE. I found facing it forward or backwards made no difference to where it sounded its loudest. I also used a Radio Shack SPL Meter in which I found difficult to use on bass freqs. so I used my ears in conjunction with the meter.

I was surprised to find there were a couple of different locations where I could locate the sub. The sub crawl works. I had to turn the gain down on the sub when finished.

(LCD - Sony KDL - XBR4) (Receiver - Sony STR-DA4ES)(Blu Ray - Oppo BDP-83) (PS3)( Dish Hopper DVR With Sling) Speakers (L & R - Paradigm Studio 20) (Center -Paradigm CC-470) (Surrounds & Back Surrounds - Paradigm SA-15R in walls) (Subwoofer 1 - Sunfire HRS-12) (Subwoofer 2 - Paradigm PW-2100)
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