# Move sub, better bass!?!



## drdoan (Aug 30, 2006)

After hearing a THX guy give a short presentation about bass, I decided to move my sub. I have an SVS PB12-Plus/2 with the 12.3 drivers. It has occupied the left front corner of my 11.8 X 15' with vaulted ceilings, HT room for many months. I eq it with the on-board AudysseyXT in my Denon AVR-2708 receiver.
I moved it the the left center along the left wall of my HT room. I re-eq'd it, and, put in the obligatory Star Wars II, WOTW, and Master and Commander. Maybe I am delusional, but, the bass seems quite stronger with less overhang (bass notes that linger too long) than before. :yay: Supposedly, this is because I located The woofer at the main room node in a rectangular room. Has anyone else tried this? I don't seem to have lost any headroom, or bass extension, but, seemed to have gained clarity, and impact. I can't use REW because the cheap sound card in my laptop is almost usless for such a test,or, I would have included the before and after graphs. Dennis


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## thxgoon (Feb 23, 2007)

Nice! I tried that in my first setup with an M&K sub and found the location to be the best overall. Haven't since had a cooperative room though...:foottap:


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## Mike P. (Apr 6, 2007)

I can relate to what you're saying. My first 2 subs were sonotubes in the front left and right corners. I ended up moving them a bit more then half way down the left and right side walls. Big improvement!


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## devicente (Jun 28, 2007)

What is a room node?


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## drdoan (Aug 30, 2006)

A Room node is an area of a room where a particular frequency of a bass signal causes the room to pressurize at predictable points in the room. This causes that spot or spots in the room to accentuate that frequency greatly. If you have a working subwoofer, play a low note that you can hear, and while it is playing, walk around your room and notice that there will be places in the room that will play the note very loudly, and other places where the note is almost absent. These are the room nodes (namely, the places where the sound is the loudest). Generally, the most prominent room node is along the walls at 1/2 the length of the wall. It is a function of the length of the bass notes wave, which is several feet at 20HZ. This is why you don't sit in the exact center of the room. That is where the note will be almost absent. Hope this helps, Dennis


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## Alex at SVS (May 13, 2008)

Great to hear. Corner placement can work great in a lot of rooms, but certainly not all and trial and error placement is a great way to find the best sounding position. EQ can fix peaks quickly and easily, but if there's a dip then moving the sub and acoustic treatments are the best ways to go. Sounds like your much happier with the performance and that's what counts ;^)


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## drdoan (Aug 30, 2006)

I should point out to anyone who does put the sub in the center of any wall that it will take a significant increase in power to get the bass to achieve the same level as corner placement. Since I have a small room and an atomic powered subwoofer:yay:, it presents no problem to achieve the correct levels as before.


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## Mike P. (Apr 6, 2007)

> I should point out to anyone who does put the sub in the center of any wall that it will take a significant increase in power to get the bass to achieve the same level as corner placement.


Not always. Mine were dead in the corners and came to life when I moved them to the side walls. Definitely a room interaction issue.


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## weeZ (Sep 10, 2006)

I did the same thing back when I had plus/2 back in '03 and has been mid-wall configured with each upgrade. In my room corner placement was boomy and uneven sounding, peaks and nulls everywhere. I moved the sub 6in at a time till I got the flattest response and best sound. The sweet spot was 8.5ft from the corner.


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