# sub placement in an open cabinet



## mexicanzero (Jan 12, 2012)

So my first post!
I'm not new to audio though, back in high school i built my own speakers and spent tons of time learning the audio scene, and although I've been out of it for a while i still know my way around

my setup is a 5.1 consisting of home made 3 way 12" mains with Polk csia4 center, Polk r15 surrounds and a martin logan dynamo 700 sub
all hooked up to the futureshop equivalent of a pioneer vsx-53
90% movies
the listening area is about 12 by 14 feet but behind the couch its completely open to the kitchen which is the same width as the living room but twice the length so in the end the whole room is 12 by 40ish

so my issue is sub related, its a small but somewhat powerful sub and from what I've heard of it so far i love it and having paid less than half retail I'm keeping it.. its more than powerful enough with the gain less than half way and it hits way lower notes than any previous sub I've had
my living room doubles as a playroom for my daughter so i basically have no choice for placement except for the right corner... my problem is the sound localization, i'd say half the time my right ear hears more than my left causing an uneven sound
I've been thinking of sticking the sub under the tv where the receiver/dvd player are now and moving them

the opening is 3" off the ground, and would leave about 3" of space above the sub and 5" on either side with both the front and back open, the back being between 6-12" from the wall depending on how far in i place the sub
i already got a sub dude on the way hoping it'll help isolate the sub from the cabinet or maybe just help the localization with it in the corner

another idea is potentially getting rid of the cabinet altogether and wall mounting the tv and then sticking the sub under there or at least on the inside of the mains but thats a lot more work and i just dont have time, i will do this eventually to free up room but rather not do it now

what would be best? if i stick it in the cabinet should i surround it with pillows or some sound absorbing materials? or is there enough breathing room?

oh and one last thing, it came with spikes but they fit onto the rubber feet so with the spikes on the rubber flexes causing the whole sub to move back and forth when shaken by hand, with just the rubber feet it doesn't do this, so no spikes or put them on anyways?

thanks!
-Alex


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## robbo266317 (Sep 22, 2008)

A quick question (or two)
What frequency are you crossing the sub over at and does your receiver have automatic setup to balance mains, surrounds and sub?

Cheers,
Bill.


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## mexicanzero (Jan 12, 2012)

crossed over at 80hz
and its a pioneer so it has mcacc, no sub eq but it does sub level/standing wave/full band phase control and everything for all other channels
i moved the sub further away from the RF speaker more into the corner (by maybe 6 inches) and i think its gotten a lot better, wont be able to test it out till tomorrow night

what is the best spot in the corner for a sub? as close to the walls as possible? equal distances from the side and back? or is there a "at least 6 inches from the wall" rule or something... i've done the bass crawl and what not but that only shows the "loudest" spot not the most "invisible" spot

thanks!
-Alex


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## robbo266317 (Sep 22, 2008)

A crossover of 80 Hz should be fine with not a lot of localisation.
However experimenting with various locations will yield the best results, depending on your options for placement.
I eventually put mine about 4 feet behind the couch and slightly off centre. It just wasn't good in the front corners and being a sonosub I couldn't put it below the telly. :rolleyesno:
When you did the sub crawl did you use REW or just listen for best results?


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## mexicanzero (Jan 12, 2012)

no spl meter so no rew for now
just did a bit of "remodeling" including removing the colourful mats that covered the floor, and then i had no place to put my daughters 5 foot tall teddy bear so i stuffed it in the corner by the sub
and voila now the bass is everywhere
I dont want to do any permanent room treatment cause i'll be buying a house in a year or 2, but that will be the first thing i do once the new home theater room is set up

still want to try it in the cabinet for the fun of it, anyone know if dampening is a good idea or should i just stick it in there?

and what about my question regarding the spikes? should it be firmly planted or is the jiggling due to the rubber feet fine?

thanks
-Alex


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## robbo266317 (Sep 22, 2008)

I do not know if spikes will help. I have a hardwood floor on concrete slab and do not want to use spikes.
Some say to put pennies beneath the spikes! I don't see the advantage. onder:

I do know that buying a good microphone and running REW gave me a lot better info than trial and error.
Listening areas are always a compromise. Do what you can within your budget.

When you find your new house show us your preferred media room and we can take it from there.
Cheers,
Bill.


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## mexicanzero (Jan 12, 2012)

so i had more time to experiment, and i even tried the sub in the cabinet (although i knew it wouldnt stay there due to lack of space for the receiver) sound wise it seemed ok although slightly less "alive" and just didnt have the same punch

I then went on and stuck the sub to the left of the tv between the left main and the tv and this is where it will stay... best sound yet and 90% of the time the bass is everywhere, however there is still a 10% mainly at higher frequencies that feels like its only coming from the right corner which leads me to believe the issue was all room related to begin with.

since im not staying here too much longer i wont bother as i can live with it, but is this what bass traps are designed to stop? if i were to decide to fix the issue whats the best/cheapest way?

thanks
-Alex


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## vettett15 (Jul 1, 2009)

Alex,

You don't by chance have REW do you? I've had it for a little while but only recently used the RTA part of it (basically you play noise through your speakers while you move them around to find the best spot). The RTA feature has to be the best invention every, really helps finding that sweet spot for your sub as well as the x over and phase. As far as traps go, I just picked up a GIK soffit which helped to tame my bass, but I also use the 1124 EQ for bass too.


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## SUMMIT AV (Jan 28, 2010)

Try lowering the XO to 60hz or lower.

Or pick up a wireless transmitter for subs and move it somwhere else (maybe behind the couch or a rear corner of the room.


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## mexicanzero (Jan 12, 2012)

I don't want to lower the xo cause most of its use is movies and I don't want to loose that bit of lfe/my surrounds and center aren't very big

I don't have rew yet but I'll be getting an spl meter along with a behringer soon so I'll wait for that

placement like I had previously mentioned really has to be on the front wall, behind the couch is the kitchen and on the sides are doors to closets/the bathroom and shelves/toy boxes... I'm actually really happy where it is now, I don't really notice the issue unless I listen for it so I can get through movies happily

thanks for the help!

-Alex


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