Subwoofer Placement: Does it matter or not?

 

Lord Alfred
I've been enjoying my Onkyo 650 for a few months now, and I have my main speakers all arranged according to the HT standard. However, I've been told that, due to the low frequencies put out by a subwoofer, it does not matter where in the room it is placed or pointed.

Due to the fact that the Onkyo sub has a distinct front and seems to project forward, I'm doubting this. What are some tips for placing a sub in a room, specifically the type that comes with the 650?
 

fartboy
One tip is to get on your hands and knees while the sub is on (placed anywhere in the room). Move about the room until you find the spot where the sub/sound is most desireable. This is where the sub should be placed.
I have my sub placed to the right of my TV with the port facing out. It looks the best there plus sounds good in my room.
You'll more or less have to compromise between looks and sound
 

miketike
I spent weeks agonizing over this. I ended up putting the sub at the back of the room and found it rounded out the system sound the best. When I had the sub up fornt, the surround impact was not as great as when it was at the back. Having it at the back of the room gave a better sense you were truly "surrounded" by sound when playing Dolby movies. Same with audio CDs and even the FM tuner.
 

po
Most experts will recommend that the sub be placed at the front of the room somewhere between the Left front and Right front speakers.

Adjust the distance to any walls based on how "boomy" it sounds once it is positioned.

-po
 

box
I placed my sub at the front right of the room with the port facing towards the left of the room, instead of facing back towards the audience. This seemed to sound better than facing the port back.
 

Lord Alfred
"Adjust the distance to any walls based on how "boomy" it sounds once it is positioned."

So is it more boomy when placed close to the wall or further away? The only complaint I have with my sub is that I am constantly adjusting the little dial based on what I'm listening to and what "mode" the receiver is in. I have to turn it up for DVDs, down for music, etc. Is there any way around that?
 

Anonymous
Just curious as to where everyone has their crossover settings. I originally had it set to 80 based on one recommendation, then more recently to 120.
I think the 120 setting gives the subwoofer more opportunity to work the lowere range frequencies and therefore don't need to adjust the volume as much.
I have mine placed in a corner near the couch with port facing out & it does the job.
 

scott
For what it's worth, I keep the cross over at 80 and placement of sub is right of right front speaker pointing away from wall. Oh, and volume on sub is in the middle.

I think placing sub in rear corner of room would be best (any corner would be better), but have yet to run cable for that location.

My room has lots of hard surfaces (hard wood floors with only a 5x8 foot rug and no curtains over windows) so having cross over above 80 is too boomy, besides, the regular speakers can handle 80 and above.
 

goto
Lord Alfred,

I've also found that I have to re-adjust the volume level on the sub according to the source; 1/3 to 1/2 for CDs and music, and about 2/3 to full for DVDs and TV. Personally, it's not that much of a nuisance for me to adjust it, since it's easily accessible in my room. It might be nice to have one setting that's "perfect" for all sources, where I wouldn't have to adjust the level each time, but I haven't put in the time to try to find that setting.

By the way, crossover of 120 really does sound much better for this system than 80. Yes, the regular speakers that come with this system can handle 80 and above, but they don't hit those lower frequencies very clearly or loudly. Your sub will do a better job of that if you set it to 120.
 

The sub frecuency is "unidirectional", this means that the bass sound travels in any direction. So, you can put it anywhere on your room. Using a corner on your room can make the sub sound a little more "booming" for the resonance effect.
 

i have an mbquart 150watt sub and it does not perform when its placed in any corner of my 6m x 3m room, doesn't perform too well between my main speakers either...i've adjusted the phase and crossover settings but to no avail - when my main speakers are turned off the sub sounds so loud that i have trouble reading text on the tv - i have been advised that the phase was not set correctly but as stated before i have altered the phase switch - my main spaekers are a pair of wharfedale 200watt speakers - could the three bass drivers on my main speakers be affecting the subs performance??
 

Greg Lee
Shalen: Could it be you have the sub's volume too high? It sounds like it, from what you say. Just in case you have not checked the volume adjustment with a sound pressure meter, I'll point out that that you cannot depend on your ears to judge the level of a calibration tone on a sub. When the sub's volume is properly matched with that of the other speakers, it is going to sound much softer to the ear. You can adjust the volume by ear, but not by using a calibration tone -- instead play music that has bass which you know the sound of, e.g. a jazz string bass that walks down low.
 

ELT
Hi I am HT beginner, My sub has Crossover level adjustment (min-max) what is that for ?
 

Anonymous
The first replay by fartboy was the most accurate for placing a subwoofer Lord Alfred. I install home theater systems currently at the professional level. First place the sub on a small table that is very close to where your listening position is located. Then crawl on your hands and knees with your system at a comfortable listening level and wherever you end up while crawling around and discovering the best sounding spot on the floor is where you place your sub. Once your sub is placed and you take its position in the listening position it will sound great. The low frequencies that your sub puts out are non-directional, however the acoustics of your room and the contents of your room are what is deciding how well, and to where the bass travels. Anymore questions e-mail me.
 

grand masta flash
ive got a gale 5 sub but dosent sound as good as i think i could get it to sound, as it sounds ratterly.does it matter about speaker wire and whats phasing.
 

timn8ter
Subs are very susceptible to room placement. As a general rule place the sub in a corner. The walls will help reinforce the sound. Every room is different so experiment a little bit trying the sub in different spots in the room. 12 gauge speaker wire is more than adequate unless your crossing long distances (over 50 feet) and don't waste your money on names like Monster. Just go to Home Depot and get the 12 gauge RCA wire. Phasing is sound waves moving together rather than in opposition which can cause cancellation. Pick up a good test disk from someplace like PartsExpress.com.
 

My $.02: Corner placement of a subwoofer makes a huge difference. In most cases, this will strengthen its ouput significantly.
 

If you want clean and accurate subwoofer sound (as opposed to just loud), then corner placement is usually not the best. It will directly excite the lowest frequency resonant modes of your room, those that typically cause the most problems.

Positioning the subwoofer is relatively easy to do if you have access to a real-time spectrum analyzer. This can simply be software that runs on your laptop PC, available as freeware or shareware from the Internet. You'll need a high quality microphone, however. Or just a good pair of ears will often work as well! The idea is to find a spot which minimally excites your room's low frequency resonant modes, or at least excites them more or less equally.

First put the subwoofer in the seat that you use to watch movies. No, I'm not kidding. The direction of sound waves can be reversed with equivalent effect, so all you have to do is switch places with your subwoofer!

With your subwoofer in your place, play some pink noise through it. Move around close to the floor with your microphone (or ears), and see where the subwoofer frequencies, those very low ones below around 100 Hz, are the flattest. That is, you should not see/hear any big, boomy peaks in these very low frequencies. This is where your subwoofer should go.
 

I am in need of some non-technical help. As interior designers, we are called upon to design cabinetry for the placement of AV equipment. Placement has been based on client preferences, functional height above the floor, number of pieces, etc. We often place the subwoofer off to one side, and not far from the R+L speakers....and generally my clients-not audiophiles at all-do not have the "ear" to discern too much of a difference.

But with a current project, a client believes there perhaps must be "rules" to follow when placing subwoofers and before we take apart this new custom cabinet to satisfy his desire for the ideal placement, I need some advice. And granted, listening is subjective at the level of most of the consumers today.

We placed the subwoofer some 3ft to the left of the left speaker, placed it sideways in the cabinet and placed it behind cloth covered doors. He believes that the only way a subwoofer should be placed is with the grill cloth facing toward the front. But with this subwoofer being deeper than the TV at 25", placing sideways in the cabinet seemed a good idea to minimize the overall cabinet depth. We reviewed this with him prior to fabrication of cabinetry.

Now that we are rebuilding his cabinet to accommodate the direction the subwoofer is placed due to its depth, it has been determined that it could be placed farther to the left without serious modifications to the cabinet. I'm saying it should not be a problem to do that since bass travels in omni-direction.

We are cutting the bottom of the cabinet away to allow the sub to sit directly on the stone floor which I understand will stop the intense vibrations he has been experiencing when playing the stereo or watching a DVD.

I've checked websites and some local "experts" but the client wants something in writing from some authority that moving the sub further out from the center and left speaker will be OK. Did we do wrong in placing the sub "sideways" in the cabinet? By the way, the powered sub has speakers on the front behind grill cloth and what appears to be a second on the back side.

Maybe there will be some good samaritan who will know how I can offer my client the help and provide him with some assurance we are doing proper placement with his equipment. H E L P!...for this Non-Technical Designer.

Many Thanks
 

Tr3vWh0r3
I have a massive horn subwoofer I made recently. I can't just place it anywhere because of its size and weight. Luckily the horn style subwoofer seems to work in the corner fairly well, but does get boomy at times. Still much better than any store bought sub I have ever heard. I have a closet right behind my listening position what I would love to put the sub into, unfortunately its too tall...
 

Walter deNoyelles
What about placement of a stereo pair of subwoofers?I have not seen much information regarding this subject.
 

To clarify what "phasing" is a bit more:

A sound wave is a pressure wave alternating between high and low pressure areas. If two sound waves of the same frequency (from a sub, and the sub's reflection off the nearest wall, let's say) are hitting your ear "in phase", it means the high-pressure parts of each wave are hitting simultaneously, and the low pressure parts simultaneously. This creates constructive interference (louder sound) and is good (in moderation). If the high-pressure area of one wave hits your ear at the same time as the low-pressure area of the other, then the low-pressure area of the first hits with the high-pressure area of the second (alternating), the sounds will add to zero amplitude. This is destructive interference.

Get out a graphing calculator for this next part.

The x-axis is time, the y-axis is pressure above and below normal room pressure. A sine pressure wave is registered as a musical pitch by the human ear.

Looking at the graph of a sine wave sin(x), you can see it has peaks and troughs. If you add another sine wave sin(x) to it, you will have sin(x)+sin(x), or 2*sin(x). Graphing it, the amplitude is greater. Now try adding (in radian mode) sin(x) and sin(x+pi). pi = 3.141593. Adding the pi inside the function basically means a time or distance difference in when the wave hits your ear. It is also described as the PHASE of the wave. Think of it as setting the wave back pi units in space or time. The two waves will cancel to zero. There are still two waves there, but you won't hear anything because the sum of the waves is zero. This is why you want to have the Red and Black speaker wires connected properly. If you have two speakers equidistant from your head, and one of them is playing the inverse waveform of the other, upon striking your head, they will cancel each other. You will find if both speakers are in phase, this problem will not occur when both speakers are equidistant from your head.

Finally, there is an effect called a "phaser" (no, not star trek). It tries to emulate what happens when you listen to something coming from two speakers, and one speakers is sliding in and out of phase with the other (either by changing the distance of that speaker, or by delaying the sound ever so slightly, which are both really the same thing.) Flanger does something a bit different, but I was really never able to figure that one out.
 


Well lets cheat here to help you get some extra DB's......Shhh.. ok....But turn your sub's over, or back around, in the corner would be best, but i'd like you to fire that at the wall, lets say 8'' before it hits the wall....have fun..Room #101 Tweek..Boom Boom....Hi to all the guys and gals i have met do far......PS...I always take a corner for my subs..only way that has never happened i use to have a Muse Model 16 Sub...that sat next to me then as a coffee table........Have fun..Don
 

Puck
My room is small and I have limited space for a subwoofer (other than putting it on the perpendicular wall to the front speakers). However, there is a shelf in my entertainment center that could fit the sub I want to get. Here's a questions that hasn't been asked: what about the VERTICLE placement of a sub? In other words, what if it's elevated from the floor? The sub is a down-firing one. Would it be a nono to but it in the shelf thats about a foot from my carpeted floor?
 

Unregistered guest
I just got a Velodyne VX-10 subwoofer, and it is placed in the corner of my room, about 15 x 15 ft, with two cambridge soundworks front speakers. I always seem to get a lot of wall ratteling, so does anyone have any suggestions for this?

And to everyone else complaining about bad bass, make sure that you do the Pink Noise test first!

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New member
Username: Gman

Post Number: 70
Registered: 12-2003
Sub placement makes a big difference. If you are getting rattling--move them out of the corner. Corner placements are good for enhancing the bass. Obviously the build quality of the room is not up to snuff for corner placement. You will lose some bass enhancement however--but that beats rattlingt sounds.
 

Dr_Acemaster
Unregistered guest
Puck brings up an issue for me as well. I'm planning on building a "chamber" into my in-wall entertainment center for the subwoofer. I plan on putting plywood on all sides except the front, and insulating it further w/ styrofoam. The chamber sits a few inches off the ground. Any ideas, suggestions?
 

Unregistered guest
Hi all, just something I've found out in the past few months... I have an mb quart 12" 150w dual ported front firing sub that never gave me the required volume or effect below 70 hz when matched with a pair of 200rms fronts. The problem was the front speakers had 3x8inch bass drivers with two rear firing ports and they were somehow cancelling out sub even after adjusting the phase switch. I dropped the crossover on the main speakers so they took over at 100hz and BOOM!!! Although it is a bit of a waste having a set of fronts that have the potential to really deliver lots of low end but are restricted to give the sub a chance, it really does sound sweet. Now for another problem, I got another sub, like my existing one and when I put them on either side of my room they sound terrible - no impact - again, I've tried the phasing adjustments and it doesn't help - but when they are in the same corner they make the kitchenware rattle, any ideas?
 

Anonymous
 
I did my room up a year ago and placed the active subwoofer in a cabinet with speaker fabric cut out of the door. This solution worked very well and did not pose any problems. I placed the subwoofer on polysterine to stop any vibrations and it worked a treat.

I know have a issue. In my living room downstairs I want to put the new systems subwoofer on top of a cabinet which I am having built. Does anyone know if the cainet will start virating beyond believer or is this not recomended. Also what about mounting the subwoofer on say a speaker bracket.

Any help would be appreciated.
 

Unregistered guest
I did my room up a year ago and placed the active subwoofer in a cabinet with speaker fabric cut out of the door. This solution worked very well and did not pose any problems. I placed the subwoofer on polysterine to stop any vibrations and it worked a treat.

I know have a issue. In my living room downstairs I want to put the new systems subwoofer on top of a cabinet which I am having built. Does anyone know if the cainet will start virating beyond believer or is this not recomended. Also what about mounting the subwoofer on say a speaker bracket.

Any help would be appreciated.
 

Bronze Member
Username: Xtremeht

Post Number: 15
Registered: 02-2004
Typically you want to place it near as many surfaces as possible, a corner being most ideal because you gain about 3 dB for every side the sub is against. In a corner it's against 3 sides.
 

Jon Perez
Unregistered guest
can anyone give me advice, ive moved into a house that has a raised wooden floor and i think my sub will really annoy my new neigbours, any thoughts on how to cut the bass from rumbling all through the apartment
 

Bronze Member
Username: Heff

Post Number: 87
Registered: 12-2003
Jon Perez, other suggestions besides turning the volume down. Use one or a combination until you have the desired result.
  1. Some A/V receivers have a "night" setting that cuts the amount of bass sent to the mains and sub. My H/K does, maybe yours does too?
  2. Reposition your sub away from the corner and closer to your listening position.
  3. Install Aura Pro Bass shakers at your listening position for enhanced LFE; with this setup, you could lower the volume of sub and still feel LFE effects
  4. make friends with your new neighbors, invite them over to hear your HT system! (open the liquor cabinet too)
If all else fails, invite them to go out to the movies while you're shaking their apartment with monstrous bass. K
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