Sub positioning

Of course every room is different and there are no real correct answers, but I will pass along my personal technique that seems to yeild good results.


I begin by actually placing the subwoofer where my chair will reside. then I literally crawl the edges of the room with an SPL meter and a pocketfull of pennies. THe places I get the most output is where I drop a penny. This usually gives me two or three good solid places ion the room where the bass output is pretty good. then I put the chair back and do some subjective listening in the three places I dropped pennies.


Once I have set the first subwoofer, i walk the room looking for weak spots. once I have identified the worst one, that is where the second sub is placed. I repeat the same procedure as above and find the second subwoofer spot.


This has been a very solid approach for me and I personally think it gives good response throughout the room.

RoomEQ Wizard (free), a Radio Shack spl meter, a computer with a sound card, and a few cables will tell you where you should place your sub. Sweeps take less than 5 seconds, and you won't have to crawl around the floor

ha ha ha ha ha ha thanks for the advice guys........ right now I can build them any where I want to......here in lies the problem...key word in that sentence is build. In order to get the WAF they will be a built in feature to the room. In an ideal world, I will be able to incorperate them into the side surround pillars and will be the bottom portion of the pillar. I was thinking of at least angleing the face plate roughly 20 degrees and then I can change the firing direction by rotating the face plate if I need to change firing direction.

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I don't think angling the port will have much of an impact due to the low freq's. and good room coupling. I was faced with this problem when I built my sub that integral to my seating riser; face the port out the front, side, or back. I wound up with front, but it was purely a guess.

The port would actually remian static towards the listening position.......it would actually change the facing firing direction of the sub. I guess I could always EQ the heck out of it if I needed to...... ha ha ha ha ha ha

To test for location take an existing sub, and place it in the listening postition. Then go around and listen to the bass in those places where it makes the most sense to locate the new subs. Where the test sub sounds good is a good place to put build-in subs


This is standard proceedure when we're helping people decide where to put their IB subs.


The other test is simply place an existing sub where you think it's going to go and sit in the sweet spot and checkout how it sounds.


If you don't have a test sub, take one of your drivers and slap together a quick sealed test box.

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This is how i did mine. Move the sub, hit "Measure", look at graph.


Just using the SPL meter & penny method (while creative ) to find the spot with the highest output probably gives you a spot where the sub has a peak at a certain frequency, which registers as "loud". What you don't see though is that there are big peaks and valleys in the freq response.


I used the method Steve mentioned to find the spot where the freq response was the flattest while still being geographically acceptable. With a BFD, i was able to get a virtually flat freq response that way.

I'm still lost on how these measurements will tell you anything about position. Wouldnt this still be all trial and error? How do you even determine where to place the sub to take the measurements?

I personally think that the measurement would be step two after getting a good rough idea where to place the subwoofers. then the measurements will help determine exact placement and even help to match the rolloff slope to the room gain characteristics to get the flattest response.

Yes, it's going to have to be trial and error, as every room is different and different subwoofers have the drivers mounted at different heights. A front corner is the most common position to get good results - other possible locations would be to one side of the listening position, behind the listening position, or between the mains.

Well after some consideration I have figured out that instead of completely gambling on one location that I am going to build my towers in a modular two piece fashion. That way, I will at least have 5 positioning options ( under front two towers, under side towers, under rear towers or even diagonaly apposing each other. If I cant EQ it or over power it from there I am going to be having issues beyond placement. It may not be ideal placment but I have to make a compromise here with form and WAF. She absolutely does not want anything to look out of place so to speak.... that is why they are being built into the towers.

If you want the smoothest bass at the most listening positions, then research and real world experience shows that placing the subs at the centerline of opposing walls gives the best results.


For slightly less smooth but stronger bass, you could place them in opposite corners.


In either case, bass trapping and/or PEQ should be used to further flatten response.

Thanks for all of the input guys........ when I get these cabinets done, and I start doing some placment testing, I will let you guys know how it works out. Thanks again!