Wed 08 Dec 10 @ 7:56 am

This is a Brief Tutorial on Sub woofer placement. This will mainly effect Mobile DJ's

Sub woofer Cabinet designs.

There are many Subwoofer Cabinet Designs.

The most common is the BASS REFLEX Cabinet

This is a ported box with one or more drivers (woofers) The reason for the popularity of this cabinet is simple: It's Cheap to make

Horn Loaded Cabinet


A horn loaded cabinet like this is mainly a mid/high cabinet but there are sub woofers built with this design. (co-axial horn Subwoofer) They have the advantage of Longer throw and usually better frequency response. Because of the woodwork involved they are more expensive than other speakers of similar size.

Folded Horn Subwoofer

These are the Monsters of Subwoofers. They offer incredible sound quality and throw. Often using much smaller speaker sizes than with sealed/vented cabinets. Most often used in concert sized P.A. (now called line arrays)

Placement.

It doesn't matter which type of speaker cabinet you use for your subwoofer. Bass sound waves are OMNI directional which means they go in all directions evenly. So placement is the same for all cabinet types. Most Mobile DJ's will bring a single subwoofer with them to a gig. Usually an 18 inch bass reflex cabinet. Most Mobile DJs will place the subwoofer in the centre of their setup directly below the mixing table. This is the WORST place to place the subwoofer.

Boundary Loading:
Using a blank wall or Corner to increase bass response. "Having subs next to a wall gets you 6dB of additional sensitivity, and putting them in a corner an extra 12dB. In most cases you’ll have best results aiming the subs towards the wall or corner with the mouth about a foot away from the boundary" (source:billfritzmaurice)

In Other words if you think your 18" pounds hard now. Wall load it or better yet corner load it. Place the speaker side of the cabinet FACING the wall or corner and allow about 12 inches of space. You'll be amazed at the difference in volume levels. It'll sound BETTER at LOWER volumes; and shake grandpa's false teeth out when you have the volume up a little.

What if there's no wall or Corner available?
If you are outside or forced to set up in the centre of a space, try this:"Outdoors is the toughest challenge, as there are no boundaries for reinforcement and no room pressurization (cabin gain). In this case create a virtual extension of the horn by facing it downward, the upper edge supported to place the mouth at about a 30 degree angle."(source:billfritzmaurice)

Use the Angle solution if you are using a folded horn only. If you are using a bass reflex cabinet FLOOR LOAD the cabinet. Take your cabinet, and place the woofer DOWN against the floor and raise it up about 6 inches. This will give you the same benefits as boundary loading your subwoofer.

If using more than one Subwoofer cabinet place them as far apart as possible in the room. Or Place them in a stack together in the same spot. Then place the mid/high cabinets as high as possible.

NEVER mix horn-loaded Cabinets with Direct radiating cabinets (sealed or Bass reflex) they are very hard to eq because of the difference in air pressure they produce.










Hopefully this helps my fellow DJ's with making their equipment sound as good as possible. With proper Subwoofer placement you can make a good sounding sound system sound amazing.

Subwoofers offer incredible benefits to P.A systems. With a single 15 inch Subwoofer, you can reduce your mid/highs down to 12 or even 10 inch speakers; and run them hotter without worry of blowing them (within reason)

Sun 06 Jan 08 @ 4:03 am