Subwoofers

Velodyne SC-600 IF/IC In-Floor / In-Ceiling Subwoofer

ARTICLE INDEX

Installation

Installation is fairly straight forward. You will need the following tools:

  • Measuring tape
  • Screwdriver
  • Drywall saw


Step one is to locate the position of the subwoofer. This is tricky as once it is installed you will not be able to move it around. So choose this position carefully. If you require the subwoofer to produce sounds above 80Hz I strongly recommend you mount the sub in the first 1/3 of the room, close to the main speakers. As my speakers can comfortably dip into the 40's I had the freedom to locate the sub beside or behind my listening position. Keep in mind that while the auto eq will help with some room issues it is not able to correct them all. In the end slight re-positioning of your listening seat may be required. So how did I end up with my final location? I chose the spot that already had a hole in it.

When I moved my projector I was left with a hole where the cables came through. Not wanting more holes in my ceiling this was a natural location. As in my wife said "naturally you are putting the sub there right?" This point is on the side wall just in front of my listening position. One often recommended procedure is to place the sub in your listening position and then take measurements in the intended locations. The idea being that the response should be similar when you put the mic where the sub will be and the sub where the mic will be. The problem with this procedure for an in-ceiling subwoofer is that the large ceiling becomes a large flat baffle. This is good for bass, yet makes it hard to take accurate readings as it will alter the microphones response. Not to mention you need a decent microphone, accurate software a computer and the know-how to do it all. In this case I wanted to see just how much the built-in DSP would correct for placement limitations.

Once the mounting location was decided on I went into the attic to find the center point for mounting the ceiling grill. Velodyne offers an optional ceiling grill which I used in my installation; a white paint-able round grill with everything you need to attach it to ceiling. The subwoofer box is 14 inches wide and designed to fit between two trusses/joists on 16" centers. Turns out mine are on 24" centers leaving me with 22" between trusses. As the sub requires mounting to two trusses I used 2x4's to fill in the cavity. Then I marked the center point of where the driver is and punched a small hole with a nail. Leaving this nail in I went back into my living room and placed the mounting guide up to the ceiling using the nail to align the centers. Using a black marker I drew out the circle and then removed the guide. Cutting the drywall is fairly easy with a standard dry-wall saw, and you do not need to be perfect as the ceiling grill will cover minor imperfections.

Step two is to prepare the site for mounting the subwoofer. First I removed the loose insulation that was between the joists. Then I mounted the four L brackets to the trusses and ran wire to the location. There was already 14gauge in-wall rated speaker wire in place from a previous speaker installation that I was able to utilize. In-wall rated wire is mandatory in most home insurance policies and does not cost much more than standard wire and is often found at your local hardware store.

Step three is when you realize just how heavy and awkward lifting a rectangular box weighing 40lbs into your attic can be. Here is when having a tall friend can help. Once it is up and moved to the general location you will want to affix the foam strips provided by Velodyne. Place them on the front baffle (the part that lies against the drywall) spacing them evenly. The function of the foam is to reduce annoying potential rattles and squeaks caused by the sub producing enormous energy. Now carefully lower the box woofer side down into position with the driver centered over the opening. Use the remaining screws to attach the L brackets to the subwoofer.

Here you can see the spacer I built to fill the cavity:

Step four: Plug in the speaker wire, install amplifier in your equipment location and begin your setup. Once you have connected the speaker wires to the amp and the amp to your audio system you can plug the supplied microphone into the front panel and place it where your head would be while watching movies. Then, warn your wife, put the cat outside and try to stay away from the listening position. Once you hold the EQ button for 3 seconds 12 short frequency bursts will emit from the subwoofer. Next you will want to level match the volume of the sub with your main speakers preferably with an SPL meter, if not tune by ear.