SC-IW Installation Retro

If you decide you are going to proceed with a retro type installation, you are going to need some basic tools to perform the installation. You will need: stud sensor (preferably one that also detects electrical), tape measure, level, straight edge, utility knife, dry-wall saw, corded or cordless drill, wood boring bits, wet vac and other assorted hand tools. The use of a Roto Zip is optional for cutting dry wall. If you choose to finish the sheetrock patches you will also need dry walling tools. The first step is to find the location of the studs in the wall for the proposed location of the subwoofer. Remember when I told you that even well prepared plans can quickly unravel in retro-fit type installations? This is exactly what occurred with my installation. When I marked out my stud framing using my stud sensor, I discovered on the left side of the front wall the 2x4 stud framing was installed 13-inches on center and the right side of the wall framing was 16-inches on center.

The reason for the extra stud framing on the left side became clear after looking in the attic and the back of the wall. The wall is partially load bearing and has a stair case that runs along the back of the wall. This framing technique is not as uncommon as one would think. Over the many years I have been installing home theater systems, I have discovered many different configuration and variants of framing in older and even newer homes. Obviously the SC-IW subwoofer will not fit into a stud cavity of 13-inches, so I had to come up with an alternate plan. Using my stud sensor, I mapped out several alternate locations with stud bays of 16-inches on center that would accommodate the SC-IW subwoofer. Not knowing how the subwoofer would perform in the alternate locations, I decided to conduct an SPL level test at different frequencies with the subwoofer freestanding in the proposed newly mapped out locations.

At the conclusion of the test, I found that installing the second subwoofer on the left wall at the rear of the room close to the listening position provided a fairly smooth response with little compromise in localization and SPL level gain. The installation instructions provided with the Velodyne SC-IW are very easy to follow and cover all aspects of installation for new and retro-fit installations. Once the stud centers have been located, its time to use the supplied template and decide on the grill type. The SC-IW has two grill options: standard grill provides easy servicing of the driver but is a large square grill. The Designer grill is the smallest grill available and is very aesthetically pleasing. The installation method is about the same for both grill types, I decided use the small designer grill.

Securing the template to the wall and making sure it was level I marked out the appropriate pattern for the designer grill. Using a straight edge you can score the drywall with a utility knife for removal. Another option is to use a Roto Zip which is much faster. If you use a RotoZip the use of a wet vac followed closely behind the running bit will minimize dust. This is a little tricky to do if you don’t have RotoZip experience so you may need a helper. When I removed the 5/8-inch sheet rock that I cut out for the subwoofer, I was in for another little surprise. The older less sophisticated stud/electrical sensor that I was using did not sense the 1/2-inch electrical conduit installed in the stud bay. This was yet another unexpected retro installation hurdle to over come but this did provide me with an excuse to purchase a newer more sophisticated sensor like the Ryobi that will detect electrical as well as metal. I got lucky and this was a relatively easy fix because the conduit was installed in the lower half of the stud bay. If the conduit had been installed up higher I would have needed to patch the wall and find yet another alternate location. The simple fix was to move the SC-IW subwoofers location up two inches and patch the bottom of the wall.

Once the sheetrock is cut out, it should be relatively easy to pre-wire to the subwoofer. The size of the cut out should provide you with plenty of room to drill trough any blocking installed in the wall. The SC-IW installation manual shows a picture of generic non in-wall approved speaker wire installed in the stud bay. Do not use speaker wire like the one pictured in the installation manual. All wire that is to be installed in the wall should be rated for in wall installation and comply with the National Electrical Code (NEC). Speaker wire approved for in wall installation will typically be stamped with the designation UL approved CL2 or CL3. I used 16-4 (13 AWG equivalence) in-wall wire with the four conductors doubled up to make one twisted pair to each subwoofer. The use of good 12-2 in-wall wire will work also. The wire should be attached to the side of the stud bay so it won’t interfere with the enclosure installation. Installing the enclosure is fairly straight forward: simply terminate the speaker wire and screw the enclosure into the studs with the provided screws. I marked the location of the oblong holes on the SC-IW installation brackets to provide a location to screw through the dry wall into the stud missing the metal bracket. Once the enclosure is installed its time to install the new sheetrock, filler panel and grill insert. Make sure to secure the existing sheetrock to the studs before finishing. Now that the rough sheet rock patch is installed, you can finish the dry wall patch. I chose to do my own drywall patching and texture work but you may choose to hire a pro depending on your skill level. One problem I discovered after the drywall compound dried was the filler panel shipped with the SC-IW is very smooth and my first patch attempt did not adhere to it after curing. This is partially my fault as I should have noticed this before doing my dry wall compound patching work.

Removing the installed filler panel, I used 60 grit sand paper and acetone to roughen up the filler panel surface. This provided the grip needed for the dry wall compound to adhere to the surface. With a wide dry wall mud knife I applied a rough and finish coat of quick set dry wall patching compound insuring each coat was dry before applying the next. Once the finish coat was complete and dry, I proceeded to sand the patch until it was smooth and blended in with the existing wall. I used canned spray texture to spray the texture coat finish onto the wall. This is available at most home improvement stores and with a little patience and practice you can achieve really great results. Installing the metal grill and painting the drywall patch is the last step in the installation process. The designer grills are paintable; you may choose to paint them the same color as your wall for a blended appearance. I took a different approach and decided to highlight the grill with gloss black paint to complement the rest of the black components in my system.