EZ DB's Installation Guide

Designing and building an enclosure is just one part of ensuring it performs at its best. Follow this step-by-step guide to set up and tune the surrounding vehicle for optimal results.

 

Walled/Forward-Firing Enclosures – For forward-firing port designs, “walling off” or sealing the enclosure completely is essential to prevent cabin wave cancellation, a phenomenon that severely hurts audible output of the subwoofers. This involves securing a trim panel to the front, sealing all edges to the vehicle interior. It’s crucial to seal thoroughly; partial sealing can still cause significant issues. In compact up-firing hatch builds, sealing the top and front can also help the performance of the enclosure.

 

Cabin Reinforcement – Reinforcing your vehicle’s cabin, especially in SUVs or vehicles with large roofs, can greatly improve performance. Common methods include attaching wood sheets or heavy sound deadener between roof braces. In some vehicles, weak spots like the firewall or top windshield brace may need extra reinforcement, such as adding a “stripper pole” for stability. Proper reinforcement helps avoid cabin cancellation that can limit performance

 

Pop Testing – Disconnect speaker leads from the amplifier(s). Using a 9V battery, repeatedly briefly touch its terminals to the speaker leads, observing that all subwoofers move equally in the same direction. Uneven movement can indicate issues with wiring or a disconnected coil. 

 

Stereo/Head Unit Settings – Adjust settings carefully: sub-level, bass boost, and EQ should be neutral or flat. Avoid boosting frequencies under ~125Hz with head unit global EQ. Ideally, use a DSP for per-channel EQ control.

 

AC Voltage Reading – With speaker leads disconnected, use a multimeter to test amplifier output in 10hz steps from 20-60 Hz, maintaining consistent volume. All voltage readings should be nearly identical. Any discrepancies may indicate unknown filters affecting signal quality. Set subsonic filters to “off” and low-pass filters to “max” for this testing. Identical voltages across the playable bandwidth insures that we are not hampering performance of our subwoofer before it even has a chance. 

 

Gain Setting – Find the head unit’s max output volume with a 0db, 40Hz track using an SMD DD-1 or oscilloscope. Then, set head unit volume to the max clean output, and switch to a -5db, 40Hz track, and then adjust amplifier gain. If using multiple amps, match their AC voltages to the lowest amp’s output within 0.1 volts. If you have a bass knob, set the bass knob to max throughout this process.

For more details on tools and downloads, visit https://damoreengineering.com/products/dd-1