Quad 8 Inch Subwoofer Boxes

How to Choose a Quad 8 Inch Box

Start from the driver and buy a matched set

Most of these cabinets are cut to one named driver. Match the model and the coil on the listing, and run four of the same driver at the same impedance. Both chambers are identical and each is cut for a matched pair, so an odd driver gets neither the volume it wants nor the same share of the power, and it unbalances the load on its own cup.

Work out the final impedance before you buy the amplifier

There are two decisions, not one: how each driver's coils are wired, and how the cups are joined. With the cups in parallel, which is what nearly every install wants, four dual 4 ohm drivers land on 2 ohms with each driver's coils in series, or 0.5 ohms with them in parallel. Dual 2 ohm drivers land on 1 ohm or 0.25 ohms the same way. Putting each chamber's pair in series, or the two cups in series, lands on 8 and 2 ohms instead, or 4 and 1. An even driver count lands squarely on the loads most mono amplifiers are actually rated into, 2 ohms and 1 ohm, which is one of the quieter advantages of running four. Calculate impedance for multiple subwoofers does the arithmetic for any set, and what 1 ohm stable means explains why the lowest reachable figure is not always the one to wire for.

Read the per-chamber volume, not the total

The total net volume tells you how big the cabinet is. The per-chamber figure tells you what each driver is working into, and that is the number that decides how the box sounds. Both are on every listing.

Sealed is the whole page

Every triple and quad cabinet we cut is sealed. At four drivers the port volume a vented box needs stops fitting in the space that made the high driver count attractive in the first place. If ported is what you want, it is a two driver or single driver build: the ported page has every vented cabinet.

Or step down a count

The dual 8 inch page and the single 8 inch page cover the same drivers in narrower cabinets.