LX Dual Monitor Arm

The LX Dual is built to the same standard as the single LX that tops our rankings: aluminum and steel, the proven Constant-Force mechanical spring in each arm, and a 10-year warranty. Each screen holds its set position without the slow droop that affects gas-spring arms, and Ergotron’s reputation for arms that still work a decade later applies here too.

It scores 9.0 rather than the single LX’s 9.5 for a structural reason inherent to dual arms: two independent arms mount to a shared base and crossbar, which introduces more joints and a longer lever than a single post. In practice the difference is small — both screens stay planted — but a dual arm is never quite as immovably rigid as a single-monitor mount, and we reflect that honestly. Among dual arms specifically, this is as solid as it gets.

Bottom line on stability: The same Constant-Force build and 10-year warranty as the #1 LX, a half-step down only because any dual arm’s shared crossbar is marginally less rigid than a single post. The most dependable dual mount we rate.

The defining feature of the LX Dual is that the two arms move fully independently. Each gets the complete single-LX range — 13″ of lift, 25″ of extension, tilt, pan, and 360° portrait rotation — so you can set one screen straight ahead and angle the second inward, raise one for reading and drop the other, or flip a display into portrait for code or documents without touching its neighbor. That independence is exactly what a two-screen ergonomic setup needs, and cheaper dual mounts that share a single pivot can’t match it.

The Constant-Force mechanism carries over too, so each adjustment is the same smooth, single-finger motion that stays put. The arms can also be brought close together to minimize the gap between two bezels, or spread wide for a broader span. It earns a strong 9.0 — a touch below the single LX’s 9.5 only because coordinating two arms on one base is inherently a little more constrained than moving one arm in free space.

Bottom line on motion: Two fully independent arms, each with the single LX’s complete range — the right architecture for a real dual-monitor ergonomic setup.

Each arm of the LX Dual is rated for 7 to 20 pounds and a display up to 27″, on standard 75×75 or 100×100 mm VESA. For the most common dual setup — two 24″ or 27″ monitors, which typically weigh 8 to 15 pounds each — that’s a comfortable fit with headroom to spare, and the side-by-side base keeps both screens aligned at a matched height.

The 8.0 reflects two honest limits. First, the per-arm ceiling steps down from the single LX’s 25 lb to 20 lb, because a dual base supports two cantilevered loads at once. Second, and more relevant to shoppers, the 27″ per-screen rating is the real constraint: if you’re running two 32″ panels, this isn’t the arm — and notably, the Amazon Basics Dual that ties it overall is rated higher, to 25 lb and 32″ per arm. For standard dual setups the LX Dual has all the capacity you need; for big-panel dual setups, look to that higher-rated alternative or a heavier mount.

Bottom line on capacity: Ideal for two 24–27″ monitors, with aligned heights and headroom. If you run dual 32″ screens, the higher-rated Amazon Basics Dual or a heavier mount fits better.

The LX Dual includes both a C-clamp and a grommet mount and goes together with Ergotron’s usual well-organized hardware and instructions. The single shared base is actually a versatility plus over running two separate single arms: it needs only one desk attachment point and keeps the two screens on a common, level reference.

It scores 8.0 because a dual arm is simply more to assemble than a single — there’s a crossbar and two arms to build and balance, and mounting two monitors is easier with a second pair of hands. As with any clamp arm, confirm your desk has a clear rear edge and enough depth to take the base, since a dual setup places more cantilevered weight on that single mounting point at full extension.

Bottom line on installation: One desk attachment for two aligned screens, with clamp and grommet included — just more assembly than a single arm, and easier with help.

Cable management uses the same integrated clips and channels as the rest of the LX line, applied to both arms — which matters more on a dual setup, where you’re routing two sets of power and video cables and want to keep them from tangling as each screen moves independently. The system keeps everything controlled through the full range of motion.

The 8.5 matches the single LX. It’s a tidy clip-and-channel approach rather than a fully enclosed cable tunnel, but for managing the doubled cabling of a two-monitor desk it does the job cleanly and keeps the setup looking organized.

Bottom line on cables: The LX line’s integrated routing applied to both arms — effective for taming the doubled cabling a dual setup brings.

Value is the LX Dual’s one amber score, and it comes down to the same dynamic that shapes the single-arm rankings: there’s an Ergotron-built alternative that costs less. The LX Dual carries a genuine premium, and while it’s worth it for the 10-year warranty and Ergotron’s support, the Amazon Basics Dual — manufactured by Ergotron on the same Constant-Force mechanism — delivers effectively the same arm, with a higher per-arm rating (25 lb and 32″ versus 20 and 27″), for a notably lower price. The main thing it gives up is the warranty, about one year against Ergotron’s ten.

That’s why the two arms tie at 8.4 overall, and why we award the LX Dual the “Best Dual-Monitor” title while naming the Amazon version “Best Value Dual.” The LX Dual is the pick if you want the decade-long warranty, the finish options, and direct Ergotron support; if you’d rather bank the savings on the same engineering — and gain a little capacity in the bargain — the Amazon Basics Dual is the smarter spend. Either way you’re buying Ergotron hardware; the choice is warranty versus price.

Bottom line on value: A fair premium for the 10-year warranty, but the Ergotron-built Amazon Basics Dual is the same mechanism with more capacity for less. Choose the LX Dual for the warranty, the Amazon Dual to save.