Rolls HR155 Powered Half-Rack Monitor Speaker with XLR Input

Rolls HR155: A Self-Powered Monitor Speaker That Lives in the Rack

The Rolls HR155 is a self-contained 5-watt powered monitor speaker in a half-rack chassis, built to let you hear any line or balanced feed right at the equipment rack. It exists for the confidence-monitoring job every AV and broadcast rack eventually needs: a quick, always-on way to listen to a signal without patching headphones or dragging over a speaker. Amplifier and speaker are combined in one all-metal box that mounts in a rack or sits on a desk, with a front level control and a choice of inputs. It sums a stereo RCA feed or takes a single balanced XLR and plays it through its built-in driver. For any rack that needs an ear on the audio at all times, the HR155 is a purpose-built listening post.

Built-In Amplifier and Speaker in One Chassis

The HR155 combines a 5-watt amplifier and a monitor speaker in a single half-rack unit, so there is no separate amp, no speaker wire, and no extra box to power. A self-powered monitor like this works by amplifying the incoming line signal internally and driving its own speaker, which is why one small chassis is all the listening station needs. Five watts is modest by design, sized to fill a rack room or a desktop area rather than a hall. A front-panel level control sets how loud the monitor plays without touching the source. For a broadcast or AV rack where you just need to confirm that audio is present and clean, having the whole monitoring chain in one rackable box is the entire point.

Flexible XLR, RCA, and 3.5mm Inputs

The HR155 accepts a female balanced XLR, a stereo pair of RCA jacks, and a 1/8-inch (3.5mm) input, so it can monitor almost any source in the rack. It sums the stereo RCA inputs down to its single speaker or takes a single balanced XLR line, with a 10k ohm input impedance that sits behind other gear without loading it. That input flexibility means the same monitor can check a console output today and a media player tomorrow with only a cable change. Balanced XLR support in particular lets it tap long professional runs without picking up hum. For an integrator who never knows exactly what will need listening to next, having three input types on one monitor keeps it universally useful.

All-Metal Chassis Built to Rack Without Clearance

The HR155 measures 7.5 by 3.125 by 1.75 inches in an all-metal chassis that dissipates its heat internally, so it can be racked with no clearance above or below. Because the metal body itself carries away the amplifier's warmth, the unit does not need fan slots or empty rack space around it, which is how it stays a clean half-rack 1RU install. Its rugged construction stands up to the vibration and handling of a working rack far better than a plastic speaker box. Paired with a half-rack tray, two such units share a single rack space. For a tightly packed AV or broadcast rack where every rack unit counts, a monitor that mounts flush and runs cool is exactly what fits.

Confidence Monitoring for Broadcast and AV Racks

The HR155 is built for the everyday task of confirming that audio is flowing and sounds right, directly at the rack. In broadcast it serves as a confidence monitor on an air feed or a return, always on so an operator can catch dead air instantly. In AV installs it checks paging, background-music, and program feeds without dedicating a large speaker to the closet. On a desktop it gives an editor or engineer a quick line-level monitor for spot checks. Because it powers itself and takes common connectors, it slots into any of these roles with one cable and one outlet. For techs who just need to hear the signal, the HR155 is the small, reliable ear that stays in the rack.