RBH UNRIVALED 81/AX – Stand Mount Active Studio Monitor Speaker

RBH UNRIVALED 81/AX – Stand Mount Active Studio Monitor

Shocking, powerful; go beyond expectations. The UNRIVALED 81/AX is a show stopper. Winner of two awards at AXPONA 2025 for Best Stand-mount Speaker, the UNRIVALED 81/AX is a master at imaging and true full range sound. With an anechoic response down to 35Hz, mid 20Hz in-room response is achievable. With countless customization options, you can really tailor the 81/AX to any listening space, and with 8 DSP presets available, the 81/AX can be suited for nearfield studio monitor duties or be set up far-field in a HiFi configuration. The choice is yours.

• 4.72" x 1" (120 x 25mm) AMT (Air Motion Transformer) tweeter
• 8" aluminum cone long throw woofer
• HDF/Acrylic Polymer enclosure
• Supplied power: 150 Watts (Tweeter), 500 Watts (Woofer)
• FIR linear phase active crossover, 48dB/Octave
• 8 Ω Impedance
• 35Hz – 40kHz (±3dB) Frequency Response
• Made in USA
• 10 Year Warranty; 3 Year (Amplifier)

Highlights & Key Technologies

Bring Surprising Full Range Sound
Big sound that exceeds its size. The powered 81/AX is more suited for larger rooms, and it can be used in a bigger studio environment as well with impeccable results. It is a 2-way DSP controlled active speaker, and you can enjoy the convenience and performance of RBH professional studio monitors at home too. The onboard DSP features Finite Impulse Response (FIR) filters to enhance phase correction of the speaker's response and also doubles as an active crossover network, providing extreme flexibility and eliminating traditional, power-robbing passive components. Powered by DSP amps for ultimate sound contour control.

Signature Series Drive Units
At the heart of these active monitors are RBH's Signature Series drivers: for bass and midrange, an 8 inch aluminum cone mid/woofer, and an AMT (Air Motion Transformer) tweeter. The long throw 8" woofer delivers deep and powerful bass, while the extraordinary proprietary AMT tweeter provides smooth and highly detailed performance. Tweeter protection is provided.

Powerful Sound
This proprietary driver duo is powered by an RBH programmed state-of-the-art dual channel class D amplifier supplying 150 Watts for the tweeter and 500 Watts for the woofer.

UNRIVALED Active Crossover System (AX)
The crème de la crème. The best of the best. Active systems are the future with unparalleled control and the most advanced FIR linear phase crossover functionality with up to a staggering 108dB/octave crossover filters, a feat that simply isn't possible with a passive system. When you buy an RBH UNRIVALED Active speaker system, you not only get a flagship DSP processor with the best Burr Brown DACs, but you also get state of the art class D amplification via the RBH UNRIVALED Alpha amplifier, configured to match the system of choice. Internal options are available for a cleaner approach; with the same quality amplification built in and the same DSP functionality as external amplification and processing, there is very little compromise. The FIR filters allow the system to achieve a ruler flat response as well as provide time alignment not only with the distance of the speaker drivers, but across the frequency spectrum, ensuring all of the sound connects with your eardrums at the same time. Welcome to the future!

Damping Materials
Wool is an excellent acoustic absorber. It has a greater density and absorptive ability over polyfill. It is the material of choice for any sealed enclosures or chambers. For ported enclosures, cabinets are lined with high quality 1 inch foam which is a terrific absorber and ensures nothing is projected out of the ports.

R.A.D. Technology (Rubberized Aluminum Dampener)
Each UNRIVALED speaker cabinet is internally lined with an anti-resonance material. This material is made from rubber and aluminum and is adhered to the internal walls of the speaker. Effectively, it adds to the absorption of unwanted vibrations.

Internally Wired with Kimber Kable
As part of the no compromise that we pledge with UNRIVALED systems, we utilize Kimber wire with their tried and true braided geometry which further improves crosstalk rejection and external influences.

R.D.A.P. (Resonance Damping Acrylic Polymer)
To further the performance of the speaker (as well as cosmetics), side panels made from acrylic polymer solid surface, which has a density similar to granite, can drastically improve the rigidity of the speaker, which substantially reduces cabinet resonance providing several benefits including: reducing smearing, improved imaging, improved soundstage, tightened response, and improved clarity.

G.A.D.S. (patent pending)
On select, sealed only, speaker systems, RBH's new G.A.D.S. (granular acoustic damping system) technology is employed. Not only does it have mass loading effects, which can further improve the rigidity of the cabinet, it is also an excellent acoustic absorber. The marvel of this technology is while the granular particulates may occupy a significant amount of space in the enclosure, the impact on the total volume is negligibly affected, therefore the tuning of the box is near unaffected.

Connections & Controls
The 81/AX provides level and preset DSP selection controls and XLR balanced connections, with 8 DSP presets available. A RCA to XLR converter is included. The rear panel carries the XLR input, programmed DSP options, and Powercon and AC Link connections.

Timbre Matching
The 81/AX provides timbre matched options for multi-channel sound across all freestanding, bookshelf, on-wall and in-wall products in the SF, SV or SI-Series.

Finish & Style Options
The 81/AX enclosure is available in Satin Black or Satin White, with Gloss Black or White side panels, and the aluminum drivers are available in black or silver. Side panels can be added to add style and a bit more sound damping, or you can opt for a more formal studio look with a smooth black satin finish.

Built in the USA
The 81/AX is designed, engineered, assembled and tested in RBH Sound's USA facility, and the cabinet is made in the USA of High Density Fiberboard (HDF). For over 50 years, RBH Sound has designed and built loudspeakers in the USA with a singular focus - accurate sound reproduction, reliability, and timeless performance.

Details & Specifications

MODEL INFORMATION
Model Name: UNRIVALED 81/AX
Series: UNRIVALED
Sold per pair

SYSTEM TYPE
DSP Powered Monitor

DRIVERS
(1) 4.72" x 1" (120 x 25mm) AMT Tweeter
(1) 8" Aluminum Cone Long Throw Woofer
Tweeter protection: Yes

AMPLIFICATION
Amplifier type: RBH programmed dual channel class D
Amplifier Power: 150w, 500w
Supplied power: 150 Watts for the tweeter and 500 Watts for the woofer

PERFORMANCE
Frequency Response: 35Hz-40kHz (±3dB)
Anechoic response down to 35Hz; mid 20Hz in-room response is achievable
Impedance: 8Ω

CROSSOVER
Crossover filters: FIR Linear Phase
Crossover Frequencies: 2300Hz
Crossover Slope: 48dB/Octave

CONNECTIONS & CONTROLS
Input: XLR balanced (RCA to XLR converter included)
Controls: Level and preset DSP selection controls
DSP presets: 8
Power: Powercon and AC Link

ENCLOSURE
Enclosure: HDF/Acrylic Polymer
Finish: Satin Black or Satin White
Side panels: Gloss Black or White
Cabinet made in USA of High Density Fiberboard (HDF)

GRILLE DETAILS
Black or White Cloth Mag Attached
Magnetic grille included (1/2" MDF)

PHYSICAL SPECIFICATIONS
Dimensions (H x W x D): 19" x 9-3/4" x 14-1/4" (483 x 248 x 362mm)
Weight: 33.85lbs (15.35kg)

MANUFACTURE
Made in USA
Designed, Engineered, Assembled and Tested in RBH Sound's USA facility

AWARDS
2024 - The Best Loudspeakers We Heard at AXPONA 2025 - Audioholics
2024 - Best Bookshelf at the Show (AXPONA 2025) - Jiles McCoy

WARRANTY
10 Year Limited Warranty (with registration within 90 days)
3 Year Limited Warranty - Amplifier (with registration within 90 days)