Short answer: the Genelec 8040B. It ranks #33 of 68 powered bookshelf speakers by sound quality, rated 4.3/5, at $1395; the Cambridge Audio L/R X ranks #48, rated 4.1/5, and costs $2399, which makes this an easy call rather than a real tradeoff.
What the Cambridge Audio L/R X does well: A 2.5-way active design with a 28mm aluminum tweeter, a front-facing 5-inch mid-woofer, a second 5-inch woofer at the base whose passband overlaps the first (the source of the “.5”), and dual 6-inch side-firing passive radiators per speaker. The catch: On-axis response is less linear than the L/R S, with dips in the bass, a peak around 1-2kHz, and a dip spanning the upper mid-range into the lower treble; Cambridge confirmed the dip is a deliberate DSP notch for a tweeter breakup resonance rather than a driver flaw, but it was audible as a mild suck-out in an AB pink-noise comparison.
What the Genelec 8040B does well: A compact professional monitor with balanced XLR input and analog room-adjustment controls. Watch for: It lacks GLM calibration and consumer streaming inputs.
Buy the Genelec 8040B. It is rated higher for sound quality than the Cambridge Audio L/R X and costs less, so the other one has nothing left to offer.
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Specifications Side By Side
| Cambridge Audio L/R X | Genelec 8040B | |
|---|---|---|
| Price | $2,399.00 per pair | $2,790 per pair |
| Ranked | #48 of 68 in Large Size Powered Bookshelf Speakers | #33 of 68 in Large Size Powered Bookshelf Speakers |
| Bass Extension (-3dB) | 43Hz (measured, Erin's Audio Corner) | - |
| Bass Extension (-10dB) | 37Hz (measured, Erin's Audio Corner) | - |
| Drivers | 28mm aluminum tweeter, 2x 5" mid-woofers, 2x 6" side-firing passive radiators | 6.5" (165mm) woofer |
| Frequency Response | 35Hz - 24kHz (±3dB, manufacturer specified) | 41Hz - 25kHz (-6dB) (Manufacturer specified) |
| Amplifier Power | 800W total (400W per speaker) | 180w Per Speaker |
| Inputs | HDMI eARC, RCA aux, RCA phono (MM), optical digital, USB-C, USB-A, Ethernet, Wi-Fi | XLR |
| Bluetooth Codecs | SBC, AAC | - |
| App | Yes | No |
| DSP | Yes, room size, wall distance, and reflective surface correction | No |
| Dimensions | 7.9" (200 mm) W x 330mm H x 260mm D (each) | 14.4"H x 9.3"W x 8.8"D (365.8 x 236.2 x 223.5 mm) |
| Weight | 22.9 lbs (10.4kg) each | 20.7 lbs (9.4 kg) each |
| Subwoofer Output | Yes | - |
| Outputs | Subwoofer | - |
| XLR Input | No | Yes |
| RCA Input | Yes | No |
| TRS Input | No | No |
| Optical Input | Yes | No |
| Coaxial Input | No | No |
| USB Input | Yes | No |
| HDMI Input | Yes | No |
| AES Input | No | No |
| Aux Input | No | No |
| Bluetooth | Yes | No |
| EQ | - | Yes (Room adjustment) |
Related Speaker Comparisons
How Genelec 8040B compares with other leading options:
- Genelec 8351B vs Genelec 8040B
- Neumann KH420 vs Genelec 8040B
- Genelec 8361A vs Genelec 8040B
- Genelec 8040B vs Genelec 8341A
- Genelec 8040B vs Neumann KH 150
Prices on this page were last checked September 23, 2026 at 11:24 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Speakers In Full
Cambridge Audio L/R X: $2,399.00 per pair Amazon eBay
Pros: A 2.5-way active design with a 28mm aluminum tweeter, a front-facing 5-inch mid-woofer, a second 5-inch woofer at the base whose passband overlaps the first (the source of the “.5”), and dual 6-inch side-firing passive radiators per speaker. Erin’s Audio Corner measured wide, even horizontal dispersion (a broad flare out to about the -6dB point around 1.5 to 3kHz) and deeper extension than the smaller L/R S, with an F3 of about 43Hz and F10 of about 37Hz. In-app DSP for room size, speaker distance from the front wall, and reflective surface type gave an audible change in bass tightness in testing. Connectivity covers HDMI eARC, RCA aux, a moving-magnet phono input, optical digital, USB-C, USB-A, Wi-Fi streaming, and a subwoofer output, making it a full living-room hub rather than just a stereo pair. Measured bass extension of 43Hz (-3dB).
Cons: On-axis response is less linear than the L/R S, with dips in the bass, a peak around 1-2kHz, and a dip spanning the upper mid-range into the lower treble; Cambridge confirmed the dip is a deliberate DSP notch for a tweeter breakup resonance rather than a driver flaw, but it was audible as a mild suck-out in an AB pink-noise comparison. Vertical dispersion is narrower and asymmetric than the L/R S, at about plus 20 to minus 10 degrees, because the greater distance between the tweeter and mid-woofer creates more lobing, so listening height and stand placement matter more. Multitone distortion rides close to the 3% threshold at 96dB measured at 1 meter in the far field, limiting headroom for loud, wide-band material. Output falls off quickly below about 50Hz, so home-theater use with deep bass content benefits from an added subwoofer.
Full Cambridge Audio L/R X review and specifications →
| AES Input | No |
|---|---|
| Amplifier Power | 800W total (400W per speaker) |
| App | Yes |
| Aux Input | No |
| Bass Extension (-10dB) | 37Hz (measured, Erin's Audio Corner) |
| Bass Extension (-3dB) | 43Hz (measured, Erin's Audio Corner) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC, AAC |
| Coaxial Input | No |
| DSP | Yes, room size, wall distance, and reflective surface correction |
| Dimensions | 7.9" (200 mm) W x 330mm H x 260mm D (each) |
| Drivers | 28mm aluminum tweeter, 2x 5" mid-woofers, 2x 6" side-firing passive radiators |
| Frequency Response | 35Hz - 24kHz (±3dB, manufacturer specified) |
| HDMI Input | Yes |
| Inputs | HDMI eARC, RCA aux, RCA phono (MM), optical digital, USB-C, USB-A, Ethernet, Wi-Fi |
| Optical Input | Yes |
| Outputs | Subwoofer |
| RCA Input | Yes |
| Subwoofer Output | Yes |
| TRS Input | No |
| USB Input | Yes |
| Weight | 22.9 lbs (10.4kg) each |
| XLR Input | No |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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Genelec 8040B: $2,790 per pair B&H Photo Video eBay
Pros: A compact professional monitor with balanced XLR input and analog room-adjustment controls. The manufacturer’s 41Hz limit is specified at -6dB, offering a useful reference for system planning without confusing it with a measured -3dB point.
Cons: It lacks GLM calibration and consumer streaming inputs. The balanced XLR connection may require an interface or controller for a typical desktop source.
Full Genelec 8040B review and specifications →
| AES Input | No |
|---|---|
| Amplifier Power | 180w Per Speaker |
| App | No |
| Aux Input | No |
| Bluetooth | No |
| Coaxial Input | No |
| DSP | No |
| Dimensions | 14.4"H x 9.3"W x 8.8"D (365.8 x 236.2 x 223.5 mm) |
| Drivers | 6.5" (165mm) woofer |
| EQ | Yes (Room adjustment) |
| Frequency Response | 41Hz - 25kHz (-6dB) (Manufacturer specified) |
| HDMI Input | No |
| Inputs | XLR |
| Optical Input | No |
| RCA Input | No |
| TRS Input | No |
| USB Input | No |
| Weight | 20.7 lbs (9.4 kg) each |
| XLR Input | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
- Head-to-Head Comparisons