Different classes, so treat this as a step-up-or-not question rather than a head-to-head. The Brane X ranks #4 of 78 large speakers by sound quality at $500; the JBL Authentics 300 ranks #32 of 75 boombox speakers by sound quality at $299.95.
The case for the Brane X: The Brane X pairs a dedicated RAD subwoofer with two midrange drivers and two tweeters to achieve extraordinary low bass for a 3.5kg portable: its measured -10dB extension is 31Hz. The tradeoff: The front-facing design has only moderate dispersion, so sound changes noticeably off to the sides or behind it.
The case for the JBL Authentics 300: Integrates both Amazon Alexa and Google Assistant simultaneously (rare for smart speakers). The tradeoff: Narrow sounding, bass not as deep as others.
Buy the Brane X at $500 for a large speaker, or the JBL Authentics 300 at $299.95 for a boombox speaker instead.
There is a real gap in water resistance: the Brane X at IP57 (brief submersion) against the JBL Authentics 300, which has no water resistance.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Brane X | JBL Authentics 300 | |
|---|---|---|
| Price | $500 | $299.95 |
| Ranked | #4 of 78 in Large Size Portable Bluetooth Speakers | #32 of 75 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | No |
| Aux Latency | 295ms default, 33ms with aux pass-through | - |
| Bass Extension (-10dB) | 31Hz | 45Hz |
| Battery Life | 12 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| Bluetooth Codecs | aptX HD, aptX, AAC, SBC | SBC |
| IP Rating | IP57 | None |
| Bluetooth Latency | 100ms | - |
| Maximum SPL | 106dB (measured by Alan Ross Reviews) | 100dB (measured by Alan Ross Reviews) |
| Party Mode | Yes (Brane app, up to 8 speakers) | Yes (Wi-Fi Multi-Room) |
| Power Input | AC Power brick | AC Power cable |
| Stereo | Yes | Partially (1 woofer) |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 7.7 lbs (3.5 kg) | 10.8 lbs (4.9 kg) |
| Wi-Fi | Yes | Yes |
| App | No | Yes |
| Built-in Microphone | Yes | Yes |
| Voice Assistants | Amazon Alexa | Amazon Alexa & Google Assistant (simultaneous) |
| EQ | No | Yes (App EQ) |
| Power Bank | No | No |
| Dimensions | 9.3" x 7" x 6.1" (236 x 178 x 155 mm) | 13.5" x 7.7" x 7.1" (342 x 195.6 x 180.3 mm) |
| Drivers | 2x 2.5" midrange, 2x 0.75" tweeters + 6.5"x9" subwoofer | 1" tweeter + 4" woofer + passive radiators |
| Frequency Response | 30Hz - 20kHz (Manufacturer specified) | - |
| Amplifier Power | 200W | 100W |
| Digital Aux Input | No | No |
| Bluetooth Version | 5.1 | 5.3 |
| USB Playback | - | Yes |
| MicroSD Playback | - | No |
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- Brane X vs Minirig 4 with subwoofer
- Brane X vs Minirig 3 with subwoofer
Prices on this page were last checked September 22, 2026 at 5:11 AM 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
Brane X: $500 Amazon eBay
Pros: The Brane X pairs a dedicated RAD subwoofer with two midrange drivers and two tweeters to achieve extraordinary low bass for a 3.5kg portable: its measured -10dB extension is 31Hz. Independent testing finds it loud, with well-balanced mids, a smooth treble balance and useful bass-level controls; Wi-Fi, AirPlay, Alexa, quality Bluetooth codecs and low-latency aux pass-through make it unusually versatile. Measured bass extension of 31Hz (-10dB).
Cons: The front-facing design has only moderate dispersion, so sound changes noticeably off to the sides or behind it. Bass response shifts at maximum volume, the default aux mode has very high latency, and some listeners find the upper register edgy or need EQ to achieve their preferred balance. Its claimed 12-hour runtime and premium cost make it more of a compact high-end system than a carefree all-day speaker.
Full Brane X review and specifications →
| Amplifier Power | 200W |
|---|---|
| App | No |
| Aux Input | Yes |
| Aux Latency | 295ms default, 33ms with aux pass-through |
| Bass Extension (-10dB) | 31Hz |
| Battery Life | 12 hours (Manufacturer specified) |
| Bluetooth Codecs | aptX HD, aptX, AAC, SBC |
| Bluetooth Latency | 100ms |
| Bluetooth Version | 5.1 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 9.3" x 7" x 6.1" (236 x 178 x 155 mm) |
| Drivers | 2x 2.5" midrange, 2x 0.75" tweeters + 6.5"x9" subwoofer |
| EQ | No |
| Frequency Response | 30Hz - 20kHz (Manufacturer specified) |
| IP Rating | IP57 |
| Maximum SPL | 106dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Brane app, up to 8 speakers) |
| Power Bank | No |
| Power Input | AC Power brick |
| Stereo | Yes |
| TWS | Yes |
| Voice Assistants | Amazon Alexa |
| Weight | 7.7 lbs (3.5 kg) |
| Wi-Fi | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: This speaker left me shocked! Brane X, they said it defies the laws of physics! More from alanrossreviews →
- Alan Ross Reviews: Brane X vs JBL Xtreme 5: Maximum Bass, No Mercy
- Alan Ross Reviews: JBL Boombox 4 HUMILIATES Brane X?! Ultimate Bass Battle!
- Alan Ross Reviews: Minirig 2.1 or the Brane X or the Harman Kardon Go Play 3?
- mark: Brane X Speaker Review 2
- mark: Brane X Speaker Review
- Head-to-Head Comparisons
JBL Authentics 300: $299.95 Amazon eBay
Pros: Integrates both Amazon Alexa and Google Assistant simultaneously (rare for smart speakers). Retro seventies design with leather and Quadrex grille. 100-watt amp, carries well with leather-trimmed handle. Rechargeable battery rated ~8 hours. Measured bass extension of 45Hz (-10dB).
Cons: Narrow sounding, bass not as deep as others. Peaky upper mids. No TWS. No IP rating. Not as loud as others. Not much battery life.
Full JBL Authentics 300 review and specifications →
| Amplifier Power | 100W |
|---|---|
| App | Yes |
| Aux Input | No |
| Bass Extension (-10dB) | 45Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 13.5" x 7.7" x 7.1" (342 x 195.6 x 180.3 mm) |
| Drivers | 1" tweeter + 4" woofer + passive radiators |
| EQ | Yes (App EQ) |
| IP Rating | None |
| Maximum SPL | 100dB (measured by Alan Ross Reviews) |
| MicroSD Playback | No |
| Omnidirectional | No |
| Party Mode | Yes (Wi-Fi Multi-Room) |
| Power Bank | No |
| Power Input | AC Power cable |
| Stereo | Partially (1 woofer) |
| TWS | Yes |
| USB Playback | Yes |
| Voice Assistants | Amazon Alexa & Google Assistant (simultaneous) |
| Weight | 10.8 lbs (4.9 kg) |
| Wi-Fi | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- JOY‘s 🎧3D🔈Audio-Show: JBL Authentics 300 - sound quality test More from Oluv’Sone →
- Oluv Patreon: JBL Authentics 300 - update
- Oluv Patreon: JBL Authentics 300 - listening session
- Alan Ross Reviews: Not quite! JBL Authentics 300 review and sound test vs Boombox 3, Encore and Stormbox Blast More from alanrossreviews →
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