These are not really the same size class, and that is the honest framing here. The Bose Soundlink Flex 2nd gen ranks #37 of 175 medium speakers by sound quality at $159; the JBL Xtreme 4 ranks #44 of 105 large speakers by sound quality at $309.95.

Different sizes. The Flex 2nd Gen is a medium 1.3 lbs (586 g) speaker. The Xtreme 4 is a large 4.6 lbs (2.1 kg) stereo speaker. Each is rated within its own class.
The Xtreme 4 is clear, punchy and refined, reaches about 106dB measured, and has a replaceable battery, IP67 and a 5-band app EQ. It benefits from EQ since it leans bass boosted by default.
The Flex 2nd Gen has a clear, well balanced midrange, AAC and aptX Adaptive, and is IP67. It is mono and cannot produce low bass rumble.
Buy the Bose Soundlink Flex 2nd gen at $159 if you want a medium speaker. Buy the JBL Xtreme 4 at $309.95 if you want a large speaker instead.
Battery life favors the JBL Xtreme 4: rated for 24 hours against 12 hours for the Bose Soundlink Flex 2nd gen.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Bose Soundlink Flex 2nd gen | JBL Xtreme 4 | |
|---|---|---|
| Price | $159.00 | $309.95 |
| Ranked | #37 of 175 in Medium Size Portable Bluetooth Speakers | #44 of 105 in Large Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Battery Life | 12 hours (Manufacturer specified) | 24 hours (Manufacturer specified) |
| Built-in Microphone | Yes | Yes |
| EQ | Yes (3 band) | Yes (5 band) |
| IP Rating | IP67 | IP67 |
| Party Mode | Yes (Bose Party mode) | Yes (Auracast) |
| Power Input | USB-C | USB-C |
| Stereo | No | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 1.3 lbs (586 g) | 4.6 lbs (2.1 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.3 | 5.3 |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) | 11.7” x 5.9” x 5.6” (297 x 149 x 141 mm) |
| Aux Input | No | No |
| Drivers | 60mm full-range driver with passive radiators | 2x 70mm woofers, 2x 19mm tweeters + 2x passive radiators |
| Bluetooth Codecs | SBC, AAC, aptX Adaptive | SBC |
| Digital Aux Input | No | No |
| Strap | Yes (built-in loop) | Yes (detachable shoulder strap) |
| Bluetooth Latency | - | 220ms |
| Maximum SPL | - | 106dB (measured by Alan Ross Reviews) |
| Power Bank | - | Yes (USB-C) |
| Removable Battery | - | Yes |
| Frequency Response | - | 44Hz - 20kHz (Manufacturer specified) |
| Amplifier Power | - | 100W |
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- Bose Soundlink Flex 2nd gen vs Soundcore Motion+
- Bose Soundlink Flex 2nd gen vs Soundcore Boost “upgraded” 2021
- Bose Soundlink Flex 2nd gen vs Minirig 4
Prices on this page were last checked October 15, 2026 at 5:41 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
Bose Soundlink Flex 2nd gen: $159.00 Amazon $159.00 eBay
Older model: the Bose Soundlink Flex (ranked lower, rated 3.8/5). See every Bose SoundLink Flex, Micro, Max and Plus generation.
Same family: the Bose SoundLink Max (larger model, rated 4.3/5), the Bose Soundlink Micro 2 (larger model, rated 3.6/5) and the Bose SoundLink Plus (larger model, rated 4.2/5).
Pros: A very portable 586g, IP67-rated speaker with a clear, well-balanced midrange that keeps voices and instruments intelligible. The second generation adds a Bose app with 3-band EQ, better-placed controls and stereo pairing with another Bose Soundlink Flex 2nd gen. It supports AAC and aptX Adaptive in addition to SBC, making it a stronger wireless option than most small rivals.
Cons: One Flex remains mono and cannot deliver genuine low-bass rumble; RTINGS also found the elevated treble can turn hi-hats and other high-frequency detail piercing. The claimed battery life is only 12 hours, and some owners report accelerated standby drain after firmware updates. It is expensive for its size, so the added app and codec support, not a transformational sound upgrade over the original, are the main reasons to choose it.
Full Bose Soundlink Flex 2nd gen review and specifications →
| Released | Sep 2024 (2 years ago) |
|---|---|
| App | Yes |
| Aux Input | No |
| Battery Life | 12 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC, AAC, aptX Adaptive |
| Bluetooth Version | 5.3 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) |
| Drivers | 60mm full-range driver with passive radiators |
| EQ | Yes (3 band) |
| IP Rating | IP67 |
| Omnidirectional | No |
| Party Mode | Yes (Bose Party mode) |
| Power Input | USB-C |
| Stereo | No |
| Strap | Yes (built-in loop) |
| TWS | Yes |
| Weight | 1.3 lbs (586 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen vs Flex More from Oluv’Sone →
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen & Soundcore Motion 300 sound test
- Oluv Patreon: Bose Soundlink Flex 2nd gen - sound demo
- Alan Ross: Hall of Fame classic vs latest Bose tech! More from alanrossreviews →
- Alan Ross - The Anti Shill!: Small speaker, mighty sound, The Flex gen 2 shatters physics!
- Alan Ross - The Anti Shill!: DBSONO X-Blast F37 vs Bose Soundlink Flex 2 - They all want to be me 😊
- Mateusz Cholewa: JBL Charge Essential 3 SE vs BOSE SoundLink FLEX 2 More from Mateusz Cholewa →
- CEONTHEMAKING: Bose Soundlink Flex 2nd Gen VS Marshall Emberton III - What’s NEW?? More from CEONTHEMAKING →
- Tô Thái Trí Hùng: Unbox & Sound Test - Bose Soundlink Flex 2
- Musou1: JBL flip 7 vs KEF muo vs Bose flex 2
- Head-to-Head Comparisons
- Bose Soundlink Flex 2nd gen vs Bose Soundlink Flex
- Bose Soundlink Flex 2nd gen vs Tribit Xsound Plus 2
- Bose Soundlink Flex 2nd gen vs JBL Charge Essential 2
- Bose Soundlink Flex 2nd gen vs Teufel Rockster XS
- Bose Soundlink Flex 2nd gen vs Huawei Sound Joy
- Bose Soundlink Flex 2nd gen vs Cleer Audio Scene
- Bose Soundlink Flex 2nd gen vs Soundcore Boom 3i
- Bose Soundlink Flex 2nd gen vs JBL Charge Essential 3 SE
- See all 146 comparisons
JBL Xtreme 4: $309.95 Amazon $309.95 B&H Photo Video $309.95 eBay
Newer model: the JBL Xtreme 5, ranked higher, rated 4.6/5, released Apr 2026. It adds USB audio input, AAC and LC3, but drops the built-in mic. Water resistance goes from IP67 to IP68.
Older models: the JBL Xtreme 3 (ranked higher, rated 4.3/5), the JBL Xtreme 2 (ranked lower, rated 3.4/5) and the JBL Xtreme (ranked lower, rated 3.2/5). See every JBL Xtreme generation.
Pros: A rugged 2.1kg portable with IP67 protection, a replaceable battery, USB-C power-bank output, Auracast, stereo pairing and a useful 5-band app EQ. Independent reviews find the midrange detailed and the sound clear, punchy and refined for outdoor use; it also reaches a strong 106dB maximum level and has excellent real-world battery life.
Cons: It cannot produce the deep rumble of a larger speaker, and bass compression increases near maximum volume. The front-facing layout has only modest off-axis consistency, Bluetooth latency is high for video, and the default balance benefits from EQ adjustment. There is no aux input, so wired sources are not supported. Out of the box it leans bass-boosted, with a dip between the upper bass and midrange that EQ cannot fix, and it pushes the upper mids and treble at high volume. It is also expensive.
Full JBL Xtreme 4 review and specifications →
| Released | Mar 2024 (2 years ago) |
|---|---|
| Amplifier Power | 100W |
| App | Yes |
| Aux Input | No |
| Battery Life | 24 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 220ms |
| Bluetooth Version | 5.3 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 11.7” x 5.9” x 5.6” (297 x 149 x 141 mm) |
| Drivers | 2x 70mm woofers, 2x 19mm tweeters + 2x passive radiators |
| EQ | Yes (5 band) |
| Frequency Response | 44Hz - 20kHz (Manufacturer specified) |
| IP Rating | IP67 |
| Maximum SPL | 106dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Auracast) |
| Power Bank | Yes (USB-C) |
| Power Input | USB-C |
| Removable Battery | Yes |
| Stereo | Yes |
| Strap | Yes (detachable shoulder strap) |
| TWS | Yes |
| Weight | 4.6 lbs (2.1 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- JOY‘s 🎧3D🔈Audio-Show: JBL Charge 6 vs JBL Xtreme 4 - outdoor test More from Oluv’Sone →
- JOY‘s 🎧3D🔈Audio-Show: JBL Charge 6 vs JBL Xtreme 4 - basstest (bigger=better?)
- JOY‘s 🎧3D🔈Audio-Show: JBL Charge 6, Xtreme 4 & Earfun UBoom X - taking sound to the top
- Joy & Oluv’Sone🔈3DAudio🎧& Music: JBL Xtreme 5 - Best Bluetooth Speaker 2026 award
- Oluv Patreon: JBL Xtreme 4 - sound analysis
- Oluv Patreon: JBL Xtreme 4 - unboxing & first impressions
- Oluv Patreon: Harman Kardon go+play 3 vs JBL Xtreme 4 - first impressions
- Oluv Patreon: SoundCore Boom 3i - first impressions & EQs
- Alan Ross Reviews: JBL Xtreme 5 vs JBL Xtreme 4 in 2026 More from alanrossreviews →
- Alan Ross Reviews: JBL Xtreme 5 2026, massive upgrade over JBL Xtreme 4! Full tests!
- Alan Ross Reviews: JBL Xtreme 4 vs Flip 7 vs Charge 6 – The ULTIMATE JBL Speaker Showdown!
- M1MTechChannel: Welche JBL Partybox ist die BESTE ? Alle Partyboxen im Vergleich | 2026 More from M1MTechChannel →
- Dominik Reviews: JBL Xtreme 4 vs JBL Xtreme 3 Sound Test 😍 Best upgrade in the history? 😂 More from Dominik Reviews →
- Dominik Reviews: Tronsmart Bang 2 vs JBL Xtreme 4 - Are both Extreme?
- Dominik Reviews: Teufel BOOMSTER 4 vs JBL Xtreme 4 - Not great for the size? Sound Test
- Dominik Reviews: Tronsmart Fiitune X30 vs JBL Xtreme 4 - Complete opposite of eachother? - Sound Test
- Dominik Reviews: Bugani Brief Pro vs JBL Xtreme 4 - Not so extreme? - Sound Test
- Dominik Reviews: Sony ULT Field 5 vs JBL Xtreme 4 - Outdoor Sound Test - Sony shines or not?
- Mateusz Cholewa: TRIBIT StormBox LAVA Deep BASS 🆚 JBL XTREME 4 More from Mateusz Cholewa →
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- Mateusz Cholewa: BOGASING S8 Pro Max 100W vs JBL Xtreme 4 Audio Test
- Mateusz Cholewa: LOEWE We HEAR Pro Super Stereo vs JBL Xtreme 4
- Mateusz Cholewa: Marshall Kilburn 3 vs JBL Xtreme 4 – OUTSIDE🤗
- Mateusz Cholewa: MARSHALL Kilburn 3 🆚 JBL Xtreme 4
- Mateusz Cholewa: TRIBIT StormBox LAVA - Unboxing.📦 Short Test vs Xtreme 4
- Techder Audios: JBL Xtreme 4 VS Teufel Rockster Cross “DEEP BASS VS BETTER MIDS !” More from techderaudios →
- YARNZO Tech: Zealot s98 vs Jbl xtreme 4. outdoor sound test 🔊 More from YARNZO Tech →
- YARNZO Tech: Zealot S79 vs JBL Xtreme 4 full review and sound battle
- YARNZO Tech: Jbl xtreme 4 vs zealot s98. both were released 2024 does size really matter here 🤔let’s find out
- BT Sound Lab: JBL Xtreme 4 vs Tronsmart Bang 2
- Head-to-Head Comparisons

