Short answer: the Earfun Uboom L. It ranks #1 of 142 medium speakers by sound quality at $49.79; the Bose Soundlink Flex ranks #36 and costs $155.78, which makes this an easy call rather than a real tradeoff.
What the Bose Soundlink Flex offers: IP67 rated; rugged enough to survive drops from several feet and floats. Around 12 hours of battery at moderate volume. Watch for: Not stereo. Warm sounding with overly boosted bass which drowns out midrange detail
What the Earfun Uboom L offers: One of the strongest small-speaker values for music: reviews praise clear vocals, a natural overall balance and a genuinely convincing stereo image when two are paired. IP67 protection, indoor/outdoor sound modes and Video Mode make it unusually adaptable; Video Mode substantially improves lip-sync for a single speaker. Watch for: It cannot produce real low-bass rumble or fill a large, noisy space, and RTINGS finds the top end loses detail. Low-latency Video Mode disables stereo pairing, so a two-speaker setup is not a good movie system. Firmware and app behavior have also varied over the model’s long life, and the physical controls can be easy to trigger in a bag.
Buy the Earfun Uboom L. It ranks higher for sound quality than the Bose Soundlink Flex and costs less, so the other one has nothing left to offer.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Bose Soundlink Flex | Earfun Uboom L | |
|---|---|---|
| Price | $155.78 | $49.79 after coupon UBOOMLWC |
| Ranked | #36 of 142 in Medium Size Portable Bluetooth Speakers | #1 of 142 in Medium Size Portable Bluetooth Speakers |
| App | Yes | Yes (firmware >= 1.2.6) |
| Bass Extension (-10dB) | 56Hz | 56Hz |
| Battery Life | 12 hours (Manufacturer specified) | 16 hours (Manufacturer specified) |
| Built-in Microphone | Yes | Yes |
| EQ | No | Yes (10 band, firmware >= 1.2.6) |
| IP Rating | IP67 | IP67 |
| Bluetooth Latency | 33ms | 400ms normal / 66ms low latency mode |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) | 103dB (measured by Alan Ross Reviews) |
| Party Mode | Yes (Bose Party mode) | No |
| Power Input | USB-C | USB-C |
| Stereo | No | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 1.3 lbs (589 g) | 1.4 lbs (650 g) |
| Bluetooth Version | 4.2 | 5.0 |
| Dimensions | 7.9" x 3.5" x 2" (201 x 90 x 52 mm) | 3.1" x 8.3" x 2.8" (78 x 210 x 72 mm) |
| Drivers | 1x 60mm full-range driver + 2x passive radiators | 2x 55mm drivers + 2x passive radiators |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC | AAC, SBC |
| Aux Input | - | Yes |
| Aux Latency | - | 216ms |
| Power Bank | - | No |
| Amplifier Power | - | 28W |
Related Speaker Comparisons
How Earfun Uboom L compares with other leading options:
- Earfun Uboom L vs Soundcore Motion 300
- Earfun Uboom L vs Soundcore Motion+
- Earfun Uboom L vs Minirig 4
- Earfun Uboom L vs B&O Beosound A1 2nd gen
- Earfun Uboom L vs JBL Charge 6
Prices on this page were last checked September 16, 2026 at 12:41 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
Bose Soundlink Flex: $155.78 Amazon eBay
Pros: IP67 rated; rugged enough to survive drops from several feet and floats. Around 12 hours of battery at moderate volume. Measured bass extension of 56Hz (-10dB).
Cons: Not stereo. Warm sounding with overly boosted bass which drowns out midrange detail
Full Bose Soundlink Flex review and specifications →
| App | Yes |
|---|---|
| Bass Extension (-10dB) | 56Hz |
| Battery Life | 12 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 33ms |
| Bluetooth Version | 4.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 7.9" x 3.5" x 2" (201 x 90 x 52 mm) |
| Drivers | 1x 60mm full-range driver + 2x passive radiators |
| EQ | No |
| IP Rating | IP67 |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Bose Party mode) |
| Power Input | USB-C |
| Stereo | No |
| TWS | Yes |
| Weight | 1.3 lbs (589 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen vs Flex More from Oluv’Sone →
- Alan Ross Reviews: Bose Soundlink Flex Review! vs JBL Flip 6 and JBL Charge 5. Travel heaven?? 🤞 More from alanrossreviews →
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen vs Flex
- Alan Ross Reviews: Beats Pill vs Harman Luna vs Bose Flex vs Soundcore Motion Plus
- Alan Ross Reviews: Tribit Xsound Mega vs the world! (JBL Charge 5, Bose Flex, Sony XB33, LG PL7) 👍
- Alan Ross Reviews: Bose Soundlink Flex vs Soundcore Boost vs Bogasing M4 - cheap or Bose?
- Alan Ross Reviews: Tribit Stormbox Flow has deeper bass than the Bose Flex but………..
- Jay’s Straight Up Reviews & More: Tribit Stormbox Flow vs Soundcore Motion 300 (LDAC) 😵 Budget Bose Soundlink Flex "Inspired" Speakers More from JaysStraightUpReviews →
- Oluv Patreon: Soundcore Motion 300 = Bose Soundlink Flex = Earfun UBoom L?
- Alan Ross Reviews: Bose Soundlink Flex or JBL Flip 6 (eq adjusted) or Denon Envaya - best speaker for travel!
- Alan Ross Reviews: Bose Soundlink Flex or Beosound A1 (1st gen) - ultimate compact speaker 😇
- Alan Ross Reviews: Bose Soundlink Flex or JBL Flip 6 (eq adjusted) or Denon Envaya - best speaker for travel!
- Jay’s Straight Up Reviews & More: Tribit Stormbox Flow vs Soundcore Motion 300 (LDAC) 😵 Budget Bose Soundlink Flex "Inspired" Speakers
- Patricio Benadon: Bose SoundLink Flex vs. Mini 2 SE. Music audio quality sound test. Listen 4 different genres!
- Patricio Benadon: Bose SoundLink Flex vs. Mini 2 SE. Music audio quality sound test. Listen 4 different genres!
- Danny Pops: BEST Bose Speaker?? Bose Soundlink Flex vs micro, Color II, and revolve + More from DannyPops →
- Alan Ross Reviews: Bose Soundlink Flex vs Minirig MK3 and Marshall Emberton - best bluetooth speaker?
- Joy & Oluv’Sone: JBL, Bose, B&O, Sonos, Earfun, SoundCore… which portable speaker sounds best?
- Alan Ross - The Anti Shill!: Small speaker, mighty sound, The Flex gen 2 shatters physics!
- Head-to-Head Comparisons
- Bose Soundlink Flex vs Bose Soundlink Flex 2nd gen
- Bose Soundlink Flex vs JBL Charge Essential 2
- Bose Soundlink Flex vs Tribit Xsound Plus 2
- Bose Soundlink Flex vs Huawei Sound Joy
- Bose Soundlink Flex vs Teufel Rockster XS
- Bose Soundlink Flex vs Soundcore Motion 100
- Bose Soundlink Flex vs Tribit Stormbox Pro
- Bose Soundlink Flex vs Soundcore Boom 3i
- See all 92 comparisons
Earfun Uboom L: $49.79 after coupon UBOOMLWC Amazon Myearfun eBay
Pros: One of the strongest small-speaker values for music: reviews praise clear vocals, a natural overall balance and a genuinely convincing stereo image when two are paired. IP67 protection, indoor/outdoor sound modes and Video Mode make it unusually adaptable; Video Mode substantially improves lip-sync for a single speaker. Measured bass extension of 56Hz (-10dB).
Cons: It cannot produce real low-bass rumble or fill a large, noisy space, and RTINGS finds the top end loses detail. Low-latency Video Mode disables stereo pairing, so a two-speaker setup is not a good movie system. Firmware and app behavior have also varied over the model’s long life, and the physical controls can be easy to trigger in a bag.
Setup: Try setting up the Earfun App (Android or iOS) to see if that works. If not, you’ll need to flash firmware 1.2.7 to work with the app and set with Oluv’s EQ in the Earfun app which sounds the best. The instructions say that you need a USB3 cable, but most USB2 cables work just fine, try the one included with your phone. Check the current firmware version by turning it on, then pressing the power and Bluetooth buttons at the same time. To flash, turn the speaker off then hold down the Bluetooth button while plugging in the cable. To flash on a mac, see these instructions. In TWS mode, long press the outdoor button for 2 seconds to change TWS to Party mode and back.
Full Earfun Uboom L review and specifications →
| Amplifier Power | 28W |
|---|---|
| App | Yes (firmware >= 1.2.6) |
| Aux Input | Yes |
| Aux Latency | 216ms |
| Bass Extension (-10dB) | 56Hz |
| Battery Life | 16 hours (Manufacturer specified) |
| Bluetooth Codecs | AAC, SBC |
| Bluetooth Latency | 400ms normal / 66ms low latency mode |
| Bluetooth Version | 5.0 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 3.1" x 8.3" x 2.8" (78 x 210 x 72 mm) |
| Drivers | 2x 55mm drivers + 2x passive radiators |
| EQ | Yes (10 band, firmware >= 1.2.6) |
| IP Rating | IP67 |
| Maximum SPL | 103dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | No |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| Weight | 1.4 lbs (650 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Joy & Oluv’Sone: Best portable speakers 2025 - get the best bang for your buck $$$ More from Oluv’Sone →
- Oluv Patreon: SoundCore Boom 3i - first impressions & EQs
- Joy & Oluv’Sone: New Beats Pill 2024: sound demo
- CEONTHEMAKING: Earfun Uboom L - This Speaker Replaced My JBL Flip 6… More from CEONTHEMAKING →
- Techder Audios: EARFUN UBOOM L VS SOUNDCORE MOTION+ More from techderaudios →
- Alan Ross Reviews: Earfun UBoom L Review Speaker tuned by a Geek vs Soundcore Motion Plus $100 dollar best portable? More from alanrossreviews →
- Oluv Patreon: Soundcore Motion 300 = Bose Soundlink Flex = Earfun UBoom L?
- Jay’s Straight Up Reviews & More: Earfun UBoom L 💣(EQ2) 🆚 Tribit XSound Mega 🔥(XBass EQ)- Bluetooth Speaker Bedroom Bash. Who U Got?🔝 More from JaysStraightUpReviews →
- Joy & Oluv’Sone: JBL, Bose, B&O, Sonos, Earfun, SoundCore… which portable speaker sounds best?
- DIY Subwoofers - Uboom L Measurements and Review
- Head-to-Head Comparisons