Short answer: the Bose Soundlink Flex 2nd gen, if you are buying new. The Bogasing M4 ranks higher than it (#26 vs #35 of 142 medium speakers, 4.0/5 vs 3.8/5) but is discontinued, so only consider it used; the Bose Soundlink Flex 2nd gen is still sold new at $159.
The case for the Bogasing M4: Use super bass mode for the most balanced sound. The catch: A bit harsh and thin sounding.
What the Bose Soundlink Flex 2nd gen gets right: Pretty much identical sounding to the 1st gen. Set against that: Not stereo.
Buy the Bose Soundlink Flex 2nd gen new; the Bogasing M4 is no longer sold new, so it only makes sense as a used find.
Battery life favors the Bogasing M4: rated for 24 hours against 12 hours for the Bose Soundlink Flex 2nd gen.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Bogasing M4 | Bose Soundlink Flex 2nd gen | |
|---|---|---|
| Price | $45.99 Discontinued | $159.00 |
| Ranked | #26 of 142 in Medium Size Portable Bluetooth Speakers | #35 of 142 in Medium Size Portable Bluetooth Speakers |
| App | No | Yes |
| Aux Input | Yes | No |
| Bass Extension (-10dB) | 54Hz | - |
| Battery Life | 24 hours (Manufacturer specified) | 12 hours (Manufacturer specified) |
| EQ | No | Yes (3 band) |
| IP Rating | IPX7 | IP67 |
| Bluetooth Latency | 150ms | - |
| Maximum SPL | 99dB (measured by Alan Ross Reviews) | - |
| MicroSD Playback | Yes | - |
| Power Input | USB-C | USB-C |
| Stereo | Yes | No |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 1.6 lbs (731 g) | 1.3 lbs (586 g) |
| Bluetooth Version | 5.0 | 5.3 |
| Amplifier Power | 40W | - |
| Drivers | 52mm speaker unit | 60mm full-range driver with passive radiators |
| Digital Aux Input | No | No |
| Discontinued | Yes | - |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) | SBC, AAC, aptX Adaptive |
| Dimensions | 3.1"H x 8.4"W x 2.5"D (80 x 214 x 63 mm) | 7.9" x 3.5" x 2" (201 x 90 x 52 mm) |
| Built-in Microphone | - | Yes |
| Party Mode | - | Yes (Bose Party mode) |
Related Speaker Comparisons
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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
Bogasing M4: $45.99 Discontinued eBay
Pros: Bogasing M4 uses 52mm speaker unit. Its 731 g, claimed 24 hours (Manufacturer specified) battery life, IPX7 protection, aux input, up to 99dB and stereo playback make it a practical option for its intended room or portable use. Measured bass extension of 54Hz (-10dB).
Cons: Bass is limited by its 54Hz specification. There is no companion app. No EQ adjustment. Discontinued.
Full Bogasing M4 review and specifications →
| Amplifier Power | 40W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | 54Hz |
| Battery Life | 24 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) |
| Bluetooth Latency | 150ms |
| Bluetooth Version | 5.0 |
| Digital Aux Input | No |
| Dimensions | 3.1"H x 8.4"W x 2.5"D (80 x 214 x 63 mm) |
| Discontinued | Yes |
| Drivers | 52mm speaker unit |
| EQ | No |
| IP Rating | IPX7 |
| Maximum SPL | 99dB (measured by Alan Ross Reviews) |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| Weight | 1.6 lbs (731 g) |
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: Bogasing M4 Review - vs JBL Charge 5 & Motion Plus - a new contender? More from alanrossreviews →
- Alan Ross Reviews: Bose Soundlink Flex vs Soundcore Boost vs Bogasing M4 - cheap or Bose?
- Alan Ross Reviews: Bogasing M4 or Soundcore Boost or Maxsound Plus for $50 champion?? 🤷♀️
- Alan Ross Reviews: Tronsmart Element Force review vs Bogasing M4 - cheap speaker 🤑
- Head-to-Head Comparisons
Bose Soundlink Flex 2nd gen: $159.00 Amazon eBay
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 →
| App | Yes |
|---|---|
| Aux Input | No |
| Battery Life | 12 hours (Manufacturer specified) |
| 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 |
| 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 →
- Oluv Patreon: Bose Soundlink Flex 2nd gen - sound demo
- Tô Thái Trí Hùng: Unbox & Sound Test - Bose Soundlink Flex 2
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen & Soundcore Motion 300 sound test
- Alan Ross: Hall of Fame classic vs latest Bose tech! More from alanrossreviews →
- CEONTHEMAKING: Bose Soundlink Flex 2nd Gen VS Marshall Emberton III - What’s NEW?? More from CEONTHEMAKING →
- Alan Ross - The Anti Shill!: Small speaker, mighty sound, The Flex gen 2 shatters physics!
- Head-to-Head Comparisons
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