Short answer: the Bogasing M4, and it’s the cheaper one too. It ranks #26 of 142 medium speakers at $45.99; the Soundlink Flex ranks #36 at $149, $103.01 more.
Both need a mode switch to sound their best. The M4’s cons recommend its super bass mode for the most balanced sound, since the default mode runs with a boosted, harsh, thin treble. The Flex doesn’t have a mode to switch, and our notes describe it as warm with overly boosted bass that drowns out midrange detail.
The Flex’s real selling point is Bose’s durability: IP67 rated, rugged enough to survive drops from several feet, and it floats.
Buy the Bogasing M4 for the better ranking and lower price. Buy the Soundlink Flex if Bose’s ruggedness specifically matters to you.
There is a real battery-life gap here: the Bogasing M4 is rated for 24 hours, the Bose Soundlink Flex only 12 hours.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Bogasing M4 | Bose Soundlink Flex | |
|---|---|---|
| Price | $45.99 Discontinued | $149.00 |
| Ranked | #26 of 142 in Medium Size Portable Bluetooth Speakers | #36 of 142 in Medium Size Portable Bluetooth Speakers |
| App | No | Yes |
| Aux Input | Yes | No |
| Bass Extension (-10dB) | 54Hz | 56Hz |
| Battery Life | 24 hours (Manufacturer specified) | 12 hours (Manufacturer specified) |
| EQ | No | No |
| IP Rating | IPX7 | IP67 |
| Bluetooth Latency | 150ms | 33ms |
| Maximum SPL | 99dB (measured by Alan Ross Reviews) | 96dB (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 (589 g) |
| Bluetooth Version | 5.0 | 4.2 |
| Amplifier Power | 40W | - |
| Drivers | 52mm speaker unit | 1x 60mm full-range driver + 2x passive radiators |
| Digital Aux Input | No | No |
| Discontinued | Yes | - |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) | SBC |
| 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
How Bogasing M4 compares with other leading options:
- Bogasing M4 vs Earfun Uboom L
- Bogasing M4 vs Soundcore Motion 300
- Bogasing M4 vs Soundcore Motion+
- Bogasing M4 vs Minirig 4
- Bogasing M4 vs JBL Charge 6
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
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: $149.00 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 |
|---|---|
| Aux Input | No |
| 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
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- See all 92 comparisons