Bose Soundlink Flex 2nd gen vs JBL Charge 4

Last updated: October 13, 2026

Short answer: the Bose Soundlink Flex 2nd gen for sound, the JBL Charge 4 for charging your phone. The Charge 4 doubles as a power bank for charging phones and tablets, but it is not stereo and uses a single oval driver. The Flex 2nd gen sounds pretty much identical to the 1st gen, though it is not stereo and its warm sound with overly boosted bass drowns out midrange detail. The JBL Charge 4 is discontinued; its replacement is the JBL Charge 6.

Bose Soundlink Flex 2nd gen vs JBL Charge 4

Buy the Bose Soundlink Flex 2nd gen. It is rated higher for sound quality; the JBL Charge 4 is no longer sold new.

There is a real battery-life gap here: the JBL Charge 4 is rated for 20 hours, the Bose Soundlink Flex 2nd gen only 12 hours.

Looking for alternatives? See the complete Portable Bluetooth rankings.

Check Bose Soundlink Flex 2nd gen price at Amazon ($159.00) →Check JBL Charge 4 price at Amazon ($94.99) →

Specifications Side By Side

Bose Soundlink Flex 2nd gen JBL Charge 4
Price$159.00$94.99 Discontinued
Ranked#37 of 175 in Medium Size Portable Bluetooth Speakers#63 of 175 in Medium Size Portable Bluetooth Speakers
AppYesYes
Battery Life12 hours (Manufacturer specified)20 hours (Manufacturer specified)
Built-in MicrophoneYes-
EQYes (3 band)No
IP RatingIP67IPX7
Party ModeYes (Bose Party mode)Yes (Connect+ up to 100 speakers)
Power InputUSB-CUSB-C
StereoNoNo
OmnidirectionalNoNo
TWSYesNo
Weight1.3 lbs (586 g)2.1 lbs (960 g)
BluetoothYesYes
Bluetooth Version5.34.2
Dimensions7.9” x 3.5” x 2” (201 x 90 x 52 mm)8.7” x 3.7” x 3.7” (220 x 95 x 93 mm)
Aux InputNoYes
Drivers60mm full-range driver with passive radiators1x 51x89mm fullrange
Bluetooth CodecsSBC, AAC, aptX AdaptiveSBC
Digital Aux InputNoNo
StrapYes (built-in loop)No
Bass Extension (-10dB)-54Hz
Bluetooth Latency-330ms
Maximum SPL-99dB (measured by Alan Ross Reviews)
Power Bank-Yes (USB-A, 5V/2A)
Frequency Response-60Hz - 20kHz (Manufacturer specified)
Amplifier Power-30W RMS
Check Bose Soundlink Flex 2nd gen price at Amazon ($159.00) →Check JBL Charge 4 price at Amazon ($94.99) →

How Bose Soundlink Flex 2nd gen compares with other leading options:

Prices on this page were last checked October 14, 2026 at 2:38 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 ranking card

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.

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Full Bose Soundlink Flex 2nd gen review and specifications →

ReleasedSep 2024 (2 years ago)
AppYes
Aux InputNo
Battery Life12 hours (Manufacturer specified)
BluetoothYes
Bluetooth CodecsSBC, AAC, aptX Adaptive
Bluetooth Version5.3
Built-in MicrophoneYes
Digital Aux InputNo
Dimensions7.9” x 3.5” x 2” (201 x 90 x 52 mm)
Drivers60mm full-range driver with passive radiators
EQYes (3 band)
IP RatingIP67
OmnidirectionalNo
Party ModeYes (Bose Party mode)
Power InputUSB-C
StereoNo
StrapYes (built-in loop)
TWSYes
Weight1.3 lbs (586 g)
Check current price at Amazon ($159.00) →Search eBay for Bose Soundlink Flex 2nd gen →

JBL Charge 4: $94.99 Discontinued Amazon $94.99 eBay

JBL Charge 4 ranking card

Newer model: the JBL Charge 6, ranked higher, rated 4.2/5, released Mar 2025.

Older models: the JBL Charge 3 (ranked lower, rated 3.2/5) and the JBL Charge 2 (ranked lower, rated 3.2/5). See every JBL Charge generation.

Pros: Doubles as a power bank for charging phones/tablets. IPX7 rated and floats. ~20 hour battery life; wirelessly links with 100+ JBL Connect+ speakers. Measured bass extension of 54Hz (-10dB).

Cons: Not stereo. 1 Oval driver. Boosted bass, top a little rolled off, warm sound. Not as loud as a JBL Charge 3. Discontinued.

Full JBL Charge 4 review and specifications →

ReleasedOct 2018 (8 years ago)
Amplifier Power30W RMS
AppYes
Aux InputYes
Bass Extension (-10dB)54Hz
Battery Life20 hours (Manufacturer specified)
BluetoothYes
Bluetooth CodecsSBC
Bluetooth Latency330ms
Bluetooth Version4.2
Digital Aux InputNo
Dimensions8.7” x 3.7” x 3.7” (220 x 95 x 93 mm)
Drivers1x 51x89mm fullrange
EQNo
Frequency Response60Hz - 20kHz (Manufacturer specified)
IP RatingIPX7
Maximum SPL99dB (measured by Alan Ross Reviews)
OmnidirectionalNo
Party ModeYes (Connect+ up to 100 speakers)
Power BankYes (USB-A, 5V/2A)
Power InputUSB-C
StereoNo
StrapNo
TWSNo
Weight2.1 lbs (960 g)
Check current price at Amazon ($94.99) →Search eBay for JBL Charge 4 →