Short answer: the Earfun Uboom Slim. It ranks #41 of 150 medium speakers by sound quality, rated 3.7/5, at $79; the JBL Charge 4 ranks #56, rated 3.5/5, and costs $94.99, which makes this an easy call rather than a real tradeoff.
Why pick the Earfun Uboom Slim: Excellent pricing, strong waterproof build (IPX7), good battery life (16 hours), smooth sound with volume compensation, speakerphone capability. The tradeoff: Not as deep bass as others.
The case for the JBL Charge 4: Doubles as a power bank for charging phones/tablets. Watch for: Not stereo.
One note: the JBL Charge 4 is discontinued, but it still ranks #56 of 150 medium speakers by sound quality, ahead of most of what is still sold new, so it is worth considering used.
Buy the Earfun Uboom Slim. It is rated higher for sound quality than the JBL Charge 4 and costs less, which makes it the one to get unless you need something the other one does better.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Earfun Uboom Slim | JBL Charge 4 | |
|---|---|---|
| Price | $79 | $94.99 Discontinued |
| Ranked | #41 of 150 in Medium Size Portable Bluetooth Speakers | #56 of 150 in Medium Size Portable Bluetooth Speakers |
| Bass Extension (-10dB) | ~63Hz | 54Hz |
| Battery Life | 16 hours (Manufacturer specified) | 20 hours (Manufacturer specified) |
| Power Input | USB-C | USB-C |
| Stereo | Yes | No |
| Omnidirectional | No | No |
| Weight | 1.2 lbs (560 g) | 2.1 lbs (960 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| Bluetooth Version | 5.2 | 4.2 |
| Built-in Microphone | Yes | - |
| Drivers | 45mm speaker drivers | 1x 51x89mm fullrange |
| Amplifier Power | 20W | 30W RMS |
| IP Rating | IPX7 | IPX7 |
| Digital Aux Input | No | No |
| Dimensions | 2.6”H x 7.1”W x 2.6”D (65 x 180 x 65 mm) | 8.7” x 3.7” x 3.7” (220 x 95 x 93 mm) |
| App | No | Yes |
| Aux Input | Yes | Yes |
| EQ | No | No |
| TWS | Yes | No |
| Bluetooth Latency | - | 330ms |
| Maximum SPL | - | 99dB (measured by Alan Ross Reviews) |
| Party Mode | - | Yes (Connect+ up to 100 speakers) |
| Power Bank | - | Yes (USB-A, 5V/2A) |
| Frequency Response | - | 60Hz - 20kHz (Manufacturer specified) |
| Strap | - | No |
Related Speaker Comparisons
How Earfun Uboom Slim compares with other leading options:
- Earfun Uboom L vs Earfun Uboom Slim
- Soundcore Motion 300 vs Earfun Uboom Slim
- JBL Charge 6 vs Earfun Uboom Slim
- JBL Flip 6 vs Earfun Uboom Slim
- JBL Flip 7 vs Earfun Uboom Slim
Prices on this page were last checked September 30, 2026 at 2:57 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
Earfun Uboom Slim: $79 eBay
Pros: Excellent pricing, strong waterproof build (IPX7), good battery life (16 hours), smooth sound with volume compensation, speakerphone capability. Measured bass extension of ~63Hz (-10dB).
Cons: Not as deep bass as others. Warm tuned, peaks in the mids and lower treble, rolled off upper treble
Full Earfun Uboom Slim review and specifications →
| Amplifier Power | 20W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | ~63Hz |
| Battery Life | 16 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 2.6”H x 7.1”W x 2.6”D (65 x 180 x 65 mm) |
| Drivers | 45mm speaker drivers |
| EQ | No |
| IP Rating | IPX7 |
| Omnidirectional | No |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| Weight | 1.2 lbs (560 g) |
- Reviews, Comparisons and Sound Samples
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JBL Charge 4: $94.99 Discontinued Amazon eBay
Newer model: the JBL Charge 6, ranked higher, rated 4.2/5.
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 Charge 3. Discontinued.
Full JBL Charge 4 review and specifications →
| Amplifier Power | 30W RMS |
|---|---|
| App | Yes |
| Aux Input | Yes |
| Bass Extension (-10dB) | 54Hz |
| Battery Life | 20 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 330ms |
| Bluetooth Version | 4.2 |
| Digital Aux Input | No |
| Dimensions | 8.7” x 3.7” x 3.7” (220 x 95 x 93 mm) |
| Drivers | 1x 51x89mm fullrange |
| EQ | No |
| Frequency Response | 60Hz - 20kHz (Manufacturer specified) |
| IP Rating | IPX7 |
| Maximum SPL | 99dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Connect+ up to 100 speakers) |
| Power Bank | Yes (USB-A, 5V/2A) |
| Power Input | USB-C |
| Stereo | No |
| Strap | No |
| TWS | No |
| Weight | 2.1 lbs (960 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: JBL Charge 5 vs JBL Charge 4 and Charge 3 - best JBL charge 5 review 2021? More from alanrossreviews →
- Alan Ross Reviews: jbl Charge 4 unboxing first impressions - vs Charge 3
- Alan Ross Reviews: JBL Charge 5 vs JBL Charge 4 and Charge 3 - best JBL charge 5 review 2021?
- Alan Ross Reviews: W King D8 Mini review vs JBL Charge 4 vs Maxsound Plus
- Alan Ross Reviews: Sony XB33 vs XB32 vs JBL Charge 4 best £120 bluetooth speaker?
- Alan Ross Reviews: JBL Flip 6 vs JBL Charge 4 and JBL Charge 3 - small one or a large one? 🤷♂️
- Flossy Carter: JBL Charge 5 vs JBL Charge 4 vs JBL Charge Essential More from FlossyCarter →
- Naresh Lal: JBL Charge 4 Vs Xdobo X8 Tell me Which one is the BEST?
- Alan Ross Reviews: LG Xboom Go PL7 vs JBL Charge 4 and Sony XB33 - best Bluetooth speaker?
- Head-to-Head Comparisons