JBL Xtreme 4 Speaker Review

When is Xtreme not Extreme?

JBL Xtreme 4 Overview

Note this review is for the UK GG version of the speaker. Different versions can sound quite different.
Firmware Tested: The JBL Xtreme 4 portable bluetooth speaker arrives three and a half years after the JBL Xtreme 3. Given that JBL are the biggest sellers of bluetooth speakers in volume then you might be expecting some huge advances and you would be alone. The JBL Xtreme series has always been a standout speaker in its extreme price given its size, capabilities and competition. At least back in the day of the Xtreme 1 it was a bit groundbreaking for its size in the amount of bass it could produce, albeit mostly upper bass. However today in March 2024 it sits at £330 UK pounds and 350 US dollars. With the likes of the Go + Play 3 being found for less than 200 dollars and the the Tribit Stormbox Blast offering great value at around £200/$200 the Xtreme 4 would need to eb a bit special to justify its high price.

The new features we get with the JBL Xtreme 4 include a replaceable battery pack. However as I write this no battery packs are offered for sale from JBL and the enclosure is proprietary JBL so without hacking it open you won’t be able to use standard batteries. However at 68 Wh this is a huge battery. AI Sound Boost will process the sound in realtime and adjust to get the most out of the drivers, not new tech by any means but new for the Xtreme range of bluetooth speakers. The marketing talks about “Playtime optimiser”, however in the JBL app this is called Playtimeboost. It simply cuts the abss and boosts the mids and highs a little to give extended playtime and a bit more volume. Again new features are welcome but this is nothing you couldn’t do yourself with EQ. Speaking of EQ we now have a 5 band graphic equaliser but you cannot save presets and they do not work anyways when pairing with other speakers. for pairing we now have Auracast which is an open standard to broadcast a signal to unlimited other devices. This should work therefore with all other auracast receivers but in this implementation JBL have locked it down to just their own speakers. They used to have JBL partyboost on the Xtreme 3 and this will still pauir with the Xtreme 4 when you do so via the JBL app.

Power delivery is now supported so you get a power delivery USB-C charger with the speaker and PD devices can be charged from the Xtreme 4 at up to 22 watts of power. The Xtreme 4 itself charges at 60 watts. Xtreme 4 now sports bluetooth 5.3 (Xtreme 3 was 5.1). The power output is advertised as 2 x 30 W RMS woofer + 2 x 20 W RMS tweeter (AC power mode) 2 x 20 W RMS woofer + 2 x 15W RMS tweeter (Battery mode) So they are suggesting this is now a 100 watt speaker. But the way the specs are written is open to interpretation. My own feeling is this remains a 50 watt speaker on AC power just as the Xtreme 3 is. My problem with the Xtreme series (not the Xtreme 1) is that it looks like hand holdable speaker but in the real world unless you have large hands you cannot pick it up with one hand and this is even more the case with the bulkier Xtreme 4. You do get a strap but a foldable handle would be very welcome.
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Frequency Response

The JBL Xtreme 4 relies heavily not just on the usual DSP but now with the addition of real time processing for the entire signal chain including drivers according to JBL. This does appear the case so I did find bare frequency response measurements do not tally fully with real world usage. It does hold up at louder volumes in real world play better against the Xtreme 3 than it does in a frequency response comparison. In terms of the frequency response measurement the JBL Xtreme 4 suffers from bass sculpting where upper bass is reduced to bring out its narrow deeper bass kick around 55hz where the passive radiators are tuned. Bass relatively reduces rapidly as you push the volumes and past 60% it becomes quite bright. By 80% the sound is quite unpleasant due to the lack of meaningful bass and the pushed mids and highs. We also have presets called Chill, Energetic and Vocal. You also get a 5 band graphic equaliser where it minimcs signature EQ in its default setting.

JBL Xtreme 4 – Sound!

Ultimately if you have heard the JBL Xtreme 3 than you will have a good idea how the JBL Xtreme 4 will sound. Both favour a 60hz ish peak for the illusion of deeper bass with some sculpting in the upper bass. At 50% volume I would give the nod to the Xtreme 3 with the Xtreme 4 lacking upper bass punch and sounding thinner and a bit brittle against the Xtreme 3. The differences are not big and -probably would require an A/B comparison for you to get the differences. At 70% and above I give the nod to the Xtreme 4 with things reversed now and the Xtreme 4 having more upper bass than than the xtreme 3. Frequency response suggested otherwise so I would suggest perhaps this is now tot eh so called AI Sound Boost getting more out of the Xtreme 4.

Overall the Xtreme 4 can sound reasonably full and enjoyable at lower volumes but get past 60% and that bass rapidly drops away leaving a somewhat unpleasant screechy sound. You can tame this using the JBL app and its 5 band graphic equaliser but only to some degree since ultimately there is no headroom to boost anything in the EQ and you will just end up losing volume if you boost bass as the EQ will just drop mids and highs instead at loudest volumes.

The JBL Xtreme 4 can get reasonably loud but not earth shatteringly so. I measured a 104.9 dB(C) @1m peak when playing Onlap – Rock Ain’t Dead. This is 1.7 dB louder than the Xtreme 3 managed on the same track.


Its hard to recommend the JBL Xtreme 4 if you already have the Xtreme 3 and dont need any of the new features. They sound quite similar with the Xtreme 4 a tad better at louder volumes and the Xtreme 3 a tad better at lower volumes. The biggest issue for the JBL Xtreme 4 is the high launch price of UK £330 pounds and US $350 dollars. When you can get a Harman kardon Go+ Play 3 which will sound much better for less money and the Tribit Stormbox Blast for not far off half that amount the only advantage the Xtreme 4 has is its smaller size and much larger battery.

Please see my youtube video review for a more detaield analysis.
Price (when last checked): £330/$350
Year Released: February 2024
Made in: China
Power Rating: 100 watts AC or 50 watts AC, the jury is out.
Drivers: dual 64mm/2.75inch woofers, dual 20mm/0.8 inches tweeters and two passive radiators
Battery Capacity : 7.2v/9444mAh
Battery Capacity (watt Hours) 68Wh
Bluetooth Codec: SBC
Bluetooth Version: 5.3
Multipoint: Yes
TWS (stereo) pairing: Yes
Party Mode (mono) pairing: Yes
Pairing Protocol: Auracast
Charging Input Type: USB-C PD
Playtime: Up to 24 hours claimed but not details on testing so meaningless!
Charging Time: 3.5 hours (claimed)
WiFi: No
Bluetooth Transmitter Power: < 15 dBm (EIRP)
Has a Microphone Input: No
Auxiliary Input: No
Can be used as a Power Bank? Yes, up to 22 watts output
Phone call Functionality? No
Flash card slot for music? No
Has Lights? No
Charging Rate: up to 11v/2a
Weight: 2100g
IP Rating: IP67
Floats? Yes
Floats with Drivers Up (not fully submerged)? No
Frequency Response Claimed: 44hz-20khz
Has Tweeters: Yes
Titanium Drivers: No
Neodymium Magnet: Yes
Bluetooth Latency (Samsung S10+): 220ms streaming youtube (poor)
Auxiliary Latency (Samsung S10+): n/a
Has an App: Yes
App has Equaliser: 5 band equaliser
App has Parametric Equaliser: No