Short answer: the Zealot ZE21. It ranks #18 of 98 boombox speakers by sound quality, rated 4.0/5, at $247.41; the Sony ULT Field 7 ranks #59, rated 3.2/5, and costs $448.99, which makes this an easy call rather than a real tradeoff.
The Zealot ZE21 is the better-sounding, deeper-bass option. The ZE21’s main attraction is unusually deep bass for a battery boombox: owner testing finds real output in the 40-50Hz region and audibility down toward the low 30s. Its bass reaches about 36Hz before falling 10dB, against 52Hz for the Sony ULT Field 7. It is rated for 40 hours of battery against 30 for the Sony ULT Field 7. Watch for: That deep-bass emphasis comes with a pronounced 60-110Hz kick-bass dip and over-loud 250-600Hz lower mids, which can make rock and pop sound hollow or boxy.
The Sony ULT Field 7 is the lighter option. At 13.9 lbs (6.3 kg) it weighs noticeably less than the Zealot ZE21 at 20.4 lbs (9.27 kg). It supports LDAC Bluetooth, which the Zealot ZE21 lacks. The tradeoff: A peak around 8kHz, and bass does not reach as deep as the top-ranked speakers.
Buy the Zealot ZE21. It is rated higher for sound quality than the Sony ULT Field 7 and costs less, so only choose the other one for a particular feature it does better.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Zealot ZE21 | Sony ULT Field 7 | |
|---|---|---|
| Price | $247.41 | $448.99 |
| Ranked | #18 of 98 in Boombox Size Portable Bluetooth Speakers | #59 of 98 in Boombox Size Portable Bluetooth Speakers |
| App | No | No |
| Aux Input | Yes | Yes |
| Bass Extension (-10dB) | 36Hz | ~52Hz |
| Battery Life | 40 hours (Manufacturer specified) | 30 hours (Manufacturer specified) |
| EQ | Yes (multiple modes) | Yes (App + ULT button) |
| IP Rating | IPX6 | IP67 |
| MicroSD Playback | Yes | - |
| Party Mode | Yes (PartyAdd up to 100 speakers) | Yes (Party Connect up to 100 speakers) |
| Power Input | USB-C | AC Power cord |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 20.4 lbs (9.27 kg) | 13.9 lbs (6.3 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC, AAC, LDAC |
| Power Bank | Yes (USB-A + USB-C) | Yes (USB-A, 5V/1.5A) |
| USB Playback | Yes | Yes |
| Built-in Microphone | No | Yes |
| Amplifier Power | 250W | 100W |
| Dimensions | 16.7” x 10.3” x 14.3” (424 x 262 x 363 mm) | 20.2” x 8.8” x 8.7” (512 x 224 x 222 mm) |
| Drivers | 130W subwoofer + 2x 50mm woofers + passive radiators | 2x 114mm x 114mm X-Balanced woofers + 2x 46mm (1.9”) tweeters |
| Maximum SPL | 116dB (Manufacturer specified) | - |
| Digital Aux Input | No | No |
| Bluetooth Version | 5.3 | 5.2 |
| Guitar Input | - | Yes |
| Microphone Input | - | Yes (Karaoke mode with echo effect) |
| Strap | - | No |
Related Speaker Comparisons
More worthwhile head-to-heads for Zealot ZE21:
- Tribit Stormbox Blast vs Zealot ZE21
- Harman Kardon Go + Play 3 vs Zealot ZE21
- JBL Partybox Encore 2 vs Zealot ZE21
- JBL PartyBox On-The-Go 2 Plus vs Zealot ZE21
- JBL Partybox Encore Essential 2 vs Zealot ZE21
Prices on this page were last checked October 12, 2026 at 4:13 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.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Speakers In Full
Zealot ZE21: $247.41 Amazon $247.41 AliExpress $187.15 eBay
Pros: The ZE21’s main attraction is unusually deep bass for a battery boombox: owner testing finds real output in the 40-50Hz region and audibility down toward the low 30s. Its TWS button can form a stereo pair with another compatible Zealot, and its large, rugged chassis gives it credible party-speaker scale. Measured bass extension of 36Hz (-10dB).
Cons: That deep-bass emphasis comes with a pronounced 60-110Hz kick-bass dip and over-loud 250-600Hz lower mids, which can make rock and pop sound hollow or boxy. The supplied sound modes do not fully correct the tuning; the most positive independent report required source-side parametric EQ. Treble is also soft and clarity trails better-tuned rivals.
Full Zealot ZE21 review and specifications →
| Released | Dec 2024 (1 year ago) |
|---|---|
| Amplifier Power | 250W |
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | 36Hz |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 16.7” x 10.3” x 14.3” (424 x 262 x 363 mm) |
| Drivers | 130W subwoofer + 2x 50mm woofers + passive radiators |
| EQ | Yes (multiple modes) |
| IP Rating | IPX6 |
| Maximum SPL | 116dB (Manufacturer specified) |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Party Mode | Yes (PartyAdd up to 100 speakers) |
| Power Bank | Yes (USB-A + USB-C) |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 20.4 lbs (9.27 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Techder Audios: JBL Boombox 4 VS Zealot ZE21 BATTLE OF THE BOOMBOXES! More from techderaudios →
- Jay’s Straight Up Reviews & More: Zealot ZE21 vs JBL Boombox 3 Tailgater Special @20ft. The Budget Beast Against the OG Boombox More from JaysStraightUpReviews →
- Jagist reviews: Jbl Boombox 4 Vs Zealot Ze21!!! More from Jagistreviews →
- Jagist reviews: Zealot Ze21 Vs Tribit Stormbox Blast 2!!!
- Jagist reviews: Yeahbox Sonic Boom Ultra Vs Zealot Ze21!!! Battle Of The Deep Bass 🥳🥳🥳
- Jagist reviews: Hopestar A90 Vs Zealot Ze21!!! Deep Bass Vs Powerful Bass!!!
- Jagist reviews: Xdobo Wow Max Vs Zealot Ze21!!!
- Jagist reviews: Zealot PT21 Vs Zealot Ze21!!! 🥰😍🥰
- Jagist reviews: Zealot Ze41 Vs Zealot Ze21!!! Battle Of The Bass Brothers!!! 👀👀👀
- J_Strat Battles: Zealot ZE51 VS ZE21
- J_Strat Battles: Zealot ZE51 vs ZE21 bass boost/vocal eq battle 💪🏻😎
- Head-to-Head Comparisons
Sony ULT Field 7: $448.99 Amazon $448.99 eBay
Older model: the Sony SRS-XG500 (ranked lower, rated 3/5). See every Sony XB and ULT generation.
Same family: the Sony ULT Field 1 (smaller model, rated 3.1/5), the Sony ULT Tower 10 (larger model, rated 3.9/5), the Sony ULT Field 3 (larger model, rated 3.4/5), the Sony ULT Field 5 (larger model, rated 3.5/5), the Sony ULT Tower 5 (larger model, rated 4.5/5), the Sony ULT Tower 7 (larger model, rated 4.7/5), the Sony ULT Tower 9 (larger model, rated 4.2/5) and the Sony ULT Tower Max (larger model, rated 4.8/5).
Pros: Sony ULT Field 7 uses 2x 114mm x 114mm X-Balanced woofers + 2x 46mm (1.9”) tweeters. Its 6.3 kg, claimed 30 hours (Manufacturer specified) battery life, IP67 protection, aux input and stereo playback make it a practical option for its intended room or portable use. Measured bass extension of ~52Hz (-10dB).
Cons: Bass is limited by its ~52Hz specification. There is no companion app. A peak around 8kHz, and bass does not reach as deep as the top-ranked speakers.
Full Sony ULT Field 7 review and specifications →
| Released | Apr 2024 (2 years ago) |
|---|---|
| Amplifier Power | 100W |
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | ~52Hz |
| Battery Life | 30 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC, AAC, LDAC |
| Bluetooth Version | 5.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 20.2” x 8.8” x 8.7” (512 x 224 x 222 mm) |
| Drivers | 2x 114mm x 114mm X-Balanced woofers + 2x 46mm (1.9”) tweeters |
| EQ | Yes (App + ULT button) |
| Guitar Input | Yes |
| IP Rating | IP67 |
| Microphone Input | Yes (Karaoke mode with echo effect) |
| Omnidirectional | No |
| Party Mode | Yes (Party Connect up to 100 speakers) |
| Power Bank | Yes (USB-A, 5V/1.5A) |
| Power Input | AC Power cord |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 13.9 lbs (6.3 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Dominik Reviews: Sony ULT Field 7 vs Tribit Stormbox Blast Both good? 😂 More from Dominik Reviews →
- Jay’s Straight Up Reviews & More: SONY ULT Field 7 💣vs JBL Boombox 3 🧨 Showdown! 🪇Let’s Shake it Up! 🔋Battery Powered Basement Battle More from JaysStraightUpReviews →
- Jagist reviews: Xdobo Wow Max Vs Sony Ult Field 7!!! More from Jagistreviews →
- Head-to-Head Comparisons
- Sony ULT Field 7 vs Skullcandy Barrel
- Sony ULT Field 7 vs Yeahbox Sonic Boom Max 3
- Sony ULT Field 7 vs Soundcore Rave Party 2
- Sony ULT Field 7 vs Teufel Boomster NG (2017)
- Sony ULT Field 7 vs Onn Medium Party Speaker Gen 2
- Sony ULT Field 7 vs JBL Partybox On the Go
- Sony ULT Field 7 vs Gemini GRV-650L
- Sony ULT Field 7 vs Sony SRS-XG500
- See all 86 comparisons