Short answer: the Harman Kardon Go + Play 3 if sound quality matters most, the Zealot ZE51 if price matters most. The Harman Kardon Go + Play 3 ranks #3 of 74 boombox speakers at $385. The Zealot ZE51 ranks #14 at $296.39, $88.61 cheaper.
What the Zealot ZE51 offers: Cleaner sound and a wider stereo soundstage than the Zealot ZE41, with less distortion at high volume for better instrumental detail and clarity. The tradeoff: The Zealot ZE41 still wins on raw bass depth and price. Large and heavy like the rest of the boombox class, and clarity still isn’t up to dedicated hi-fi speakers.
On the Harman Kardon Go + Play 3 side: Warm sound with boosted bass. Deepest bass out of any speaker in this size. Sound is more natural than the Go + Play2. Set against that: Just a little over half as loud as the higher rated boomboxes. Only 8 hours of battery at medium volume. No water rating.
Buy the Zealot ZE51 when the price outweighs sound quality for you, and the Harman Kardon Go + Play 3 when sound quality outweighs the price instead.
If water resistance matters to you, the Zealot ZE51 at IPX5 (water jets) holds up far better than the Harman Kardon Go + Play 3 at no water resistance.
Specifications Side By Side
| Zealot ZE51 | Harman Kardon Go + Play 3 | |
|---|---|---|
| Price | $296.39 after coupon | $385 |
| Ranked | #14 of 74 in Boombox Size Portable Bluetooth Speakers | #3 of 74 in Boombox Size Portable Bluetooth Speakers |
| App | Yes | Yes (Harman Kardon One app) |
| Aux Input | Yes | Yes |
| Battery Capacity | 48000mAh (12x4000mAh) | - |
| Bluetooth Version | 5.3 | 5.2 |
| Dimensions | 22.1" x 9.4" x 13" (562 x 238 x 331 mm) | 17.3" x 9.4" x 7.6" (439 x 240 x 192 mm) |
| EQ | Yes (Hi-Res, 3D Surround, Extra Bass, Vocal and other sound modes) | Yes (App EQ) |
| Frequency Response | 20Hz - 20kHz (Manufacturer specified) | - |
| IP Rating | IPX5 | None |
| Microphone Input | Yes (Karaoke mode) | - |
| MicroSD Playback | Yes | - |
| Output Power | 250W | 160W RMS |
| Power Bank | Yes (USB-A + USB-C) | Yes |
| Power Input | Type-C | AC Power brick |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| USB Playback | Yes | No |
| Weight | 26 lbs / 11.81 kg | 10.4 lbs / 4.7 kg |
| Digital Aux Input | No | No |
| Aux Latency | - | 112ms |
| Bass Extension (-10dB) | - | 35Hz |
| Battery Life | - | 8 hours (Manufacturer specified) |
| Built in Microphone | - | Yes |
| Bluetooth Latency | - | 120ms |
| Max Volume | - | 103dB |
| Bluetooth Codecs | - | SBC, AAC |
| Party Mode | - | No |
| Drivers | - | 1x 130mm (5") subwoofer + 2x 70mm midrange drivers + 2x 20mm tweeters |
Related Speaker Comparisons
A few more comparisons worth a look in the same class:
- JBL Partybox Encore 2 vs Harman Kardon Go + Play 2
- JBL Partybox Encore 2 vs JBL Boombox 3
- JBL Boombox 3 Wifi vs Zealot ZE41
- Harman Kardon Go + Play 3 vs Harman Kardon Onyx Studio 7
- Harman Kardon Go + Play 3 vs JBL Authentics 300
Prices on this page were last checked August 29, 2026 at 8:52 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
Zealot ZE51: $296.39 after coupon Amazon Aliexpress eBay
Pros: Cleaner sound and a wider stereo soundstage than the Zealot ZE41, with less distortion at high volume for better instrumental detail and clarity.
Cons: The Zealot ZE41 still wins on raw bass depth and price. Large and heavy like the rest of the boombox class, and clarity still isn’t up to dedicated hi-fi speakers.
Full Zealot ZE51 review and specifications →
| App | Yes |
|---|---|
| Aux Input | Yes |
| Battery Capacity | 48000mAh (12x4000mAh) |
| Bluetooth Version | 5.3 |
| Digital Aux Input | No |
| Dimensions | 22.1" x 9.4" x 13" (562 x 238 x 331 mm) |
| EQ | Yes (Hi-Res, 3D Surround, Extra Bass, Vocal and other sound modes) |
| Frequency Response | 20Hz - 20kHz (Manufacturer specified) |
| IP Rating | IPX5 |
| MicroSD Playback | Yes |
| Microphone Input | Yes (Karaoke mode) |
| Omnidirectional | No |
| Output Power | 250W |
| Power Bank | Yes (USB-A + USB-C) |
| Power Input | Type-C |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 26 lbs / 11.81 kg |
- Links
- Reviews, Comparisons and Sound Samples
- J_Strat Battles: ZEALOT ZE51 VS JBL BOOMBOX 4 (OLD FIRMWARE VERSION) 🧨🧨🧨
- J_Strat Battles: Zealot ZE51 VS ZE21
- J_Strat Battles: ZEALOT ZE51 VS W-KING X20 🥳🥳
- J_Strat Battles: Zealot ZE51 vs ZE21 bass boost/vocal eq battle 💪🏻😎
- J_Strat Battles: Zealot ZE51 short hz test video
- Reddit Search for Zealot ZE51 Review
- Head-to-Head Comparisons
Harman Kardon Go + Play 3: $385 Amazon eBay
Pros: Warm sound with boosted bass. Deepest bass out of any speaker in this size. Sound is more natural than the Go + Play2.
Cons: Just a little over half as loud as the higher rated boomboxes. Only 8 hours of battery at medium volume. No water rating.
Setup: Use the hidden EQ modes to adjust the bass up when outside and down when inside. To adjust bass, quickly press the bluetooth and volume down buttons together, the number of light flashes tell you what mode you’re in. To adjust treble, quickly press the volume up and phone buttons at the same time, the number of yellow flashes on the light tell you what mode you are in.
Full Harman Kardon Go + Play 3 review and specifications →
| App | Yes (Harman Kardon One app) |
|---|---|
| Aux Input | Yes |
| Aux Latency | 112ms |
| Bass Extension (-10dB) | 35Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC, AAC |
| Bluetooth Latency | 120ms |
| Bluetooth Version | 5.2 |
| Built in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 17.3" x 9.4" x 7.6" (439 x 240 x 192 mm) |
| Drivers | 1x 130mm (5") subwoofer + 2x 70mm midrange drivers + 2x 20mm tweeters |
| EQ | Yes (App EQ) |
| IP Rating | None |
| Max Volume | 103dB |
| Omnidirectional | No |
| Output Power | 160W RMS |
| Party Mode | No |
| Power Bank | Yes |
| Power Input | AC Power brick |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | No |
| Weight | 10.4 lbs / 4.7 kg |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: Harman Kardon Go+ Play 3 vs Go Play 2, the holy grail has arrived? ✔ More from alanrossreviews →
- Alan Ross Reviews: Harman Kardon Go + Play 3 hidden eq modes - world has gone crazy! 🤣
- Alan Ross Reviews: Minirig 2.1 or the Brane X or the Harman Kardon Go Play 3?
- Alan Ross Reviews: JBL Distortion Fest vs my favorite speaker today! I wasn’t expecting this!
- Mateusz Cholewa: BOGASING S8 Pro Max „HiFi” 🎶🧐🆚 Harman Kardon Go Play 3 „HiFi”🔊 More from Mateusz Cholewa →
- Oluv Patreon: Harman Kardon go+play 3 - best sounding? More from Oluv’Sone →
- Oluv Patreon: Harman Kardon go+play 3 vs Tribit Stormbox Blast - outdoor soundtest
- Oluv Patreon: Harman Kardon go+play 3 vs JBL Xtreme 4 - first impressions
- Reddit Search for Harman Kardon Go + Play 3 Review
- Head-to-Head Comparisons
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- Harman Kardon Go + Play 3 vs Tribit Stormbox Blast
- Harman Kardon Go + Play 3 vs Earfun Uboom X
- Harman Kardon Go + Play 3 vs JBL Partybox Encore Essential 2
- Harman Kardon Go + Play 3 vs JBL Partybox Encore
- Harman Kardon Go + Play 3 vs JBL Partybox Encore Essential
- Harman Kardon Go + Play 3 vs Harman Kardon Onyx Studio 8
- Harman Kardon Go + Play 3 vs Harman Kardon Onyx Studio 6
- See all 48 comparisons