Short answer: the Partybox 520. At essentially the same price, it ranks #7 of 12 large party speakers against the Tower 9’s #9, and the Tower 9 does not have a clean counter-argument on price to make up the difference.
The Tower 9’s own cons are the story here. Its notes say it is not as deep of bass and loses more bass at high volume, even compared to lower end Partybox speakers, with bass dropping off a lot as you turn it up. It is also listed as not quite as loud as its own sibling, the ULT Tower 10. The 520 has no such complaint in its notes, and it is rated at 400W against the Tower 9’s 148W, driven by dual 7.5 inch woofers rather than the Tower 9’s single 12.6 inch woofer and midrange array.
Durability favors the JBL too. The 520 carries an IPX4 splash rating; the Tower 9 has no water resistance rating at all. That matters more on a speaker this size, since it is the one most likely to end up outdoors at a party.
What the Tower 9 does better: battery life is a real advantage at 25 hours against the 520’s 15, it supports AAC and LDAC over Bluetooth where the 520 is SBC only, and its 10 band EQ is finer grained than the 520’s 5 band EQ. Sony’s own listed strength for the Tower 9 is that it sounds slightly better than the ULT Tower 10, so it is not without merit as a listening device, just not one that outsells the 520 on price or output.
Buy the Partybox 520 unless you specifically need the Tower 9’s longer battery life or its wider codec support. It costs about the same, hits harder, and holds up to splashes the Tower 9 cannot survive.
Buy the Tower 9 if all-day unplugged runtime and hi-res Bluetooth codecs matter more to you than raw output and weather resistance.
If sound quality matters at all to you, skip the Sony ULT Tower 9. It ranks near the bottom of the 12 large party speakers, so look higher up the list instead.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| JBL Partybox 520 | Sony ULT Tower 9 | |
|---|---|---|
| Price | $799.95 | $748.00 |
| Ranked | #7 of 12 in Large Party Size Portable Bluetooth Speakers | #9 of 12 in Large Party Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Aux Input | Yes | Yes |
| Battery Life | 15 hours (Manufacturer specified) | 25 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC | SBC, AAC, LDAC |
| EQ | Yes (5 band) | Yes (10 band) |
| Guitar Input | Yes | Yes |
| IP Rating | IPX4 | None |
| Microphone Input | Yes (Karaoke mode with echo effect) | Yes (Karaoke mode with echo effect) |
| Party Mode | Yes (Auracast) | Yes (Auracast up to 100 speakers) |
| Power Bank | Yes (USB-C) | Yes (USB-A, 5V/1.5A) |
| Power Input | AC Power cord | AC Power cord |
| Removable Battery | Yes | No |
| TWS | Yes | Yes |
| USB Playback | Yes | Yes |
| Weight | 56.2 lbs (25.5 kg) | 65.3 lbs (29.6 kg) |
| Built-in Microphone | No | No |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Wi-Fi | No | No |
| Bluetooth Version | 5.4 | 5.3 |
| Dimensions | 16.3" x 30.3" x 14.5" (415 x 769 x 369 mm) | 16.1" x 35.8" x 18" (410 x 910 x 456 mm) |
| Drivers | 2x 7.5" woofer, 2x 1" dome tweeter | 7 drivers: 1x 12.6"x12.6" woofer, 2x 4.7" midrange, 2x 2" tweeter, 2x 1.6" rear tweeter |
| Amplifier Power | 400W | 148W |
| Digital Aux Input | No | No |
| Lights | Yes | Yes |
| Wheels | Yes | - |
Related Speaker Comparisons
More worthwhile head-to-heads for JBL Partybox 520:
- JBL Partybox 520 vs Sony ULT Tower Max
- JBL Partybox 520 vs JBL Partybox Ultimate
- JBL Partybox 1000 vs JBL Partybox 520
- Teufel Rockster 2 vs JBL Partybox 520
- JBL Partybox 520 vs JBL Partybox 720
Prices on this page were last checked September 22, 2026 at 5:11 AM 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
JBL Partybox 520: $799.95 Amazon B&H Photo Video eBay
Pros: JBL’s biggest battery-powered PartyBox combines very high output, deep chesty bass, wheels and a telescoping handle with a capable app EQ, lights, USB-C audio and mic/instrument inputs. RTINGS finds it loud enough for backyards and unusually well-equipped for a battery party speaker.
Cons: It is very large and heavy, Bluetooth latency is high for video, and its front-facing design loses much of the mids and treble to people off to the sides. The bass-heavy default can also make dialogue less clear without EQ.
Full JBL Partybox 520 review and specifications →
| Amplifier Power | 400W |
|---|---|
| App | Yes |
| Aux Input | Yes |
| Battery Life | 15 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.4 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 16.3" x 30.3" x 14.5" (415 x 769 x 369 mm) |
| Drivers | 2x 7.5" woofer, 2x 1" dome tweeter |
| EQ | Yes (5 band) |
| Guitar Input | Yes |
| IP Rating | IPX4 |
| Lights | Yes |
| Microphone Input | Yes (Karaoke mode with echo effect) |
| Omnidirectional | No |
| Party Mode | Yes (Auracast) |
| Power Bank | Yes (USB-C) |
| Power Input | AC Power cord |
| Removable Battery | Yes |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 56.2 lbs (25.5 kg) |
| Wheels | Yes |
| Wi-Fi | No |
- Links
- Reviews, Comparisons and Sound Samples
- Oluv Patreon: JBL Partybox 520 & 720 - indoor listening session More from Oluv’Sone →
- Oluv Patreon: JBL Partybox 520 vs 720 - outdoor test
- Oluv Patreon: JBL Partybox 320 vs 520 - indoor listening session
- Oluv Patreon: JBL Partybox 320 vs 520 - outdoor test
- Oluv Patreon: JBL Partybox 520 vs Teufel Rockster Neo
- Oluv Patreon: W-King T12 vs JBL Partybox 520
- AudioTribe: JBL PartyBox 520 Loudness & BASS Test Will Shock You!
- GYMCADDY: JBL Partybox 720 Vs JBL Partybox 520 More from GYMCADDY →
- AudioTribe: JBL Partybox 720 vs JBL Partybox 520 Who’s Better?
- M1MTechChannel: Welche JBL Partybox ist die BESTE ? Alle Partyboxen im Vergleich | 2026 More from M1MTechChannel →
- Head-to-Head Comparisons
- JBL Partybox 520 vs Teufel Rockster
- JBL Partybox 520 vs JBL Partybox 710
- JBL Partybox 520 vs JBL Partybox 720
- JBL Partybox 520 vs Sony ULT Tower 10
- JBL Partybox 520 vs Teufel Rockster 2
- JBL Partybox 520 vs JBL Partybox 1000
- JBL Partybox 520 vs Sony SRS-XV900
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- See all 15 comparisons
Sony ULT Tower 9: $748.00 Amazon eBay
Pros: Slightly better sounding than the ULT Tower 10
Cons: Not as deep of bass and loses more bass at high volume even compared to the lower end Partybox speakers. Bass drops off a lot at higher volumes. Not quite as loud as the ULT Tower 10
Full Sony ULT Tower 9 review and specifications →
| Amplifier Power | 148W |
|---|---|
| App | Yes |
| Aux Input | Yes |
| Battery Life | 25 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC, AAC, LDAC |
| Bluetooth Version | 5.3 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 16.1" x 35.8" x 18" (410 x 910 x 456 mm) |
| Drivers | 7 drivers: 1x 12.6"x12.6" woofer, 2x 4.7" midrange, 2x 2" tweeter, 2x 1.6" rear tweeter |
| EQ | Yes (10 band) |
| Guitar Input | Yes |
| IP Rating | None |
| Lights | Yes |
| Microphone Input | Yes (Karaoke mode with echo effect) |
| Omnidirectional | No |
| Party Mode | Yes (Auracast up to 100 speakers) |
| Power Bank | Yes (USB-A, 5V/1.5A) |
| Power Input | AC Power cord |
| Removable Battery | No |
| Stereo | Yes |
| TWS | Yes |
| USB Playback | Yes |
| Weight | 65.3 lbs (29.6 kg) |
| Wi-Fi | No |
- Links
- Reviews, Comparisons and Sound Samples
- Oluv Patreon: Sony ULT Tower 9 vs JBL Partybox 720 - indoor listening test More from Oluv’Sone →
- Oluv Patreon: Sony ULT Tower 9 vs JBL Partybox 720 - power generator test
- GYMCADDY: Sony ULT Tower 9 Vs Sony ULT Tower 10 - Size Doesn’t Matter More from GYMCADDY →
- GYMCADDY: Sony ULT Tower 9 Review - Amazing Instrument Separation
- GYMCADDY: JBL Partybox 720 Vs Sony ULT Tower 9
- Joy & Oluv’Sone 3DAudio & Music: Sony ULT9 vs JBL Partybox 720 - the king of battery powered party speakers
- Head-to-Head Comparisons
- Sony ULT Tower 9 vs Sony ULT Tower 10
- Sony ULT Tower 9 vs Teufel Rockster
- Sony ULT Tower 9 vs Sony SRS-XV900
- Sony ULT Tower 9 vs JBL Partybox 710
- Sony ULT Tower 9 vs Marshall Bromley 750
- Sony ULT Tower 9 vs JBL Partybox 720
- Sony ULT Tower 9 vs Teufel Rockster 2
- Sony ULT Tower 9 vs JBL Partybox 1000
- See all 14 comparisons