These are not really the same size class, and that is the honest framing here. The Sony ULT Tower 9 ranks #9 of 12 large party speakers by sound quality at $748; the Soundboks Mix ranks #25 of 40 party speakers by sound quality at $799.
The case for the Sony ULT Tower 9: Slightly better sounding than the ULT Tower 10. The catch: Not as deep of bass and loses more bass at high volume even compared to the lower end Partybox speakers.
Why pick the Soundboks Mix: USB-C fast charging (65W) for the swappable battery, up to 40 hours of battery life at mid-volume, IP65 dust/water resistance, and TeamUp linking with up to 5 other SKAA-equipped Soundboks speakers. The catch: Doesn’t have as deep of bass as higher-ranked speakers, and can sound somewhat bright in the treble.
Buy the Sony ULT Tower 9 at $748 for a large party speaker, or the Soundboks Mix at $799 for a party speaker instead.
There is a real gap in water resistance: the Soundboks Mix at IP65 (water jets) against the Sony ULT Tower 9, which has no water resistance.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Sony ULT Tower 9 | Soundboks Mix | |
|---|---|---|
| Price | $748.00 | $799 |
| Ranked | #9 of 12 in Large Party Size Portable Bluetooth Speakers | #25 of 40 in Party Size Portable Bluetooth Speakers |
| App | Yes | No |
| Aux Input | Yes | Yes |
| Battery Life | 25 hours (Manufacturer specified) | 40 hours (Manufacturer specified) |
| EQ | Yes (10 band) | No |
| Guitar Input | Yes | - |
| Microphone Input | Yes (Karaoke mode with echo effect) | - |
| Party Mode | Yes (Auracast up to 100 speakers) | Yes (TeamUp, up to 5 speakers) |
| Power Bank | Yes (USB-A, 5V/1.5A) | No |
| Power Input | AC Power cord | USB-C |
| Removable Battery | No | Yes |
| TWS | Yes | No |
| USB Playback | Yes | No |
| Weight | 65.3 lbs (29.6 kg) | 21.4 lbs (9.7 kg) |
| Built-in Microphone | No | - |
| IP Rating | None | IP65 |
| Stereo | Yes | No |
| Omnidirectional | No | No |
| Wi-Fi | No | - |
| Bluetooth Codecs | SBC, AAC, LDAC | SBC (additional codecs unverified) |
| Bluetooth Version | 5.3 | 4.2 |
| Dimensions | 16.1” x 35.8” x 18” (410 x 910 x 456 mm) | 19.1” x 13.5” x 10.9” (484 x 342 x 276 mm) |
| Drivers | 7 drivers: 1x 12.6”x12.6” woofer, 2x 4.7” midrange, 2x 2” tweeter, 2x 1.6” rear tweeter | 10” woofer, 1.2” tweeter |
| Amplifier Power | 148W | 72W |
| Digital Aux Input | No | No |
| Lights | Yes | - |
| Strap | No | - |
| Frequency Response | - | 40Hz - 20kHz (Manufacturer specified) |
| Maximum SPL | - | 121dB (Manufacturer specified) |
Related Speaker Comparisons
More worthwhile head-to-heads for Soundboks Mix:
- Sony ULT Tower 7 vs Soundboks Mix
- Soundboks Mix vs JBL Partybox 330
- JBL Partybox Stage 320 vs Soundboks Mix
- Sony ULT Tower 5 vs Soundboks Mix
- JBL Partybox Club 120 vs Soundboks Mix
Prices on this page were last checked September 26, 2026 at 11:14 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
Sony ULT Tower 9: $748.00 Amazon eBay
Older model: the Sony SRS-XV900 (rated 3.7/5).
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 |
| Strap | No |
| 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 JBL Partybox 520
- 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
- See all 20 comparisons
Soundboks Mix: $799 Soundboks Amazon eBay
Older model: the Soundboks Go (rated 3.1/5).
Pros: USB-C fast charging (65W) for the swappable battery, up to 40 hours of battery life at mid-volume, IP65 dust/water resistance, and TeamUp linking with up to 5 other SKAA-equipped Soundboks speakers. High efficiency drivers reach 2-3x the volume of typical speakers for the same wattage.
Cons: Doesn’t have as deep of bass as higher-ranked speakers, and can sound somewhat bright in the treble. Only 72W of output and a single 10-inch woofer, less powerful than the Soundboks Go or Soundboks 4, and no microphone input for karaoke like the Pro Panel models.
Full Soundboks Mix review and specifications →
| Amplifier Power | 72W |
|---|---|
| App | No |
| Aux Input | Yes |
| Battery Life | 40 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC (additional codecs unverified) |
| Bluetooth Version | 4.2 |
| Digital Aux Input | No |
| Dimensions | 19.1” x 13.5” x 10.9” (484 x 342 x 276 mm) |
| Drivers | 10” woofer, 1.2” tweeter |
| EQ | No |
| Frequency Response | 40Hz - 20kHz (Manufacturer specified) |
| IP Rating | IP65 |
| Maximum SPL | 121dB (Manufacturer specified) |
| Omnidirectional | No |
| Party Mode | Yes (TeamUp, up to 5 speakers) |
| Power Bank | No |
| Power Input | USB-C |
| Removable Battery | Yes |
| Stereo | No |
| TWS | No |
| USB Playback | No |
| Weight | 21.4 lbs (9.7 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons