These are not really the same size class, and that is the honest framing here. The Sony ULT Tower 9 ranks #10 of 13 large party speakers by sound quality at $898; the Soundboks Mix ranks #36 of 53 party speakers by sound quality at $799.
The case for the Sony ULT Tower 9: A battery powered party tower with good sound, a long battery, karaoke inputs, and a detailed app EQ. It has an adjustable EQ, which the Soundboks Mix lacks. It plays in stereo from a single unit, unlike the Soundboks Mix. The tradeoff: Not as deep of bass and loses more bass at high volume even compared to the lower end Partybox speakers.
The Soundboks Mix is the longer-running, lighter pick. A rugged, weatherproof party speaker with a swappable battery that runs all day at mid volume and fast USB-C charging. It is rated for 40 hours of battery against 25 for the Sony ULT Tower 9. At 21.4 lbs (9.7 kg) it weighs much less than the Sony ULT Tower 9 at 65.3 lbs (29.6 kg). It is rated IP65, while the Sony ULT Tower 9 has no water resistance. The tradeoff: 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 $898 for a large party speaker, or the Soundboks Mix at $799 for a party speaker instead.
Want more options? Browse the full Portable Bluetooth rankings.
Prices on this page were last checked November 7, 2026 at 7:34 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.
Specifications Side By Side
| Sony ULT Tower 9 | Soundboks Mix | |
|---|---|---|
| Price | $898.00 | $799 |
| Ranked | #10 of 13 in Large Party Size Portable Bluetooth Speakers | #36 of 53 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 | Yes | Yes |
| 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: