Short answer: it depends on whether you need a battery. The JBL Partybox Ultimate runs only on mains power, while the Sony ULT Tower 9 has a battery rated for 25 hours. The JBL Partybox Ultimate ranks higher on sound quality (#3 vs #10 of 13 large party speakers, 4.7/5 vs 4.2/5). Get the JBL Partybox Ultimate if it will always be plugged in, or the Sony ULT Tower 9 if you want to play away from an outlet.
The Partybox Ultimate’s whole case is bass. It packs 1100 W into two 9” subwoofers alongside 4.5” midranges and 2.75” tweeters, and our notes call it the absolute deepest bass of any Bluetooth speaker. The ULT Tower 9 runs a single 12.6” woofer at 148 W, and its own con notes admit the bass isn’t as deep and drops off more at high volume, even compared to cheaper Partybox models.
The ULT Tower 9 answers back with features, not output. It supports AAC and LDAC on top of SBC, where the Partybox Ultimate is SBC only. It also has a 10-band EQ versus the Ultimate’s 3-band EQ, and it’s the only one of the two with WiFi. The Partybox Ultimate counters with IPX4 splash resistance, where the ULT Tower 9 has no water resistance rating at all.
Everything else matches: both include a microphone input with karaoke echo, a guitar input, USB-A power bank output, and Auracast party mode. The main practical difference is weight: 86 lbs (39 kg) for the Partybox Ultimate against 65.3 lbs (29.6 kg) for the ULT Tower 9, and the Tower 9 can also run up to 25 hours on its internal battery when it isn’t plugged in, something the Ultimate cannot do at all since it has no battery.
Buy the Partybox Ultimate if it will always be near an outlet and you want the deepest, loudest bass available in a Bluetooth speaker, and don’t mind the size, weight, or the higher price.
Buy the ULT Tower 9 if you need to play away from an outlet, or you’d rather have real EQ control, better Bluetooth codecs, and WiFi, and you can live with less bass extension at the top of the volume range.
Looking for alternatives? See the complete Portable Bluetooth rankings.
A huge party speaker with deep, powerful bass and clear sound at extreme volume, plus Wi-Fi and karaoke inputs.
A battery powered party tower with good sound, a long battery, karaoke inputs, and a detailed app EQ.
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.
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Specifications Side By Side
| JBL Partybox Ultimate | Sony ULT Tower 9 | |
|---|---|---|
| Price | $1,899.95 | $898.00 |
| Ranked | #3 of 13 in Large Party Size Portable Bluetooth Speakers | #10 of 13 in Large Party Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Aux Input | Yes | Yes |
| Battery Life | No Battery | 25 hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC, AAC, LDAC |
| EQ | Yes (3 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) |
| Power Bank | Yes (USB-A, 5V/2.1A) | Yes (USB-A, 5V/1.5A) |
| Power Input | AC Power cord | AC Power cord |
| TWS | Yes | Yes |
| USB Playback | Yes | Yes |
| Weight | 86 lbs (39 kg) | 65.3 lbs (29.6 kg) |
| Wi-Fi | Yes | No |
| Built-in Microphone | No | No |
| Party Mode | Yes (Auracast) | Yes (Auracast up to 100 speakers) |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Bluetooth Version | 5.3 | 5.3 |
| Dimensions | 17.9” x 41.3” x 17.3” (455 x 1049 x 440 mm) | 16.1” x 35.8” x 18” (410 x 910 x 456 mm) |
| Drivers | 2x 9” subwoofer, 2x 4.5” midrange, 2x 2.75” tweeter | 7 drivers: 1x 12.6”x12.6” woofer, 2x 4.7” midrange, 2x 2” tweeter, 2x 1.6” rear tweeter |
| Amplifier Power | 1100W | 148W |
| Digital Aux Input | No | No |
| Lights | Yes | Yes |
| Wheels | Yes | - |
| Strap | No | No |
| Removable Battery | - | No |
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