Sony SRS-ULT70 Hi-fi

Sony SRS-ULT70 ULT FIELD 7 Wireless Portable Speaker

The Sony SRS-ULT70, sold as the ULT FIELD 7, is the largest of Sony’s ULT FIELD portable speakers, built around one priority: bass you can feel, delivered anywhere, for a very long time. Two X-Balanced woofer units and two tweeters, a pair of ULT POWER SOUND modes, up to 30 hours of battery life and an IP67 waterproof, dustproof, rustproof and shockproof body make it a genuine indoor-outdoor party speaker rather than a living-room accessory. It can lie flat or stand upright, links with up to 100 compatible speakers through Party Connect, pairs in stereo with a second unit, and doubles as a karaoke and guitar amp through its dedicated instrument input. This is Sony’s answer to the question of how much low end a 6.3 kg portable speaker can honestly produce.

Key features

• Two 114 x 114 mm X-Balanced woofers and two 46 mm tweeters
• ULT POWER SOUND button with ULT1 Deep Bass and ULT2 Attack Bass modes
• Up to 30 hours of battery life, with 3 hours of playback from a 10-minute charge
• IP67 waterproof and dustproof, also rustproof and shockproof
• Bluetooth 5.2 with LDAC, AAC and SBC codec support
• Microphone and guitar input with echo control for karaoke and practice
• Party Connect for up to 100 compatible Sony speakers, plus Stereo Pair
• Multi-colour LED lighting that reacts to the music, and USB playback and phone charging

X-Balanced drivers and the ULT modes

Sony’s X-Balanced Speaker Unit replaces the conventional circular woofer diaphragm with a non-circular shape that increases surface area within the same cabinet footprint. More area moves more air, and the ULT FIELD 7 uses two of these 114 mm woofers alongside two 46 mm tweeters in a two-way layout, so the low end has genuine physical authority while vocals and detail stay clear. The ULT button then chooses the flavour of that authority. ULT1, Deep Bass, emphasises the lowest frequencies for a heavy, resonant weight suited to hip-hop and electronic music. ULT2, Attack Bass, trades some depth for drive and punch, lifting the energy in rock, dance and pop. A 7-band custom equaliser in the Sony Music Center app refines the result further, and sound is tuned to stay composed in either horizontal or vertical placement.

Battery, charging and durability

Thirty hours of rated playback covers a full weekend of use between charges, and the quick-charge function returns about 3 hours of listening from just 10 minutes connected to power, which rescues a forgotten charge before guests arrive. The enclosure carries an IP67 rating, meaning it is dustproof and can be submerged in up to a metre of water for 30 minutes, and Sony additionally rates it rustproof and shockproof, so poolside splashes, beach sand, rain and the occasional knock are working conditions rather than accidents. At 512 x 224 x 222 mm and 6.3 kg with integrated handles, it is sized to be carried by one person and to fill a garden, terrace or hall when it gets there.

Connections for parties and performers

Wireless playback runs over Bluetooth 5.2 with support for LDAC high-quality streaming alongside AAC and SBC, at a range of up to about 30 metres. Wired options include a 3.5 mm stereo input and a USB-A port that plays music from a flash drive and can charge a phone from the speaker’s battery. The 6.3 mm microphone and guitar input, with its own level and echo controls, turns the speaker into a karaoke system or a portable practice amp without any extra equipment. Party Connect synchronises music and lighting across up to 100 compatible Sony speakers for large spaces, while Stereo Pair links two ULT FIELD 7 units as a true left-right system. The Fiestable app adds control over the multi-colour LED lighting that rings the cabinet and pulses with the beat.

Who it is for

The ULT FIELD 7 suits hosts, venues and performers who need serious portable output: house parties that move outdoors, farmhouse and terrace gatherings, boutique fitness and dance sessions, and small events where a mic input matters as much as the music. It is a mono-point party speaker in a single unit, honest stereo comes from pairing two, and it makes no claim to be a studio reference. Judged as what it is, a rugged, long-running, bass-forward portable speaker with real party infrastructure built in, the SRS-ULT70 sits at the top of Sony’s field range for good reason.