Sony ULT Tower 9AC

Introduction

The ULT Tower 9 is Sony’s latest super-sized party speaker. It’s a direct replacement for the older SRS-XV900, and it effectively replaces the slightly smaller XV800 that I tested in 2024.

The ULT Tower 9 comes in two flavours. There’s one with a built-in battery, called the Tower 9, and one that only works on mains power, dubbed the Tower 9AC. I have the latter model in for testing, but other than needing to be plugged into an outlet, it has the same features and sound output as its battery-powered sibling.

I was impressed with the older model, so I’ve got high hopes for this one. It’s physically larger and has one of the largest square-shaped woofers I’ve ever seen, so all signs point to a thunderous bass response.

The Tower 9AC retails for £599, while the battery-powered Tower 9 will set you back £849. That means these behemoths are up against some stiff competition from the likes of the JBL PartyBox 710, AlphaTheta Wave-Eight and Soundboks 4.

How does Sony’s latest effort stack up? I’ve been annoying my neighbours for the past week in an effort to find out.

Design

• Understated, boxy design
• Built-in wheels and carry handles
• Reactive RGB lighting and backlit control panel

The ULT Tower 9 is a very big speaker; It stands just shy of 3 feet tall and weighs almost 30kg. Thankfully, there are large built-in grab handles to make it easier to manoeuvre, as well as wheels on the rear so it can be rolled behind you like a suitcase.

A chief complaint I had about the XV800 was that it had tiny wheels, so it could only roll on the smoothest of surfaces. On this model, they’re much larger, which is a big improvement.

However, they’re still constructed like office chair wheels, so they’re still mostly suited to surfaces like wooden floors, tiles or linoleum. If you’re looking to drag a speaker into the woods for a rave, you’ll likely need to look elsewhere.

The speaker is only available in black, and it has an angular, boxy construction. I like that each edge is now covered with a durable plastic trim, as it’s quite easy to dent perforated metal grilles when they wrap around a corner (like they did on the older models). I’m much more confident in this speaker’s ability to handle a few knocks.

Speaking of durability, there’s no official IP rating for this one, but Sony says it has a splashproof top panel. There are also rubber bungs that cover the inputs on the top and rear, which should help in this regard. In any case, with my sample being mains powered, I wouldn’t want to risk using it in the rain.

The physical controls are all found on the top, and the majority are backlit capacitive touch buttons. Only the power switch and ULT mode switch have tactile buttons. There’s also an inset ridge that can be used to prop up a phone or a tablet, and a thick rubber flap that covers two 1/4-inch microphone inputs. Each mic input has its own dedicated volume knob, and one doubles up as a guitar input, with a guitar mode switch.

On either side of the speaker, there are hidden microphone holders that pop out if you push on them – a lot like the cupholders you find in some cars. It’s a really nice touch, but unfortunately, I didn’t have any appropriate microphones to test it out with.

Around the back, a separate rubber flap covers the other inputs. You get a USB-A port, which can be used to play songs from a thumb drive or charge other devices, as well as an optical input and a 3.5mm aux input.

All in all, it’s a fairly understated and professional-looking speaker. The Sony logo has a bit of a holographic shine to it, which is a nice touch, but elsewhere it’s a mostly matte-black finish. When you turn the speaker on, though, it becomes more of a head turner.

Bright LED lights shine down from the grab handles and illuminate the sweeping curves of the top panel. At the bottom, you get a similar effect that fires down towards the ground. The effect is more pronounced than the one produced by its predecessors, as the LEDs now fully encircle the speaker, shining light in all directions.

That said, it’s still fairly subtle compared to the forward-firing LEDs on JBL’s party speakers. Personally, I find Sony’s approach a little more tasteful, and it’s still impactful enough to create a nice party atmosphere.

Features

• 3.5mm, 1/4-inch and optical connections
• Wireless sync with Party Connect
• Microphone, guitar and TV sound support

The array of inputs means that it’s easy to connect almost any source to the Sony ULT Tower 9, and of course, it has Bluetooth for your phone, tablet or laptop. What’s a little less common is that Sony has designed this speaker to be used with a TV, too.

There’s an optical cable supplied in the box for this purpose, and while I don’t think the form factor is ideal for most living rooms, Sony has clearly put some thought into this functionality.

You can either connect the speaker and have it handle all of the audio, or you can activate “TV Sound Booster” mode. When active, it will funnel the dialogue through your TV’s speakers and only utilise the woofer and rear-firing speakers to widen the soundstage and add some more oomph to the low end.

It works quite well, but it’s a little fiddly. You end up needing to use the TV remote to adjust the volume of dialogue, and the app or physical speaker controls to change the bass output. I can’t imagine most people will want the hassle, but if you’re unfazed, it does sound quite good.

Another attractive feature is the ability to use this speaker as a karaoke box, PA or guitar amp. I’ve already mentioned the built-in mic holders, but Sony also offers an optional wireless mic kit. The ULTMIC1 kit is sold separately for £129, but it adds two compatible wireless mics, allowing you to belt out the ballads without getting tangled.

If you find that one of these speakers isn’t enough (which would be astonishing, because it’s insanely loud), then you can wirelessly sync up to 99 more compatible speakers with Party Connect.

The full list of supported speakers can be found here, but it includes the older XV500 / 800 / 900 party speakers, as well as the entirety of the new ULT range, from the pint-sized Field 3 to the gigantic Tower 10.

Most of the speaker’s functions can be controlled directly on the top panel, but to access everything, you’ll want to use the Sony Sound Connect companion app. It works on both Android and iOS, and it gives you access to everything from a custom 10-band EQ to comprehensive lighting control. On previous models, you needed to use two separate apps to access all of the features, but thankfully, it has now been consolidated into one place.

Some of the more unusual features include a DJ mode, complete with a sampler and live effects, and a karaoke mode, with key control, echo, a voice changer and more. You can also set up multipoint connection in the app, if you want to connect the speaker to both a phone and a laptop, for example.

Sound Quality

• Thunderous output
• Big bassy sound signature
• Omni-directional sound

As you might expect from the looks of this speaker, it’s all about the bass. That front-firing 12-inch square woofer kicks out a booming low end that you can feel just as much as you can hear. It has all the energy of a pounding night club sound system – in a package that remains somewhat portable.

That said, it’s a party speaker, and to some extent, that’s par for the course. What surprised me the most was the clarity and texture in the midrange and higher frequencies. While this speaker is certainly bass-forward, it’s surprisingly well balanced elsewhere.

The unique driver arrangement allows for a surprisingly wide soundstage, too. There are two angled tweeters on the rear corners, which help to spread the sound in all directions. It still sounds best when you’re in front of it, but its placement is far less critical than with other party speakers, and you’ll get a very decent sound no matter where you’re standing.

As standard, you get two sound profiles, which are labelled ULT 1 and ULT 2 in the app, and pressing the ULT button on the speaker toggles between them. ULT 1 is the ultra-bassy mode that delivers maximum rumble, while ULT 2 has a more balanced sound. Don’t get me wrong, it’s still bassy, but it’s not quite as in-your-face.

I love ULT 1 for genres like DnB, House and Hip-Hop, while Rock, Jazz and Funk sound better on ULT 2. For the most part, I was happy with these two presets, but there was the odd track where the bass felt too imposing. For those occasions, I switched the custom EQ, which can easily be dialled in to your preference.

When it comes to volume, this speaker can get loud enough to soundtrack the most raucous parties. I was barely ever exceeding 30% volume around the house, and even that was pretty loud. If you host large gatherings, it’s safe to assume this speaker can keep up. Overall, I’m very impressed with the sound quality from the ULT Tower 9.

Yes, it’s bassy and boisterous, but it’s a party speaker, and it should be. At the same time, I think there’s enough fidelity and refinement in the higher frequencies to please a more discerning ear. To be clear, though, this speaker is for bass heads, and if that’s not your thing, you should look elsewhere.

Should you buy it?

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