The Acoustic Energy AE509 Loudspeakers Review - A sleek and affordable heavyweight

Unpacking the AE509 Loudspeakers

The packaging of these speakers is very nice indeed. Large, double-boxed and over each speaker is a full-length dust cover. And in addition, there’s another box containing the floor spikes and outrigger stabilisers. When the boxes came to the door, I was very surprised by how heavy these things were. 

At a healthy 22kgs each, they have a healthy, stable weight. Lifting them from the box wasn’t going to be easy, so standing the box on its end and leaning them out was a much safer way of removing them from the packaging. Once out and with the dust covers off, it was just a matter of fitting the outriggers to the base. The outriggers are very solid, and the fitment of the spikes is very easy indeed. 

Fixing them to the speakers is just a matter of 4 cross-head (Phillips) bolts, and once done, it was time to place them in position. The speaker grilles are thin and very lightweight and magnetically click into place. I generally don’t like grilles on speakers because some bash the high frequencies too much, but the material on these is so thin, I will have to see how they sound.

First aesthetic impressions and technology:

With something like loudspeakers, for me, they need to have an attractive and/or serious look to them. I don’t like any fussy design over function nonsense. They need to have balance, an overall collective in tech and design. 

Once in place with the grilles removed and the drivers exposed, it was clear to see that these are of fantastic build quality and look really great, blending into the decor rather seamlessly. First, the cabinets. These are finished in a lovely piano gloss white, but they also come in a gloss black and a lovely American walnut veneer. 

Upon looking closely at the cabinets, everything is flawless, the finish is even all around, no blemishes or rough areas. The spaces where the drivers fit flush into the front are perfectly tight. A further in-depth look at the construction of the AE509s is quite fascinating. 

The cabinet isn’t made from a single layer of material like many loudspeakers; it’s made from two layers of MDF, one 6 mm and another layer of 9 mm. Then, sandwiched between them both is a layer of inert dampening bitumen material. This overall construction brings the cabinet walls to 18mm thick and is called RSC (Resonance Suppression Composite). 

 Knocking on the side of the cabinets, you can hear that it’s deadened, with no real noticeable resonance or boxy sound feedback. For sure, they are of a very precise build and rock-solid construction.

At the bottom front of each loudspeaker is a nice, unobtrusive Acoustic Energy logo and around the back is a high-mounted rectangular bass port reflex, making them much more placement friendly within a room. 

At the bottom is the connection panel where we find a nicely made connection plate fitted with silver-plated binding posts, which can accept 4mm bananas or spade connectors, so the connection is a breeze. The crossovers are situated in their own separately tuned compartments at the base of each loudspeaker. 

The given crossover response is 32Hz – 28kHz (+/- 6dB) mid, bass and tweeter at 2.9kHz. Standing at a reasonable 100 cm tall (excluding decoupling base spikes), 185 mm wide and 280 mm deep, the AE509s certainly look impressive and sit with conviction. Then there's the drivers. 

The AE509s have two newly designed and wonderful-looking 125 mm carbon fibre cone mid/bass drivers, joined with a central cast aluminium waveguide 25 mm carbon fibre tweeter. 

The design incorporates a feature which brings the tweeter closer to both drivers, this is called MTM (Mid/Tweeter/Mid), which centralises the sound. The carbon fibre drivers are the next step up from their ceramic type technology, which gives the cone a faster response by being much lighter. Same goes for the tweeter, being lighter, it responds much faster to conventional types of dome materials, thus presenting a much more realistic sound. 

 Rated at a very healthy 175W max power and 6 ohm impedance. They’re very well suited to solid state and at 89 dB sensitivity, maybe some higher-rated valve amplifiers.

I asked James Luce, Creative Director of Acoustic Energy, what their goal was in the design of the AE509s. “The design goal for the 509 and 500 Series in general was to offer an affordable entry into high-end Hi-Fi, featuring tech which is very rare at this price point. 

The Carbon Fibre drivers (extremely rare in a tweeter, I think we may be the only ones making one - a benefit of bespoke design and manufacture rather than buying off the shelf!) and Constrained Layer MDF/Bitumen sandwich cabinets being the stand-out points, along with solid aluminium trim & feet assemblies and very high quality piano lacquer/real wood veneer finishes. 

The 509 specifically benefits from being a large two-way with the MTM design, so you get the timing and coherence of having a simpler crossover with added power and depth vs a standmount, they dig surprisingly low for a slimline design. 

Using the same diaphragm material for all drive units with relatively small 5" mid/bass drivers in that slim cabinet really helps integration and dispersion, so they're also very room-friendly, which is one of the most overlooked hurdles in achieving good sound at home!” 

 Q: In comparison to the older ceramic types, how do you see the carbon fibre drivers evolving? 

“The Carbon Fibre drive units have some unique and beneficial characteristics (rather than just being used for the prestige or expense of flashy materials for the sake of it) - they offer similar stiffness for around half the mass of ceramic/aluminium drivers and being a woven composite material have relatively smooth & benign break-up characteristics, avoiding the strong "ringing" of metal cones which needs controlling in the crossover. 

 In our newer flagship Corinium speaker we've already been refining the Carbon cone profile and suspension system to further extract more performance, as with all materials it has an acoustic signature, generally sounding light, open, smooth and fast - this is taken into account with all other aspects of the speaker design to create the final "flavour". 

There's no one perfect solution, but the Carbon Fibre certainly offers a lot of positives with very few drawbacks. Generally speaking, our ethos is to offer great performance and value together - not so easy with global difficulties in recent years, but we're always trying to find ways to offer more while keeping within reach for most Hi-Fi enthusiasts.” 

 Q: Tell me more about the ‘tuned’ crossover area where the crossovers are situated. 

 “The chamber that the crossover sits in at the base of the speakers serves a dual-purpose; being one of our taller models, we were starting to experience internal vertical standing waves with the 509, a common problem in speakers like this and one of which companies often try to mitigate with complex internal baffles, but this adds unnecessary cost. 

 Being that we try to be smart rather than add cost, we cancelled out that frequency with a "Helmholtz Resonator", the fancy term for the hole at the top of the crossover chamber which the wires pass through, made to the exact size required to match the frequency of the wave and nullify it.” 

There's no doubt that Acoustic Energy has put a lot of work into the 509 speakers. But, how do they sound, and will they impress? Let’s find out.

How do the AE509 loudspeakers sound?

Before we start, let’s go through some of the equipment used in this review. For source, I’ll be using analogue and digital sources such as conventional CD and higher resolution DSD audio and Qobuz running through my Weiss DAC204 into my Ultrafide U4PRE preamplifier. Moving on to analogue with the U4PRE’s phono stage. 

I’ll be using the legendary Trio/Kenwood L-07D turntable with a Denon DL103R-C1 cartridge. And lastly, amplification is the matching Ultrafide U500DC power amplifier. As for cables, I use Klotz MC5000 balanced cables for source signals and doubled up Van Damme 4mm black touring cable with Cardas solid copper spades. 

 Placing the AE509 loudspeakers in the same position as my rather huge 15” Tannoy Monitor Gold loudspeakers, I start with digital, bog standard 44.1 kHz Redbook through the Weiss DAC. The 509s have arrived directly from AE, so as with all loudspeakers, some breaking in is always necessary.

Burning in:

One of my best tools for this is a burn-in/demagnetising CD, which runs through all of the frequencies for 10 minutes. So, for the first 3 days, it’s a combination of music and using the burn-in CD. 

From out of the box, the 509s sounded very promising, a haze of a little scratchiness maybe, which is totally normal for any brand-new loudspeaker, but in this case, it wasn’t too noticeable. 

After the first day, however, the sound had changed quite a bit, and I could tell they were on the path of only getting better. You could instantly tell that they had great separation qualities. And at the end of the second day, there were different speakers. 

A much more developed sound was becoming evident through an increase of extended bass and high frequencies, starting to become smoother and more airy. At the end of the 3rd day, they had hit the, what I call, the midway spot. Bass, midrange and the high frequencies were much more aligned, and the speed became much more apparent. 

Not only that, but a good amount of sub bass was also more prominent. After a week. I felt it was time to start analysing the sound and find out what these lovely little floorstanders can offer. Before each listening session, a quick 5-minute burst of the test CD is always good to get all the kit warmed up. And so, the first album on CD was something with real atmosphere, Brian Eno - Atmospheres. Not the most engaging of music, I know. 

But it has space, and I wanted to get an idea of the width and depth of the soundstage, and that's important. Adjusting the toe-in slightly, the first thing I noticed was the midrange. The great thing about these drivers is that they can really focus on certain frequencies, and on this album, the music and vastness of the sound became very real. 

In fact, I had to repeat a few tracks because it just grabbed me. By the end of the second week of general use, and a few 24-hour constant overnight burn-in sessions. I took a day's rest to allow my senses to reset.

Getting down to the sound - Digital:

(Using standard Redbook, DSD and Qobuz with the Weiss DAC204 and Denon DN961FA)

Starting up the system again, it was time to get down to it and get them going. Digitally, I have chosen two albums from many to include in this review. One of my favourite albums is an oldie, the 1992 remaster of Pink Floyd’s The Dark Side of the Moon. 

The heartbeat thump from the first track, Breathe (in the Air), of this album, for me, is one of the ways I determine the control of the bass and the way it pronounces the manipulated strangeness of the heartbeat. And I wasn’t disappointed. The texture and the airy nature were quite beautiful. 

The crescendo at the start of this track wasn’t disappointing, full-bodied and impactful. My notes from listening to this album were that the whole album sounded accurate in all frequencies with no harshness or boxiness. On the Run, Money and especially The Great Gig in the Sky really showed off the midrange of these speakers, it’s quite something. 

 Moving on to another Redbook standard album, The Stone Roses' debut album from 1989. Again, the build-up at the start of the album gave a wonderful insight into how this will sound once it’s got going. Tracks such as Waterfall, Fool's Gold, and I am the Resurrection all sounded full and detailed and powerful. My next choice is something a bit more up-to-date and has even more sonic craziness. Shpongle’s Museum of Consciousness. 

Shpongle are one of my go-to artists because the amount of frequencies swing, fluctuate and weave so nicely. From the off, I was quite astonished. The bass on this album is really quite amazing, and the AE509s don’t disappoint. 

 Next, it was time to stream some stuff. As well as straight DSD audio, Qubuz was also used through the Weiss from Queen and Led Zeppelin. My first choice was ‘A Night at the Opera’. Although neither Led Zeppelin nor Queen albums are, I would say, of audiophile quality. The presence of how they were recorded and accepting their foibles is part of the charm. 

Sometimes, that ‘charm’ can be lost by bringing in too much resolution, and overstepping the realism. How that charm came through the AE509s was impressive in the fact that they can certainly do the warm hugging analogue sound without sounding clinical, and still give that rock-punch is really something. 

 Another great album I find is Overpowered by Roisin Murphy of Moloko fame. Wow… very nice separation and really great, deep bass. The 509s take on the challenge without any strain with the opening track, Overpowered. A track which has a defiant groove and needs great timing with no overblown or out-of-control bass. The 509s took great care here, not overstepping into a bloated mess, which was very impressive.

Getting down to the sound - Analogue:

(using Trio/Kenwood LO-07D, Denon DL103R-C1 and Ultrafide U4PRE internal Phono Stage)

Leaving the world of digital and moving on with vinyl reproduction, I was a little apprehensive about how the AE509s would cope with, for me, a more complex source. For me, not all loudspeakers get digital right, and not all do analogue, so AE have their work cut out in this realm. 

 Analogue needs to sound full, more organic, easy, fluid, and reproduce those basic, powerful characteristics of vinyl. This is, for me anyway, what I believe is the difference between digital and analogue. So, starting with Paul McCartney’s - The Fireman on vinyl. This heavy box set from 2016 has some wonderful moments. Lots of effects and tape loops with a delicate air of ambience. Dropping the needle and starting this album was a real pleasure. 

 To be honest, I was only going to include the first A/B sides for this review, but I ended up listening to the whole album. What a great sound, the AE509s handled this album with ease and timing, with an uncluttered separation and zing. My next choices were from Curtis Mayfield, Roots and Superfly. Again, not an audiophile recording, but with attitude, amazing groove and timing. 

Roots kicked off with the ‘wooh, hey’s’ and that dirty fuzzed out bassline, yeah… this is great. Again, the 509s brought the groove alive. Same with the album, Super Fly, the groove just gets you and moves you through the album, by not thinking or trying to find fault, it was evident that the 509’s enjoy 70s Funk. Next was something from the 90s. 

The fully remastered albums from Twisted Records (Shpongle) and Halloucigen. In Dub was one of my favourite albums from back in the day, and it’s an album that, without a good bass, falls flat; still enjoyable, of course, but without some of that deep bass, it can sound a bit, well, meh. This is a ‘Sub Bass department’ record and, well, the AE509s handled it with a sterling performance. 

Okay, we’re not going to get down to those louder subs without a sub or without bigger cabinets, but it was very surprising that they got down so low because looking at these speakers, they’re slim and not that large, so they’re very deceptive looking. 

Grilles on or off? - Well, to be honest, the material on the grilles doesn’t make a huge difference to the sound, which is excellent. It’s extremely thin, so it has hardly any effect. What effect it has is a personal thing, and because I like to see those great-looking drivers, 

I prefer them to be removed. But the grilles don’t bash the high frequencies enough to not enjoy the music. Rather, they reduce the high end slightly, so for some, the grilles will be preferable.

Conclusion verdict of the AE509 loudspeakers:

The technology included in these loudspeakers is what makes them punch above their weight at their entry-level prowess. The price point for the 509s is a very affordable £2400, and for that, what you get is a pair of very elegantly styled, well-thought-out loudspeakers with a very natural reproduction factor. 

The technology and design dovetail very nicely indeed with the MTM (Mid-Tweeter-Mid) configuration. The bass is tight, focused, fast, precise and deceivingly bigger in scale than one would imagine (in regards to their physical size), allowing that groove to keep bouncing. Nothing is overblown. 

The mid-range holds its own in the fact that it keeps everything together, nice and smooth, with no overly coloured or forward sounding shrillness or spikeyness. In the high-frequency department, this is where, for me, the magic happens. 

Those carbon fibre tweeters have a very natural way of not being in your face, they have a pleasant and natural sparkle, and you simply don’t need to argue with them. I always say, if you don’t notice the tweeters, they’re working perfectly and doing what they should by creating a solid soundstage. 

 The 509s produce a nice holographic and deep soundstage, beautifully wide, detailed and fun. They can handle a medium to large room with total ease. My listening room is approximately 5m x 13m, and they fill the room with dynamic sound. They do have a sweetspot of around a maximum distance of approximately 3.5m with a bit of a toe-in. 

But further out than that, they still sound very impressive and extremely good fun. And, the great thing about the 509s is their size. They will fit and sound great in a small apartment or a larger room. AE have got this model down to be a really impressive all-rounder. And, yes, they would also be an excellent choice for an AV system, too. 

The Audiophiles amongst us needn’t worry about any lossiness in reproduction whilst using these speakers. Voices are very well reproduced, which keeps your attention grounded. They’re excellent with both digital and analogue sources and ooze sophistication in how they look and perform. 

 The build quality is very nice indeed. They’re solid, heavy and have a beautiful finish. The floor spikes are high quality, and fitting them is a doddle. To finish. The AE509 loudspeakers are very aesthetically pleasing; they sit proudly and are very elegant to look at, blending seamlessly in with home decor. 

They’re also deceptive in regards to their size and how they sound. They’re dynamic, they ooze quality with a driven, wider, and bigger/punchier soundstage than you would have thought by looking at them. 

They tick all the boxes for any Hi-Fi or AV setup, regardless of cost. Like me, you will certainly have a lot of fun with the 509s. They are beautiful in appearance, build, and have a lovely sound. The AE509 loudspeakers come highly recommended to anyone who is looking for something to fill a space with dynamic sound. 

At this price tag, they are a very addictive bargain. The next level up from the AE509 is the AE520 to which looks very impressive again, and then there's the Corinium loudspeakers, which intrigue me even further, and it would be amazing to review either of those for you in the future - I’m certainly hopeful.