Review: Fluid Audio FPX7

Continuing his series of recent studio monitor reviews, Nigel Palmer unearthed a few surprises when he unboxed this new coaxial specimen.

Another month, another small active loudspeaker review – if nothing else it’s indicative of what a crowded market sector this has become, especially with two-ways built to a price, and there’s good reason for it through the continued rise of project studios.

With design knowhow based in the US and manufacturing in China, Fluid Audio as a company is a relative newcomer to the field. However, there’s no lack of background experience in its founder, loudspeaker veteran Kevin Zuccaro. Of particular note in the product range is an interest in coaxial, or dual-concentric speakers, where “the individual driver units radiate sound from the same point or axis” (Wikipedia). Although this is something I associate with Tannoy speakers I’ve used in the past, it’s an idea with much to commend it still in terms of time-alignment, larger listening sweet spot and a potential for smaller cabinet size. It’s nice to see it dusted off once more in Fluid’s latest offering, the FPX7, which has the additional twists of the first time an Air Motion Transformer (AMT) tweeter has been used in such a configuration, together with DSP control for better room integration.


The Fluid Audio FPX7 is a smart-looking and compact loudspeaker with box sides curved on the vertical axis to help reduce internal standing waves, rounded corners and a silver baffle plate set in a black MDF enclosure. Measuring 308 x 217 x 264mm (HWD) and weighing 7.5kg, working down from the top of the plate is firstly a power indicator in the form of an illuminating Fluid Audio logo next to a detented fader volume control, which I found worked best in my system at the -6 detent. Below this is the coaxial driver array consisting of a 7in paper cone woofer with a 28 x 43mm AMT tweeter mounted centrally in a waveguide. I’ve now reviewed a number of speakers using Air Motion Transformer technology, and have become a fan – this type of transducer with a pleated diaphragm, in this case made of polyester, potentially offers clarity and imaging without harshness and can provide detail while avoiding consequential listening fatigue. The amplifiers are – perhaps unusually when Class D has become so common in this type of product – Class A/B, delivering 50W for the high frequencies and 90W for the LF. Completing a tour of the front panel is a slot-shaped reflex port contributing to the speaker’s 42Hz-27kHz frequency response.

At the top of the rear are the audio inputs: analogue-only XLR (no latch on this, so care may be needed to ensure the plug isn’t accidentally pulled out), ¼” jack and phono/RCA. Next to these are the two DSP control switches: HF Trim and Acoustic Space. HF Trim adjusts the tweeter’s output by ±2dB – I left this in the ‘flat’ position – and Acoustic Space helps tailor low frequency response if there’s a wall behind the speaker by applying a low frequency shelving EQ below 200Hz; settings are 0dB, -2dB and -4dB, and in the Lowland Masters room -2dB gave the best result. Rounding off the rear panel’s features are a large metal heatsink for the amplifiers (I found this rang acoustically when tapped but couldn’t hear any effect during normal listening) and power input facilities.

In Use

Once set up on stands, I played my usual range of reference material through the review pair of FPX7s, and was immediately rewarded with a very usable presentation. The crossover point of the Fluid is 3.5kHz, and it was apparent that work has been done to ensure the transition between drivers is as seamless as possible – it’s within the vocal region and also the ear’s most sensitive area, and I’m pleased to report no obvious problems. Rock, dance music, jazz and pop all played predictably and well on this speaker, with the AMT providing its typically clear presentation – a nice firm feel from the woofer and the promised good phase performance of the array as a whole.

I recently mastered a new orchestral soundtrack for the groundbreaking 1927 silent film Napoléon, and was pleasantly surprised at what the FPX7s could do with it – the need for minor corrections made when I did the work was still audible when playing the unmastered version, and the speaker made a decent fist of handling the extremes of dynamic in the piece. In fact, acoustic music in general, which can be something of a loudspeaker torture test, came across well – another recent mastering through here, the album The Furthest Tree for acoustic guitar virtuoso Clive Carroll, spoke on all the right levels emotionally and sonically. My one comment would be that there’s a slight but noticeable forwardness in the midrange of the FPX7, but to me this manifests as a conscious design decision to zoom in a little on an important region rather than a vice.


Designing loudspeakers to a price point while retaining acceptable performance is a talent not granted to many, but it seems Kevin Zuccaro has it. I always appreciate an unfussy approach, keeping things as simple as they need but no simpler, and I can see the Fluid being the first of a line of speakers to further this particular take on the coaxial idea. The bottom line: if you’re in the market and recording and mixing either at home or in a commercial facility, the Fluid Audio FPX7 is definitely worthy of your attention.

Key Features

  • 7in composite cone, low-frequency driver
  • Air Motion Transformer (AMT) tweeter
  • Bi-amplified 140W Class A/B amplification
  • 42Hz-27kHz frequency response (+/- 3dB)
  • Tweeter high frequency trim control (+2, 0, -2dB)


Nigel Palmer has been a freelance sound engineer and producer for over 20 years. He runs his CD mastering business Lowland Masters from rural Essex.