Author Archives: Mark Craven

Mark Craven wrestles this beefy multichannel amplifier into place, and then gets drunk on power

Here’s something I wasn’t expecting. Musical Fidelity, the audio brand known for its high-end hi-fi products, and association with turntable maker Pro-Ject, which acquired the company in 2018, has launched a seven-channel power amplifier. And it’s a big old beast of an amp too.

Available now via UK distributor Henley Audio, the M6x 250.7 is the first of three multichannel amplifiers incoming from Musical Fidelity – apparently there are five-channel and 11-channel models, based around the same technology, due to launch. This begs the question of whether the manufacturer will also unleash a multichannel processor, but there’s no word on such a thing yet. Still, as I wrote in my recent review of the seven-channel Emotiva BasX A5 (HCC #335), multichannel power amps aren’t exactly common, so even if Musical Fidelity doesn’t add a partnering processor, I’m not going to grumble.

Backside Story

If any processor does arrive, it will no doubt offer a balanced output to match the M6x 250.7’s seven balanced inputs, on XLR connections, found on the rear panel. There’s also the option of an unbalanced connection via RCA. Musical Fidelity doesn’t, however, provide the usual switch to select between the two. Don’t connect both types at once, then…

Other back panel features include something else a little unusual – seven further RCA output terminals. These enable the input signal to be fed to the adjacent amplifier output, for bi-amping. There are also in/out triggers for system integration (with on/off switch), IEC socket and power button, and a bank of well-spaced gold-plated multi-way speaker terminals.

The front panel is, as expected, uncluttered. Musical Fidelity says it ‘gives you a clear understanding of what is going on with the amplifier,’ which basically means there are small LED status lights for each channel, and a standby button.

Those who believe the principle espoused in Jurassic Park of ‘if it’s heavy, it’s expensive’ might imagine the M6x 250.7 sells for more than £3,099, because it tips the scales at an impressive 32.5kg. Consideration should be given to this when deciding where to place it, as should its dimensions – this amplifier is slightly wider than standard at 45cm, as well as 43cm deep and nearly 20cm high. It sits on four chunky chrome-finish feet.

Because of its size, its presence will be felt unless you rack it away out of sight, but the all-metal chassis (available in either black or silver), with bevelled milled aluminium fascia, does at least look quite smart.

Quiet Please!

The amp’s weight is explained by Musical Fidelity’s use of Class A/B amplifier technology, and the presence of not one but two toroidal transformers. These are in-house ‘audiophile-grade’ Super Silent designs, also seen in the company’s stereo hardware including its M6x DAC (HCC #334), and, says Musical Fidelity, are a key part of the amp’s ‘high dynamic range and detailed soundstage’.

Beneath the pressed steel lid, the M6x 250.7 features a neat modular construction, with the seven individual power modules lurking behind the twin transformers. The audio circuit design follows the ‘same principles’ as other models in the brand’s upper-tier M6 series.

Each amp module gets it own side-mounted heat-sink, allowing Musical Fidelity to eschew any internal cooling fans that might whirr into action and spoil your enjoyment of a movie.

Mark Craven enjoys the highs and lows of a premium compact 5.1 system from American audio marque GoldenEar

US brand GoldenEar was the third loudspeaker company founded by famed designer Sandy Gross, following in the footsteps of Polk Audio and Definitive Technology. Gross has now left, but his parting gift is the £1,499-per-pair Bookshelf Reference X.

This moderately sized bookshelf (or standmount, although GoldenEar doesn’t sell any matching stands) is the last design to bear Gross’s input, and joins two other pre-existing smallscale models in the Bookshelf lineup – the Aon 2 (£899) and Aon 3 (£1,100). However, it doesn’t share much in common with those, instead being designed more as a baby brother to the brand’s high-end Triton Series floorstanders. In other words, it’s GoldenEar’s premium smallscale model, and ripe for deployment on both front and surround duty in a multichannel system where larger loudspeakers aren’t desired or possible.

Braced For High Velocity

The BRX’s aesthetic design is typical of the brand, which means it’s perhaps a bit of an acquired taste. The speaker is wider at the rear than the front, and its MDF enclosure is given a hand-rubbed piano black lacquer that looks swish but will show up finger prints. Curved magnetic grilles can be attached, although these sit on a protruding lower (plastic?) lip that looks a bit incongruous. Build quality is excellent, though, and the curved top to the cabinet is a nice touch.

Adding to the somewhat unusual look, when grilles are removed, is GoldenEar’s HVFR (High-Velocity Folded Ribbon) tweeter, which is the same drive unit that graces the manufacturer’s pricey (£11,000) Triton Reference model. This driver claims a reach up to 35kHz, which should make any break-up modes inaudible. It’s joined on the BRX by a 6in bass/mid driver with computer modelled cone geometry, also a trickle-down from GoldenEar’s Reference products.

Unusually, there’s more bass low-frequency potential here, as the left/right sides of the speaker house (grille-covered) 6.5in auxiliary radiators, in place of a more conventional bass-reflex cabinet design.

Superheroic Siblings?

Our system features BRX models fore and aft. For the centre, we’re using GoldenEar’s SuperCenter X (£799), the smallest of the brand’s dedicated centre speakers. Okay, I say small – it’s actually 50cm wide, the space necessary to fit a driver complement of two 5.25in bass/mids, one HVFR tweeter, and a 10in x 7in auxiliary radiator that sits up top and is again covered by a grille. The cabinet is again black, although not quite as glossy, and its shape is more of a match for the trapezoidal Aon models. So this system isn’t ideal for those who fuss about a uniform aesthetic.

Our system subwoofer is GoldenEar’s SuperSub X (£1,549), which carries on with the more-drivers-than-you-might-think vibe. Two 8in woofers, fed by a rated 1,400W ForceField onboard amp, are horizontally opposed, while top and bottom sit 10.5in x 9.5in radiators. All this is in pursuit of a claimed low-end trawl of 12Hz (albeit with no quoted roll-off).

The sub is cute enough, and also slightly trapezoidal. Rear panel connections and controls are set-and-forget (there are no preset EQs, for instance). One minor niggle is that it has a blue LED status light which I couldn’t work out how to dim. With lights-off viewing, the glow it placed on my side wall was sometimes distracting.

Whoever said the best things come in small packages likely hadn’t met this 2 x 15in, 92kg subwoofer, reckons Mark Craven – and the D215s is a brilliant blend of brains and brawn

Perlisten Audio certainly knows how to make an entrance. A new brand out of Wisconsin in the US, it debuted with its S Series loudspeaker range (HCC #331), which culminates in the £16,000 S7t floorstanders, and to avoid the trap of only appealing to music lovers, it delivered a range of subwoofers to match. The biggest of the bunch is the D215s, auditioned here.

And, yes, this woofer really is big. It’s certified THX Dominus for use in largescale home theatres, but that alone doesn’t necessitate its portly dimensions – Perlisten does, after all, sell smaller Dominus-flavoured subs. What also contributes to its size (approximately 80cm high and half a metre wide) is its dual 15in driver complement.

These carbon fibre woofers operate in a sealed, push-pull configuration – one front facing and the other firing into the D215s’ cavernous enclosure. Rated power is a monstrous 3,000W ‘short term RMS.’

On the inside is a Texas Instruments ‘floating point’ DSP engine, and an ARM processor. The latter monitors the amp power rails, input voltage and thermal characteristics, and handles fault detection and distortion limiting.

While the sub has the expected rear-panel in and outputs (on RCA and XLR connection) there’s no physical dial for crossover, phase or gain – setup is via either the sub’s top-panel LCD touchscreen, or more detailed Android/iOS app with full control over crossover, phase and trim, access to three preset EQs (THX, Large Room and Small Room), plus multiband parametric EQ. Distributor Karma AV says those who buy a D215s from a licensed dealer should expect them to offer to setup and EQ the sub, using a third-party measurement system such as REW.

Unlike some of Perlisten’s loudspeakers, the D215s is only available in a black finish. This is understandable, as I doubt there’d be much of a market for a glam piano white or walnut veneer version. However, a few design flourishes, included the curved edges of the front baffle, and Perlisten’s bronze-effect logo, means the D215s looks like home audio equipment and not something that’s been left behind by the festival PA crew.

It seems immaculately put together too. Both the front baffle and cabinet are made from HDF, reaching a thickness of 80mm at the front and 30mm elsewhere. Chunky horizontal and vertical bracing inside aims to keep it rigid and vibration-free. Positioning the sub might be a bit of a chore, because it’s so heavy, so unbox it as close to what you hope is the optimum position…

Gunning For Trouble

Chapter 9 in Sherlock Holmes: A Game of Shadows (4K Blu-ray) marks the appearance of the ironically named ‘Little Hansel’ artillery cannon. It’s a brilliant sequence, replete with director Guy Ritchie’s favoured slow-mo photography, and some bass-rich sound design that’s tailor-made for subwoofer lovers – even before the big gun makes its appearance.