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MJ Acoustics Pro 100 - Issue 12 - June 2002

 

Following on from last issue's glowing report of the Pro 50 subwoofer, MJ Acoustics has hit an admirable new low with the Pro 100 sub.

An elongated version of its predecessor, the Pro 100 is twice the size of the Pro 50, complete with twin, downward-firing 8" drivers, providing arguably a greater bass impact than two combined Pro 50 subs. The Pro 100 shares the same classy, smooth design, and for a measly £100 extra you could opt for the sumptuous cherry wood veneer finish for a look that practically oozes luxury.

The two subs house a similar set of connections, along with the corresponding gain, phase and frequency controls. The Pro 100 has a 100w DC-coupled MOSFET amplifier (twice that of the Pro 50) to provide the power, whilst the Automatic Speaker Protection ensures that when you push the sub to its limits, the input is instantly reduced to avoid clipping. The performance isn't compromised though, as this only kicks in when the amplifier exceeds its dynamic range.

Across the whole audio range, the Pro 100 turns the growl of a speeding car into the roaring impact of a jet turbine. The low-level sounds are handled with sufficient subtlety but it's with the guns and bombs mayhem of the Hollywood blockbuster that the Pro 100 really comes into its own. We've seen it many times with many speakers, but rarely has each explosion in T2 felt closer or more realistic. Even in scenes where the impact isn't so heavy, the Pro 100 adds an extra dimension.

The £600 price tag mat be a little discouraging for many - twice the impact also comes at twice the price of the £299 Pro 50 - and the size and strength of the Pro 100's output is far less suited to the smaller room. However, if you do have the space and more than a few quid to spare, this sub makes sure that every thump you feel has the punch of Mike Tyson and the smooth style of Mohammed Ali.

If you want the best bass, buy it now.

FINAL VERDICT
Ease of use:  *****
Looks:              ****
Features:         ****
Sound:           *****
Value:              ****

Overall:  
An almost flawless performance. Although the price may discourage some, the quality is well worth splashing out for.

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MJ sub loves to make music
MJ Acoustics Pro 100 - April edition 2002
Subwoofer from £599

For - Superb bass weight from what is still a very compact cabinet.
Against - Pro 50 may be better in very small rooms; that's all.
Verdict - The Pro 100 is able to deliver a superbly deft punch along with excellent extension.

We loved MJ Acoustics' Pro 50 subwoofer when we first heard it, and this larger model is sort of like two Pro 50's in one box, packing twin 20cm long-throw dual-magnet bass drivers and a 100w amplifier - as against one driver and a 50w amp in the Pro 50.

The amp itself actually develops 180w peak, and the usual controls - seperate gain for the high and low-level inputs, phase continuously adjustable from normal to full 180° reverse, and crossover roll-off from 40 to 240Hz - are provided. The drivers fire downward, and the cabinet is available in black paint at £599, or as here in a choice of wood veneers at £699.

With its high level inputs connected across the main speaker terminals of a stereo amp, the Pro 100 performs that usual subwoofer trick of not just extending the bass, but also freeing up the midband and treble. That's very much the case in combination with good small speakers such as the Mission 780's, with everything from thundering dance tracks to chamber music benefiting. Take the extra bass for granted: what's more impressive is that the subwoofer seems to make instruments with little bass content in their tonal range sound so much more real.

Fed at line level from an AV processor, and with the bass filtering thus under external control, the Pro 100 puts in an impressive performance, whether with the superb DTS remaster of Close Encounter Of The Third Kind, or the battle sequences in Pearl Harbor. But its low-end clout is also highly musical, as is clear with Moulin Rouge.

Yes, if you have a very small room, the Pro 100 might drive the air within it a bit too hard, and the Pro 50 would perhaps be more suitable. Otherwise we have no reservations.

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MJ Acoustics Pro 100 - March 2002
A step-up subwoofer for even better bass

Based on the little Pro 50 subwoofer, can the twin-driver Pro 100
from MJ Acoustics win over Andrew Everard?
Regular readers of these pages will recall James Vesey's review of the MJ Acoustics Pro 50 subwoofer in the December issue. To say that he was somewhat taken with it is something of an understatement. Indeed he, and I, liked it so much that this small subwoofer is now a part of my reference system.

So it was with interest that I received the latest model from MJ, the Pro l00. This is a development of the little Pro 50, using the same 20cm long-throw driver with a heavy-duty chassis and double magnet. But this time two of these units are used in a single cabinet for greater bass impact and extension. It's one of two ways to get bigger bass from a system such as this, the other being to employ a truly huge single driver. The trouble is, big drive units mean big enclosures, and are also hard to control. They need lots of amplifier 'grip' to stop and start their relatively high mass.

Such bass is fine for big action films, where the requirement is to shift air on a massive scale. The sound of an explosion is an impact followed by a rumbling decay, which -if one were to be cynical could be said to be the forte of big, loosely-controlled sub-bass drivers! For music, however, the demands are somewhat different. The need for the drive unit to keep pace with what's being played is every bit as important as its ability to move enough air to deliver realistic low frequencies.

That's clearly a good part of the thinking behind the Pro l00, not that its amplifier lacks grip. In this case -and as the model number suggests -it's a 100W DC-coupled MOSFET device, capable of 180W peak, and monitored by an Automatic Speaker Protection system. This keeps an electronic eye on the amp's power supply lines and, when they approach their limit, reduces the input to avoid clipping and thus potential speaker damage.

The Pro100 is bigger than its junior sibling -as you'd expect, given the need to accommodate that extra driver -but otherwise is very similar. At high-level, the inputs are (from an amplifier's speaker terminals) on a single Neutrik Speakon connector. At preamp level, they use a pair of phono sockets. Both inputs have their own level adjustments.

There are also controls for phase and the upper frequency, at which the subwoofer rolls off. The latter is set to the '240Hz LFE' position for use with a preamplifier or processor with its own bass filtering, as is usual in home cinema equipment. However, when the sub is connected in parallel with stereo speakers for music reproduction, it's possible to use this control to give a seamless integration with the stereo pair.

As has been said many times before -but it bears repeating the best set-up for a subwoofer used for playing music is that point at which you're just unable to hear the unit working. The Pro l00's relatively simple controls make it easy to achieve the correct set-up, and are sufficiently subtle in their action to allow plenty of fiddling to get the right balance.

Performance

The Pro l00 looks smart in its cherry veneer -a £l00 optional extra, with the standard black satin version costing £599 -and, although larger than the Pro 50, isn't exactly hard to position. And of course, once it's dialled in correctly, it can be placed almost anywhere, low bass being non-directional.

It also delivers better weight and authority than the smaller model, (which itself is pretty respectable in this respect), and is just as impressive with music in stereo from CD as it is when used with source material having a dedicated LFE content. Even when used with large speakers, it's surprising just how much it adds to the scale of the music. The extra weight in the low end has a liberating effect across the frequency range, making soundstage pictures seem bigger and more open. There's greater depth and even a hint of better imaging, aided no end by the fact that the sound is more real.

It's not only with big orchestral and choral works that the subwoofer brings benefits. Even solo piano gains from the added authority in the bass, while the low-frequency harmonics bring greater scope to the timbre of a string quartet. True, the sub isn't actually handling any of the direct sound of the instruments -rolling off at 240Hz maximum, it wouldn't -but switching it on and off makes it clear that it is contributing something to the overall life of the presentation.

Switch to film music from DVD, where there is a dedicated LFE channel, and the Pro 100 handles the bass stuff with complete composure. If those big, bold, action blockbusters are part of your viewing and listening, the subwoofer, fed from TAG McLaren Audio's excellent AV32R processor, provides deft reinforcement rather than disconnected thumps and rumbles.

With the Pro 100, the battle scenes in Gladiator were truly bone-jarring. At the same time, the excellent heroic music found extra life and impact. This subwoofer may even encourage you to listen to the occasional score separately from the film. A striking example is the stunningly recorded music (by James Homer) for Edward Zwick's 1989 film Glory, with its ethereal choir, bells and big military percussion.

However, the Pro l00 is just as good with the likes of the recent disc of Verdi's Falstaff (BBC) from the Royal Opera House, which has superb Dolby Digital 5.1 sound. Without the subwoofer in harness it's impressive. With it, the sound has a weight and power that's hard to resist, with excellent orchestral weight and increased intelligibility in the voices.

The same is true with TDK's excellent music DVDs, which are setting the standard when it comes to sound quality on such releases. So few classical DVDs actually have real 5.1 sound on them -many from the big labels prove to be little more than PCM two-channel- but a system with a good subwoofer makes the most of the immaculate engineering TDK has done on its releases.

This is a very fine subwoofer by any standard, and while the £299 Pro 50 will be sufficient for the needs of many users -especially those with small listening/viewing rooms -the added authority of the Pro 100 more than justifies the extra cost if you have the space to use it. I recommend it without reservation.