From the makers of practically the industry standard FOH desk, and some heavyweight pro power amps too, Yamaha's powered mixer should prove a strong contender. PAUL WHITE checks out the new EMX3500.

Over the past couple of years, combined mixer amplifiers have gained a respectability never previously afforded them. This is largely due to the efforts of companies such as Soundcraft and Yamaha who have introduced properly designed and engineered packages, rather than simply shoe-horning a couple of power amps into an existing mixer design. Over the same period, we've seen the introduction of integrated digital effects, making the powered mixer simple to connect up and simple to use with no need for outboard equipment. Indeed, all you need is a couple of full-range speaker cabinets, a few mics, and you're up and working.

Of course, there's a downside to everything, and putting the power amps in the mixer means that the further the mixer is from the stage, the longer the speaker cables need to be. Long speaker cables inevitably equate to power loss, so being realistic, powered mixers are best suited to applications where the band either do their own mixing from the stage or for small venues where the mixer is relatively close to the stage. For medium sized gigs, there is no reason not to add an external power amp and further speakers, so the fact that you have limited amplifier power in the mixer itself isn't as restricting as it might at first appear.

Yamaha's new EMX3500 is without doubt the most straightforward powered mixer I've come across — which is just as well considering the manual wasn't available at the time of review. The mixer section is a conventional 16:2 design with mic/line switching on every channel, and this is complemented by a stereo nine-band graphic equaliser and a digital effects section (a 12-channel version is also available). Powering the EMX3500 are two fan cooled 350 Watt (into 4 Ohms) power amplifiers, and all the connections are at the rear of the console's top panel for easy wiring up. Two sets of speaker jacks are fitted, allowing the use of one pair of 4 Ohm cabs or two pairs of 8 Ohm cabs. Although I don't really feel comfortable with jacks as speaker connectors when any degree of power is involved, they seem to work well enough on this system.

You probably know, but I'll say it anyway, that instrument leads are not suitable for loudspeaker connection, because the conductors are too resistive to carry the power efficiently. You should always use heavy-duty twin speaker cable, and it's a good idea to have some kind of visual identification to prevent these being mixed up with guitar leads and suchlike. For this kind of power, orange high current power tool cable is adequate, providing the cable lengths are kept to under about ten metres.

While the mixer is designed to be simple to use, lifting it isn't so easy. The heavy, all-steel construction and the physical width of the console makes this a two-person lift, if you aren't to risk back injury. Although I appreciate both the strength and the uncluttered layout, I think that a smaller, lighter package might have been more attractive for the band on the move.

THE TOUR

Each of the 16 input channels is identical, with switchable jack or balanced XLR inputs and globally switchable phantom power for those using active DI boxes or capacitor microphones. It is quite safe to use dynamic mics with a console that has phantom power applied, providing the mics are wired for balanced operation (as mics with XLR output connectors invariably are). A 20dB pad reduces the gain of either input socket by 20dB, and the practical outcome of this is that both the jack and XLR inputs can accommodate both mic and line level signals. The XLR input (A) accepts professional low impedance mics or low impedance line signals, while the jack (B) input accepts instrument level line signals or unbalanced microphones. A green LED adjacent to the input shows that a healthy signal level is being received and a red LED warns of imminent clipping.

"... the Yamaha EMX3500 does everything you'd sensibly need it to do, and it does it well."

The input gain control should be adjusted so that the red LED flashes on signal peaks, then it should be backed off slightly until the red LED no longer flashes. By doing this, the mixer channel gain structure is optimised so the mixer will be running as quietly as possible.

A TRS jack provides an insert point for additional effects or signal processors, and there is also an 80Hz low cut switch to prevent unwanted bass sounds getting into vocal mics. Three bands of equalisation are provided, and the mid control may be swept in frequency between 250Hz and 5kHz. All three bands provide up to 15dB of cut or boost, and although there's no EQ bypass button, the cut/boost controls are centre-detented, making it easy to find the 'flat' position.

Moving on down, there is a single pre-fade Monitor send for feeding a foldback system. A nice touch is the provision of two Monitor outputs, each with their own level control. Although these always carry the same signal, at least the mix engineer can retain control over the levels of two separate foldback systems, and because most small foldback systems are run from a two-channel power amplifier, this is a very practical arrangement.

There are two post-fade effects sends, the second being routed to the internal effects processor. The effects processor, however, may be turned off, and there are sockets for connecting an external unit to this send. Plugging in an external unit doesn't disable the internal effects, so by using the internal effects' bypass switch, you can use the internal effects, an external effect or even both at once. Pan operates in the usual way. There is a channel On button, which allows unused channels to be switched off. 70mm travel faders are used to control the channel levels, the two effects send levels, and the stereo mix output level.

"... a great sounding, high performance powered mixer that's unsurpassed for ease of use."

MASTER PLAN

Some mixers have very confusing master sections, but the EMX35OO makes things very easy. Beneath the twin moving coil VU meters are the effects section, the graphic equaliser, a few knobs relating to aux, monitor and tape levels, and the level faders.

The effects section is based on 15 effects types — these are listed on the front panel — with amber LEDs indicating which is active. A peak LED shows if the effects section is being overloaded, and a blue On button brings the effects in or out of the mix. To select an effect, all that is needed is to turn the Program knob until the yellow LED lights up next to the effects type you want. You can then change the main effects parameters (usually delay or reverb decay time), by turning the Parameter knob. The current parameter value is shown in the 3-digit LED window. When you change a parameter, it stays changed, even if you switch to another effect or power down the mixer. Next time you switch on, you get back the effect you were last using with the modified parameter still intact. A recessed reset button allows the parameters to be restored to the factory defaults if required.

Graphic equalisers are invaluable in helping to compensate for room acoustics and for pulling back frequencies that are particularly prone to feedback. To make operation simple, Yamaha have used one set of faders to control both channels, so you don't have to try to move two faders at once. There is plus or minus 12dB of range at one octave intervals between 63Hz and 16kHz. Although this doesn't offer the same precision as a 30-band, third-octave equaliser, it is still reasonably effective as well as being a lot easier to set up. Master insert points are provided both pre and post EQ. As the console has no dedicated stereo output to feed additional power amplifiers, it would be possible to take a feed from here. However, it would have been much more sensible to provide a main stereo output on balanced XLRs, on the basis that all decent power amps are balanced.

Unbalanced mix outputs are also available on phonos for feeding a tape recorder, with a further pair of phones to accept a tape return for playback. Level controls are provided for both tape input and tape return, but if you forget to turn down the tape return level when recording, you create a feedback path through the tape machine. Perhaps a record/replay monitor switch would have been a practical way of preventing this by muting the tape returns during recording and the tape sends when playing tapes.

Separate level controls are provided for each of the two stereo effects returns, and a further pair of knobs makes it possible to add any amount of either effect to the monitor mix. Separate controls are provided for the two monitor output jacks, and there are two CD inputs with a button to switch between them and an overall level control. The selected CD input is added to the main mix, ostensibly making it suitable for feeding in backing tapes or CDs. However, there is no way to feed the CD input to the monitors, so for performance involving backing tapes where there's a need to monitor the backing (in most cases I would have thought), you'll need to feed the backing into the console via two of the input channels.

Finally comes the phones level control and the phantom power slide switch with red Phantom status LED.

"... wonderfully accessible and supremely predictable in operation..."

USABILITY

Leaving aside for the moment the physical grief of even getting this mixer out of its cardboard box, let alone up the unlit, ice covered steps of the three storey fire escape at the back of the local British Legion club, the EMX3500 is a doddle to use, even for those who've had little previous experience of mixers. The generous panel size means all the controls are nicely spread out, and to simplify navigation, there's clear legending, reinforced by colour-coded knob caps.

A perennial problem with mixers is where to put the connectors. Put them at the back and they're hard to get at; put them on top and they look a mess. Yamaha have compromised by putting all the connectors (other than the phones jack) on a rear-sloping panel on top of the meter section. All the connectors are quarter-inch jacks, other than the XLR mic inputs and phono tape connections. Less satisfactory is the captive mains lead. Given the weight of this console, the cable could easily get damaged while getting the mixer in and out of its flightcase.

The ease of use philosophy carries through to the effects section and to the graphic EQ, the latter sounding surprisingly musical if used sensibly. The channel EQ is also very effective in a workmanlike way, with adequate range and a suitably assertive mid-range. If the EQ is used in moderation, it actually sounds very musical, but if you start to pile on too much upper mid, the sound becomes a little gritty. This is true of many small console EQs, but in reality, you should rarely need to use more than 2 or 3dB of mid-range boost. Ideally, you should use the graphic EQ to get the PA sounding reasonable, with the channel EQs set flat, then just use the channel EQs to finetune individual sounds rather than attempt major surgery with them.

Jumping back a moment to the effects, these are mainly reverbs, delays or a mixture of the two, but there are a couple of special treatments, including gated reverb and chorus detuning. Qualitatively, these are clean and representative in quality of what you'd expect from a reputable budget effects unit — the combined reverb/delay patches are particularly flattering on vocals. I don't know which Yamaha effects engine is used, but the choice of presets and the ability to tweak one key parameter per patch covers most eventualities. I particularly like the way parameter changes are saved without having to use any kind of save routine, and also the simple way you can navigate through all 15 presets by following the yellow LEDs.

Yamaha have a strong reputation in the power amp field, so it is no surprise that this part of the package behaves faultlessly — even the dual fans are quieter than those used in most fan-cooled studio equipment. If there is an omission here, it is that no form of power amp clipping indication is provided, and because moving coil VU meters are used to monitor the output level, you really have little idea what the peaks are doing. Other than that, the much used term, 'plug and play', seems apposite.

HOW WAS IT?

Yamaha have succeeded in building a great sounding, high performance powered mixer that's unsurpassed for ease of use. There are, in my opinion, minor design flaws in the lack of balanced outs for feeding further power amps, the lack of monitoring on the CD input, and the lack of a proper output peak indicator, but what is provided is wonderfully accessible and supremely predictable in operation. One point I'd like to raise is that most powered mixer manufacturers seem reluctant to fit limiters between their mixer and power amp sections, yet overdriving loudspeakers is a major cause of failure, especially of high frequency drivers in passive systems. Perhaps potential purchasers should raise this issue when enquiring about new equipment?

Whether the tank-like quality of construction is a pro or a con depends on who has to carry the thing, but there's no arguing that the EMX3500 is built to last. Yamaha have tried to help out by creating a lifting handle on the underside of the mixer end cheeks, but they are just too far apart for one person to lift safely. There is one advantage however — it is heavy enough to deter opportunistic thieves when you're packing up after a gig!

If you're in the market for a powered mixer, there are now quite a few to choose from, all offering a slightly different slant on features and packaging. Some offer more features than this, but being realistic, the Yamaha EMX3500 does everything you'd sensibly need it to do, and it does it well.