Mackie HDA & HD1801

Mackie have added to their popular range of active PA speakers with this modular line-array system. Does it deliver the goods?

Mackie have been major players in the portable live-sound market for a few years now, and it's unusual to visit too many venues without coming across some of their gear. I've used and owned Mackie mixers and speakers of various types, and in my experience, their range of two-way and three-way speakers is broad enough to meet the requirements of most smaller venues.

When it comes to larger live-sound opportunities, though, there's a limit to how much output can be coaxed from even the more upmarket traditional 'point and shoot' speakers. These are typically engineered to produce a 90 x 60-degree (horizontal by vertical) high-frequency dispersion, and therefore cannot easily be used in multiples without significant pattern interference issues arising. Side-by-side arrays do work, provided they are splayed wide enough to avoid interference, but what we're seeking is an increase in forward power and projection, not extra output in unwanted directions — like up to the roof and reflecting off every surface in sight!

The favoured solution is to use a line array. These are multi-speaker systems which employ a combination of constructive and destructive interference to produce tightly controlled vertical coverage and focus acoustic energy to the front and sides, with a relatively sharp cutoff angle between individual array components. For an owner-operator or band, the issue with moving up to array systems has generally been one of cost (and possibly flexibility, if you only have one rig), and that's where Mackie's HDA speakers come in, offering true line-array performance at an attractive price. The HDA system has been developed in collaboration with one of Mackie's sister companies, Eastern Acoustic Works (EAW), who specialise in large-scale touring PA systems and provided the DSP speaker-management expertise that makes the HDA design possible.

For this review, I had the opportunity to take out a Mackie HDA/HD1801 rig and use it at an outdoor live event, where my normal gear would have been struggling to provide enough coverage over the large audience area.

Going Array

The only controls on the HDA are a three-way array-voicing switch and a button for extinguishing the front-panel power LED. Power comes in via a Neutrik PowerCon socket, and the audio input and link output are present on XLRs.

The HDA is a self-powered, two-way speaker that can be pole- or stand-mounted, flown or ground-stacked as required, using the appropriate hardware. Each individual HDA speaker incorporates dual power amps rated at 500W RMS for the low-frequency section and 100W RMS for the highs. Material below the 2kHz crossover frequency is handled by a single front-mounted 12-inch driver, and the high end is delivered courtesy of two Beyma compression drivers coupled to a vertical-slot waveguide assembly. The HDA is the only product in the Mackie line that uses these particular drivers, but I believe that they are also found in some EAW products. The maximum SPL available from a single HDA unit is specified as 124dB (pink noise, measured at 1m before limiting). However, the theoretical maximum, based on available amplifier power and driver efficiency, is 10dB above this, from which I assume that the limiter is set conservatively.

The amp section consists of two Class-D circuits, which are cooled by convection thanks to a large, finned heatsink on the rear panel, and some airflow slots at each side. Under normal conditions these arrangements are more than adequate (after a whole afternoon and evening's outdoor use in fair weather the heatsinks were only just warm), but there is an emergency fan inside which will operate if abnormal thermal conditions are detected.

The control panel is very simple, and provides XLR input and link output connectors, a switch to turn off the little Mackie trademark blue LED on the front, and an Array Mode switch. This optimises the internal DSP according to how many units are in your array, and has three different settings, marked '1-2', '3-4' and 'Long Throw'. The first two settings correspond with the number of HDA speakers in a rig, and the last setting increases the high-frequency output to compensate for HF loss over long distances. There is no input level control, so system level is controlled entirely by the desk or whatever is sending signal to the HDA input.

Construction

The HD1801's rear panel houses the input connectors, and both full-range and high-pass-filtered outputs. The sub's level can be adjusted via a rotary control, and a switch inverts the output polarity.

The HDA enclosure is made from 15mm birch plywood and is finished in Mackie's usual black paint finish, which I think is attractive and hard-wearing; I've used older Mackie speakers for many years and the finish has stood up well in that time, and is easily touched up with a bit of satin black plaint if needs be. The black powder-coated steel grille covers the entire front surface (which is good from a driver-protection point of view), seems strong enough to withstand rough handling, and makes for an attractive and understated overall appearance. Being array boxes, the HDAs have built-in locking bars so that they can be coupled together in a constant-curvature array, and I'm pleased to say that these lock the units firmly together and are really easy to use. Apart from a difference in angle, this hardware is virtually identical to that used on the high-end EAW JFL series, and on the Mackie web site there's a link to a little video animation illustrating its operation. A flybar yoke is available as an optional accessory for manoeuvering a built array of coupled units, and each HDA has four individual rigging points built in too.

Inside, the two Beyma compression drivers are mounted one above the other. Their acoustic output is combined and delivered by means of a waveguide that gives them 20 degrees vertical coverage. This waveguide is constructed of two thin wooden plates sandwiched together, resulting in a narrow vertical aperture that is hidden behind, and protected by, the front grille. The use of this simplified structure is made possible by the HD processing, which is a key element in the the HDA's performance at this relatively low price — more of which later.

The single 12-inch driver is a Celestion product made to an EAW design, and has a neodymium magnet assembly which keeps the weight down and the efficiency high. As the HF drivers are self-contained units, the whole internal cabinet volume is available for the woofer, with two tubed ports on the front baffle.

The amp module contains a power supply board, a main amp board (which contains both LF and HF amps), and a separate input/DSP board. The internal components are technically field-serviceable: the amp module is completely self-contained and only requires a screwdriver to remove and refit, and the woofer can be swapped if the front grille is removed. When I asked the Mackie gurus they did say that the HF drivers require a bit more work to swap out, but that as far as they knew there hadn't been any failures yet, so no-one's had to do it: a good sign!

Tuning Up

The HDA's mounting hardware is based on that used by EAW, and it allows multiple HDA boxes to be securely locked together.

The HDA design sounds simple enough, and in operational terms it certainly is, but there's a lot of signal processing involved to deliver the required level of performance and protection, especially concerning the area of the HF waveguide. This is where the experts at EAW have made critical contributions to the HDA design, as a product of this nature cannot simply be a matter of bolting together some expensive components and expecting it to perform well. There are so many acoustical and physical issues around the management of reflections, phasing and so on that a major programme of design, measurement and testing is the only way to achieve results.

When all the requirements, including size and price, are taken into account then every portable live-sound speaker is, to some extent, a design compromise. Here's where the magic wand of digital signal processing is carefully waved so that the desired performance can be approached within the overall limitations of the drivers and enclosure. Simply put, what the EAW team have done is to tune the signal processing to address any undesirable acoustic behaviour, by applying various DSP corrections specifically for this product (ie. this amplifier, these drivers and this enclosure), so that the whole thing performs at its best. Extensive field testing has also been carried out, and again the processing — incorporating fine adjustments fed back from live tests — is the key technological factor in producing the overall results. You can read more detailed information about the processing in HDA speakers at www.mackie.com/products/hdseries/pdf/hd_explained.pdf.

A Walk In The Park

With its wide horizontal dispersion, the HDA array proved a highly capable system at this outdoor event.

I had at my disposal four HDA array boxes and a pair of HD1801 active subwoofers, which are the recommended subs for a HDA-based system (you can read more about them in the box). I was going to use the system at an outdoor event where the audience of 400-500 would be spread over quite a large area: roughly 80 metres wide by about 60 metres front-to-back. This charity event was one of those 'picnic in the park' type affairs, held at the home of a major UK VIP and featuring three acts using mainly acoustic instruments (including piano) and vocals. The host was keen that the audience should be able to spread throughout the park and still hear the performance no matter what grassy spot they chose, so the HDA system seemed to fit the requirement perfectly. For a number of reasons, I found myself loading the van having not even had time to unpack the HDAs from their shipping boxes, so I did feel that I was taking Mackie's quality control very much on trust!

I positioned the HD1801 subs on the grass area in front of the stage and levelled them up with some thick plastic shims, then two of us mounted the HDA units on a pole using the subwoofer as a base. There are two pole-mount sockets: one at the rear for straight-ahead use, and one at the front for a downward tilt. Using the former gave a perfect angle for the lower HDA to fire into the front section of the audience, and locking the second box on top took only a few seconds — the coupling mechanism is very easy to use with enough tolerance and quality manufacturing in the metalwork to ensure an easy but secure fit. The rubber strips on the bottom of one HDA locate into shallow grooves on top of the one below for extra security. The generous handles made lifting and carrying the HDAs an easy matter, and the main speakers were all in place about 10 minutes after we had unloaded the gear.

Powering Up

The HDAs are equipped with Neutrik PowerCon mains connectors and also have a power link output, so I needed to run only one power lead up to each pair of speakers, whereupon the supplied link cable neatly powered up the second unit. In common with many other units designed for flying, the HDA doesn't have a power on/off switch; this means it's impossible to leave one accidentally switched off and discover your error only once the array has been hoisted aloft, though the PowerCon connector can be turned to provide a switching action. It's worth being careful with your connection sequence, though, as the speakers will be turned on and at 'full gain' as soon as they are connected to mains power, and good practice dictates that this really needs to be the final action in the setting-up process.

I decided to let the DSP do its work, so for the purposes of this test I dispensed with all of my usual outboard gear, patched the main left/right bus straight to the snake returns and disabled all the output processing on the desk. I ran the returns straight into the HD1801 subs, then used their high-pass outputs to feed the HDAs, which were all set to position '1-2' as there were only two speakers per side. In the absence of an input trim control on the HDAs, I sent a low-level music signal to the system and increased the sub level until the balance sounded about right, and used that as my starting point. I did find it a bit strange not being able to trim the input at the amp, but unless the mixer isn't putting out a 'standard' signal level then there shouldn't be any gain-structure issues.

Listening In

So, with recorded music playing through the system and all the desk EQ set flat I went for a walk around the park to listen, and my initial impression was that the HDA/HD1801 system sounded very well balanced, clear and smooth. It had a natural warmth and fullness in the mid- range and a lovely clarity in the vocal range, which was maintained right up to the highest levels I dared use given the occasion.

Many of my outdoor live-sound jobs land (in terms of coverage and level requirements) right on the boundary between needing traditional two- or three-way speakers and small line arrays, and I generally go with 'point and shoot' boxes as they have a nice, comforting mid-range solidity — but I immediately liked the sound of the HDA rig and didn't find it harsh or in need of any serious EQ work.

I experimented with the array settings, and found that the recommended configuration worked best overall, but there is the option to tweak the response if needed. In terms of coverage, intelligibility was maintained well to the sides: my mix position was well offset to stage right, and it was pleasing not to have to keep walking across to check what the 'real' sound was like. The bass/mid/high balance didn't change much when listening at various positions between 20m and 50m from the stage, while the overall system level was easily more than adequate for the venue — and could, according to several earwitness accounts, be clearly heard in the two neighbouring villages.

When it came to the three soundchecks I started liking the HDA system even more, as they were just about the easiest checks I've ever done. True, we were working in a good outdoor space with nothing nearby enough to cause major problems, but the performers were more-than-usually critical, and the venue owner was very focused on having everything 'just right' for the invited audience.

I had begun the afternoon with a slight worry that the two HD1801 subs wouldn't keep up with the HDA top boxes, but they performed very nicely and provided a good, deep, solid and always clean foundation. Towards the end of the last band's performance I was pushing the levels quite hard with plenty of yellow segments lit on the desk's main output meters, but the output from the HDAs remained clean and clear — one guest came over and remarked that it sounded just like a giant hi-fi, and I couldn't really disagree.

At the end of the night the HDA boxes were quick and easy to unclip and pack away, and at less than 27kg in a modest-sized package they don't fall into the dreaded 'late-night lift' category, where the whole crew are pretending to be busy doing anything rather that tackle the main speakers. During the setup, soundchecks, performance and afterwards I had received nothing but enthusiastic and wholly positive comments from people (both performers and audience members) about the sound, and if I could have kept the HDA/HD1801 rig for another month I'd definitely have used it on several more gigs, no question.

In A Nutshell

In employing digital processing to create a great-sounding yet affordable line array, Mackie have really come up with a product that goes beyond the capabilities of their most powerful 15-inch three-way speakers. These should appeal to anyone who often wishes they could squeeze that bit more from their rig at those slightly larger venues or outdoors, but for whom the cost and complexity involved in moving up to a decent array solution has always been just too big a step. For dedicated Mackie users the HDA represents an ideal way of moving up a gear, yet its scalable nature means it has the flexibility needed by users who only want to own one system for a variety of applications.

I don't think Mackie regard the HDA as a simplified array unit, rather as a natural progression from their other portable live-sound products. An easily transportable set of four HDAs plus a pair of HD1801 subs would cope with just about any medium-sized gig, indoors and out, installed or portable, and the price makes such a system tempting indeed.