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Reviewer: Marja Vanderloo & Henk Longbeard Boot
Source: Apple iPod Photo and EAC'd .wav files
Amplified Speaker: Avantgarde Acoustic Solo
Cables: Crystal Cable Piccolo iPod XLR; Crystal Cable CrystalPower
Review Component Retail: $8,940/pr for Solo, $994/pr for matching stand; starting at $399 for Crystal Cable Piccolo iPod; starting at $450 for CrystalPower Micro; starting at $399.99 for Apple iPod Photo 60GB; nothing for EAC freeware

Last January at CES 2005 in Las Vegas, USA importer Jim Smith was the proud host for the latest offspring of famed German hornspeaker firm Avantgarde Acoustic. Here the novel Meta Primo made its first public appearance [right]. Next to this awe-inspiring large horn system, a much smaller setup combined the smallest Avantgarde model called Solo with an iPod as source "just for fun" as Jim Smith grinned. This small setup was not only good-looking but also quite pleasant sounding. The placement within the room was not optimal and the use of the iPod's headphone socket to drive the Solo's built-in power amplifier outright sub-optimal. Nonetheless, the concept itself kept turning the windmills of our minds.
One of the main arguments for the Meta Primo's costly launch was space - or to be more accurate, the sore lack thereof in many homes. The largest Avantgarde loudspeakers occupy a fair amount of real estate just for placement. A pair of Trios with Basshorns is far too demanding for most spaces' square footage. Engineer Matthias Ruff's design brief thus stuffed the Trio/Basshorn system into a total footprint no larger than our Duos and the ambitious Meta Primo was born. This idea of compaction plus our Las Vegas experience with the iPod-cum-Solo formed the base for a personal project wherein we attempted to combine the most compact pieces of audio equipment without suffering any performance compromises. The resultant system was supposed to be very compact, highly musical and multi-functional. On top of that, it should also become a system that could be used as a secondary study or library rig where it would assist with concentrating on studies or writing, by playing back music at low levels without losing life and persuasiveness.


The iPod+Solo concept thus became our starting point. We contacted Avantgarde in Germany and explained our idea. Their gents were instantaneously in for it. Ditto for Apple Holland who had never been involved in a high-end audio review before. As for cabling, we contacted Crystal Cable who had just introduced a dedicated cable for the iPod in their Piccolo series of ultra-thin interconnects. We requested a Y-cable terminated with XLR connectors and a length of 2.5 meters for each leg of the Y. Within a few weeks, we received a shipping pallet from Avantgarde Acoustic with a pair of pearlescent white Solos, a small package from Apple Holland with a 60GB iPod Photo and a box with one of the thinnest cables we have ever worked with from Crystal Cable. To complete the setup, we used two mains cables of the same Dutch make.


Setup was easy and straightforward. With the two Solo horns to the left and right, the iPod Photo in its docking station ended up dead center.This docking station provides the lineout connectors and a multi-pin connector that is a USB, FireWire and power connector all in one. Using the lineout, the Crystal Piccolo Y-cable connected to both Solos by means of the XLR sockets. The system total added up to three components and four cables. Our idea of compactness began to manifest right in front of our eyes.

The Avantgarde Solo is a special loudspeaker. In essence, it's a two-way bass reflex system loaded by two spherical horns. The bass unit measures 11.8" and a 0.98" driver reproduces the mids and highs. The tweeter horn doubles as phase plug for the bass unit and is mounted in the middle of the woofer voice coil. The tweeter is thus solidly connected to the speaker's chassis and contrary to other dual-concentric designs, neither uses the woofer cone as part of its horn/ waveguide nor does it move to and fro atop the woofer. Here the tweeter horn is completely autonomous and not prone to interference effects from the woofer. Tapping on the tweeter horn reveals a massiveness not even found on the large horns of the top Avantgarde systems where the flares are composed of single-layer ABS. With the Solo horn tweeter, the flare goes back to the base again to form a solid double layer. This construction has the added advantage of a straight edge on the outside of the tweeter horn to make for an ideal phase plug. A flare like the tweeter horns of the other Avantgarde loudspeakers would cause all manner of break-up modes. The chosen solution even bestowed added extension to the woofer's upper frequency response.


That <12" woofer driver is equipped with a 3.93" voice coil, leaving the requisite central space for the tweeter housing. The voice coil operates within a massive 7.87" magnet of 19 lbs substance. The woofer cone is of a simple paper pulp type, light and rigid at the same time. This woofer is coupled to a horn a mere 2.75" short. For the lowest octaves, the woofer breathes through two rear-firing ports in a bass-reflex alignment. While playing, it is astounding to see the woofer's cone move up to 10mm outwards. The woofer's sensitivity is rated at 97dB. The shy-of-1" aluminium dome tweeter is of the compression type and, just like the woofer, equipped with an oversize 6.83 lbs magnet to arrive at a sensitivity of 102dB.


The speaker's enclosure is made from a polyurethane composite which, together with varying material thickness, makes for a really dead enclosure when you "knock on wood". Following the curvature of the outer horn rim, the entire loudspeaker has a very friendly appearance though the combined magnet weights of 26.5 lbs plus the internal amplifier add up to a total poundage of 66. To drive the transducers, each Solo is equipped with a 250-watt solid-state amplifier. The design of the Solo with its small horn loading the woofer does not, by itself, allow for bass extension to 30Hz. To achieve this, the amplifier is equipped with an equalizer that boosts the lower octave according to a preset curve.

The crossover used is -- just as so many Avantgarde concepts -- truly avantgarde. Technical maven Matthias Ruff has selected a simple coil for the bass driver and one capacitor for the tweeter. That's it, a passive shallow crossover. However, there's a little more to it than that. We already mentioned the 97dB sensitivity of the woofer and the 102dB for the tweeter. Without some attenuation of the high frequencies, tonal balance would be off-kilter. Instead of adding resistors to the tweeter circuit and thereby into the signal path, Herr Ruff came up with one of his infamous Matthias solutions. This patent-pending solution -- meaning no further information is available yet -- basically integrates crossover parts into the amplifier's feedback loop. The result is that the amplifier now sees two separate drivers and is aware of the two processed frequency ranges and can thus be preset to lessen the output power for the tweeter. The amplifier only accepts XLR connectors but the choice of input source is completely open to the user. Speaker-level signal from a power amplifier is just as welcome as an input from a preamplifier. For the latter scenario, the Solo is shipped with RCA-to-XLR adaptors.


At the back of the Solo, the cast-aluminium amplifier casing has several switches and attenuators. Power on/off can be remotely controlled via a 12-volt trigger. For use with an iPod setup like ours, such a trigger device can be obtained from Avantgarde. Depending on the situation, the power supply ground can be lifted to kill ground loop hum should it be present. A high-EQ switch helps to voice the Solo for certain situations. Next to flat/0, the switch can boost the treble by +3dB or cut it by -2dB. The Solo is often used in home cinema environments where the +3dB setting can be helpful to compensate for treble rolloff by having a Solo become as center speaker behind a projection screen. In bright modern rooms, the -2dB instead could be just the ticket. Extensive further voicing is possible with the low-EQ control. A higher setting adds more warmth to the tonal balance, albeit at the costs of losing some of the typical directness of a horn system. Some experimentation with the options here really pays off. The high-pass filter has an on/off switch and an attenuator to select the crossover frequency. The full-range setting with the switch in the off position completely bypasses the filter network and worked best for us. The last attenuator is the master gain or system volume. The only disadvantage of our chosen setup? The lack of a remote volume control. Using the lineout of the iPod prevents that. There is volume control when the headphone connection is used, however for remote control thereof, a third-party solution like an iJet, iDirect or naviPod becomes necessary.