Audio recensies tests

“Holland is a true electrostat country. It has surprisingly many manufacturers of electrostatic loudspeakers. Some enjoy a long-standing international reputation for high quality products. One of these manufacturers is Solosound.

Solosound has been around for many years. George Vermeulen, who died in the mid-nineties, founded the company in the seventies. In the following years, Solosound earned an excellent reputation among electrostatics lovers.

While numerous manufactures increasingly focused on large high-end types, Solosound rather concentrated on affordable types. Reliability has always been a key feature as well. Solosound has every reason to be proud of the large number of old-timer sets that are still playing after countless hours of faithful service.

“We still regularly receive old customers with models from the very beginning that require small repairs or modifications,” says Mark Huinder, Solosound’s managing director. “Usually, these customers can return home after just a brief visit to our factory.”

Solosound’s electrostatic loudspeakers have been put to market under the brand name Solostatic for many years. The current Solostatic portfolio comprises seven types.

Hifi Video Test tested the 102, one of the types of the 100 series. The 100 series is intended for the true electrostatics lover. The 102 is over one metre high and requires a separate sub woofer for the low range.

How low can they go?

This question always turns up in discussions about electrostatics. What you frequently hear is that small electrostatics underperform in the low ranges, whereas on the whole, everybody agrees that the high and mid-ranges are unparalleled in terms of definition and level of detail. But, as mentioned before, there is always discussion about the low ranges. Whether this is always fair, is hard to say, since this is largely a matter of taste. On the other hand, it is a well-known fact that using the electrostatic loudspeaker concept to create a constant, deep bass is not an easy thing to do.

Creating a fully balanced sound from the highest to the lowest tone ranges requires a large membrane. And there lies an important problem. Large electrostatic membranes are difficult to build. In addition, transmitting the signal to such membranes is not easy. Because an electrostatic loudspeaker is an open system, placing the system will be another challenge. With dynamic systems this is less critical.

Although Solosound has developed several fully electrostatic systems, they have always been in favour of hybride solutions. In hybride setups, dynamic speakers are used for the low ranges.”In practice, such setups usually work best,” Mark Huinder says. In the past, Solosound supplied comprehensive systems whose electrostats, sub woofers and cross-over electronics were all built in-house. “Nowadays there is ample supply of good quality active subs. We have very good experiences with Velodyne,” says Mark.

Solostatic 102

The 102 has attractive dimensions: over one metre high and 35 cms wide. The loudspeaker stands on an oval platform measuring 20 by 40 cms. The electrostatic pane of the 102 has a three-way structure. The pane consists of three segments with a genuine electrostatic point-source tweeter inside. “This helps us improve the radiation behaviour,” says Mark Huinder. Solosound uses a relatively low high tension level of 2.7 kilovolts. This has the advantage that you can expect less seepage problems. There is also less accumulation of dust. The high tension is internally generated and fed from a small network adapter. On the back side, there are four loudspeaker clamps for signal transmission. This suggests a bi-wiring ability, but that description is not quite accurate. The attached diagram shows the concept.

In the upper part the membrane is located that is driven from the step-up transformer. The upper two connections are directly connected with the transformer. The lower two connections run through a resistor network. If you use the lower two connections, the 102 draws less on your amp. If you only use the upper negative pole and the positive connection through the three resistors, the high range is slightly muted. Bi-wired connection is also possible, in which case you combine both functions, in a manner of speaking.

Listening

In the listening room at HVT I could run elaborate tests to see how the concepts described previously work in practice. During the tests, the 102 was connected to an Advance Acoustic MAP305 integrated amplifier and a Cambridge Audio Azur 640C CD player. According to the specifications, the 102 Solostatic has a -3dB point in the low range that does not reach beyond approx. 80 Hertz. Therefore, the really deep low requires a sub woofer, and for that purpose Solosound brought a Velodyne SPL R1000. Solosound themselves have very good experiences with Velodyne, but of course, you can also use other sub woofers. Right from the start you can hear that the Solostatic 102 is a genuine electrostat. The level of detail and definition in the mid, high and top high ranges are perfect. The sound picture is tranquil and clean, so you can distinguish the most subtle details. Any rough edges that might occur definitely originate from the source or the amplifier, or perhaps even from the recording process.

The wide positioning, which is characteristic of an electrostat in both the width and the depth, is fully present in the 102. The sound beautifully separates itself from the speakers. As a listener, you step straight into the concert hall. For example, in combination with the beautiful recordings on the new HVT sampler (Naim sampler 5), for example, you can hear this very well.

The Velodyne subwoofer really only takes care of the lowest tones. In most cases, you do not even notice it is doing anything at all. If you turn if off, however, you immediately hear the difference. Not using a sub is definitely not an option. The Solostatic/Velodyne combination works perfectly.

In general, the output of an electrostat is low, and the 102 is no exception. 85 dB is not very much, and therefore a good, robust amplifier is an absolute requirement. The Advance Acoustic works fine, but a heavier amp is a good option. A heavier amp, however, does not change anything about the dynamic performance of the 102, which is characteristic of an electrostat and this means modest and very tranquil. Deep booming basses or heartrending mid-ranges are not to be expected from the 102. However, this is amply compensated for by the superb definition and level of detail.

Conclusion

Electrostats are not the easiest loudspeakers. The Solostatic 102, however, performs way above the average at an excellent price. Dynamic speakers are still no match for electrostats in terms of definition and level of detail. On the other hand, an electrostat has its dynamic limitations and the 102 is no exception. I cannot determine on your behalf whether this is a problem. The best thing you can do is go and listen for yourself. There is a good chance that you decide in favour of the 102 because of its excellent definition and level of detail in the high and mid-ranges”.

Specifications:

Brand: Solosound
Type: Solostatic
System: Electrostat three way membrane
Impedance: Nominally 4 or 8 ohm (see text)
Sensitivity: 85 dB/1m/1W
Recommended power for amplifier: 50 to 200 Watt at 4 ohm
Bi-wiring: Yes (see text)
High tension: 2.7 kilovolts
Supply: 14 VAC (through adapter)
Dimensions: 118 x 36.5 x 6 cms
Weight: 20 kg.

HVT: Test Solostatic 102 by Marnix Bosman June 2007