by Sergey Samarin
04/24/2007 | 05:57 PM
Today we are going to invite you to get acquainted with a very interesting multimedia acoustic stereo system – Swans S200A from HiVi Company. It is especially interesting to take a look at because it is positioned as a High-End solution and is targeted for PC users!
Before we start discussing this interesting product let me say a few words about HiVi Company. It is very popular in the US market and its products are beloved by the most pretentious user group: music lovers. Broad model range and diversity of products that are presented on the company’s official web-site give us every reason to believe that HiVi has very solid production base. And this is absolutely true. If you check out the Company section of their site, you will see that a lot of well-known people who have contributed greatly to electro-acoustical science are among the founders of the company. Moreover, it is HiVi that owns the patent for Planar Ribbon Tweeters that have been employed by numerous industry top-brands.
The merger with Swans provided the opportunity for complete system research and design. Within a few short years, the company’s strategy bore its fruit: they won numerous awards from prestigious shows.
We would like to thank HiVi Swans Company for giving us the opportunity to take a closer look at the acoustic system – S200A. It won our hearts at first glance. But before we continue let’s take a look at the official specification sheet.
2.0 multimedia Hi-End stereo system
Low-frequency driver (woofer)
High-frequency driver (tweeter)
Supported frequency range
47Hz – 20kHz (-6dB)
100Hz – 20kHz <1% (2.83V/1m)
32W x 2
When I opened the box I took out two nice-looking speakers wrapped carefully in special soft cloth bags. Having taken the speakers out of the package I continued my search for accessories inside the box. Here is what the package contained:
The speakers’ surface was covered with black piano lacquer, which not only indicates that this is an extremely high-quality solution, but also makes its undoubtedly attractive from the aesthetic standpoint. Most of you will agree that we usually see much cheaper materials used for speakers finish, such as plastic or veneering. Actually, most manufacturers try to get the price of their acoustic system down at any rate by using cheaper materials and components, so that their solution could look competitive and appealing against the background of other alternatives. However, when it comes to High-End economy is not taken into consideration any more.
The front of the satellites is decorated with cloth grills with the Swans logo (swan). The grills can be easily removed revealing the appearance of the front panels enforced with metal front pads. The pads most certainly serve to make the black dynamics stand out against the background of the black casing. Without them the whole thing wouldn’t look as impressive as it does, for sure.
Swans S200A feature phase-inverter acoustic design. As you can see from the picture, the tweeter is located right beneath the woofer. The phase-inverter port is on the back, a little above the woofer axis and is 35mm in diameter and 85mm deep.
Below the phase-inverter port there are balance and RCA Outs.
These are brand name clamping connectors of the right and left satellite.
The left satellite is connected to the right one with a thick multiple-strand acoustic cable. Its ends are tightened in big beautiful clamping connectors. All the electronics, including the power supply unit, fit inside the right satellite. As you can clearly see, there is a treble-unit and a volume control knob. All knobs are made of metal.
The system can be connected to the audio source in two ways: you can either use an RCA-connection or AES3 (XLR3) ports that are common on professional equipment.
Swans S200A has a power switch on the back of the right satellite. The system is protected against power instabilities with a safety fuse.
I am sure that most of you are willing to know what is hidden beneath the beautiful piano lacquered surface. Before we get to the actual tests, let’s take a look inside the system by removing eight screws on the back of the right satellite:
As soon as we opened the system we saw that the external casing is 16mm wide and the internal capacity of the satellite is 7l. The satellites have no sharp edges, the rounded shape is created with special cutting technique and there is a cross-piece in the upper part of the case. All electronics, except the frequency separation filters, is placed on the back panel of the right satellite case. Note that there is no lining of sound-absorbing material inside.
The phase-inverter port is set at 50Hz, but it turned out too loud because of the too small diameter, especially when you are listening to it at over 10W power (you can notice some side sounds).
During the test session we detected some bouncing sound at 300Hz frequency, which could be the internal case resonance (standing waves). The woofer impedance graph in box and in free air demonstrates evident presence of resonance peaks. I believe that internal lining with sound-absorbing material could help solve this problem.
Low-frequency and high-frequency separation filters (from left to right).
Filters inside the satellite case.
Principal circuitry for separation filters: high-frequency drop – C3, low-frequency – C2.
Separation filters (high-frequency and low-frequency links) are placed on small individual PCBs installed into the side panels of the satellites cases. The coils are of thick wire and there are just a few film capacitors around them.
Our next measurements revealed that the Rz graph (active resistance) is not quite even, however, its value doesn’t drop below 4Ohm. The delta is less than 1dB, the unevenness of the amplitude-frequency characteristics of the acoustic system can be squeezed into +/-3dB.
5532 - one of the operational amplifiers.
LM3886 output amplifiers use rear metal panel of the satellite case
to dissipate heat.
The amplifier is put together following a classical schematic: using two low-noise operational amplifiers 5532 from Texas Instruments and two LM3886 integral chips from National Semiconductor at the output. 5532 operational amplifier is known for high performance and low level of distortions. LM3886 micro-chip belongs to the “Overture” family and allows obtaining 135W of instantaneous peak power. The harmonic distortion coefficient doesn’t exceed 0.06% in 20Hz-20kHz frequency range. Typical ripple rejection equals 120dB, therefore the integrated circuit design is fairly simple. These characteristics of the IC ensure high-quality sound that is why they are used all over the place starting with boom-boxes and all the way into luxurious high-end. By the way, LM3886 has become very popular in the DIY sector, too, so with the price of only $2 a piece it is being widely used in “home-made” designs also.
As you see, both LM3886 are installed onto the very edge of the PCB. They cool down by dissipating the heat through the rear panel of the right satellite, which also carries all the other electronic components of the acoustic system. So in the end, it warms up pretty significantly.
Next to the output IC on the PCB there are capacitors with maximum recommended capacity of 10000MF (microfarad). They are installed along the power circuit of each channel branch. The maximum calculated power of these channels is 2x25W. As for the schematic peculiarities of the acoustic system amplifier, there are none to talk of.
Power supply unit transformer.
Power supply transformer is screened with copper plates, which helps eliminate the background noise when the amplifier is mounted very close inside the system.
The system is equipped with Hi-End neodymium tweeters with 28mm membranes. The tweeter dome is made of reinforced polymer. The high-frequency driver is placed into isolated resonance-free casing, which protects it against woofer’s influences. The nominal DC impedance of the tweeter is 6Ohm, own resonance frequency – 1350Hz. The tweeter is screwed to the metallic pad that serves as a megaphone.
You can see distortions because of the non-optimal acoustic design of the tweeter dome.
The graph above shows very unfavorable amplitude-frequency characteristic (AFC) for filtering; at 30 degree angle the AFC improves a little bit – it may result from the non-optimal acoustic design of the tweeter dome. As a result, the manufacturer had to use a third order filter with Q-factor of about 1, which also increases the distortions.
As a result, the amplitude-frequency characteristics of the system feature
a dramatic drop between 1.5kHz and 4kHz.
The system is equipped with S5N-5 Hi-End low-frequency drivers 5.5 inches in diameter. The diffuser of this speaker is made of polypropylene on rubber suspension.
Low-frequency driver (woofer)
The diffuser is not too hard and features straight cone. In the middle of it there is corrugated plastic dust-protective cap. The loudspeaker excursion equals +/-4.5mm. It consists of large ferrite magnet (NdFeB), stamped frame and an inch coil. Its DC resistance is 5Ohm, and nominal power – 80W.
Thiele-Small parameters measurement.
Well, the system uses an excellent high-frequency driver with high sensitivity and low resonance. The total q-factor equals 0.36, and Bl/Mms ratio = 0.65, which is excellent result!
During the test session on Swans S200A our audio experts noticed pretty rough sounding of the tweeter with somewhat metallic shade. Vocals sound without the proper level of detail. The bass is quite deep, but lacks punch and foundation.
Purchasing high-quality acoustic systems is a very complicated task, that if successfully accomplished may bring the owner to a completely new lifestyle level. In fact, most of us start caring about Hi-End when something significant happens in our lives, when we buy a house or a prestigious apartment, when we get a pet, a luxurious leather sofa, huge TV-set and other attributes of successful life. And equipping the office usually gets down to buying a powerful computer system that would fit perfectly into some designer vision for the room.
The acoustic system we have just discussed in our article is probably an ideal of designer art and features all external attributes of the high-end piece of equipment. I can’t help mentioning excellent construction and high-quality finish of it. But, the looks is not all you need from a system like that.
Our audio experts agreed that Swans S200A needs a different tweeter and hence new crossover design. It would also be good to at least double the phase-inverter diameter and change its setting to 60Hz. This will reduce acoustic noise from the phase-inverter and make the bass sound more vivid. At the same time, the bottom frequency level will get a little higher.
Judging by the results of our tests and the positioning of the system as High-End we have to admit that its sound quality can be characterized as average. Hopefully, some of the suggestions we made here will help the manufacturer improve their solution.