SEKD pioneered the development of 24‑bit/96kHz soundcards for PCs, and their lead has been followed up enthusiastically by other manufacturers. Does the new Siena have the features to take them back to the top of the pile? Martin Walker finds out.
SEKD's ProDif 96, which I reviewed in SOS September '98, was one of the first ever 24‑bit/96kHz‑capable soundcards. At the time it cost £600 and had only 20‑bit D‑A converters for monitoring purposes, and no A‑D converters at all. How times change! The new SEKD Siena soundcard offers eight analogue inputs and eight analogue outputs, all with 24/96 capability, along with two MIDI Ins and two MIDI Outs, for the very reasonable price of £399.
Drivers are supplied for Windows 95, 98, and NT 4.0, and support up to four cards in one machine: one card is designated the Master, and the others can be slaved to it in perfect sync for an impressive 32‑in/32‑out system. Users of SEKD's Samplitude (reviewed last month in SOS) also get a few extra features such as Auto Punch and Auto‑Record‑Monitoring — more on these later. However, SEKD are no longer so far ahead of the game: several other manufacturers have already launched budget 24‑bit 8‑in/8‑out soundcards at competitive prices, such as the Terratec EWS88MT and Gadget Labs Wave/8*24. So how does the Siena compare?
Overview
The Siena uses four AKM AK4524 codec chips to provide A‑D and D‑A conversion. These are identical to those used in both the Terratec EWS88MT and the Aardvark Direct Pro 2496 (reviewed in SO S October 1999 and April 2000 respectively). However, both of these mount their converters in external breakout boxes, while Siena houses them on the PCI card. I was intrigued to find out whether this made a measurable difference to audio performance.
There are just two connectors on the backplate — a 44‑way D‑type socket for the audio wiring, and a 9‑pin one for MIDI. Rather than a breakout box, Siena uses flying cables similar to those provided with Midiman's Dman 2044: the supplied 44‑way plug has 16 screened audio cables emerging from it, each about a foot long. These terminate in eight red phono in‑line sockets for the analogue inputs, and eight black in‑line phono sockets for the analogue outputs. The supplied MIDI adaptor cable has a 9‑way plug at one end, from which emerge four separate screened cables a few inches long that terminate in standard 5‑pin DIN in‑line sockets for the two MIDI Ins and two MIDI Outs.
Each of the 20 cables has an identifying collar attached near its plug end, but connecting Siena to the rest of your studio still involves shuffling through the whole lot looking for the appropriate label. However, it does have the advantage that you are not limited by the length of a supplied umbilical cable; you can attach whatever length of standard screened cables you need to reach your mixing desk or patchbay.
Installation And Setup
The Siena PCI card is tiny at under five inches long, and apart from the two backplate connectors already mentioned, the card itself has just one additional 8‑way connector marked 'Sync'. This allows up to four Siena cards to be connected via a proprietary 'SyncBus', so that they are locked together in sample and phase‑accurate sync. Driver support for multiple cards is provided from version 2.08 onwards, and these drivers also cure a MIDI input problem when recording audio that was present in the previous version 1.03 drivers supplied with my review soundcard. Just five weeks separate these two driver versions, so although the version I tested was not bug‑free, I was nevertheless impressed by the efficiency of SEKD's software development team.
The card fitted into my PC with no problems, was correctly detected by Plug and Play on rebooting, and the Windows 95/98 driver software installed without a hitch. When I emerged onto the desktop I simply had an extra icon on my Taskbar to launch the Siena Manager utility. The audio outputs and inputs appear to multimedia applications as 'Siena Playback 1‑2, 3‑4, 5‑6, and 7‑8', along with 'Siena Record 1‑2, 3‑4, 5‑6, and 7‑8', while the MIDI connections appear as 'Siena Midi In 1 and 2' and 'Siena Midi Out 1 and 2'.
The version 2.08 drivers support DirectSound as well as MME, but not ASIO. This will please those running stand‑alone softsynths, but not Cubase VST and Logic Audio owners who want to achieve the lowest possible latency values. However, on the day before I submitted this review I made a final check for new developments on SEKD's web site, and found that German version 3.0 drivers had just been released, which do support ASIO as well. I downloaded these to test out their new features for this review, and I'm sure by the time you read this the English language version 3.0 drivers will be available for download as well.
Management Issues
Siena Manager is launched by double‑clicking on the Taskbar icon. Initially, a small Manager window appears where, using tick boxes, you can open any combination of three further windows that display the 'Analog Inputs', 'Analog Outputs', and 'Settings'. A fourth tick box forces all Siena windows to be 'Always on Top'. You can individually close any of the three main windows at any time either directly, or from the small Manager window, while closing the small window closes the others as well. The Manager window also remembers the position and display options of the input and output windows.
Both the Analog Inputs and Analog Outputs windows are configurable using further options that determine which features are active and visible, and which are deactivated. These options can be toggled from their 'Window Control Area' — a small area at the bottom of each window containing various tick boxes — or directly from the drop‑down menu that appears when you click on the small icon at the top left‑hand corner of each window. Here you can toggle the functions directly, and remove the Window Control Area and tick boxes from the main display to save space on your screen. The menu also has an extra toggled option for 'Hints'; these are tool‑tip‑style descriptions that appear when you hold the cursor over any window control.
The Inputs window has two tick options: Fader and Level Meter. Clicking on 'Fader' launches four pairs of vertical sliders corresponding to the eight input sockets, along with individual Mute buttons for each input, and four link boxes to gang together the stereo pairs. The faders are all calibrated with input gain settings from +18dB down to 40dB, and default to 0dB. It's unfortunate that they don't display the current position in dBs in text readout boxes, since you may find it difficult to achieve repeatable settings by eye. However, whenever you click on a Link switch the lower of the two faders always jumps to exactly the same position as the higher one, so at least stereo channels remain perfectly matched. Clicking on 'Level Meter' displays peak‑reading meters for each channel, with a 60dB range and peak‑hold facility. This works well, although once again providing a readout of the maximum peak level to date would help when setting up input levels.
The Analog Output window is rather more comprehensive, and has four switchable sections: Level Meter, Fader, Monitoring, and PunchIn Mon. The Level Meter section is identical to that of the Input window, but strangely its Fader section is calibrated from 0dB down to ‑60dB, so it isn't possible to fade any output level to zero.
The Monitoring section lets you set up 'zero'‑latency hardware monitoring using a matrix of four buttons per stereo output. By the way, the reason I always place the word 'zero' in inverted commas in this context is that although hardware monitoring is a huge improvement over typical software latency values, your signal will still undergo a tiny delay as it passes through the A‑D and then D‑A converters. This may only be of the order of 1mS in total, but would still cause comb‑filtering problems if you mixed it with the original signal, just as it would with any hardware effect unit.
The monitor matrix buttons are labelled 'In 1‑2', 'In 3‑4', 'In 5‑6', and 'In 7‑8', and allow each stereo output pair to directly listen to the signal at any one of the stereo input pairs. If none of the buttons is activated then you hear normal WAV audio playback. An additional OnRec button activates monitoring only when you switch to record mode in your software — many musicians find this is a useful way to work, since you hear the existing WAV audio playback until you reach a punch‑in point, where it will switch to monitoring the desired input signal with 'zero' latency.
The optional PunchIn Monitor tick box adds a further button to each output marked OnPunch, which works in conjunction with SEKD's Samplitude software, switching from track playback to input‑signal monitoring automatically for the duration of the punch recording. Although this will undoubtedly prove useful to those using SEKD software, the version 3.0 drivers not only support ASIO, but also ASIO 2.0 Direct Monitoring, which provides the same functions to anyone whose sequencer can use ASIO drivers.
If you have multiple cards installed, the Input and Output displays expand to display them all side by side. This is an improvement over some other soundcard mixers that require you launch a separate mixer for each installed card; their size can also be reduced horizontally right down to a scrolling single‑channel‑width window to suit the size and resolution of your screen.
The Finer Points
The Settings window has two tabbed pages labelled Audio and Midi, and this time multiple cards are treated separately. A button marked '>' opens an additional settings window for the next Siena card if you have mor e than one installed, and the title bar of each window displays the number of the card currently selected: #1 for channels 1 to 8, #2 for channels 9 to 16, #3 for channels 17 to 24, and #4 for channels 25 to 32.
The Audio page has three sections labelled Synchronisation, DirectSound, and Common. Synchronisation Mode can be set to Master, Slave or Autonomous, and the various settings depend on whether or not you have installed multiple Siena soundcards. If you are only using one card then Autonomous mode should be used, but to synchronise multiple cards one must be set to Master and the others to Slave — the Master card then sends clock, start, and stop signals to the SyncBus, while the others lock to this. You can also select Start/Stop sync for Playback Devices, Record Devices, or both. This overcomes a common Windows problem with multi‑channel soundcards where starting more than one pair of channels simultaneously may result in offsets between them, and the mode you choose will depend on how you wish to operate. Those using Siena for multitrack recording and playback are likely to choose the latter option to keep everything in sync, but those who want to run stand‑alone soft‑synth applications alongside their MIDI + Audio sequencer may want to try the other options.
The available settings when using DirectSound are unusually comprehensive, although SEKD do admit that not all applications will be affected by them. The default tick box is 'Automatic Latency Adjustment': this loads data into the Siena card only when needed, to keep latency values as low as possible without ever causing glitches (theoretically at any rate!). Only if you click on the 'Adjust Latency Manually' tick box does the slider become functional, and you can then tweak the latency to a value anywhere between 1mS to 100mS, with a default of 60mS. Once again some applications may ignore this setting, and if you set it too low then glitches will certainly occur with those that don't. Optimised Cursor Handling is yet another option that may help reduce latency for the current application, by using "various positioning methods for the current application". An additional option is available in the version 3.0 drivers that lets you choose the default playback bit depth and sample rate for use in applications that support DirectSound but don't provide such options internally (you can choose 8‑ or 16‑bit, and 22kHz, 44.1kHz, or 48kHz). The final section on the audio page is a tick box to suppress error messages if you attempt to run the card at a non‑supported sample rate.
The MIDI page provides a huge number of filtering options, which are separately configurable for both MIDI Ins and both MIDI Outs, by selecting the appropriate Device from a drop‑down box. For both outputs a tick box is available to enable MIDI Stream Optimising. This automatically removes redundant data such as repeated status bytes when multiple MIDI On commands are being sent, and can increase the responsiveness of synths. Each of the four MIDI ports has a separate 'Filter Active' tick box, and once this is ticked the various types of filter displayed beneath become available.
There are seven types of channel‑related messages — Note on and Note off, Polyphonic and Channel aftertouch, Program change, Control/mode change, and Pitch Wheel control — and these can be viewed in one of three ways. View by Channel lets you see and alter the seven settings for one particular channel at a time, View by Command lets you see the filter settings for all 16 channels by selected message type, and View by Matrix shows the entire collection as 16 columns of seven tick boxes (see screenshot page 59). Further tick boxes for Global system filters are also provided in a separate area, to remove 11 different data types including System Exclusive, MIDI Time Code, Time Clock, and Active Sensing.
Although many sequencers do have similar filtering options built in, being able to remove MIDI data en route can be useful, especially with some soft synths that you connect directly to a MIDI input, and which may take a dislike to any extraneous data sent out by some keyboards along with such things as program change commands.
In Use
As I find myself writing on many occasions nowadays, the Siena's 16‑bit audio playback quality was a definite improvement on that of my Echo Gina card. The bottom end of the Siena seemed to go slightly deeper, while its top end was more open and focussed, making vocal and other acoustic recordings sound slightly more natural, and also giving you the impression of being able to hear further into the music. This is hardly surprising, since the Gina has been available for over two years and its 20‑bit converters are showing the test of time, although the differences between the two were not as large as some people imagine.
I couldn't directly audition the Siena alongside the Terratec EWS88MT or Aardvark Direct Pro 2496 to compare the sound of their identical AKM 24‑bit converters, but I still heard similar improvements in stereo imaging and high‑end clarity, although from memory I suspect that the more expensive Direct Pro would be slightly ahead in a side‑by‑side comparison.
As mentioned earlier, the official English version 2.08 drivers were the latest available when I reviewed the card, but I did install and run the just‑released German version 3.0 ones which also provide ASIO support. Unusually, you can enable any combination of input and output pairs in the ASIO Control Panel utility, and the buffer size doesn't just offer a few preset selections — you can enter any size in bytes. The default buffer size is 800 samples, which gives a latency of 18mS, but on my Pentium II 450MHz PC I managed to drop it right down to 128 bytes without glitching, for an excellent latency figure of 3mS. This compared to a value of 7mS with the Terratec, and 12mS with the Direct Pro.
However, even with the version 2.08 MME drivers I managed a superb 93mS latency inside Cubase VST using its ASIO Multimedia driver. The lowest value accepted by Siena's version 3.0 ASIO driver is 64 bytes, which gives a latency value of 1mS. I did try this briefly, although not surprisingly it glitched on my PC, and the huge increase in the number of interrupts also gave significant increases in CPU overhead. Mind you, it's there for you to try out, and despite glitching it still seemed perfectly stable.
Sadly I didn't have as much luck when investigating the DirectSound latency settings. Seer Systems' Reality exhibited lots of glitches when using the Automatic Latency adjustment, and frustratingly Siena Manager insists that you shut down any application using the card before it lets you change latency settings, which makes adjustments rather tedious to carry out. I did manage to adjust the Manual latency setting right down to 13mS without glitching, but there was still a noticeable latency during play that was certainly more than double this, so I was rather suspicious of the displayed value. However, Native Instruments' Reaktor managed a very respectable 15mS using the automatic setting with no glitches at all, which rather suggests that latency is still somewhat application‑dependant.
Final Thoughts
The Siena's combination of eight analogue ins and eight analogue outs along with two MIDI Ins and two MIDI Outs will certainly suit those who are after an all‑in‑one solution, and who don't require digital audio connections. The ability to sync multiple cards together is also valuable to any musician who wants to start small and then expand to a larger setup later on, since up to four cards should run alongside each other with sample‑accurate positioning, and still only require a single driver using one IRQ.
When I'd only tried the version 2.08 drivers I wasn't convinced that SEKD had a strong enough product to compete in an already crowded market, but having tried out the latest version 3.0 drivers with ASIO support (albeit in German) the situation changes considerably. Once the English version arrives they should find a lot of potential customers who are using Cubase or Logic Audio and want a new soundcard with very low latency and versatile options to run soft synths alongside.
At £399 the Siena already faces some stiff competition. This includes the Gadget Labs Wave/8*24, but although this has 24‑bit converters it only manages a top sample rate of 48kHz, which might put some musicians off. The most obvious competitor is the identically priced Terratec EWS88MT. This has exactly the same analogue audio facilities and identical converters; though it has only a single MIDI In and Out, it does provide S/PDIF In and Out for digital transfers. In addition, although audio performance is fairly similar, the EWS88MT also has a smart 5.25 inch breakout box containing the converters, which is considerably more elegant than the Siena's bunch of flying cables. However, if having extra MIDI I/O is more relevant to your studio than being able to make digital transfers, then the Siena will certainly be of interest, although I suspect that SEKD would sell rather more in the UK if its price were just a little bit lower.
Measured Noise Performance
The Siena's background noise proved tricky to measure, since it varied a great deal depending on the input gain, and with no text readout for the Siena fader positions it was difficult to guarantee repeatable settings. However, I also found that with Siena input gain settings below 0dB it proved impossible to achieve a 0dBFS meter reading without overloading its input stages, and since noise levels rose significantly as the gain was increased beyond 0dB (as you might expect), I adjusted all input faders close to 0dB to measure the background noise.
At 16‑bit/44.1kHz the RMS background noise, as measured in Wavelab 3.0, was between –89dB and 94dB depending on which input I used. Changing to 24‑bit caused the noise level to drop by a few dBs to between –91dB and –96dB, again depending on which input I tried. These figures are reasonably in line with the published figure of 95dB for signal‑to‑noise ratio, although still somewhat higher than for many similarly‑priced cards.
However, all three cards I've reviewed to date using these AK4524 codec chips have had higher than expected noise figures when measured using Wavelab. This may be partly because manufacturers are deliberately increasing dither noise for a better sound; and if this is the case then the figures would be more in line with other designs of card once they were A‑weighted. Even so, all Siena figures measured a couple of dBs higher than those of the Terratec EWS88MT. Mind you, there is more to soundcard performance than background noise: subjectively the Siena sounded clean and quiet, and of course when using a sample rate of 96kHz its wider 40kHz frequency response further improves the recorded sound.
Brief Specifications
- Analogue Connectors: unbalanced gold‑plated in‑line phono sockets.
- Analogue Inputs: 8 with additional 18dB gain available.
- Maximum Input Level: +8dBu.
- Analogue Outputs: 8.
- MIDI: 2 x MIDI In, 2 x MIDI Out.
- A‑D Converters: 24‑bit 64x oversampling (part of AK4524 Codec chip).
- D‑A Converters: 24‑bit 128x oversampling (part of AK4524 Codec chip).
- Signal‑to‑Noise ratio: 95dB.
- Total Harmonic Distortion + Noise: <0.005 percent (90dB).
- Frequency Response: 20Hz to 40kHz at 96kHz sampling rate.
- Supported Bit Depths: 8, 16, and 24.
- Supported Sample Rates: 11.025kHz to 96kHz.
Pros
- Good audio quality and support for 24‑bit/96kHz format.
- Well‑written drivers with low‑latency ASIO support in version 3.0.
- The drivers support up to four cards running in sample‑accurate sync if required.
- The provision of two MIDI Outs may save having to buy an additional MIDI interface.
Cons
- Fiddly flying leads for all connections.
- Background noise measures slightly higher than other similarly priced soundcards.
- No support for digital I/O.
Summary
The SEKD Siena provides plenty of features for the price, and will suit those who want 24/96 audio capability with low latency or 'zero'‑latency ASIO 2.0 Direct Monitoring, provided they don't need digital I/O at all.