1. History. Summary.
2. Driver Support.

Back in 1992, Turtle Beach Systems, a subsidiary of ICS (Integrated Circuit Systems), introduced a revolutionary product in the sound industry called MultiSound. In a matter of fact, it was a real engineering master-piece aimed at sound professionals. Unlike all other sound cards for the ISA bus, it didn't utilise DMA channels because the Hurricane architecture it was built upon required only a single IRQ, an I/O port and a 32Kb window in upper memory. So, this 4-layer board 34 centimetres long was populated by a whole lot of fine silicon hardware:

• a 40MHz 24-bit Motorola DSP56001 with three 8x256Kbit 70ns SRAM chips;
• a 10MHz 16-bit Motorola 68000 processor with two 8x256Kbit 70ns SRAM chips and one 512Kbit EPROM chip;
• an E-mu Proteus 1/XR (PDF manual, 750Kb) synthesiser with four 8Mbit Asahi Kasei ROM chips;
• two Altera EP1810 (EP1810LC-20T — PDF datasheet, 164Kb) 48-macrocell programmable gate arrays;
• two Crystal 4328 (CS4328 — PDF datasheet, 153Kb) 18-bit DACs with 64x oversampling;
• one Crystal 5336 (CS5336 — PDF datasheet, 141Kb) 16-bit ADC with 64x oversampling;
• three Philips NE5532 (PDF datasheet, 104Kb) dual 140KHz operational amplifiers;
• two Dallas 1267 (DS1267 — PDF datasheet, 206Kb) dual 256-position resistor arrays;
• one Philips NE558 (PDF datasheet, 67Kb) quad timer;
• some ISA bus buffering logic.

The heart of this design was Motorola DSP56001, a fast 24-bit universal digital signalling processor responsible for audio data transfers and effect processing. It was connected directly to one CS4328 DAC and one CS5336 ADC through internal serial interfaces. These excellent audio converters together with low noise NE5532 op-amps and DS1267 volume regulators made quality of MultiSound's analogue paths superior to those of all consumer and many professional sound cards for a long time. The card could process 44KHz 16-bit stereo audio for both play back and recording in full-duplex mode, i. e. to play back while recording. Another strong feature was wavetable MIDI synthesis. E-mu Proteus 1/XR (eXtra RAM) was capable of true 32-voice polyphony while working with uncompressed 16-bit samples stored in 4Mb of on-board ROMs by Asahi Kasei (IP5001EMU, IP5011EMU, IP5021EMU, IP5031EMU). The synthesiser was supported by Motorola 68000 which helped to render MIDI sounds through the second CS4328 DAC. However, E-mu Proteus 1/XR was incompatible with General MIDI and utilised a patch set of its own. There was a real MIDI in/out/through interface, not that one to make digital joysticks happy indeed. Finally, two Altera EP1810 chips were programmed to produce non-standard logic. Oh yes, one more thing. Proteus 1/XR supports up to 8Mb of sound samples, and it takes another set of 4 ROMs to add those extra 4Mb. In case of MultiSound, you can see four unpopulated layouts on the board for this purpose, though I've never met a factory confugured card with all 8 ROMs.
 

Turtle Beach MultiSound Classic

(click to enlarge, 412Kb)

By the way, what was offered by others at those glory days of the ISA bus? There was Creative SoundBlaster Pro with crappy audio converters capable of either 44KHz 8-bit mono or 22KHz 8-bit stereo, half-duplex only, and no effect processing at all. It was complemented by a frequency modulated (FM) synthesiser built of two Yamaha OPL2-compatible chips, which was inferior significantly to a good wavetable synthsesiser with quality samples such as ICS GF1 (1st generation of Gravis UltraSounds) or AMD InterWave (2nd generations of these cards). Well, some people at Creative had got some wicked sense of humour to give this SoundBlaster a "Pro" suffix. Although SoundBlaster 16 was introduced in 1992, it wasn't much better. Once again, crappy audio converters and a poor FM synthesiser. Oh yes, it got a so-called effect processor aimed at stereo enhancement, but it was so good that most people preferred not to enable it at all. Forthcoming SoundBlasters of AWE32 and AWE64 series were capable of wavetable MIDI synthesis through use of on-board E-mu 8000 which wasn't as good as Proteus though. These boards were manufactured until the end of the ISA bus.
 
In 1993, Creative acquired E-mu Systems and made Proteus unavailable to Turtle Beach. The original design of MultiSound had to be modified, so Proteus and the accompanying hardware had to go — Motorola 68000 with its EPROM chip and two SRAM chips, also four Asahi Kasei ROMs and one Crystal 4328 DAC. A standard interface for an external MIDI daughter-board was implemented instead. The first card to feature this connector was Creative SoundBlaster 16, and it was supposed to be there for Creative WaveBlaster, a crappy wavetable MIDI daughter-board. Although other hardware manufacturers started to produce sound cards and daughter-boards for this interface soon after, hence it became a kind of standard eventually. The new design of MultiSound was about 12 centimetres shorter than the previous, but the other internals and the architecture remained the same. This sound card entered the market somewhere in 1994 under the name of MultiSound Tahiti while the original design had been renamed to MultiSound Classic. Finally, MultiSound became the family name.
 

Turtle Beach MultiSound Tahiti

(click to enlarge, 229Kb)

There was also MultiSound Monterey, a marketing creature. Well, it appeared because of Rio, a wavetable MIDI daughter-board designed by Turtle Beach engineers. Rio was powered by ICS 2115 (ICS2115 — PDF datasheet, 315Kb), a General MIDI compatible synthesiser and programmable effect processor capable of either 24-voice polyphony at 44KHz or 32-voice polyphony at 32KHz. The board came with 4Mb of uncompressed 16-bit samples. In addition, up to 16Mb of memory for loadable samples could be installed in one 30-pin SIPP (Standard In-line Pin Package). So, a Tahiti bundled with a Rio was sold as Monterey at a special discount price. Therefore, everything related to Tahiti applies to Monterey as well.
 

Turtle Beach Rio with a 1Mb SIPP

(click to enlarge, 124Kb)

In 1996, the last two members of this family appeared, MultiSound Fiji and MultiSound Pinnacle. Although they were of the Hurricane architecture still, this 2nd generation of MultiSounds was different significantly from the 1st one. In a matter of fact, almost all silicon hardware of the previous designs were replaced:

• a Motorola DSP56002 instead of a Motorola DSP56001;
• a Xilinx 5210 (XC5210 — PDF datasheet, 440Kb) field programmable gate array with a boot-up serial ROM instead of both Altera EP1810 chips;
• a Crystal 4327 (CS4327 — PDF datasheet, 597Kb) 20-bit DAC with 128x oversampling instead of an 18-bit Crystal 4328 with 64x oversampling;
• a Crystal 5335 (CS5335 — PDF datasheet, 223Kb) 20-bit ADC with 128x oversampling instead of a 16-bit Crystal 5336 with 64x oversampling;
• three Crystal 3310 (CS3310 — PDF datasheet, 118Kb) dual op-amps and 256-position resistor arrays instead of two Philips NE5532 and two Dallas 1267 chips.

Support for the S/PDIF interface was implemented through a little Digital I/O daughter-board sold separately which was based upon Crystal 8425 (CS8425 — PDF datasheet, 165Kb), an audio network transceiver. While Fiji was given a connector for an optional MIDI daughter-board, Pinnacle accommodated Kurzweil MA-1 [manufactured by Young Chang], a wavetable synthesiser supporting up to 48Mb of memory in two 72-pin SIMMs, also an on-board IDE interface. Although the 2nd generation of the MultiSound family was built using more advanced parts, it wasn't much superior to the 1st when it came to quality of analogue audio paths. That's hard to make an excellent thing even better. Check SoundBench: 17 PCI and ISA Sound Cards Tested if you're looking for some figures.
 

Turtle Beach MultiSound Fiji with Digital I/O

(click to enlarge, 292Kb)

Turtle Beach MultiSound Pinnacle with two 16Mb SIMMs

(click to enlarge, 349Kb)

In 1997, Turtle Beach Systems, struggling financially, was sold to Voyetra Technologies, an audio software developing company, and became a division of the latter. From today's point of view, it hasn't developed anything really outstanding since, just some good but regular multimedia products. Although the brand of Turtle Beach is still visible, it's just a shadow of the past. That's sad to see crap spreading and excellent things falling into oblivion.
 
By the way, Turtle Beach designed and manufactured many sound cards which didn't belong to the MultiSound family. They weren't as good as the MultiSounds, but less expensive considerably. There were several ISA sound cards of the Monte Carlo and Tropez series, also Malibu one. About PCI sound cards, there were Daytona (based upon S3 SonicVibes), Montego (based upon Aureal Vortex), Montego II (based upon Aureal Vortex 2), Santa Cruz (based upon Crystal 4630), Riviera (based upon C-Media 8738), Montego DDL (Dolby Digital Live; based upon C-Media 8768) and Catalina (based upon VIA Envy-24HT). Vortex based Montegos and Santa Cruz sound cards have been sold in large quantity through OEMs such as Dell and IBM.
 
Here are list prices for the MultiSounds as far as from December of 1994:
 

MultiSound Classic	about 430 USD
MultiSound Tahiti	about 260 USD
MultiSound Monterey	about 310 USD

 
A lot of money, but I can recall that Creative SoundBlaster 16 cost about 200 USD those days. It's hard to believe that such a piece of junk could cost so much, but it was.

Although MultiSounds have never reached sales comparable to those of Creative SoundBlasters, Ensoniq SoundScapes or Gravis UltraSounds, they brought professional quality of sound processing to regular PCs. They were of no use when it came to gaming in those old times of MS-DOS because they carried absolutely no compatibility with other sound cards. Besides, the Hurricane architecture itself was not for gaming needs definitely. It was designed to operate with long continuous audio streams, not short soundforms injected here and there.
 
Even though so much time have passed, MultiSounds are still better than most consumer-level sound cards or audio codecs installed onto mainboards. It's a pretty expensive and time-consuming thing to develop and manufacture a very good design. Of course, modern high-end sound cards with 24-bit audio converters and handsome sets of digital interfaces are tasty things, it would be silly to deny that. Nevertheless, they cost hundreds of bucks and their driver support is Windows-limited typically. About modern inexpensive sound cards... Well, fates of those lame board layouts populated with poor electrolytic capacitors and regular low-quality jacks are regretful. So, I prefer to stay with my MultiSounds even though the ISA bus is also a history now. Really good things should never die.