Soundblaster Audigy 2 ZS and Linux

I started recently to look a bit around for a good audio card to get to a "studio" quality recordings under Linux. I didn't want to invest much money so I decided to buy something on ebay.

A short investigation pointed me in the direction of the Audigy 2 ZS sound card. A Creative product with interesting specifications:

• 24bit 96kHz sampling (in and out)
• 108dB signal noise ratio
• EMU10K1/2 processor
• Hardware wavetable synthesizer (4x 16 channel polyphony)
• Firewire interface (which became the best feature of this card)

And that all in an attractive package for only 10.50 Euro:

Creative SoundBlaster Audigy 2 ZS

By The original uploader was Swaaye at English Wikipedia. - Transferred from en.wikipedia to Commons by Lockal using CommonsHelper., CC BY-SA 3.0, Link

The mixer options look great:

Alsamixer for Audigy 2 ZS

Reality

While a quick scan suggested that this card is supported under linux is the reality rather disappointing.  The Alsa page gives some information.

It looks that this card is in practice only supported for  44.1kHz or 48kHz sample rate. And the playback and capturing is mainly 16bits with some support for 24bits. This is an alsa limitation and in that sense is the card not really an upgrade from the "crapy" audio of a normal main-board.

This forces me to look a  further for a new solution that does deliver 24bit at a high 96kHz or 192kHz sample rate.

Wavetable synthesizer

This part has some hardware limitations.  According to alsa information page is the address bus only 31bits, which gives problems with a 64bit operating system and more than 4 Gigabyte memory. When this card was released was this probably a none issue, but now with only 64bit Operating systems and 16Gbyte of memory is this a bit of pity.
A work arround is saving some bigger memory block by using the following kernel parameter within the grub2 boot menu:

memmap=2048M\$6144M

It can be unfortunately necessary to play a bit with single (\), double (\\) or triple (\\\) to escape the $ sign within grub2 config file to make this work correctly automatically on boot time.
Furthermore can it be necessary to increase the normal 128MByte memory for the wave table to 200MByte to make the FluidR3_GM.sf2 sound font fit. This can be done by using the following kernel module parameter:

options snd-emu10k1 max_buffer_size=<size_in_MB>

This parameter can be put in the /etc/modprobe.d/alsa-base.conf file.

If this is correctly working can be checked with the following commands:

hansan@Desk-computer:~/Music/mid$ cat /proc/asound/cards
0 [FW             ]: BeBoB - PHASE 24 FW
                      TerraTec Electronic Gmb PHASE 24 FW (id:4, rev:1), GUID 000aac0400239b18 at fw2 
1 [PCH            ]: HDA-Intel - HDA Intel PCH
                      HDA Intel PCH at 0xef410000 irq 30 
2 [HDMI           ]: HDA-Intel - HDA ATI HDMI
                      HDA ATI HDMI at 0xef360000 irq 31 
3 [Audigy2        ]: Audigy2 - SB Audigy 2 ZS [SB0350]
                      SB Audigy 2 ZS [SB0350] (rev.4, serial:0x20021102) at 0xc000, irq 16 
4 [U0x46d0x9a2    ]: USB-Audio - USB Device 0x46d:0x9a2
                      USB Device 0x46d:0x9a2 at usb-0000:00:14.0-3, high speed

And to check the status of the synthesizer:

hansan@Desk-computer:~/Music/mid$ cat /proc/asound/card3/wavetableD1
Device: Emu10k1
Ports: 4
Addresses: 29:0 29:1 29:2 29:3
Use Counter: 0
Max Voices: 64
Allocated Voices: 0
Memory Size: 134217728
Memory Available: 103062476
Allocated Blocks: 866
SoundFonts: 1
Instruments: 14491
Samples: 864
Locked Instruments: 14491
Locked Samples: 864

A new sound font can be loaded with:

hansan@Desk-computer:~/work/sf2$ asfxload  "GeneralUser GS Live-Audigy v1.44.sf2"
hansan@Desk-computer:~/work/sf2$ asfxload -M
DRAM memory left = 100714 kB

And a midi file can be played with:

hansan@Desk-computer:~/work/sf2$ aplaymidi -l
 Port    Client name                      Port name
 14:0    Midi Through                     Midi Through Port-0
 16:0    PHASE 24 FW                      PHASE 24 FW MIDI 1
 28:0    SB Audigy 2 ZS [SB0350]          Audigy MPU-401 (UART)
 28:32   SB Audigy 2 ZS [SB0350]          Audigy MPU-401 #2
 29:0    Emu10k1 WaveTable                Emu10k1 Port 0
 29:1    Emu10k1 WaveTable                Emu10k1 Port 1
 29:2    Emu10k1 WaveTable                Emu10k1 Port 2
 29:3    Emu10k1 WaveTable                Emu10k1 Port 3
hansan@Desk-computer:~/work/sf2$ aplaymidi -p 29.0  test.mid

This does works at least.... But I have say that fluidsynth is maybe an even better solution, given the performance of modern processors.

Conclusion

All with all this was not really a good very invested 10.50 Euro. The selling features like the high bit rate and resolution are not really delivered on the linux platform.
The only good item is a firewire interface, which enables me to look into a different class of audio cards.


(updated and corrected a few items on 3/11/2018)