1 ============================================== 1 =================================================================
2 Low latency, multichannel audio with JACK and 2 Low latency, multichannel audio with JACK and the emu10k1/emu10k2
3 ============================================== 3 =================================================================
4 4
5 This document is a guide to using the emu10k1 5 This document is a guide to using the emu10k1 based devices with JACK for low
6 latency, multichannel recording functionality. 6 latency, multichannel recording functionality. All of my recent work to allow
7 Linux users to use the full capabilities of th 7 Linux users to use the full capabilities of their hardware has been inspired
8 by the kX Project. Without their work I never 8 by the kX Project. Without their work I never would have discovered the true
9 power of this hardware. 9 power of this hardware.
10 10
11 http://www.kxproject.com 11 http://www.kxproject.com
12 12 - Lee Revell, 2005.03.30
13 13
14 14
15 Until recently, emu10k1 users on Linux did not 15 Until recently, emu10k1 users on Linux did not have access to the same low
16 latency, multichannel features offered by the 16 latency, multichannel features offered by the "kX ASIO" feature of their
17 Windows driver. As of ALSA 1.0.9 this is no m 17 Windows driver. As of ALSA 1.0.9 this is no more!
18 18
19 For those unfamiliar with kX ASIO, this consis 19 For those unfamiliar with kX ASIO, this consists of 16 capture and 16 playback
20 channels. With a post 2.6.9 Linux kernel, lat 20 channels. With a post 2.6.9 Linux kernel, latencies down to 64 (1.33 ms) or
21 even 32 (0.66ms) frames should work well. 21 even 32 (0.66ms) frames should work well.
22 22
23 The configuration is slightly more involved th 23 The configuration is slightly more involved than on Windows, as you have to
24 select the correct device for JACK to use. Ac 24 select the correct device for JACK to use. Actually, for qjackctl users it's
25 fairly self explanatory - select Duplex, then 25 fairly self explanatory - select Duplex, then for capture and playback select
26 the multichannel devices, set the in and out c 26 the multichannel devices, set the in and out channels to 16, and the sample
27 rate to 48000Hz. The command line looks like 27 rate to 48000Hz. The command line looks like this:
28 :: 28 ::
29 29
30 /usr/local/bin/jackd -R -dalsa -r48000 -p64 30 /usr/local/bin/jackd -R -dalsa -r48000 -p64 -n2 -D -Chw:0,2 -Phw:0,3 -S
31 31
32 This will give you 16 input ports and 16 outpu 32 This will give you 16 input ports and 16 output ports.
33 33
34 The 16 output ports map onto the 16 FX buses ( 34 The 16 output ports map onto the 16 FX buses (or the first 16 of 64, for the
35 Audigy). The mapping from FX bus to physical 35 Audigy). The mapping from FX bus to physical output is described in
36 sb-live-mixer.rst (or audigy-mixer.rst). 36 sb-live-mixer.rst (or audigy-mixer.rst).
37 37
38 The 16 input ports are connected to the 16 phy 38 The 16 input ports are connected to the 16 physical inputs. Contrary to
39 popular belief, all emu10k1 cards are multicha 39 popular belief, all emu10k1 cards are multichannel cards. Which of these
40 input channels have physical inputs connected 40 input channels have physical inputs connected to them depends on the card
41 model. Trial and error is highly recommended; 41 model. Trial and error is highly recommended; the pinout diagrams
42 for the card have been reverse engineered by s 42 for the card have been reverse engineered by some enterprising kX users and are
43 available on the internet. Meterbridge is hel 43 available on the internet. Meterbridge is helpful here, and the kX forums are
44 packed with useful information. 44 packed with useful information.
45 45
46 Each input port will either correspond to a di 46 Each input port will either correspond to a digital (SPDIF) input, an analog
47 input, or nothing. The one exception is the S 47 input, or nothing. The one exception is the SBLive! 5.1. On these devices,
48 the second and third input ports are wired to 48 the second and third input ports are wired to the center/LFE output. You will
49 still see 16 capture channels, but only 14 are 49 still see 16 capture channels, but only 14 are available for recording inputs.
50 50
51 This chart, borrowed from kxfxlib/da_asio51.cp 51 This chart, borrowed from kxfxlib/da_asio51.cpp, describes the mapping of JACK
52 ports to FXBUS2 (multitrack recording input) a 52 ports to FXBUS2 (multitrack recording input) and EXTOUT (physical output)
53 channels. 53 channels.
54 54
55 JACK (& ASIO) mappings on 10k1 5.1 SBLive card 55 JACK (& ASIO) mappings on 10k1 5.1 SBLive cards:
56 56
57 ============== ======== ============ 57 ============== ======== ============
58 JACK Epilog FXBUS2(nr) 58 JACK Epilog FXBUS2(nr)
59 ============== ======== ============ 59 ============== ======== ============
60 capture_1 asio14 FXBUS2(0xe) 60 capture_1 asio14 FXBUS2(0xe)
61 capture_2 asio15 FXBUS2(0xf) 61 capture_2 asio15 FXBUS2(0xf)
62 capture_3 asio0 FXBUS2(0x0) 62 capture_3 asio0 FXBUS2(0x0)
63 ~capture_4 Center EXTOUT(0x11) 63 ~capture_4 Center EXTOUT(0x11) // mapped to by Center
64 ~capture_5 LFE EXTOUT(0x12) 64 ~capture_5 LFE EXTOUT(0x12) // mapped to by LFE
65 capture_6 asio3 FXBUS2(0x3) 65 capture_6 asio3 FXBUS2(0x3)
66 capture_7 asio4 FXBUS2(0x4) 66 capture_7 asio4 FXBUS2(0x4)
67 capture_8 asio5 FXBUS2(0x5) 67 capture_8 asio5 FXBUS2(0x5)
68 capture_9 asio6 FXBUS2(0x6) 68 capture_9 asio6 FXBUS2(0x6)
69 capture_10 asio7 FXBUS2(0x7) 69 capture_10 asio7 FXBUS2(0x7)
70 capture_11 asio8 FXBUS2(0x8) 70 capture_11 asio8 FXBUS2(0x8)
71 capture_12 asio9 FXBUS2(0x9) 71 capture_12 asio9 FXBUS2(0x9)
72 capture_13 asio10 FXBUS2(0xa) 72 capture_13 asio10 FXBUS2(0xa)
73 capture_14 asio11 FXBUS2(0xb) 73 capture_14 asio11 FXBUS2(0xb)
74 capture_15 asio12 FXBUS2(0xc) 74 capture_15 asio12 FXBUS2(0xc)
75 capture_16 asio13 FXBUS2(0xd) 75 capture_16 asio13 FXBUS2(0xd)
76 ============== ======== ============ 76 ============== ======== ============
77 77
78 TODO: describe use of ld10k1/qlo10k1 in conjun 78 TODO: describe use of ld10k1/qlo10k1 in conjunction with JACK
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.