No subwoofer and center speaker Ubuntu 20.04.2 LTS

A sound card Creative Labs Sound Blaster Live 5.1 EMU10k1 is installed. Driver: snd_emu10k1.Pavucontrol settings: analog surround 5.1 output + analog stereo input. Alsamixer center and lfe have been activated.
There is no sound from the center speaker and the subwoofer. I tested the speakers through speaker-test -t wav -c6: front center comes from front left and LFE comes from front left and says rear center.
What could this be?

Kernel: 5.4.0-73-generic x86_64 bits: 64 compiler: gcc v: 9.3.0
Desktop: Gnome 3.36.7 Distro: Ubuntu 20.04.2 LTS (Focal Fossa)
Type: Desktop Mobo: ASRock model: N68-S3 UCC serial:
BIOS: American Megatrends v: P1.30 date: 05/27/2010
RAM: total: 7.77 GiB used: 2.75 GiB (35.4%)
RAM Report:
permissions: Unable to run dmidecode. Root privileges required.
Topology: Dual Core model: AMD Athlon II X2 250 bits: 64 type: MCP
arch: K10 rev: 3 L2 cache: 2048 KiB
flags: lm nx pae sse sse2 sse3 sse4a svm bogomips: 12056
Speed: 3000 MHz min/max: 800/3000 MHz Core speeds (MHz): 1: 3000
2: 800
Device-1: NVIDIA GF119 [GeForce GT 610] vendor: ASUSTeK
driver: nvidia v: 390.143 bus ID: 02:00.0
Display: x11 server: X.Org 1.20.9 driver: nvidia
unloaded: fbdev,modesetting,nouveau,vesa resolution: 1920x1080~60Hz
OpenGL: renderer: GeForce GT 610/PCIe/SSE2 v: 4.6.0 NVIDIA 390.143
direct render: Yes
Device-1: Creative Labs EMU10k1 [Sound Blaster Live! Series]
driver: snd_emu10k1 v: kernel bus ID: 01:08.0
Device-2: NVIDIA GF119 HDMI Audio vendor: ASUSTeK
driver: snd_hda_intel v: kernel bus ID: 02:00.1
Sound Server: ALSA v: k5.4.0-73-generic
Device-1: NVIDIA MCP61 Ethernet vendor: ASRock 939NF6G-VSTA Board
type: network bridge driver: forcedeth v: kernel port: c480
bus ID: 00:07.0
IF: enp0s7 state: up speed: 100 Mbps duplex: full mac:
Local Storage: total: 465.76 GiB used: 100.04 GiB (21.5%)
ID-1: /dev/sda vendor: Hitachi model: HDS5C1050CLA382
size: 465.76 GiB