SD Cards & Network Switch information

Information about SD Cards

SD Cards or SDHC cards can be used in myMix for multi-track recording and play back as well as firmware updates. There are many cards available on the market, but not all work with myMix and not all achieve the same quality result.

Compatibility

In order to work with myMix SDHC cards need to be compliant with the SDA 2.0 specification. From firmware version 1.41 on, myMix will check SD cards for SRC entries. If these are not available, myMix will create an error message (CRC Error). In this case please use a different SD card (see recommendations below).

The biggest card size supported in myMix for recording is 32 GB.

UPDATE: We have tested also SDCX cards with 64GB and 128GB. While these cards do not get recognized for the first time when inserted into myMix, they can get formatted. After formatting they are recognized and work like SDHC cards.

IMPORTANT: For firmware updates SD cards should not exceed 16 GB.

Performance

SD cards differ in performance such as reading and writing speed and quality of data (data errors in bad sectors). Especially recording onto a SD card is challenging. myMix can record up to 16 mono or 8 stereo tracks plus the stereo mix. As 24-bit / 48kHz time-stamped wav-files this represents a 1,152 kBits/s data flow, per channel, so nearly 21 MB/s.

Also important are good sectors. There are software tools available to check the actual performance of an SD card, such as h2testware.

Recommendations

With these SD cards we have achieved consistently good results**) for up to 14 channels:

  • Transcend SDHC Class 6: 8 GB, 16GB
  • Kingston SDHC Class 6 & Class 10: 8 GB, 16 GB
  • Transcend SDHC Class 10: 8 GB, 16 GB

With these SD cards we achieved consistently good results**) with 16 channels:

Samsung mico SDXC card (with adapter), EVO and EVO+, 32GB, 64GB, 128GB

  • Toshiba SDHC Class 10: 8 GB, 16 GB
  • ADATA SDHC Class10: 16GB, 32 GB
  • PNY Pro Elite UHS1/Class10: 16 GB, 32 GB
  • Lexar Professional 600x: 16 GB, 32 GB (best in our tests)

**) we tested several cards of the same make, but we can’t guarantee for them.
Note: for firmware updates you need a SDHC card less or = 16GB.

Recording Time

The recording time is depending on the numbers of recorded channels and the size of the SD card. As an indicator a 16 GB card can record 16 + 2 tracks for about 1 hour 40 minutes. Below some calculated values, the actual value depends on the individual card and is displayed in the myMix control bar next to the SD card symbol.

Click on the image for an overview of average recording time:

Important information about myMix and off-the-shelf Ethernet switches

Info: For the configuration of CISCO 300 switches read here (download a AutoConfig file and PDF information file).

Three or more myMix require an Ethernet switch (two myMix can be connected directly to each other). A myMix system with 16 or less channels, powered by the included power supplies, can use a standard 100Mb/s unmanaged Ethernet switch. The switch will simply forward all the data necessary for myMix to operate. You can also use POE (Power-Over-Ethernet) switches to power each myMix.

A myMix requires about 15 watts. The best way to tell if a POE switch will power all of your myMix is to find the overall POE budget of the switch and divide that by 15. This will give you the number of myMix that can be powered by the switch. In case a switch has less POE budget (e.g. 60 W) than your number of myMix (e.g. 6) x 15, you can still use the external power supplied that ship with myMix to power the remaining units (e.g. 2).

On a unmanaged switch you need to keep the myMix system exclusive and can’t mix it with other traffic, as this might disturb the performance.

The current firmware allows a myMix network to contain up to 250 devices and manage a maximum of 500 audio channels. For myMix systems with more than 16 audio channels a managed switch is required. While unmanaged switches work with myMix plug-and-play, managed switches need to be configured.
the myMix network uses two VLANs: VLAN 1 = discovery, VLAN 2 = audio and clock.
Here a list of the most important topics (different manufacturers use different nomenclature):

  • Create a VLAN 2 (VLAN 1 is set by default).
  • Under Port Settings, set all ports within VLAN 2 to General
  • Under VLAN to Ports, set all ports within VLAN 2 to Tagged

Creating VLAN2 is mandatory to transport audio, for more than 16 audio channels additional multicast filtering is needed:

  • IGMP Snooping status must be enabled for VLAN 1 and 2
  • IGMP Querier status must be enabled for VLAN 1 and 2
  • Bridge Multicast Filtering must be enabled for all VLAN
  • Unregistered Multi-cast must be set for Filtering on all ports

To allow proper synchronization (myMix uses PTP IEEE1588-2008, layer 2 transport), the clock needs to be exempt from filtering.

If you plan to use multiple switches you need to configure a GB port on the switch as uplink to forward receive all data.

Note: myMix devices generate their IP addresses automatically (IPv4 Link-Local).
If you are connecting multiple switches you must assign a unique IP address to each switch.

If you integrate myMix in an existing network make sure VLAN2 is exclusively used for myMix devices.

If you are unsure about all of the above: we offer pre-configured Cisco 300 series switches.

See our product page switches for more details.

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