The Qu range of mixers includes SD Card port for Multitrack recording and Playback.
The file allocation format required for this feature is FAT-32; Formatting your SD card to FAT-32 can be done directly in the Qu UTILITY / USB Utility / Status/Format screen. This will also setup the correct folder structure.
There is a wide range of brands and models for SD cards in the market, as well as multiple differences in technical specifications among them, which relate to type, speed-class ratings, and capacity.
While it might seem easier and better to simply use the highest and fastest SD Card, this doesn’t always result in the best performance!
To guarantee an SD Card performs at its advertised speed rate while writing or reading data, the host hardware and SD specification must match.
For example, speed of U3 class will only be achieved if both the SD card and the host support U3 speed. If an SD card has a UHS speed class of U3 but the hardware of the host has speed class of U1, this can result in a data transfer speed lower than that of a U1 Card and create errors while writing or reading data.
The hardware of Qu consoles support SD cards SDHC, Class 10, UHS-I / U1, for best results, we recommend SD cards with the following markings:
Type: SDHC (SD High Capacity) has a maximum storage capacity of 32GB. While it may seem like a higher capacity is more convenient, a SDXC card with higher capacity may also have a different writing speed.
SDHC cards are also usually formatted to FAT32 by default.
Capacity: Due to the recommendation of SDHC over SDHX, the maximum capacity will be 32GB.
Speed: Writing and reading speed of the card, based on its Speed-Class rate.
Speed Class: Industry standard C10 (Class 10) has a minimum write speed of 10MB/s
UHS Speed Class: UHS-I (Ultra High Speed) theoretical maximum transfer speeds up to 104MB/s
U1 has a minimum sustained write performance speed of 10MB/s
Both U1 and U3 memory cards can utilise the UHS-I bus interface but are not compatible with the UHS-II bus interface.
Video Speed Class: This is in fact not relevant for our application, but it’s worth clarifying the meaning of this marking to avoid confusion.
FAQ
I have an SD card with different specifications which my Qu console can detect and read, can I use this?
Users are welcome to test and use any SD card. However, due to the hardware installed on the console, the recommended SD cards are the only ones guaranteed to provide best performance.
Can I use Micro SD Cards?
Yes, Micro SD cards inside of an adapter can be used, following the above specifications.
What happens if I use a lower speed class SD card?
When writing audio data, the rate of MB/s required depends on the number of channels being recorded, their Sample Rate and their Bit Rate.
To cover a maximum of 32x32 @ 48kHz or 16x16 @ 96kHz, an absolute minimum speed of 4.6 MB/s is required
Selecting a lower speed class SD card means that the minimum write speed is lower, which can result in errors of data being written.
Where the Qu can detect the speed or performance of the card and finds it lower than Class 10, it will automatically reduce the total number of channels which can be armed.
What is the buffer usage?
Buffer usage meters indicate the performance of the connected storage device by displaying how full the buffers are. If buffers are filled and the meter peaks into the red, data will be lost and an error will be counted.