The Qudelix-5K is the world's 1st Bluetooth DAC/AMP to support all the latest codec technologies, including aptX Adaptive, LDAC, AAC, aptX HD,  aptX, and SBC. 

aptX Adaptive is Qualcomm next generation dynamically adjustable audio codec designed to deliver robust, low-latency, low-bit rate, high quality wireless audio. 

*aptX and aptX-HD are also supported.

Please check official aptX website: Qudelix-5K

For more Information : aptX Adaptive

Sony's LDAC™ is a new audio technology from Sony that allows you to enjoy high quality wireless audio via Bluetooth. With 3x the data transmitted, LDAC provides an enhanced wireless listening experience for all your music.

*LDAC and LDAC logo are trademarks of Sony Corporation. Qudelix is an official Technical Partner of SONY LDAC.

For more Information : Sony LDAC

Advanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at the same bit rate.

*Please note that aptX Low Latency is not supported.

Only the Bluetooth source devices (i.e., smartphone or PC) have the privilege to choose the codec. 5K is a Bluetooth sink device and provides the supported codec list to the source device at the beginning. And then the source device selects one of them upon.

You can opt-out the codecs to get a specific one active. The source device may remember the codec list received at the prior connection. You may need to remove Qudelix-5K from the system Bluetooth paired list and make it paired again after making any change in the codec option.

For LG V60 users:

Qudelix-5K is the only receiver that supports both aptX-Adaptive and LDAC. LG V60 selects aptX-Adaptive over LDAC. To have LDAC active with LG V60, please follow the step below.

1. 5K APP --> INPUT --> CODEC, Uncheck aptX-Adaptive. Reboot 5K.
2. Remove Qudelix-5K from the LG V60 Bluetooth paired list.
3. Pair Qudelix-5K again with LG V60.

Please note that you will need to completely remove/forget Qudelix-5K from the smartphone Bluetooth paired list once you change the 5K codec list setting.

Optimal LDAC Sample Rate

Sony LDAC supports the sample rate up to 96KHz. Typically, most source audio is 44.1KHz, and YouTube Audio streaming is 44.1KHz as well. Android automatically selects the highest LDAC sample rate, 96KHz, and it upsamples the source audio to 96KHz for the LDAC encoder. For a 44.1KHz source, encoding 44.1KHz@909kbps would provide slightly better sound quality than encoding 96KHz(Oversampled)@990kbps. From the Qudelix-5K FW v1.7.1, You can opt-out the supported LDAC frequencies and fix the LDAC sample rate to 44.1KHz. If you usually listen to 44.1KHz sources, fixing the LDAC sample rate at 44.1KHz, as is, would provide the best sound quality as well as slightly longer battery time.