Intro
Contents
HiFi and High End audio and Bluetooth don’t really go hand in hand. There are numerous reasons for this, including a gigantic amount of prejudice. And yes, admittedly: we have that too…. Sometimes it is justified, but sometimes we have to admit that it’s time to adjust. Do the Advance Paris WTX bluetooth receivers convince us?
Anyone who thinks of Bluetooth audio thinks of heavy compression, distortion, sloshy treble and a fuzzy stereo image. Or perhaps car audio. After all: there it does come in handy to be able to use the phone as a source.
Something about profiles and codecs
Now there are various protocols and codecs with BT audio. This is to transfer data reliably and in the best possible quality without too much overhead. After all: bandwidth is not unlimited with Bluetooth. Although it does seem so. But know that theory and practice differ. And there is more to audio streaming than just bandwidth.
Let’s start by explaining A2DP. This is an Advanced Audio Distribution Profile. It is a Bluetooth profile for audio transport. This is separate from “regular” audio transmission which is meant for voice. A2DP is meant for music.
It is important to view profiles and codecs separately. A profile basically defines how something should and can be done and which components are needed. Including codecs. The A2DP profile must include at least the SBC codec, to name just one example. However, many manufacturers will support more than one.
The most basic codec is SBC. This codec actually always works and has a bandwidth of up to 510Kbps, but typically it will be around 345Kbps in “High Quality” mode. (At 48KHz).
Now in 2009, Qualcomm launched a better codec to transmit music: aptX. This comes in a few flavors, including aptX, aptX LL (low latency), aptX HD and now aptX Adaptive. AptX HD has the highest bit rate at up to 576 Kbps, which is not bad for wireless audio.
Sony has its own LDAC codec that delivers an even higher bitrate than aptX HD. Sony’s LDAC goes up to 990 Kbps at 32bit / 96 kHz. That’s just impressive. This should offer virtually lossless audio, but without a wire.
Huawei has its L2HC (Low Latency Low Complexity High Resolution Audio Codec). This enables high-res audio over Bluetooth. The codec is lossless and offers bandwidth up to 1.5 Mbps, which should be enough for lossless high-res streaming.
Finally, there is Apple’s AAC. This codec – with which we are all familiar – should make it possible to stream high-quality music via Bluetooth. The advantage is that – if you stream AAC – no éxtra conversion or transcoding is required. However, AAC is not lossless.
Advance Paris WTX
We have the Advance Paris WTX Tubes (349 Euros) and Advance Paris WTX 700EVO (149 Euros). Both bluetooth receivers are based on bluetooth 5 and support the SBC codec, aptX and aptX HD. The WTX Tubes also support AAC. We don’t see that in the sheet for the 700 EVO, but perhaps it is available. We can’t test that, unfortunately. Sony enthusiasts will regret that the LDAC codec is not implemented.
The WTX Tubes uses a WM8740 DAC. The 700 EVO has a Texas PCM 5102 DAC. Both can convert high-res audio.
The unique feature of the WTX Tubes, of course, is the addition of two Raytheon 5703 tubes. According to Advance Paris, that should take playback to the next level with a warm touch that will please many audio enthusiasts. We’ll see!
Pair
Pairing the streamers is really a piece of cake. When the LED flashes, the streamer is in pairing mode. This is automaticly done when it is turned on. We simply need to open the phone’s bluetooth menu and then pair with a single tap. Done!