I’ve got a lot of tech-oriented keywords in my alerts on slickdeals and google, so, like anyone else with even a trace of interest, I’ve been more than inundated, pretty much deeply buried in alerts for endless outfits selling endless mediocre-or-worse Bluetooth speakers.
Sorry, but I have no desire to buy mediocre-or-worse speakers of any kind. The addition of Bluetooth doesn’t make crappy sound reproduction suddenly desirable.
Like lots of folks with a long-standing interest in tech stuff I’ve got a lot of stereo gear of various vintages and quality around. As always with such gear, the digital components tend to be the least quality-sensitive (and subject to Moore’s Law, so the acceptably good stuff gets cheaper FAST), the solid-state analog components much more so (where factors like the actual construction of resistors and capacitors starts to make a difference), the tube components (if any) still more so, and the transducers, that is, the components that convert one form of energy into another (in this case, the speakers) are absolutely quality-sensitive (except for the rare and treasured exceptions when some inexpensive item performs far above its price category by pure serendipity, by accident rather than design). The transducers, the speakers and microphones, are generally where you want to spend most of your money for the best experience.
So, nobody who knows this and has invested in decent speakers is going to be thrilled with having to replace them with an overpriced single meh-quality or poor quality speaker just to utilize Bluetooth. Still, I get literally hundreds of “alerts” for this or that Bluetooth speaker a month. That makes sense, it’s great for the sellers, if they can sell any. It’s lousy for the consumers.
There have been lots of cheap, Chinese external Bluetooth receivers on the market for a long time, most of them virtually identical, usually selling at anywhere from $12 to $20. They typically enclose a rechargeable cell to make them “portable” (usable in a car), the receiver, and have a mini-stereo plug for output. Some of them may have a pair of RCA jacks as well, but usually it’s just the mini-stereo plug. These are the devices that the manufacturers want you to use to Bluetooth-enable various receivers and amplifiers that don’t have the capability, or perhaps have the capability but only for older versions of Bluetooth that didn’t have the bandwidth for decent stereo sound reproduction.
That last is part of the problem- the highest-tech parts of any system tend to be the ones that obsolesce most quickly, so you want them as modular as possible, so that you can replace only the parts that obsolesce… and these devices, like the ubiquitous Bluetooth speakers, are not as modular as possible.
Obviously, Bluetooth is a digital protocol, and the mini-stereo jack output is analog, so the device doesn’t only contain a Bluetooth receiver, it contains a digital-to-analog converter, or DAC… and with that step we’ve set foot in the analog universe with a very, very inexpensive piece of gear. Is it a good DAC? Is it even adequate? We have no clue, they’re trying not to even bring the issue to mind.The one thing we do know is, whatever the DAC is, it’s cheap.
That may not be a problem for long. I’ve got a lot of DACs here, ranging from $5 up to about $150, and my impression is that the ones that do their job correctly all sound very much the same, even if the output is analog. The DAC circuitry itself is increasingly-commonly on a single integrated circuit, so we should, over time, reach a point where virtually all of them do their job correctly regardless of price.
For whatever engineering reasons I can’t fathom, we’re not there yet. There is at least one brand of USB-dongle DAC (and ADC) that sounds just fine if, and only if, you find the version that contains a particular chipset. Just recently I ended up returning a couple of mini-amplifiers I bought. The sound out of them was just fine with an analog input, but they had a USB jack as well, and when I tried to use that as the input the sound was unacceptably distorted, in an odd pattern. A single voice or instrument sounded okay, but once the music got more complex the reproduction started to break down.
We’re just not there yet, for some reason even after good, cheap IC DACs are available, some cheap gear manufacturers aren’t using them.
Just recently a new wave of cheap Chinese external Bluetooth receivers has hit the market, as usual many different brands all seemingly pretty much identical, but these have optical Toslink digital-out jacks. They still have their own analog-out jacks and internal DAC circuitry, but at least now we can bypass and ignore it.
What would be ideal, and what we don’t seem to have yet (I’ve written about this before) is a stripped-down internal Bluetooth receiver module that handshakes as an audio “sink” device, has some output pin or whatever that can be used to turn the power on to an external amplifier (you don’t want a very powerful amp on 24/7 just in case someone uses it with Bluetooth), passes out the decoded digital, not analog signal, and is less complex than a full Linux system like a Raspberry Pi. I’m pretty sure it can be done with a Raspberry Pi, and maybe I’ll even do it, but it shouldn’t be that hard.
While we’re wishing, it would be very nice indeed if there were some way to send the digital signal for each channel to a separate receiver to be played back for each speaker. There are such systems, but they tend to be integrated into speakers and amplifiers , are as proprietary as the manufacturers can make them, and horribly expensive. I understand that there are non-trivial problems with regard to synchronization and timing, but honestly, well into the 21st Century, it shouldn’t be this difficult to get stereo into a bedroom or music playing in multiple rooms without physically running and hiding wires all over the house to carry analog signals. Anyone can effortlessly get music streamed in from anywhere on the planet, it’s just ridiculous that the biggest struggle may well be to get one channel playing on each side of the bed.
– Robert the Wombat