Wireless Toslink Transmitter / Receiver: 1Mii

This discussion focuses on finding a solution to a particular issue. I decided against using a television in my San Antonio cave and opted for a projector instead. My reasoning is that televisions tend to be left on for extended periods, creating a chaotic energy in the space. I wanted a setting that is quieter and more meditative, something zen-like. If I watch shows, it should be a purposeful choice, like a true theatrical experience. Plus, I've always preferred the aesthetic of a projector.

The photo below was taken during the day. I’m happy to report that the Epson Cinema 4010 is bright enough for daytime use. At night, when set to "Cinema" mode, it offers deeper blacks than the Epson LED projector I owned a decade ago. I plan to eventually build a larger dedicated screen painted in an appropriate shade of white, as well as darken the other walls in the room. For now, this setup works beautifully. While the blacks don’t reach the "blackness" of an OLED display, I’m among the few who don’t mind—my aim is to recreate the movie theater experience, where even high-end laser projectors often produce grey blacks upon close inspection.


Brick wall, ugh. Need larger screen.

Here’s the situation: the projector is mounted on the back wall, paired with an Apple TV, while on the opposite side, a DAC connects to two JBL monitors. Ideally, I’d run an optical cable up behind the back wall, across the ceiling, and back down to the projector wall, but there’s a hitch—the front wall is made of brick! I’ve broken several cheap drill bits trying to secure the screen and eventually had to use expensive carbide ones to complete the task.


The Epson Cinema 4010 project is massive!

Even though affordable wireless "Best Buy" audio solutions do exist, I’d prefer to steer clear of them. My long-term plan includes integrating a Syn system, adding a center channel, upgrading the speakers, and incorporating surround sound. My question is whether there’s a solution for wirelessly transmitting 2-channel Toslink audio from the Apple TV.

 

After some research, I decided to take a chance on the 1Mii 2.4GHz Wireless Audio Transmitter Receiver, which you can find here: https://www.amazon.com/gp/product/B0CDPRYCWB.

1Mii offers various models, so it can be a bit confusing. The model I chose features optical, coaxial, and 3.5mm ports. The 3.5mm ports are TRS phono and designed for analog signals. I assume the transmitter (TX) side includes an ADC, while the receiver (RX) side has a DAC. However, I didn't use this interface, so I can't comment on its effectiveness.

I did test the Toslink connection, and it works wonderfully. The optical output from the Apple TV connects to the TX box, while the RX box's optical output plugs into the Burl DAC. I’m curious about the coaxial output and whether the 1Mii can also function as a digital Toslink to coax converter; I plan to test this soon and will report back. For your information, 1Mii includes short optical cables, which means I didn’t need to spend extra on Toslink cables. Power cables (USB) are also included.


Oh, I forgot to mention, Apple TVs no longer have optical outputs. Everything is self contained in the HDMI output, thus necessitating an Amazon Basics HDMI / optical splitter. The Amazon Basics box feeds the TX the digital optical TOSLINK. I guess will write about this in later posts.

The 1Mii RX with toslink optical to the Burl B2 Bomber DAC. This DAC has cool meters.

Before diving into this, my main concerns were: Would it even work? How well would it maintain sync, particularly if I powered one unit off? Given that it operates on the 2.4GHz frequency, would it interfere with other wireless devices, or would other wireless devices interfer with the 1Mii?

After about a month of use, I can report that I’ve had generally had no issues. The boxes sync with each other and display a blue light indicator upon powering on. I manually initiated a sync to test the process, and they connected without any issues. They even resynced perfectly when I powered one side off and back on. I did experience some static once, lasting only a second, but it could have been due to an internet or streaming issue. Overall, I’m very pleased with this setup.

As for measurements or subjective audio quality: I DO NOT CARE. Not everything needs measurements or paragraphs of verse*. Besides, I have true galvanic isolation from digital source to DAC. Neener, neerer, neener**.

*What the old audiophile joke? If a product isn't two-channel grade, then it's AV grade.
**I am mocking how us audio nerds were so obsessed with galvanic isolation back in the days of USB de-fuckifiers.

 

Yeah. No basements in Texas. Elevation is too low and too many flood zones. Had basement when I lived in Michigan where it freezes, but it won't freeze in Texas for months at a time like up north. From Austin to San Antonio and further south, there's a big gigantic aquifer with a bunch of limestone on top. The cheap way is to dig up topsoil and lay slab, so no crawlspaces.

Wires run down the wall behind the brick. Didn't feel like hammer and chisel or saw and resultant mess of brick dust that could be used as the surface at the French Open. Also outdoors is like 100F right now, so didn't feel like going up into the attic. The 1mii Toslink TX/RX deal just seemed x20 easier, assuming it worked, which it did.

The delay is about 20ms, and I would expect maybe another 20ms with the DAC. I use Apple TV and do the wireless audio sync calibration thing (TBH, I didn't think it needed sync calibration anyway). BT sound applications on the other hand have always seemed to have significant delay, but assuming this is because of tricky encoding and decoding algorithms running on cheap hardware with mandated transmission power limits.

The 1Mii runs at 2.4GHz. I don't think I have much else running in the house at 2.4GHz (other than BT airpods and a keyboard - all in other rooms), so no issues (unless I get a wireless keyboard with a dong that runs at 2.4GHz and polls at 1000Hz). My WiFi is 802.11ac and computing devices are connecting at 5GHz.

 

Doh! I didn't realized I could do pi2AES with Volumio and use AirPlay! (but of course obviously because I current do Spotify to pi2AES). Now this would be interesting. I would be curious to compare the sound quality between the 1Mii and pi2AES.