It's hard to complain about these, since they are literally unicorns. I found these years ago and bookmarked them in hopes of finding something better and more up to date. But, there is nothing else like them on the market, period. There are plenty of two channel wireless devices out there, but all are single sender, single receiver designs, which means that both speakers must home run to the same receiver unit. This simply would not work in my situation, where that would require me to run wires across a hard-surface floor or run up and across my ceiling. I needed something with 2 independent receivers and this puppy is it.

I considered a bunch of different options before finally pulling the trigger on these. I've previously used the AudioEngine W1 (now W3) in a house where I could wire the rears to a common point with minimal visual pollution, but they require an amplifier on the remote end or powered speakers. Two W3s can be used to achieve the objective in this house, but aside from another $150 for the second unit, I'd need small amps for my satellite speakers- or buy amplified speakers. Also, I looked at Sonos and other contemporary soundbar+wireless speaker systems, but then I'm essentially scraping my current investment in speakers and AV receiver.

This thing gets great reviews, which is comforting and factored into my decision. I figured if I kept stalling trying to find a better solution, these might disappear from the market and I'd be stuck. Ordered on December 3, arrived 10 days later. I can't blame the vendor for the slow shipping, since the tracking shows it left their location in Missouri on December 5 via USPS 2 day service and somehow languished in the postal system for days before finally getting delivered here in Florida.

Impressions:
While the kit is brand new, the design is old- I mean, it has a 30-pin Apple dock on the sender unit. The last iPhone to use the 30-pin connector was the iPhone 4- remember those? Not that I intend to use it as a iDevice dock, but it provides a reference point for era this was manufactured. Now, good audio gear can be timeless, so who cares. On the other hand, this uses 2.4 GHz radios (or is it 5.8 GHz?), which is very busy with wifi, bluetooth, and other things competing for channels. Being an older radio, I was concerned it might not cooperate well with other stuff I have going on in the house. I am confused about the operating frequency, since on the back of the box it says 5.8 GHz in large typeface. But everywhere else, including on the box, manual, and Amphony's website it says 2.4 GHz. Googlng the FCC ID on the bottom of the sender unit shows that it is 2.4 GHz (registered in 2011). Regardless, I'm happy to report that so far, everything is getting along.

Build quality is on the cheap side. Like cheap Chinese toy cheap. But, it's what's inside that counts. However, I can't help to think that this is way overpriced. A benefit of the cheap construction is that the receivers are very lightweight (80 watts? riiiight!) and I used some Command strips to stick them to the back of my satellite speakers.

My A/V receiver has pre-outs for the rear channel, so I used the line-level input on the transmitter. Heeding warnings from other reviewers, I set the receivers' gain to a little less than the midway point and used my AV receiver's Audessey to set up the environment. Audessey detected the rear speakers and everything is working! One observation: Audessey calculated the distance to the rear speakers at 30'. They are about 8' away from the where I set the Audessey microphone and Audessey generally reports reasonable distance estimates for wired speakers. So my assumption is that there is a small delay in this wireless setup, however that should not be a problem since Audessey compensates.

I have the transmitter unit connected to the switched outlet on my AV receiver, so it goes off with the rest of the components. However, the receivers don't have power switches and don't appear to auto-power off when the transmitter is off or disappears. Maybe they do, but they revert to endlessly blinking their red light indicting no radio connection. I have no idea if these can stand up to being powered 24/7, but the alternative- plugging and unplugging the wall warts everyday is a non-starter. The manual does say in the 'Important Safety Information' section to unplug if not being used for 'long-periods of time'. So there's that. I've experienced no random pops or noise from the system, whether the transmitter is on or off- good news.

In all, pleased that these do what they promise- hopefully, they will last.

Moved into a new house where I wanted to have good surround sound in the family room. Due to the construction type and level of finish all of the usual cable tricks were off the table. So I ordered up these things to see what would happen. As it turns out they are great! Easy to install and it work well with Audyssey audio correction. Since my lower end Denon does not have surround pre-outs I had to use the speaker outs, which I didn't like but it works fine so no complaints or issues there.
I have a lot of wireless going on in this room so I was a bit concerned about introducing another 2.4G radio, my router is located in the same room as it turns out and is only four feet away from the right rear speaker and Amphony receiver.
Running Audyssey setup for the first time in this configuration, (surrounds are NHT SuperZero's 2.0) the left speaker was perfect, but during Audyssey level adjustment the right speaker would experience drop-outs on a regular interval every few seconds. I figured this was caused but the proximity of the router and could likely be attributed to network polling on the 2.4G band.
Before having to move everything I looked at the router config; after all, the Amphony's say they use frequency hopping to avoid this type of interference. Sure enough the Router (Netgear Nighthawk X4S) was configured to auto select the channel on the 2.4G band (never a good idea if you can avoid it) and, worse, it auto-selected channel 2. As this is sort of a non-standard channel that might have interfered with the Amphony's frequency hopping. I hardcoded this to channel 1, retried everything, and viola! both surrounds were perfect and I did not have to go and move everything. A few more details, my surrounds and the Amphony receivers are only about 25 feet away from the transmitter; Same room, the receivers are on the floor zip-tied to speaker stands and the transmitter is on the table under the TV. Only furniture and people block line-of-sigjht.
These Amohony's work great and are more then powerful enough to drive the surrounds really loud if you want, sound quality is great, power supply does not run hot, build quality is good and setup was quite easy. I have used other wireless speaker things in the past and most of the time they are awful.. These are not and are well worth the money.

It performs flawlessly. I had some issues linking the units. I may be holding the buttons too long. It would help to have some detailed instructions on this procedure (which unit to start with, if any, how long to press the button, etc.). The audio cord that came with the units caused much more background noise when connected than not connected. I replaced it with a highly rated cord and noise level was greatly reduced with this cord connected (similar noise level than when not connected to the transmitter). I have had no pops, dropouts, etc. The receiver is in a wooden cabinet with the majority of the electronics. I am using wired network connections (via units that transmit Ethernet over the house electrical wiring) to minimize wireless interference in that room. The receivers are hidden behind the surround speakers and connect to a pair of old RadioShack Minimus 7s for the rear presences channels. (The Minimus 7s are aimed toward the ceiling). There is no time delay that I can detect. I have boosted the output from my Yamaha 3060 to these channels by about 4 dB so I can keep the output levels of the transmitter and the receivers down to help minimize the background noise. Also, I use a power strip that turns off when the Yamaha is turned off. This turns off the Amphony transmitter along with other electronics to eliminate background noise when the room is quiet. I leave the receivers on and don't notice any background noise with current settings. I would prefer the receivers would go to sleep, as the flashing red lights are noticeable in the dark.

I have been using another wireless kit from Amphony for the last 3 years. It has worked well until recently. There was a directional telecom data link set up a few weeks ago that hits my house and works at 5 GHz. Ever since I am having signal reception issues. I contacted tech support and they advised me to upgrade to this model. I set it up a few days ago and so far it has been working great. It is not affected by either the data link nor my home wireless router. I also have several neighbors who use wireless networks and this product is not affected by those.
Also, I found that the wireless range of this product is improved over the set I was using. With the old set, reception was pretty much restricted to line of sight. As long as I was in the same room it was fine but it would not transmit upstairs. This set, however, transmits fine from my basement to my upstairs bedroom. So overall this product is improved quite a bit. The sound quality is as before which is pretty darn good.
Another difference is the iPod dock. However I have no use for it since I am connecting the transmitter base via speaker wires. But if I wanted to stream from an iPhone to my speakers then I could just dock the phone in the base which would also recharge the phone. Note though that the iPhone connector is the legacy style connector, not the lightning type connector (an adapter would fix that though).
While the transmitter base has changed dramatically from the old one, the wireless amplifiers still look and feel the same as the old ones with the exception of a pairing button underneath the unit. After some research I found out that I can operate several transmitters in the same space without cross interference. Nice to know if some day I wanted to set up more speakers. Note though that one transmitter only sends to 4 wireless receivers at most. With the old product there was no limit on how many receivers could be used but the old unit did not allow multiple transmitters in the same space.
To summarize, I am glad that this product works so well. This has several major improvements and I would recommend upgrading to this model. If you do not already own a wireless speaker kit then I would recommend this because the sound quality is great and it does tolerate wireless interference.

The seller was very responsive when one of them was DOA and replaced it quicker than it shipped. They seem to work decently in a 20x20 room.