Bluetooth Receiver Transmitter, Keedox V4.0 Bluetooth Music Receiver Transmitter Wireless Audio Receiver Stereo Transmitter with aptx for Headphones Car TV

I am using this device to TRANSMIT to a pair of Soundpeats Qy7 Bluetooth Earbuds for private listening from my older Sony TV. Overall it works extremely well in this application. It replaced a TaoTronics TT-BA06 Bluetooth Transmitter that failed after three weeks (first it unpaired and refused to re-pair, then the USB socket broke off and fell inside the unit, making it impossible to charge.) I have not purposed it as a RECIEVER; according this review speaks only to transmitting.The positives for this Keedox unit is pretty much the same.First the major positives:Setup was a snap, 1-2-3.(1) I purchased a 5' Red&WhiteRCAMales-to-3.5mmMiniAudioFemale wire (since the equivalent wire Keedox supplied was far too short for my application). I plugged its Red&WhiteRCAMales into the "Audio Out" Red&WhiteRCAFemales on the back of my TV. Then I used the supplied 3.5MiniAudioMale-to-3.5MiniAudioMale to connect the other end of the 5' purchased wire into the back of the Keedox. That wiring accomplished the audio connection.(2) Next, to accomplish constant power/charging, I connected the MicroUSBFemale on the back of the Keedox chassis to the supplied 4' USBMale-to-MicroUSBMale and ran THAT wire to the wall socket. Then I plugged the USBMale end of that wire into a (purchased) USBWallCharger (specifically a PowerGen Black 4.2-Amp 20 Watt Dual USB Wall Charger). (Keedox does NOT supply any such wall charger unit.) Plugged that into the wall socket. Let the Keedox charge up for several hours, until the sold red "charging-in-process" light went dark.(3) To accomplish pairing the Keedox with my Soundpeats Earbuds, first I turned off all the other Bluetooth devices in the vicinity that would broadcast for pairing (such as my phone, the Roku, etc.). Put the Keedox into pairing mode by holding down its main power button for about 3 seconds, until it powered up and displayed a rapidly flashing green light indicating pairing mode. Then, while holding the Soundpeats right next to the Keedox, I put the Soundpeats into pairing mode by holding down its main power button for about 5 seconds, until it flashed red then blue in an alternating cycle. The two units then completed pairing automatically and almost instantly. When paired and connected, the Keedox LED lights solid green.Mission accomplished.Sound quality is excellent. Maximum volume is very high. There is a slight latency (and any Bluetooth transmitter will have such) but since I just toggle from TV speakers to AudioOut (using my TV's remote control) for private listening, this is not an huge issue for me. There is no stuttering or break-up. The unit is stylish in appearance. The User's Manual is mediocre in instruction and translation, as is so often the case anymore. However, overall, this appears to be a very high quality product.The major SHORTCOMING is that as soon as I turn my earbuds off, the Keedox unpairs with them, and starts flashing the rapidly flashing green LED, as if it wants to re-pair. However it does not actually re-pair in that mode. The Keedox must be turned off, then turned back on again to truly obtain pairing mode. Then I have to re-pair the earbuds all over again. Not good. Not good at all.It shouldn't be difficult to presume how the user will use such a transmitting device. Accordingly, product engineers & designers should easily realize that it should(1) power down after the audio feed has been ended for a while,(2) power up automatically when an audio feed is re-detected and(3) it should remember its pairing and automatically connect to its paired device when that paired device is powered up.This unit does NONE of those three things. Hence my three-star rating.My prior set-up, Sennheiser headphones with a 110 volt-wired transmitter, DID provide (1) & (2). And since it was not Bluetooth, I didn't even have to deal with pairing at all.I am going to guess that (1) & (2) don't happen because the designers wanted to avoid the constant draw on the battery. I am going to guess that (3) doesn't happen because the designers wanted to avoid the cost of a non-volatile memory chip.I say add a dollar to the price and throw in constant trickle power draw with an adapter … and also throw in the memory chip … and customers will surely be a lot happier with the product.UPDATE [2015-8-27]: I am still using this Keedox device and I do not expect to search to replace it. Again, it does forget its pairing as soon as I turn my SoundPeats earbuds off. So each time I use it I have to:(1) turn on the SoundPeats earbuds -- AND hold the ON button down long enough for them to go into pairing mode, then(2) turn on the Keedox device -- AND hold the ON button down long enough for IT to go into pairing mode. It will automatically re-pair to the earbuds very quickly.(3) Then, when I am done using the earbuds and turn them off, I also have to go turn off the Keedox device.Also, if I take the earbuds out-of-range, they announce that fact then cut off ... and in that case I, again, have to follow the three steps above.A bit of a hassle, but not a deal-breaker.

This is a simple, basic Bluetooth transmitter that just plain works. I was looking for a transmitter that would allow me to attach it to an audio source such as my amplifier's "phones" jack and then listen to the audio on my new Bluetooth "Beats" headphones. This transmitter works perfectly. I am keeping it plugged into a micro USB power adapter so I can't comment on how power-efficient it is. After a short time with no device synched to it, it goes to sleep and upon activation must be resynched. That takes only a few moments though.Typically, I turn on the headphones, put them on, and plug the Bluetooth transmitter into the amp. Then I hold down the power/sync button on the transmitter for a few seconds until the it shows a green flashing light. Then I press the center button on the left ear cup of the headset for two seconds, and after a pairing sound is emitted by the headset the transmitter and headset pair. From that point forward the program audio comes from the headset. I have also connected the transmitter to the audio outputs of various other devices using various adapters with perfect results.All the necessary adapters are inexpensive and all are available on Amazon. You have to start with a mini phone jack at one end and whatever you are getting the audio from on the other end. In my case a I am using a cable with a mini phone jack on either end. One end plugs into the transmitter and the other into a 1/4" phone jack adapter. The 1/4" adapter plugs into my amplifier. for other devices I use a cable with a mini phone jack on one end to plug into the transmitter and RCA plugs on the other to plug into an analog audio output.

Using as a transmitter, worked as expected for a couple of days, 2 hours or so each day. Always recharged, before use. Then, it began to cut off, not stop transmitting, completely shut off. First time this happened, it had been working for 5 minutes before shutting off. Next time I used it, it lasted for 2 minutes. Currently, it will transmit for about 15 seconds before dropping out. 1 or 2 devices paired, it does not matter.Update: Contacted Keedox support within a couple days of the original review and explained the issue. They indicated that it was likely a battery issue and quickly sent a replacement unit. Charged it and, to date, it is working without issue. High praise for customer service.

This little gizmo left me surprisingly happy. This is the connection point between my bedroom TV and a bluetooth speaker by my bed. I'm hearing impaired and need something close to keep the audio levels to a minimum for the benefit of the rest of the house. It paired up with the speaker unit right away, no muss/no fuss. Remembering to charge it every day is a bit of a challenge (okay, my memory's a bit impaired as well...), but I didn't find a unit with an onboard power supply that wasn't big and bulky. I was prepped for annoying lag between audio and video - if I'm really focused on it, I can notice just a bit of lag, but for casual viewing it's not noticeable at all. Awesome piece of technology.