TRONDBluetooth 5.0 Transmitter Receiver, Bluetooth Adapter for TV, 2 in 1 Wireless Audio Transmitter for PC MP3 Gym Airplane, Receiver for Speakers Headphones Boat Car

Review of the following two items purchased together:Tx/Rx: TROND Bluetooth V4.1 Transmitter Receiver / Wireless 3.5mm Audio Adapter with aptX Low Latency & aptX for Both TX & RX, Dual Stream and Volume ControllerRx: TROND 3.5mm Bluetooth V4.2 Audio Receiver Adapter with AptX Low Latency & Volume Control, for Home Stereo, Wired Headphones & SpeakersBoth are 5 stars IMO. Here’s what I was looking for and what I found:Main objective: Use a BT receiver to allow me to use wired high quality headphones (Sennheiser HD650, HD598, HD555 mod to 595) with BT enabled devices (TV, computers, iPhone 7+, iPods and iPads) and secondary objective of using wired headphones with non-BT enabled legacy devices (iPod classic, older TVs)Why? Good quality BT enabled headphones are expensive and have a limited frequency range (Bose QC35 $349, and Sennheiser HD-1 Wireless $499, 28 ohm impedance, 16-22000 Hz) compared to higher quality headsets (Sennheiser HD650 300 ohm impedance, 10-41000Hz; HD598 50 ohm, 12-38,500 Hz, HD280 64 ohm, 8-25000 Hz). Even though BT has improved up to BT 4.2 and codecs for sound transmission have improved to decrease latency and transmit a broader range of frequencies, it is still cheaper to convert wired headset to BT capability at the inconvenience of managing a dangling cable. I don’t expect the BT transmission to have the same quality as a headphone wired directly to a receiver or iPhone/iPod/iPadWhy did I purchase both?a. Reviews of many bluetooth (BT) receivers (Rx) used to drive headphones reported lag between video and audio. I wanted the receiver, but if there was going to be lag, then I’d pair the Rx/Tx with the Rx to see if that helped. I looked for low latency drivers.b. For non-BT devices (old iPod classic, non BT TV, I needed a BT Tx, so a combo Rx/Tx made sense.What features were I looking for?a. Volume control on the Rx. Why? because the wired headphones don’t have volume control unless I put a volume control between them and the Rx. Samsung Series 6 600D and Series 7 700D UHDTVs with BT don’t provide volume control using the TV remote; therefore the receiving end of the BT Rx has to control the volume.b. Most up to date BT 4.1 or 4.2 so that it maintains backwards compatibility with other BT units (not all BT are the same — i.e. my iPhone 7+ can pair to a Jaybird Freedom, but my iWatch series 2 won’t pair with the Jaybird Freedom).My intended uses:1. Pair Bluetooth TV to Rx connected to headphone, if there is latency, then connect Rx/Tx to TV RCA outs and pair Rx/Tx to Rx connected to headphone2. Pair iPads/iPhone/iPod blue tooth to Rx/Tx in Rx mode or Rx connected to headphone3. Pair Rx/Tx to Rx connected to headphoneDESIGN.Both have the same small form factor, plastic box except the Rx has an on off sliding switch rather than just a single button that has to be held 3 seconds to turn it on. Rx/Tx no sliding on off switch, just a button that has to be held down 3 seconds.EASE OF CONNECTION:Charged both fully. Tx/Rx set to Tx and turned on, Rx turned on 1st time and they paired within 5-10 seconds. Tx/Rx goes to solid blue; Rx goes to LED off blinking blue every 10 seconds instead of solid blue to indicate connection. No I can connect any nonBT device (TV, older iPods, iPod Classic) via male to male 1/8” plug to the Tx/Rx set to Tx mode and headphone connected to Rx and I have a functioning BT system. I just wrap the headphone cords up with velcro and put it on one side of the headband … looks geeky but I’m using it for function, not looks.To set either unit to pair, just double tap the “power button” and they immediately blink red blue red blue until paired. Once paired, Tx/Rx light goes to solid blue, Rx blinks blue every 10 seconds. Even if a connection is active, the double tap “power button” breaks the connection and sets the units to pair mode. Pairing is quick.Pairing to Samsung 600D, 700D UHDTV is easy. Go to Menu Settings > Audio > Select Speaker > Bluetooth. The Trond unit will show up no screen, select pair and it’s done in 5 seconds. Volume control is on the Trond unit; Samsung remote cannot control volume from TV. NO LATENCY on both TVs to Rx/Tx or Rx. Very nice. Don’t need to implement the Rx/Tx —> Rx method. This gives me a BT Rx for each TV now.Caveat, iWatch series 2 cannot pair to either Trond Rx/Tx set to Rx mode or Trond Rx. But iWatch series 2 cannot pair to Jaybird Freedom BT earphone. iPhone 7+ pairs to Tronds and Jaybird Freedom BT and work without problems. This seems to be more of a problem with the iWatch than the Trond units.DROP OFFS and DISTANCE:Connection good to HDTV BT 30 feet away unobstructed. No drops offs of signal or loss of connection with iPhone in pants pocket and received on opposite side of my head indoors. Haven’t tested outdoors where BT can’t bounce off walls. Intermittent breakup when BT Rx separated from BT Tx by a floor (i.e. receiver on 1st floor, Tx in basement, but of course it gets better when I’m standing 1 floor immediately above the Tx in the basement).If paired to iPhone 7+ and I turn on the car to which the 7+ is paired, the Trond connection shuts off and the car and 7+ become paired to give priority to car-phone handsfree connection. Trond doesn’t have a speaker and can’t be used for answering calls (which is not what I got this for).SOUND QUALITY:No lag from Samsung UHDTV Series 6 and Series 7 using the TVs BT. No audio-video lag between TV and Trond Rx, iPad and Trond Rx playing movies on Amazon Prime and Youtube.Sound quality depends upon type of headphone connected to Rx, but the Rx and Rx/Tx can both drive a 300 ohm impedance Sennheiser HD650 without problem. (Avantree Quick Clip reportedly has a hiss and can’t drive anything more than 32 ohm from what I’ve seen on reviews on Amazon).The sound quality (frequency spread) is not as wide as wiring the HD650 directly to my iPod classic, but it’s almost as good (i.e. like listening to an MP3 at 320 kbps instead of a lossless MP4/M4A at up to 1444 kbps sampling). I use MP4 lossless music files as I can hear the difference in quality between 1444 kbps sampling MP4/WAV and MP3 320 kbps max. I am very satisfied with the BT performance from iPhone 7+ to Trond Rx to HD650, and iPod Classic to Trond Rx/Tx to Trond Rx to HD650. Even though reviews say an HD650 is best used with an external amp, I have been more than satisfied with the performance with an un-ampped HD650 driven by an iPod classic or iPhone 7+ lightning to 1/8” plug given the type of recordings I use (which are much better than the 128 kbps stuff found off of iTunes music store … the stuff that many are satisfied using less refined headsets and earbuds).Works just fine with the other HD598, HD 555 mod to HD 595, so it should work just fine with anything lesser. Even the slightly truncated sound of the Tx/Rx to HD650 is still better than any of the other headsets. Wired is always better than BT, but BT is getting close. Other specs:HD280 8-25000 Hz, 64 ohm impedanceHD555 12-38599 HzHD598 12-38500 Hz, 50 ohmHD650 10-39500 Hz, 300 ohmHD1 16-22000 Hz, 28 ohm; this is Sennheiser’s $499 BT headsetBose QC35 $349, QC2, QC3 — I can’t find specs on these, but the Trond’s drive my QC3 just fine. Haven’t tested QC2 and of course the QC35 doesn’t need this. In general, Bose headphones tend to muddy the mids and are thus more bass heavy than balanced headphones.Sennheiser HD700 8-44000 Hz, 150 ohm, $419Sennheiser HD800 19-44900 Hz, 300 ohm, $990I’d rather spend my money on an HD700 than on the $499 HD1, so the Trond BT are a workable solution for me. If they can drive the HD650, I’d anticipate it should do just as well with an HD700.Things I haven’t tested:I haven’t tried the Rx/Tx bind to two Rx to drive two headphones, but this is what would be needed to drive 2 headsets from one TV. I haven’t tested how week the signal would get from an Rx connected to a 1/8” splitter to drive two headsets.FINAL THOUGHTS:1. Trond Rx/Tx and Rx are both 5 star.2. BT pairing is easy, quick and simple.3. No lag between audio and video from Samsung UHDTV BT to either Trond unit.4. Trond Rx able to drive 300 ohm Senheisser HD650 without hiss5. Less cost than the Avantree Quick Clipper Pro and Priva III (which I considered prior to purchasing these). Reportedly the Clipper can’t drive anything >32ohm per specs.If you don’t need a BT Tx, then I’d just buy the $20 Trond BT Rx. If you want flexibility, then get the Trond BT Rx/Tx with volume control which are $37 as of 3/20/2017. Even though iPhone and iPod Classic can control the volume transmitted to the Rx, the Samsung TVs don’t; therefore, I wouldn't get the BT Rx/Tx without volume control or volume at the headset will be loud unless you put a volume control between the Rx and the headset plug.3/24/2017 Update:I liked these so much, I bought another pair of Tx/Rx and Rx. Amazon had a lightning deal on the Tx/Rx for around $25. Great deal.To get them to initially pair, make sure no other BT devices are on. I couldn't get them to pair initially when my BT Samsung UHDTV was on because the TV seems to automatically pair to devices like this. Once I turned off the TV, I could get the Rx/Tx to pair to the Rx. After that, pairing was quick as long as the two were in near contact with each other though other BT devices were on.Update: 4/10/2017When using these with a sensitive, low impedence in ear monitor -- Shure PTH500/530, there is background noise when played at low levels; the Shure can play really loud at a lower volume setting than >50ohm impedance headphones (i.e. No low level noise using Sennheiser HD280 (64 ohm), HD 555/598 (50 ohm), HD 700 (150 ohm), and HD 650 (300 ohm).Paired to Samsung Series 6/7 UHDTVs as well has headphone output on a Yamaha RX-3060 receiver running a connected BluRay, I find no lag between audio and visual, even after putting the movie through various digital signal processes on the Yamaha.

There appears to be a lot of confusion about the various Bluetooth transmitter/receiver products and what they can and cannot do, and what is required to get the benefits of advances in Bluetooth technology. To clarify, there are currently three ‘flavors’ of music quality audio Bluetooth- A2DP, AptX and AptX LL. A2DP is standard Bluetooth that most cell phones, computers, wireless headphones and speakers use. It is serviceable with decent audio quality but up to ½ second of delay. When just listening to music, the delay doesn’t matter, but for watching TV it can be annoying, leading to a batter hitting a ball and the sound coming a beat later, or messing the sync of lips with the words they’re saying. AptX has been around for a while as a higher quality version of Bluetooth audio, with better sound quality and less delay, but relatively few devices support it and it still has a delay of roughly 1-2 tenths of a second. Better than A2DP, and good enough for people who aren’t as sensitive to the delay. But obvious and annoying when the TV sound is on (for people in the room), while someone is listening through wireless headphones.So the AptX people developed AptX LL, standing for ‘Low Latency’, a fancy term for low delay. AptX LL delay can be as low as 40 milliseconds (less than half of a tenth of a second), and for TV watching, is almost undetectable. In order to benefit from AptX LL however, you need a source that is transmitting it and a headphone or speaker that is receiving and reproducing it. This is where I think a lot of negative reviews are coming from- if you don’t have AptX LL at both ends, you won’t get any benefit. Since there are only a handful of AptX LL headphones, and no TV or hifi manufacturers have adopted it yet, miniature devices like the DUO S are designed to let the vast majority of existing audio devices take advantage of this technology.The Trond Duo S provides the most advanced Bluetooth audio experience currently available, and I am very happy with its performance. I bought it specifically to obtain satisfactory wireless headphone listening to my Sony XBR TV. When connected to a continuous source of power via the microsd port, it pairs almost instantly when I turn my headphones on (note many TV’s kill the power to their USB ports when they are turned off, and the Trond will shut off after some time to save the battery, and then need to be turned back on and re-paired when the TV is turned back on, so I would recommend using an old phone charger to power it). I’m using the Avantree Audition Pro, one of the only headphones on the market with AptX LL built in, and the sound is excellent, with negligible delay. The DUO S can also act as a receiver, to turn any pair of headphones with an ⅛” jack into AptX LL wireless headphones, but of course you need two of the DUO’s, one transmitting from the TV or other device and one connected to the headphones.Finally, I must comment on Trond customer service. This has been by far the most responsive company I’ve done business with in the internet age. We’re talking a $40 device from China. I was not expecting much when I emailed them a question. And yet I have experienced a level of communication that would make Apple envious. My emails were responded to promptly, in detail, by individuals with excellent spelling and grammar who clearly want my experience to be as positive as possible. I originally had some issues with getting the LL version of AptX working with my Avantree Audition Pro’s, and instead of blaming the other company, Trond bent over backwards to get to the bottom of the issue and offer solutions. So 5 stars for Trond customer service as well as the DUO S.

I purchased this to connect my AirPod Pros to my Minelab metal detector.So far, so good, with unnoticeable latency. The only thing is I need to use both AirPods instead of one - to help with situational awareness.We’ll see how durable they are!