I got the opportunity to beta-test the brand new wireless MIDI system, called "MIDISTREAM", from Kenton UK.
With this unit the Yamaha WX-5 becomes a cordless electronic wind instrument. I have used some Velcro to attach the transmitter to the bottom end of the WX5. Normally, six AAA batteries in its battery compartment provide the necessary power for the WX-5. The MIDISTREAM transmitter uses a 9V block battery. Due to power consumption and the fact that rechargeable batteries have a lower voltage than non-rechargeables, I modified my WX5 and Kenton transmitter so they both run of 8 rechargeable AAA batteries inside the WX-5 which are charged through a special stand. Power from the WX-5 goes to the transmitter using a formerly unused lead of the MIDI cable. See Yamaha WX-5 Modification 2 for more info about this. A standard 5 pin DIN MIDI cable connects the WX5 to the transmitter. The receiver has two antennas to optimise reception of the signal which is transmitted at 869.75MHz for the UK/EU models. (For the USA Kenton has developed a model transmitting at 914.5MHz to comply with USA rules.)
The latency is very low; 2ms according to Kenton. I didn't time it, but I have never noticed any difference between the cable or the wireless unit. This is a major improvement compared to stories about other units that were on the market some time ago. As to range, I play in a small combo and my rig is never far away from me, so I have not even had the slightest chance of getting out of range, which is according to Kenton at least 80 meters (260 feet) in ideal conditions. I did try to walk away from the unit when it was in my upstairs home studio and walked down two stairs to the living room and closed the doors. I increased the volume so I could hear the synths. The unit did not even miss any notes.
This makes this unit a very handy piece of equipment when you are recording in a studio with a separate live room and want to sit in with other musicians and have your synths and other MIDI equipment connected directly to the desk in the control room.
The Kenton MIDIStream Wireless has actually two receiving channels, A and B, that work simultaniously. This design prevents stuck MIDI data; if one channel is two weak the other one saves the operation.
There's one thing to keep in mind and that is the power consumption of the transmitter. When I started with this unit, I invested in NiMH rechargeable batteries for both the WX-5 (2 sets of six AAA 750 mAh) and the transmitter (2 sets of one 9V block battery 150 mAh). Especially the 9V batteries don't last very long. Since the transmitter draws about 50 mA the 150 mAh will last about 3 hours. I have seen normal, non-rechargeable, 9V block batteries with a power of up to 1200 mAh. These will last about 24 hours, aren't cheap and can't be used again. I have been looking for more powerful 9V blocks, apparently there are 350 mAh NiMH versions on the market, which should last long enough. At that time, it wasn't a problem for me, since I didn't play the WX-5 all the time. Whenever I changed to one of the acousitc saxes, I switched off the WX-5 and the transmitter to extend the life of the batteries. This got me by for a night gig without changing batteries. The Kenton gives an alarm through a blinking LED on both the transmitter and the receiver when it's time to exchange the battery. Next to that, everybody will have a minute time during a gig to exchange a battery, since that's how long it only takes.
The six 750 mAh AAA batteries in the WX-5 lasted about 6 hours, when fully charged, since the WX-5 draws approximately 60 mA. That was good enough. Non-rechargeables will last much longer because their power can go up to about 1500-2000 mAh.
The power consumption was the main reason to build the Rechargeable WX-5 with stand. Since I now only play wind controller it needs to stay on much longer.
Another option would be a special WX version of the transmitter that could power the WX as well as the transmitter. As long as it would have room for 8 AAA or AA batteries (or other 9.6 V battery pack with at least 900 mAh of juice), a WX connector (which is available on the WX5 and holds both MIDI signals and power) and a quick charge connection it would be ideal. A special charge stand could make the package complete.
ATTACHING THE TRANSMITTER TO THE WX-5
I use black Velcro tape to attach the Kenton transmitter to the WX-5. The soft Velcro side is taped to the bottom of the WX-5.
A piece with the same length (length of the transmitter box) of the rough Velcro side is taped to the Kenton transmitter box.
I shortened a standard MIDI cable to easily fit between the transmitter and the 5 pin DIN MIDI connector of the WX-5.