A few months ago, after performing considerable online research and talking with club members, I purchased a Cardo Scala Rider G4 headset to have a wireless connection to my my Garmin Zumo 550 GPS receiver. For some time, I had been using a wired hookup between my GPS and my favorite ear buds (Etymotic ER-6i's, which are unfortunately no longer being made), but I really wanted to "cut the cords." If feasible, I also wanted a headset that would also allow me to receive phone calls while riding. One week out of every five, I am on-call for work and have been very hesitant to ride for fear of missing one of these work-related call outs (missing one could result in time off-without pay). After considering both the Sena SMH-10 and Cardo's Scala Rider G4, I settled on the G4 headset, especially after positive recommendations by fellow club member and G4 user Paul Winter.
The G4 kit consists a base unit, which you attached to your helmet using either a clamp fit, or if necessary, with an adhesive mounting pad. The standard base includes a boom-style microphone and two small speakers with Velcro backing to mount inside the helmet.
The standard base unit should work well in most full face and three-quarter face helmets. For those with very tight –fitting full-face helmets, an optional base is available with a wired microphone instead of the boom mic. The transmitter/receiver (shown below) mounts to the base by sliding into the base.
The transmitter/receiver uses a Bluetooth connect with your GPS or cell phone. Unlike many older Bluetooth headsets, which are mono audio, the Scala Rider G4 supports stereo Bluetooth. This is a great improvement if you are a rider who likes to listen to music or XM radio from your GPS, while riding.
Placement of the base unit's speakers inside your helmet is critical if you want to have sufficient volume for clear communications. The speakers need to be mounted such that they are directly over your ears when the helmet is being worn. Speaker placement is probably less of a problem if you do not wear ear plugs while riding, but is very important if you do wear ear plugs and this is something that I always do. I was never completed satisfied with the speaker volume and began to explore ways to use ear buds with the Scala Rider G4.
I saw a post on ADVRider.com where an individual, Eileen Kelleher (aka JetGrl), had modified her G4 base to replace the helmet-mount speakers with a 3.5mm stereo plug for ear buds. I learned that the base unit, which you mount to your helmet, includes a small circuit board to which the speaker leads are soldered. It turned out that Eileen Kelleher had been offering her services to make the same modification for a few other ADVRider inmates. (Members of the ADVRider forum are referred to inmates in this asylum.)
Not being an experienced user of a soldering iron and not being inclined to destroy my base unit's circuit board, I contacted Eileen, shipped her the base module, and in slightly more than one week, I received my modified base module. If you are soldering-challenged like me, her $35 charge (which included the return shipping) seems very reasonable. Installation of the 3.5mm plug makes for a very clean configuration, as you can see from this photo.
Having tested the modified unit using my Etymotic ER-6i ear buds, the output volume is significantly improved. The only initial criticism was that the volume adjustment increments were not quite incremental as I would like when using the ear buds versus when using the speakers. Fortunately some experimentation with setting the audio output level on my GPS versus the audio output setting on the Scala Rider G4 eventually arrived at very satisfactory sound output level and the level control desired.
The Scala Rider G4 is an excellent Bluetooth-type headset that I can strongly recommend. If you have been less-than-satisfied with the G4 speaker volume, of if you prefer using ear buds while riding, making the ear bud modification to the base module can significantly improve the headset's functionality.