Test three: Performance
When testing the transmitters on the road, there didn't seem to be anything to choose between all the models we tested when it came to the quality of the sound they produced. Perhaps the Belkin sounded a fraction louder than the others, but it was too close to call.
Obviously, the Logic 3 didn't perform well when plugged into an iPhone rather than an iPod, but it does say it's meant for iPod only on the packaging, so won't judge it harshly. We didn't experience any signal drop with any unit, and none of them lost its station more frequently than any others, so in this respect we can't fault any of them.
The overall quality of sound has more to do with your car's stereo system than it does with which type of FM transmitter you use.
And the winner is… Belkin TuneBase FM LIVE - £30
Top quality for a great price. This has everything you'd want from an FM transmitter
We have to give this to the Belkin. It's got all the features we could ask for from an FM transmitter, and at a superb price, but most important is the convenience of having a stand for your iPhone or iPod when using it. Without a cradle to sit in, we can guarantee that at some point your precious iPhone will end up taking a hard knock on the floor as you brake sharply or take a tight corner and it flies off the passenger seat.
Inevitably, as you drive along you'll move into the range of new local radio stations, which can interfere with the frequency you've chosen, so you'll need to change frequency, and without a stand you'll have to hold your iPhone or mess about with buttons on the transmitter to do this, which isn't exactly safe driving. With the Belkin, you only need to give its app a little glance and tap the screen to change frequency, minimising distractions.
The only downside is that your iPhone being so accessible tempts you to do more with it while you're driving, such as texting, which is not only stupid and dangerous, but also illegal. We're sure you'll use it responsibly, though.
The Griffin iTrip Auto is a strong second place in our group test. It's a nice product, and we should note that Griffin also do a RoadTrip HandsFree that has the same benefits of the Belkin model on test here and costs £65, although at time of writing Amazon were doing it half price.
If you're after a budget FM transmitter, the cheeky little KitSound MY FM gets our vote. Sure, it's a strictly no-frills product that lacks the option for having any preset stations, but it's got a very readable display, autoscans for frequencies and it just works. In contrast, it makes the Monster iCarPlay Wireless (which does have presets, but no autoscan), with its '80s clock radio style LED display and fiddly control system, look very long in the tooth.
We should note that the Logic 3 is the only transmitter at the lower end of the price scale that includes all the bits you need to actually charge your device in your car; it's just a shame they don't do a charging version that supports the iPhone.
Note that Logic 3 also sells an FM transmitter that looks exactly the same as the KitSound MY FM, just with different logos on it; we'd imagine this performs exactly like the KitSound, since it's essentially identical.