DIN sockets and plugs are a fine connection system for line‑level signals, but they were never designed to carry this level of power, and to my mind there are many better alternatives — the Neutrik Speakon for example. One TAS5754 is connected in bridge mode to the left and right channel woofer while the other amp is connected in bridge mode to the left and right channel ribbon tweeters. An interesting characteristic of the tweeter revealed by the response curves is that its horizontal dispersion at 20kHz is actually slightly wider than at 10kHz. So instead of getting on with the review, I had to walk away for a quick coffee while I grumbled to myself for half an hour, Enough of irritations, though. The cooler running temperature of the voice coil also has the benefit of a more reliable loudspeaker since a cooler voice coil means much less chance of speaker failure.

The new Airblade tweeters have the same build quality as their other drivers, no surprises there really! Moving on, Diagram 3 illustrates the A300's low‑frequency response measured using a microphone positioned very close to the bass/mid driver.Well, the wobbly optical port connection and the sound output from the same is front and centre, the clinical Bluetooth output is another piece of evidence. The mid-woofer features an under-hung high power neodymium motor to provide a high magnetic flux to cover the whole voice coil of the loudspeaker. Inductance varying with coil position will result in both intermodulation distortion and dynamic changes in frequency response.

Before I go on to explain the whats and whys of an underhung voice coil, I suspect you might be wondering who Airpulse are, and what the A300 is.Bass, treble and volume controls are located on the back panel and the A100 come with a remote control too, which is at the nicer end of mini plastic remote quality.

The quantity being measured is how much of the subwoofer’s output is distortion and is shown here as a percentage. For a product as premium as this I would have expected at least one more input, allowing for a bit more flexibility. These graphs neatly illustrate the difference - and advantage- of the heavier-duty driver in the PB-2000 Pro.By the time we are testing with real purpose, the treble has opened up a little but there are still no rough or prickly edges to complain about; certainly, in a sense of being obtrusive, this pair of speakers is easy to listen to. By the way, the A300 does come with a nice little remote that lets you toggle all the functions of the speaker to your heart’s content.

There is a small hump on the inside of the battery door whose task is to push the battery into the remote itself. What you do see occasionally on tweeters with relatively narrow dispersion, however, is the raised level above 10kHz that the A300 demonstrates.That is, midrange sounded rather thin and weedy while treble lacked depth or any real sense of fragility.