Windows Phone Thoughts: Thinking 'Out Loud' - TDK's Imaspeaker Reviewed

Power
The stereo version requires three AA-size batteries, while the mono version only requires two. I haven’t done an extensive run-down test, but I’m finding the battery life to be exceptionally good. I’ve used the unit for about two weeks now, about 10 to 15 hours a week, and everything seems to be just fine. Unfortunately, this also adds to the overall weight of the unit, but I didn’t find it to be unbearable.

Sound
Generally, the quality of sound from Imaspeaker is pretty good. You can certainly get a better, more even response from a good set of headphones, but we went to speakers for a reason, didn’t we?:-) The frequency response is good and I didn’t notice any particular peaks or valleys. I couldn't find a response graph, but I suspect the specified range is the usual +/- 3db. It’s interesting to note from the specifications that the stereo version has better bass response and weaker treble capability. This fits with what I heard, in that while the bass was pretty solid, higher notes sounded a bit weak and mushy.

You certainly won’t get concert hall quality from these speakers, but it is much, better than that available from the laptop or your Pocket PC speakers. Unfortunately, on the stereo model, the left and right speakers are mounted directly beside each other on one side of the case. Thus, there is no way to get any separation of the left and right channels. This also contributes to a bit of mushiness, especially in the mid-range and higher frequencies. You will also lose some of the ambient sound from concert hall and live performances.


Figure 5: TDK’s Imaspeaker in normal use.

Volume
The volume of sound produced by Imaspeaker is reasonable, but be careful not to overdrive the speakers’ amplifier from the source, as they will distort badly. I didn’t push it, but too much input from the source may actually damage the amplifier in Imaspeaker or the speakers. (The specs say no more than 10 watts peak per channel.) At three watts, the volume is sufficient for a large boardroom of people, but it’s not going to make much of a dent in a booth on a busy convention floor. And it certainly wouldn’t work as a Public Address System, but that isn’t really the point, is it? The volume level is set by the controls on the source system (laptop, Pocket PC, MP3 player, etc.). There is no volume control in the Imaspeaker unit.

Specifications
The figure below, courtesy of the TDK Web site, provides the complete specifications for both the stereo and mono models of Imaspeaker.


Figure 4: Imaspeaker specifications (courtesy TDK).

The plug provided with Imaspeaker is the standard 1/8th inch (3.5mm) plug which should allow it to connect to almost any sound device available. Unfortunately, the cord is very short, but I guess the idea is to keep the source in the mesh pocket within Imaspeaker.

I suspect the weight specs provided are for the unit without batteries installed.

Conclusions
I think this is a neat concept. It provides a very portable package for personal listening when you don’t want to use headphones, or for presentations on-the-go. Maybe we can get separable speakers and a smaller overall design for the next version. :)