Just a follow-up regarding the Helsinkis' bass capability. As a very, very discriminating dealer of fine audio, I was very skeptical of the Helsinki's ability to reproduce a coherent, correctly timed frequency response throughout a a full range.
We were enchanted with the sound of the speaker at CES, and even more interested in bringing these in house for use with multiple types of electronics in multiple applications. Based upon our subsequent experience, I must disagree with Kana813's assessment of the Gradient's bass capability. In all likelihood, they were not properly setup. By design, the Helsinki's exposed bass drivers function as dipoles and will cancel out if the speakers are setup with zero toe-in. Further, what little dispersion remains will be 90 degrees to the listener.
These speakers MUST BE toed in. Gradient recommends as much as 45 degrees. The bass response, accordingly, can be absolutely remarkable and clearly well below 50Hz. We have had the luxury of experimenting and tweaking these speakers with fantastic results. Further, the speakers can actually be tuned in many rooms more easily than many conventional speakers via the toe-in process.
It has been joy to watch the stunned response of customers who have had the opportunity to listen along with us. We consistently hear "Where is the bass coming from?"
Trust the designer, he knew what he was doing. As with so many audio products, proper setup and system matching make all the difference. Hope this helps.