Avantgarde horn systems are among the most neutral sounding horns in the world - and it's no secret that the best-sounding Avantgarde installations use Symposium Platforms - which bring out the best from these fine German loudspeakers. Here is a Duo on a Svelte Shelf, which is also isolated and coupled by a set of Series 2 Rollerblocks. This combination elicits absolute top performance from the Avantgarde's active woofer system, and blends the three speaker driver elements (mid horn, tweeter horn and woofer system) together even more seamlessly.