The enclosures feature bass-reflex and passive radiators construction, which helps create their superior bass response, with tilted profile for perfect listening position.

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In 2011, KfW helped finance the construction of about 3, 000 passive houses in Germany.

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Portfolio Solutions, LLC is dedicated to the study of index construction, asset allocation, and portfolio implementation using index funds, ETFs and other passive investments.

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"The majority of our clients are at or nearing retirement, " said Kevin Murphy, construction manager at Anchorage Building Corp. in North Carolina, which specializes in green and passive houses.

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