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<blockquote data-quote="Frank Koenig" data-source="post: 72061" data-attributes="member: 416">Re: Reasonably Priced Large Format Line ArraysJust as an aside, one place where you get a 9dB/octave penalty is from the relationship of reference efficiency, box volume, and cutoff frequency for vented-box direct radiators.For a fixed box volume the reference efficiency varies as the&nbsp; cube of the cutoff frequency, which gives 9dB/octave.This is from eq. 35 in &quot;Vented-Box Loudspeaker Systems - Part 1: Small Signal Analysis&quot;, R. H. Small, JAES June 1973, Vol. 21, Number 5.We have to be careful what we&#039;re talking about here: horns or direct radiators, efficiency (small signal) or power output (large signal).For large signals, in the normal operating range of a direct radiator away from the box resonance, excursion varies as the inverse square of frequency, giving a 12dB/octave penalty when we are excursion limited.--Frank</blockquote>

[QUOTE="Frank Koenig, post: 72061, member: 416"] Re: Reasonably Priced Large Format Line Arrays Just as an aside, one place where you get a 9dB/octave penalty is from the relationship of reference efficiency, box volume, and cutoff frequency for vented-box direct radiators. For a fixed box volume the reference efficiency varies as the cube of the cutoff frequency, which gives 9dB/octave. This is from eq. 35 in "Vented-Box Loudspeaker Systems - Part 1: Small Signal Analysis", R. H. Small, JAES June 1973, Vol. 21, Number 5. We have to be careful what we're talking about here: horns or direct radiators, efficiency (small signal) or power output (large signal). For large signals, in the normal operating range of a direct radiator away from the box resonance, excursion varies as the inverse square of frequency, giving a 12dB/octave penalty when we are excursion limited. --Frank [/QUOTE]

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