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<blockquote data-quote="Art Welter" data-source="post: 132171" data-attributes="member: 52">Re: PK SoundGuy,You were not wrong.You can see what happens with two subs under three conditions in post #18 here:<a href="https://soundforums.net/threads/9787-Stair-Cardioid-Subwoofer-Array" target="_blank">https://soundforums.net/threads/9787-Stair-Cardioid-Subwoofer-Array</a>1) Green trace- 18&quot; cabinet alone.2) Blue trace- 18&quot; cabinet with another along side, the input terminals shorted.3) Purple trace- 18&quot; cabinet with another along, the input terminals not connected (open circuit).Of interest, the Fb/Fc (box tuning) of the horn cabinets in the link is about 35 Hz, the &quot;suck out&quot; is above the Fb.As far as what happened with two bass reflex boxes with two different tunings, hard to say without measuring in the room.It likely would be a similar effect as in the measurements in the link above, the added frontal area (barn doors) of the non-powered sub would provide gain over the entire sub range (more gain in the upper range), while frequencies somewhere around or above the Fb of the non-powered box would be attenuated.The Rat Subs Fb (IIRC) is 28 Hz, probably a bit lower than the PK, the LD saying the PK subs did not have the LF of the Rat Subs could be due to the LF &quot;suck out&quot; the&nbsp; (un-shorted)&nbsp; non-powered subs.</blockquote>

[QUOTE="Art Welter, post: 132171, member: 52"] Re: PK Sound Guy, You were not wrong. You can see what happens with two subs under three conditions in post #18 here: [url]https://soundforums.net/threads/9787-Stair-Cardioid-Subwoofer-Array[/url] 1) Green trace- 18" cabinet alone. 2) Blue trace- 18" cabinet with another along side, the input terminals shorted. 3) Purple trace- 18" cabinet with another along, the input terminals not connected (open circuit). Of interest, the Fb/Fc (box tuning) of the horn cabinets in the link is about 35 Hz, the "suck out" is above the Fb. As far as what happened with two bass reflex boxes with two different tunings, hard to say without measuring in the room. It likely would be a similar effect as in the measurements in the link above, the added frontal area (barn doors) of the non-powered sub would provide gain over the entire sub range (more gain in the upper range), while frequencies somewhere around or above the Fb of the non-powered box would be attenuated. The Rat Subs Fb (IIRC) is 28 Hz, probably a bit lower than the PK, the LD saying the PK subs did not have the LF of the Rat Subs could be due to the LF "suck out" the (un-shorted) non-powered subs. [/QUOTE]

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