| Food For Thought For Builders [message #21877 is a reply to message #21876] |
Wed, 17 October 2007 19:33   |
DrD
Messages: 19
Registered: May 2009
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Chancellor |
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It needs to be pointed out that although the PAWO and Mini Onken work well with the 5.5, these alignments were not intended for this driver, making it a sub optimal load. I had Scott Lindgren, who is a wiz at Martin J King's MathCAD tables do his own calc for me, for a BIB, which concurred with my own calcs. With the bigger cabinet, and long 138 inch line to keep the driver in check, I would bet a paycheck that as good as the PAWOs and Onkens sound, the BIB will be streets ahead in all ways, including SPL, and fantastic bass reach, we both calcd F0/34Hz, F5/30Hz, with ~92db in the presence region, and all this without room gain. Imagine what a bipole 5.5 BIB would be like...
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| From DrD [message #21882 is a reply to message #21881] |
Wed, 17 October 2007 22:39 |
Eric Gonzales
Messages: 32
Registered: May 2009
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Baron |
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By the usual T/S pipe-horn calculations Greg Monfort came up with, it'd need a bloody big box due to that high 0.657Qt (see specs sheet 003 you sent). Footprint would be ~150in^2, plus build materials, which is a bit daft for a small driver.
However, due to Vas being low, an under-sized box with a CSA of 65in^2 can be used, because although the LF drops off compared to the ~'ideal', in the LF it's still at least 10db over the driver's nominal IB response, & ~flat to about 34Hz & that's before room-gain kicks in. See the example FR I've attached for a 64in tall box with driver 27.75in down & 65in^2 terminus CSA. The low Vas also means the box air-mass should still be sufficient to help keep the the driver in check. Basically, it's not going to be too critical. Minimum CSA 65in^2, anything you can add to that up to about 145in^2 is a bonus. The 64in tall box BTW looks favourite to me, so it's tuned fractionally below Fs.
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| Re: FRP [message #21884 is a reply to message #21883] |
Wed, 17 October 2007 22:54 |
DrD
Messages: 19
Registered: May 2009
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Chancellor |
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Note that the program calcs the 5.5 ~95db SPL in half space, and this is without added room gain, which with the bigger BIBs is considerable. Note F7 is 30Hz. Note also how it can be EQ'd from the lower register right through into the treble region, at greater than 90db, more like 95db. Note also that if one subtractively EQ'd to ~90db, F3-30Hz. Interested yet? Thanks Eric for doing the thang.
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| specs [message #21929 is a reply to message #21867] |
Tue, 13 November 2007 16:10 |
Eric Gonzales
Messages: 32
Registered: May 2009
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Baron |
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Here are some specs I received courtesy of DrD http://homepage.mac.com/vizion8/DCA5.5M-specs1.jpg
http://homepage.mac.com/vizion8/DCA5.5M-specs2.jpg
http://homepage.mac.com/vizion8/DCA5.5M-specs3.jpg
http://homepage.mac.com/vizion8/DCA5.5M-specs4.jpg
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