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Old 6th May 2008, 12:29 PM   #1
flaevor is offline flaevor  United States
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Default How should I implement these...

I have two of these:
Peerless CSX-257W
24 cm bass driver with sandwich cone.
power handling (continuous/programme) = 120 / 160 W
resonance frequency fs = 28 Hz
impedance R = 8 Ohm
SPL = 88,2 dB (2,83V; 1m)
Re = 5,5 Ohm
BL = 10 N/A
L = 2,9 mH
Sd = 330 cm2
effective mechanical mass incl. air load 51,9 g
Vas = 144 l
Qts = 0,35 (Qms=2,56, Qes=0,4)
xmax = +/- 9 mm
mounting diameter d = 220 mm
overall diameter d = 257 mm
mounting depth (not countersunk) t = 99,6 mm

I want to build a sub, but not just any sealed or bass reflex sub.
I want something, anything slightly different. It doesn't have to be small but ridiculously large is also out of the question. It will likely be powered by a plate amp or sub amp like the one from Reckhorn.

I was thinking about isobaric, or TL variations. or an isobaric TL iso MLTL, a tapped horn.

I want it to go deep as possible while still being relatively clean. Basically I really only want the lowest octave or maybe on up to 50 or 60Hz.

My room is about 6m x 6m with an 1,75m opening into another 5m x 5m room. I get good extension with my mains (4- 4" tangbands in a small array BR loading per side) but the last octave is clearly missing.

So anyone with any cool ideas, please share.
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Old 6th May 2008, 06:06 PM   #2
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This is only an idea. A BR box, a 4.order bandpass and a 6.order bandpass sub.
The 4.order doesn't need protection against over excursion.
Boxes 1 and 3 need protection under 25Hz for cone excursion (as an example). When you are set you will be able to choose between TL, Isobaric, BR, PR, Horn, Bandpass or other.

Peerless CSX-257W sub
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Old 6th May 2008, 06:07 PM   #3
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Peerless CSX-257W sub-cone excursion
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Old 6th May 2008, 06:08 PM   #4
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Peerless CSX-257W sub-max spl
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Old 6th May 2008, 06:15 PM   #5
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Peerless CSX-257W sub-spl
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Old 6th May 2008, 06:21 PM   #6
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Peerless CSX-257W sub-vents size
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Old 6th May 2008, 07:59 PM   #7
flaevor is offline flaevor  United States
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interesting suggestions. Just out of curiosity what makes you tend towards bandpass?
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Old 7th May 2008, 12:20 AM   #8
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Quote:
Originally posted by flaevor
interesting suggestions. Just out of curiosity what makes you tend towards bandpass?
If you don't like it you don't have to eat it. Maybe you know already what you want and I am just showing off. I said it's only some suggestions or "an idea". I am not "towards" anything if it doesn't work out for you.

You said: "I want it to go deep as possible while still being relatively clean. Basically I really only want the lowest octave or maybe on up to 50 or 60Hz."..."I get good extension with my mains (4- 4" tangbands in a small array BR loading per side) but the last octave is clearly missing.", you decide. Look at it as an exercise to compare with other options that you will have.
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Old 12th May 2008, 04:47 AM   #9
GM is online now GM  United States
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Well, a ~14 Hz isobaric TH meets your performance goals if 320+ L isn't too big........

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Old 15th May 2008, 11:09 PM   #10
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these (now unobtainable) drivers are almost too good to use for sub duty only, they have excellent low distortion response up to over 1.6 Khz, probably best used as a woofer in a 3-way. I'm getting good results using them in 90L BR cabinets tuned to the high 20s, but if you want something different, how about sealed cabinets around 40L and a Linkwitz Transform filter?
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