P.A. 18 TH (18tbw100 30x38x22.5")
Ran a quick rough calculation and rough sims, here is what i came up with.
internal cabinet width 21"
external dimms 30"x38"x22.5"
driver is b&c 18tbw100
$387 from P.E.
$352 shipped from savinglots.com
and with 2.83V
and with 900w
Same exact fold as the PAL12. Driver center (10" from s1) is moved up in the throat so it will physically fit in the cabinet. Other lengths shortened accordingly.
18mm Baltic birch recommended.
cabinet can likely handle more power...the 18tbw looks to be a good strong driver
I'm not in fromt of the computer anymore. I will run it later.
Reason I did it this way was due to Art's suggestion in my other thread, using two different subwoofers...
Wanted to keep the same fold as the PAL12 just with a wider cabinet
just a sugestion
Ang=2.0 x Pi
edit/ah yes i remember the topic now.
anyway you can try, it maybe a testbox .
looks like you can get a bit more in the 60-80 range
seller TSG at Ebay has or had some custom Eminence 18 with claimed 5" coils and 160oz slug
TSG 18 inch Subwoofer 5 inch Voice Coil Free Shipping Any Reasonable Offers | eBay
TSG 18-250 18" Subwoofer
with 5 Inch (125 mm)Voice Coil
Call 801-771-1820 with any questions.
Nominal Basket Diameter 18", 460mm
Nominal Impedance* 8 ohms
RMS Watts 800W
Music Program 1600W
Usable Frequency Range 34Hz-3.7kHz
Sensitivity*** 99 db
Magnet Weight 160 oz.
Voice Coil Diameter 5", 125 mm
THIELE & SMALL PARAMETERS
Resonant Frequency (fs) 35 Hz
DC Resistance (Re) 5.0 ohms
Mechanical Q (Qms) 9.21
Electromagnetic Q (Qes) .29
Total Q (Qts) .28
Compliance Equivalent Volume (Vas) 249.4 liters / cu.ft.
Peak Diaphragm Displacement Volume (Vd) cc
Mechanical Compliance of Suspension (Cms) mm/N
BL Product (BL) 24.3 T-M
Diaphram Mass inc. Airload (Mms) 148 grams
Efficiency Bandwidth Product (EBP)
Maximum Linear Excursion (Xmax) mm
Surface Area of Cone (Sd) cm2
Maximum Mechanical Limit (Xlim) 12 mm
Baffle Hole Diameter
Front Sealing Gasket Fitted as standard
Rear Sealing Gasket Fitted as standard
Mounting Holes Diameter 0.28", 7.1mm
Mounting Holes B.C. D.
Net Weight 35.7 lbs.,
Shipping Weight 73.9 lbs.,
MATERIALS OF CONSTRUCTION
Coil Construction Aluminum voice coil
Coil Former Polyimide former
Magnet Composition Ferrite magnet
Core Details Vented core
Basket Materials Die-cast aluminum basket
Cone Composition Paper Cone
Cone Edge Composition Cloth cone edge
Dustcap Composition Solid composition paper dust cap
Would you post a comparison or the two responses?
Both sims show a 4db dip. Once I get back on my computer ill do a direct comparison of the two
In testing the dip on the PAL12 cabinet wasn't that bad. It was there, but not as exaggerated as hornresp made it seem
Is there any way you can adjust the scale on the REW measurments to match the scale of hornresp? i have no idea why REW rrpresents data on a 10db scale, cause that pretty much makes everything look 'flat'
This is from the PAL12 measurement.
Ignoring the 80hz and up peak, from 38hz up with no EQ....it's +/- 2-3db.
The sim showed more of a dip in there...
I agree that below 80hz it is quite flat. however, without actual 2.83v 1 meter measurement ithink its hard to say this is actually due to 'better results' when compared to the sim. while i agree you are only about -2/3db between your 40hz peak and your 60hz valley, its still about 6db down from its 95hz peak, which is more in line with the sim. this suggest to me that rather than 'gaining sensitivity' in the 50 to 70hz range, you've just lost a little bit of the low freq peak, which makes it appear flatter, but is a result of lost sensitivity.
This could also be a product of slight lf rolloff of the measurement mic i suppose, and initialy i thought this was one of the 30hz filter graphs, which would put it like 1.5db down at 40 hz but at second glance that doesnt seem to be the case
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