I picked these up from a friend that is an audio engineer. He said they came out of a regal cinemas which seems kinda strange. The cabinets are homemade, but are really well made with 1.5" thick mdf. The woofers have no labels which makes me think cheap, but everything else from this regal cinemas has been nice stuff so who knows. I just thought I would check to see if they caught anyones eye. They are 18" and have different dust caps, but are the same woofers. If they end up being crap oh well, I didn't pay a whole lot and just got em to mess around with.
Attachments
Here is what I hear back from eminence:
This product was for Premium Performance (GE). The specification is 18449.
T/S Parameters:
Date is 6/23/2003
Fs is 30.36 Hz
Qt is 0.30
Vas is 476.76 liters
Re is 6.24 ohms
SPL is 98.2 dB
Qe is 0.31
Qm is 10.62
Xmax is 6.03 mm
Le is 1.01 mH
Bl is 20.96 T * m
Eff is 4.19 %
Mms is 115.6 grams
Cms is 0.2379 mm/N
Rms is 2.0751 Ns/m
Sd is 1188.00 sq. cm.
EBPR is 98.6
The product has a 120 oz magnet, with a 3” voice coil.
This product was for Premium Performance (GE). The specification is 18449.
T/S Parameters:
Date is 6/23/2003
Fs is 30.36 Hz
Qt is 0.30
Vas is 476.76 liters
Re is 6.24 ohms
SPL is 98.2 dB
Qe is 0.31
Qm is 10.62
Xmax is 6.03 mm
Le is 1.01 mH
Bl is 20.96 T * m
Eff is 4.19 %
Mms is 115.6 grams
Cms is 0.2379 mm/N
Rms is 2.0751 Ns/m
Sd is 1188.00 sq. cm.
EBPR is 98.6
The product has a 120 oz magnet, with a 3” voice coil.
Nice catch !!!, I'm betting many of us are plugging in those TS parameters to the SIMS as we speak, to see "how low" one can get these...
----------------------------------------------------------------------------------------------------------------------------------------------------Rick...
Ha, I got it...my SIM gets a "recommend values of 179.4 liters worth, but a disappointing -3.04 Db @ 46.06 hertz...sad face ...but by tweaking things I get 350 liters, fb of 39.7 hertz for a decent -3.04 Db @ 36.61 hertz.
Sounds like a big two-way with a giant horn up top reaching down some 1K hz....with the sensitivity of said horn dialed back.
----------------------------------------------------------------------------------------------------------------------------------------------------Rick...
Ha, I got it...my SIM gets a "recommend values of 179.4 liters worth, but a disappointing -3.04 Db @ 46.06 hertz...sad face ...but by tweaking things I get 350 liters, fb of 39.7 hertz for a decent -3.04 Db @ 36.61 hertz.
Sounds like a big two-way with a giant horn up top reaching down some 1K hz....with the sensitivity of said horn dialed back.
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Sounds like the builders of Blazemaster's boxes went for something like that.
For flat and low (F3 ~26Hz, Fb 29Hz) the 18449 requires a huge box the size of it's Vas (476L).
27 volts (~80watts at Fb) will reach 6mm of excursion, the driver's Xmax, with over 115dB at 30Hz:
In a 180L box it requires more voltage (~35v Fb 30.6, 40v Fb 43.4Hz) to reach Xmax, output increasing above 40Hz:
As expected, the smaller box reduces LF efficiency and output potential compared to the huge box.
That said, for home use, lowering the 180L box Fb to 30Hz (near the driver's Fs) and applying EQ gain at Fb and a HP filter ~26Hz, the pair of subs could do ~124dB ~30Hz.
In Blazemaster's boxes, the ports would probably require right angle bends to accommodate the length required to drop the Fb that low.
Art
