If you look at the impedance curve it's unclear what the fs actually is, whether it's in the 0 - 100 hz bandwidth or whether it even has a traditionally defined fs (not sure it's analogous to a mass on a spring).
Eminent Technology: home
Maybe 35 hz fs? Maybe no, I don't know.
Either way, I don't think that's what he wants. It doesn't look like he understands how drivers work though, so his goal is probably misguided, therefore all successive steps to achieve it will be misguided.
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Well with an attitude like that I seriously doubt anyone around here will miss you. Good luck over at AVS dude, with an attitude like that you'll soon wear out your welcome over there too.
Was kind of intended as a joke. 🙂
Clearly something he didn't wanted. But it doesn't have a fs >15hz?. (fs = n/a?)
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Couple more things I could add about the RE XXX...
It's not necessarily uncommon, a few people at avs use it, but it's extremely high inductance and the xmax rating is quite exaggerated.
There was a proposed group buy for that driver at avs not too long ago. Maybe one or two people showed interest, and after a bit of discussion on the driver itself everyone pulled out. There are better options for the price.
interesting portion of spec list :
- Impedance: 8 ohms 0Hz : 0Hz
- Frequency Response: 1Hz : 30Hz ± 4dB
Eminent Technology, Inc. Planar Magnetic Loudspeakers and Audio Technology
* something with which many might disagree?
as for the RE audio - any idea as to price for this beast?
Omni - out of curiosity, if it's not too late to ask before your taillights disappear in the sunset, what exactly is the application - or is that on a need to know basis?
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Disagree if you like, I explained that the only way to change fs is adjusting the suspension or the moving mass, this was unacceptable to OP and he claimed -
"Honestly, I have not gotten any suggestions which lead me to believe no one can offer any suggestions on a woofer that can offer an fs of 15 Hz or lower. What I am hearing is alternatives which, I mentioned would not work under the given circumstances. As I mentioned to Sretan feel free to offer some models and I will be happy to give you more details.
If the only way to affect fs is the suspension and moving mass characteristics, and neither of these are acceptable to OP and he thinks there is another way, he doesn't know how drivers work.
800 bux - RE Audio XXX18V2D2 (XXX18 V2D2) 18" Car Subwoofer
The proposed avs group buy featured them much cheaper but no one was interested.
Hi,
All I can assume given the OP refuses to give details,*
is he simply has no idea what he is doing, and does
not understand how Fs is related to Sd, Vas + Mms.
rgds, sreten.
* Nearly always a smokescreen for not having a clue.
All I can assume given the OP refuses to give details,*
is he simply has no idea what he is doing, and does
not understand how Fs is related to Sd, Vas + Mms.
rgds, sreten.
* Nearly always a smokescreen for not having a clue.
If we assume a piston area of 1330 cm^2, then according to the given Thiele-Small parameter values, Mmd for the RE Audio XXXv2-18D2 is 517 grams, a little over half a kilogram! That is a lot of dynamic mechanical mass to keep under control...
(Assuming Sd = 1330 cm^2 gives a Bl value of 18.16, as shown in the specs. It would be much easier though if the Sd value was given directly by the manufacturer).
I believe the newer one is the split coil version. Here's Ricci's data-bass measured t/s, I bolded Sd and Mms. Yup, almost 600 grams. And the driver itself is almost 80 lbs.
Qts 0.581
Qes 0.674
Qms 4.23
Fs 16.4 Hz
Res 4.2 Ω
Le 1khz 5.41 mH
Sd 0.121 m2
Vas 322.8 liters
Mms 597.1 grams
Cms 158 μm/N
BL 19.58 Tm
BL2/Res 91.2 N2/W
L/R Time Constant 1.29 milliseconds
SplSens 85.08 dB
Data-Bass
Don't forget to check the measurements for this driver. it's a terrible case of extremely high inductance resulting in sims that don't match the measurements.
EDIT - I forgot that you already saw the measurements of this guy and the overhung version and quite a few other drivers in some detail when we were working on the inductance paper.
Ricci also tested the older overhung version of this driver. IIRC it was even worse.
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