strange looking T/S of an 8" speaker/woofer

cykeltur

Member
2016-04-13 12:02 pm
Hi
I have a strange looking T/S of an 8" speaker
sending to me..

This is the claimed paramerters

[book=FMS: 33.6 Hz
Res: 84.4 ohm
RE: 4 ohm
Qms: 3.94
Qes: 0.49
Qts: 0.44
Rms: 10.5 kg/s
Cms: 0.11 mm/N
Mms: 195.8 gr
Nref 0.04 %
Bl: 18.4
SPL: 78.3 dB
VAS: 5.7 liter
Rp: 37.3 ohm
Lp: 51.7 mH
Cp: 566.9 uF
Le: 2.55 mH
Xmax (one direction): 20-25mm
Pmax 500w (?...)
]%[/book]
Is a 3-6liter close box to prefered,
or is is a pasive radiator version of box.
or a 3-6liter EQ(like miniDSP) a solution?
 
Okay, so you've got a heavy cone, a stiff suspension, and low efficiency. The plus side is you can put it in a very small box.
The minus side is you'll need to shove a rocket up it to get much SPL, and you'll still need to EQ the low end if you go for a sealed box. It'll probably drop to [email protected]@1m at the bottom end, so you'll need 1KW peaks to hit what most would call decent listening volumes.

Its almost certainly a driver for use in cars, where the cabin gain can add quite a lot of output.

Chris
 

cykeltur

Member
2016-04-13 12:02 pm
Okay, so you've got a heavy cone, a stiff suspension, and low efficiency. The plus side is you can put it in a very small box.
The minus side is you'll need to shove a rocket up it to get much SPL, and you'll still need to EQ the low end if you go for a sealed box. It'll probably drop to [email protected]@1m at the bottom end, so you'll need 1KW peaks to hit what most would call decent listening volumes.

Its almost certainly a driver for use in cars, where the cabin gain can add quite a lot of output.

Chris
thanks!:)
so can you please tell me what to change, so it become descent?
the speaker cad strangely be a little custom made (?!), and the have not shipp this yet..

but the SPL vant go over 78, wiithout changing the parts (probably the Xmax then become lower) .. what is your "dream scenario" for a 8"?
 
so can you please tell me what to change, so it become descent?
How about changing the driver??? Putting a small diameter driver (even one with a ridiculously high Xmax like this) in a small box is definitely NOT a way to get good low bass in a home environment.

Because the driver is a high Xmax design you have low efficiency because the driver uses a long voice coil (more mass of wire means heavier and harder to move) and the magnetic field may be spread out over a larger gap, meaning it is weaker. Like another poster said, this is a driver that should be used in a car, not in a home environment. It just won't work there without extreme amplifier power to increase output enough to match your other speakers.

Driver design involved many tradeoffs (efficiency, power handling, low end response, excursion, motor and suspension materials, etc.) and there is no "best" or "optimum" solution. If you can have something modified, I would try to focus the magnetic field with a smaller gap, reduce the length of the voice coil and former so that Xmax works out to about 12mm, and increase the suspension compliance. This should increase efficiency, reduce Q, increase Vas, and reduce Fs. The driver might then be more suitable for home use and might be similar to this:
Tang Band W8-1363SBF 8" Paper Cone Subwoofer Speaker

If you want to look elsewhere for options, get something that will work well in a modestly sized vented box. Or get a larger diameter (e.g. 12") subwoofer driver, a plate amp, a 2-3 cuft box and be done with it. There are many, many options for that approach that end up being much better than this driver ever could be.
 
Hi All,

FYI:

b:)
 

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