Hi theAnonymous1,
With a woofer that stiff you have to change your thinking. Trow out your concepts of T/S parameters (it's hard to imagine). Now consider that woofer is simply a piston. Similar to those tiny Sunfire subs.
I don't agree with this, but I may be wrong. Several designers have got this concept to work.
-Chris
With a woofer that stiff you have to change your thinking. Trow out your concepts of T/S parameters (it's hard to imagine). Now consider that woofer is simply a piston. Similar to those tiny Sunfire subs.
I don't agree with this, but I may be wrong. Several designers have got this concept to work.
-Chris
anatech said:
I understand what your saying, but I was thinking of more traditional automotive designs. Subs like the sunfire use heavy EQ Linkwitz style.
If you put a driver with a 44hz Fs in a normal sealed or vented box and throw it in a car without any EQ, you will be wondering where the lows ran off to.
for what it is worth ..( not much )
no brand name
the magnet is 8" thick and this 10" driver must weight something near 50-60lbs alone ..crazy
there seems to be a regular cone type paper under the flat front baffle, the frame is casted alum i believe
and its vented
i can move it approx 1inch in and 1 inch out without distorting the surround rubber ( happens a bit faster going in then out ) and i don't hear anything touching aka coil botomming
neway i'm done with this shitty stuff
still don't undestand the goal of this driver
any buyers??
no brand name
the magnet is 8" thick and this 10" driver must weight something near 50-60lbs alone ..crazy
there seems to be a regular cone type paper under the flat front baffle, the frame is casted alum i believe
and its vented
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
i can move it approx 1inch in and 1 inch out without distorting the surround rubber ( happens a bit faster going in then out ) and i don't hear anything touching aka coil botomming
neway i'm done with this shitty stuff
still don't undestand the goal of this driver
any buyers??
That looks like the HiVi SP10.......
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=297-460
If you were closer I would take it off your hands. It would probably do OK in a small sealed box with a Linkwitz Transform and >1000w amp.
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=297-460
If you were closer I would take it off your hands. It would probably do OK in a small sealed box with a Linkwitz Transform and >1000w amp.
If it is from Swan as "JinMTVT" was told then it would be the HiVi SP10.
http://www.swanspeaker.com/product/htm/view.asp?id=50
http://www.swanspeaker.com/product/htm/view.asp?id=50
ok!! that is why i was told about Swan ..
i knew i had seen this somewhere ...on parts express
but that was some time ago
so those are the Hi-Vi for sure!!
but why aren't they playing at all ??
there is a problem with those drivers for sure ..
how should i diagnostic that?
and sorry but i won't sell em for 20$ each
give me some time to play with them a bit!
what should i do next ??
i knew i had seen this somewhere ...on parts express
but that was some time ago
so those are the Hi-Vi for sure!!
but why aren't they playing at all ??
there is a problem with those drivers for sure ..
how should i diagnostic that?
and sorry but i won't sell em for 20$ each
give me some time to play with them a bit!
what should i do next ??
Didn`t I read that the VC Z was 3.4 ohms or something low like that? If this is the case it is unlikely a consumer cheapo digital multimeter on low ohms scale is going to lead to a conclusive measurement unless one also had a known good speaker at the ready to make a comparison.
A more meaningful test would take some basic test equipment.
Ideally (and the simplest) an LCR meter could be used to measure the VC inductance and compare it to the value posted in the specs.
One could use a variac on the 60 Hz AC line and develop a voltage (start from zero and advance slowly, but not going very high) across the loudspeaker VC and a resistor in series that is the same ohms value as the inductor is supposed to be in reactance at 60Hz. A DMM in low volts AC range is then used to determine if the voltage seen across the VC is the same, higher, or lower than that seen across the resistor. If the same, the VC is OK. If the VC measurement is lower that the resistor voltage the degree of such will indicate if the VC is partially shorted or completely shorted. If the VC reading is higher than that of the resistor the ONLY explanation is that you have chosen an incorrect resistor value for the test, based on bad L value data given in the specs for the driver, or a mathematical error determining the value of the test resistor occurred.
The formula in this application to determine inductive reactance is
1/ [2 pi (60 x L)]
Where pi is not in the oven and L is in henries.
A more meaningful test would take some basic test equipment.
Ideally (and the simplest) an LCR meter could be used to measure the VC inductance and compare it to the value posted in the specs.
One could use a variac on the 60 Hz AC line and develop a voltage (start from zero and advance slowly, but not going very high) across the loudspeaker VC and a resistor in series that is the same ohms value as the inductor is supposed to be in reactance at 60Hz. A DMM in low volts AC range is then used to determine if the voltage seen across the VC is the same, higher, or lower than that seen across the resistor. If the same, the VC is OK. If the VC measurement is lower that the resistor voltage the degree of such will indicate if the VC is partially shorted or completely shorted. If the VC reading is higher than that of the resistor the ONLY explanation is that you have chosen an incorrect resistor value for the test, based on bad L value data given in the specs for the driver, or a mathematical error determining the value of the test resistor occurred.
The formula in this application to determine inductive reactance is
1/ [2 pi (60 x L)]
Where pi is not in the oven and L is in henries.
I also have one of them really stiff subs. but I could push the cone in and out with one hand.
I'm using the MOFO 15". although I'm not having the efficiency issue here. I'm getting a lot of low end output (25-40Hz) in a 5cuft 35Hz ported box with about 72sqin of port area.
one thing though, since these subs have really heavy moving mass, I have a big hole at 80Hz (around -10 to -12db). sub is low passed at 80Hz 3rd order.
as others have posted, these stiff subs really do handle low frequencies well. I have driven it to below 10Hz without bottoming out driven at around 800-1kW rms.
I'm using the MOFO 15". although I'm not having the efficiency issue here. I'm getting a lot of low end output (25-40Hz) in a 5cuft 35Hz ported box with about 72sqin of port area.
one thing though, since these subs have really heavy moving mass, I have a big hole at 80Hz (around -10 to -12db). sub is low passed at 80Hz 3rd order.
as others have posted, these stiff subs really do handle low frequencies well. I have driven it to below 10Hz without bottoming out driven at around 800-1kW rms.
one of the reasons of a stiff suspension is for automotive spl contest style style subwoofers
the stiff suspension is a form of stored energy and it raises the fs making it preform better at a higher tuning, again better for competing
as far as 5ooo crappy watts from a kid as much as i agree it is a form of trickle down theory from company's like dd and atomic who's speakers aren't normally used to play music at all
to some guys its all about 50-80hz and as much power as you can get to a speaker for 3-5 second
they never play music on them and never play for longer than a few seconds
i recently reconed a Digital Design sub with 5 spiders on it all of different thickness's, colors and textures it was one of their top models in their lineup
some of the top competitors recone after just a few uses because the resins used to make the material in the spider stiff break down and they loose the stiffness
the stiff suspension is a form of stored energy and it raises the fs making it preform better at a higher tuning, again better for competing
as far as 5ooo crappy watts from a kid as much as i agree it is a form of trickle down theory from company's like dd and atomic who's speakers aren't normally used to play music at all
to some guys its all about 50-80hz and as much power as you can get to a speaker for 3-5 second
they never play music on them and never play for longer than a few seconds
i recently reconed a Digital Design sub with 5 spiders on it all of different thickness's, colors and textures it was one of their top models in their lineup
some of the top competitors recone after just a few uses because the resins used to make the material in the spider stiff break down and they loose the stiffness
A point of clarification
Obviously we're talking about subs here, and specifically this beastie, but let's just be clear- there are plenty of high Fs drivers that are superb, mostly high efficiency pro-style stuff.
Just don't want anyone dismissing drivers based solely upon high Fs.
Those aren't subs, of course, but mid/basses, typically designed to operate up to 1k+. And many aren't crappy, indeed, the high Fs helps make them suitable to horn loading in many instances.
Oh, and the low efficiency SPL-comp style drivers are not high fidelity in any instance I've encountered them. The "Sunfire sub" is a real sack of crap imo.
theAnonymous1 said:
Obviously we're talking about subs here, and specifically this beastie, but let's just be clear- there are plenty of high Fs drivers that are superb, mostly high efficiency pro-style stuff.
Just don't want anyone dismissing drivers based solely upon high Fs.
Those aren't subs, of course, but mid/basses, typically designed to operate up to 1k+. And many aren't crappy, indeed, the high Fs helps make them suitable to horn loading in many instances.
Oh, and the low efficiency SPL-comp style drivers are not high fidelity in any instance I've encountered them. The "Sunfire sub" is a real sack of crap imo.
Re: A point of clarification
Sorry badman, again my train of thought was on automotive drivers with a high Fs due to the stiff suspension. These make crappy "subwoofers" IMHO.
I didn't mean to lump high efficiency pro drivers in to the bunch. Pro drivers usually have a high Fs because of their relatively low moving mass which translates into better transient response and higher efficiency.
badman said:
Sorry badman, again my train of thought was on automotive drivers with a high Fs due to the stiff suspension. These make crappy "subwoofers" IMHO.
I didn't mean to lump high efficiency pro drivers in to the bunch. Pro drivers usually have a high Fs because of their relatively low moving mass which translates into better transient response and higher efficiency.
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