I'm sure the pd2450 is a fine driver, but what's the point? Gee Whiz factor?
Are you planning to open a rave club or go on tour with a signed band? If not, what's the point? Good driver, wrong use.
A Hummer is bigger than a Ferrari, but it won't go as fast or make as much noise, if you know what I mean.
Are you planning to open a rave club or go on tour with a signed band? If not, what's the point? Good driver, wrong use.
A Hummer is bigger than a Ferrari, but it won't go as fast or make as much noise, if you know what I mean.
Hi,
this is rarely true:
A well designed ClassA amp can nearly manage constant voltage drive, but only up to the point when current is just about to leave ClassA.
Similarly a well regulated power supply allows a classAB amp to nearly hold constant voltage into varying loads, but usually the regulation version is less good at this than a good ClassA.
That was why I referred to using separate amps on each speaker as the numbers went up. That is the only way I know of that can maintain constant voltage into the increasing numbers of speakers.
this is rarely true:
Even solid state power houses do not manage to maintain constant voltage into varying load impedance.
A well designed ClassA amp can nearly manage constant voltage drive, but only up to the point when current is just about to leave ClassA.
Similarly a well regulated power supply allows a classAB amp to nearly hold constant voltage into varying loads, but usually the regulation version is less good at this than a good ClassA.
That was why I referred to using separate amps on each speaker as the numbers went up. That is the only way I know of that can maintain constant voltage into the increasing numbers of speakers.
punkrokr1701 said:
I thought you had alimited budget?
Now suddenly you plan for one of the most expensive PA cone woofers on the market?
AndrewT said:
Whaaaa??? Must be some pretty bad amps, or overdriven. Or maybe you're talking about minute voltage changes.
What amp can't maintain 2.83 volts from 8 ohms to 4?
Hi,
I am not specifically referring to 1W output, but output voltages over the whole range available upto near maximum power.
An exceptional amp will just about manage a drop of a little less than 0.5db when driving a load of half the impedance.
Most will suffer a drop of 0.5db to 1.5db.
The bad ones will be worse than -1.5db when driving 4r with reference to 8r and some lose near 3db (71% of voltage).
I am not specifically referring to 1W output, but output voltages over the whole range available upto near maximum power.
An exceptional amp will just about manage a drop of a little less than 0.5db when driving a load of half the impedance.
Most will suffer a drop of 0.5db to 1.5db.
The bad ones will be worse than -1.5db when driving 4r with reference to 8r and some lose near 3db (71% of voltage).
well, I'm not right now I'm just planning for the FUTURE that's that key word. I do have a budget for the BBBIB.
And I do plan on opening something like a club, probably a skating rink because you'd make a killin round here in the middle of nowhere where there's 1000+ kids who have nothin to do on the wekkends (if you get my drift). Fine that is unrealistic for now but I don't how else to say it than I like the biigest driver I can get. Now The fostex I've seen but it doesn't impress me cause it has a light magnet and really isn't what I want esprcally for arond 3k - 4k.
a
BTW for the record I dispise Hummers but I can't resist big speakers.
Car wise I'm a huge Mustang fan and I dream of owning a Mustang GTR with dual 106mm T4/T3 turbos and a 547 Pro Street engine to handle to turbos . What? I was born to dream up extremely cool and unrealistic ideas.
And I do plan on opening something like a club, probably a skating rink because you'd make a killin round here in the middle of nowhere where there's 1000+ kids who have nothin to do on the wekkends (if you get my drift). Fine that is unrealistic for now but I don't how else to say it than I like the biigest driver I can get. Now The fostex I've seen but it doesn't impress me cause it has a light magnet and really isn't what I want esprcally for arond 3k - 4k.
a
BTW for the record I dispise Hummers but I can't resist big speakers.
Car wise I'm a huge Mustang fan and I dream of owning a Mustang GTR with dual 106mm T4/T3 turbos and a 547 Pro Street engine to handle to turbos . What? I was born to dream up extremely cool and unrealistic ideas.
mmm I'm guessing but perhaps 36mm? or 1 1/3 inch?
6 inch voice coil mmmm thats big!!! same size voice coil that 27 inch woofer that lenard audio used, wonder if this driver can work from 15 hz aswell?
mmm should have read the specs closer 30 hz
Im assuming that X mass is same as Displacement limit
6 inch voice coil mmmm thats big!!! same size voice coil that 27 inch woofer that lenard audio used, wonder if this driver can work from 15 hz aswell?
mmm should have read the specs closer 30 hz
Im assuming that X mass is same as Displacement limit
yeh it costs near 1k apiece in US $ 7 or 8 mm ? is that a calculation or did you see that on a spec sheet?
a good approximation of xMag...
...is calculated from the height of the magnet gap, and the length of the voice coil...but depending on other aspects of the the design may not be identical to xMax.
The maximum physical displacement xSus (1.42"), is quoted, but this is well past the point of magnetic linearity, ie generating a lot of distortion, so I think it likely that the xMax we are interested in is going to be closer to xMag...
For this monster, the mag gap height is 15mm, while the voicecoil is 30mm, so the xMag is (30mm-15mm)/2. We have to divide by two because the VC needs to sit in the centre of the gap and can move in either direction...
Since we know the suspension is not the limiting factor, the point at which the coil beings to leave the gap is approx 7.5mm in either direction, which I believe is where Andrew got his figure...
HTH
Stuart
...is calculated from the height of the magnet gap, and the length of the voice coil...but depending on other aspects of the the design may not be identical to xMax.
The maximum physical displacement xSus (1.42"), is quoted, but this is well past the point of magnetic linearity, ie generating a lot of distortion, so I think it likely that the xMax we are interested in is going to be closer to xMag...
For this monster, the mag gap height is 15mm, while the voicecoil is 30mm, so the xMag is (30mm-15mm)/2. We have to divide by two because the VC needs to sit in the centre of the gap and can move in either direction...
Since we know the suspension is not the limiting factor, the point at which the coil beings to leave the gap is approx 7.5mm in either direction, which I believe is where Andrew got his figure...
HTH
Stuart
Hi Stuart,
spot on!
But let Punk do his own homework.
He is beginning to sit back again and let us do HIS research.
spot on!
But let Punk do his own homework.
He is beginning to sit back again and let us do HIS research.
Yeh thanx Stuart, and for AndrewT at least now I can go and figure the Xmax of drivers that dont have one stated. S0 the pd2450 would have a displacement close to 3.6 liters of air, correct?
I think I have found out the formula for calculating displacement, to me if this is right: SD(xmax*.0002)
ex: 1029 (12*.0002) = 1029 * .0012 = 2.4696 ltrs
ex: 1029 (12*.0002) = 1029 * .0012 = 2.4696 ltrs
not sure if I understand correctly
But here's what I think you're asking...
The maximum swept volume displaced by the driver will be the surface area of the cone, multiplied by the xmax...
Of course before we can start we need to convert the various parameters to the same system, ie all metric or all imperial...lets do metric, since you quoted the answer in litres...
Converting from inches to cm we need to multiply by 2.54, so the driver has a diameter (d) of 27 * 2.54 == 68.58cm. The surface area is pi * d^2 / 4, so 3.1415 * 68.58 * 68.68 / 4 or 3693cm^2, while xmax is approx 0.8cm, so we have a swept displacement of 0.8cm * 3693cm^2, which is 2955cm^3 or just about 3 liters...
HTH
Stuart
But here's what I think you're asking...
The maximum swept volume displaced by the driver will be the surface area of the cone, multiplied by the xmax...
Of course before we can start we need to convert the various parameters to the same system, ie all metric or all imperial...lets do metric, since you quoted the answer in litres...
Converting from inches to cm we need to multiply by 2.54, so the driver has a diameter (d) of 27 * 2.54 == 68.58cm. The surface area is pi * d^2 / 4, so 3.1415 * 68.58 * 68.68 / 4 or 3693cm^2, while xmax is approx 0.8cm, so we have a swept displacement of 0.8cm * 3693cm^2, which is 2955cm^3 or just about 3 liters...
HTH
Stuart
You both have the formula for displacement right. Punk, your multiplication by 0.002 causes your figure to represent displacement of the peak-to-peak cone motion.
When it comes to speakers, displacement isn't really a scientific number. It's just a "ballpark" sort of thing for comparing bass capability of a driver in a large sealed box, open baffle dipole, or other similar excursion limited arrangement.
When you start talking about ported boxes, horns, or small sealed boxes, you need to worry about other things like the power rating.
When it comes to speakers, displacement isn't really a scientific number. It's just a "ballpark" sort of thing for comparing bass capability of a driver in a large sealed box, open baffle dipole, or other similar excursion limited arrangement.
When you start talking about ported boxes, horns, or small sealed boxes, you need to worry about other things like the power rating.
well yeh my figure is lookiung at peak to peak Xmax but I dont exactly think there's gonna be much of a problem with power handling with what Im lookin at.
of course I mean the pd2450
of course I mean the pd2450
I know its car audio but has any heard of the Clarion SRW8000 I googled it and I can't find anything about it at Clarions site and all the reviews I've read aren't very clear. Personally it looks like a beast but I doubt it will live up to its size. Overrated iis what Id call it but I haven't heard it so can anyone here enlighten me?
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