I'm having a bit of a conundrum.
I'm getting ready to order the drivers, which will set me back 120GBP for all the drivers including VAT and delivery.
The Hawthorne Audio Silver Iris 15 is 200GBP for the drivers, delivery AND crossovers. No tweaking, no messing, just put them on a baffle.
With the Eminence drivers I have to play with filters until it sounds good. But this is more fun than just mounting a coax driver on a baffle!
I don't know what to do!
I'm getting ready to order the drivers, which will set me back 120GBP for all the drivers including VAT and delivery.
The Hawthorne Audio Silver Iris 15 is 200GBP for the drivers, delivery AND crossovers. No tweaking, no messing, just put them on a baffle.
With the Eminence drivers I have to play with filters until it sounds good. But this is more fun than just mounting a coax driver on a baffle!
I don't know what to do!
bigwill said:
take two papers ;
on one of them write Iris
on other Beta
put them in hat
mix 'em
and pick , with closed eyes
first you pick - buy first and make
second - buy and make later
why not have both ?
:clown
Wonder how Silver Iris will do in a 500liter closed box 
There is also a 10" Silver Iris ... might work as an IB in 300liter ... looks pretty smooth to me 😀
There is also a 10" Silver Iris ... might work as an IB in 300liter ... looks pretty smooth to me 😀
I happened to have a pair of Beta 12LT on me shelf, would be keen to build a pair over an weekend if plans are available.
I came across this driver:
Monacor SP-30PATC
Compared to the Eminence Beta 12LTA it has a flatter response, higher efficiency, a better frame, bigger magnet, and a wider bandwidth.
It only costs about £24 more than the Eminence. Should I get a pair of these instead? They look superior.
Monacor SP-30PATC
Compared to the Eminence Beta 12LTA it has a flatter response, higher efficiency, a better frame, bigger magnet, and a wider bandwidth.
It only costs about £24 more than the Eminence. Should I get a pair of these instead? They look superior.
Looks nice with smooth impedance
But high Fs and low Qts = low on bass ... you may need help from Scottmoose or GM 😀
No one liked the 10" Silver Iris in 300liter closed ???😎
But high Fs and low Qts = low on bass ... you may need help from Scottmoose or GM 😀
No one liked the 10" Silver Iris in 300liter closed ???😎
tinitus said:
I plan to counter the low Qts with a big series resistor until I get some dedicated woofers for the bass...
Its a 100db driver, it will have very little bass, no matter what you do
But with a couple of woofers it might make a nice mid driver, hard to say from looking at such "handdrawn" graphs
But with a couple of woofers it might make a nice mid driver, hard to say from looking at such "handdrawn" graphs
tinitus said:
The Pioneer 20B most likely has more low end to offer, after having looked at the response curve for that PA speaker. It's really nice looking and the upper response curve is nice, where an added tweet would really make the upper end. However, you would still have to have a sub, I would think. That may well be why it is called a PA driver.
I've calculated that an 8 ohm resistance in series with that Monacor will raise its Qts to 0.7. Will this be an acceptable solution? Remember, I'm not looking for deep bass just a speaker that doesn't sound "thin"
Here is my math:
(0.7 / 0.28) * 5.2 - 5.2 = 7.8
where 0.7 is the wanted Qts, 0.28 is the actual Qts and 5.2 is the DCR of the driver..
Here is my math:
(0.7 / 0.28) * 5.2 - 5.2 = 7.8
where 0.7 is the wanted Qts, 0.28 is the actual Qts and 5.2 is the DCR of the driver..
Not quite right.
Qt=(Qms*Qes)/(Qms+Qes)
Qes'=Qes*[(Re+Rs)/Re]
Where Rs is the series resistor. If you put that into the equation for Qes', you get Qes'=0.762 and then if your replace Qes with Qes' in the Qt equation, you get Qt=0.63.
If you want a Qt of 0.7, you will have to work backwards through the equations. I get a series resistance of 9.75 to achieve the 0.7. Not to much difference in the resistance, but its the correct way of doing it I believe.
Qt=(Qms*Qes)/(Qms+Qes)
Qes'=Qes*[(Re+Rs)/Re]
Where Rs is the series resistor. If you put that into the equation for Qes', you get Qes'=0.762 and then if your replace Qes with Qes' in the Qt equation, you get Qt=0.63.
If you want a Qt of 0.7, you will have to work backwards through the equations. I get a series resistance of 9.75 to achieve the 0.7. Not to much difference in the resistance, but its the correct way of doing it I believe.
davidallancole said:
Aha, thank you very much! Funnily enough, 10 ohms was the resistance I guessed at before performing that calculation. A value in that ballpark does seem intuitively "right" for some reason
Greets!
Agreed, you beat me to it, though I got 9.77 ohms just plugging in different values in my spreadsheet based on Ron E's math, not that you'll hear a difference 😉:
And to fill it out:
Vas is unchanged
n0 = 9.6352*10^-10*Fs^3*Vas(liters)/Qes'
SPL = 112.018+10*Log(n0)
So calc'd efficiency drops to ~93 dB.
GM
Agreed, you beat me to it, though I got 9.77 ohms just plugging in different values in my spreadsheet based on Ron E's math, not that you'll hear a difference 😉:
And to fill it out:
Vas is unchanged
n0 = 9.6352*10^-10*Fs^3*Vas(liters)/Qes'
SPL = 112.018+10*Log(n0)
So calc'd efficiency drops to ~93 dB.
GM
Hi GM,
What is n0, I don't remember seeing this before. Does the formula for n0 read like this when doing the math:
n0 = 9.6352*10^-10*Fs^3*[Vas(liters)/Qes']
Are these the formulas that a company would use to calculate a SPL level for a driver?
What is n0, I don't remember seeing this before. Does the formula for n0 read like this when doing the math:
n0 = 9.6352*10^-10*Fs^3*[Vas(liters)/Qes']
Are these the formulas that a company would use to calculate a SPL level for a driver?
Greets!
It's the way some folks were writing the Greek symbol 'eta' to define reference efficiency in percent when I started reading the early audio BBs, while some others used 'no'.
Math's not my strong suit, so all I can say is that I have it just as I posted it in an Excel SS (minus the (liter) notation of course) and it spits out the right answer as a decimal point value that you can multiply by 100 to get a percentage if you want.
Manufacturers normally measure it, but there's no industry standard frequency point per se, so they often use higher frequency break-up modes to get a bigger number to tout, ergo the often lack of correlation between it and the formula's result and why I calc each driver under consideration for an app so that I can ~accurately compare 'apples to apples' since it's the most accurate for most box design types.
GM
It's the way some folks were writing the Greek symbol 'eta' to define reference efficiency in percent when I started reading the early audio BBs, while some others used 'no'.
Math's not my strong suit, so all I can say is that I have it just as I posted it in an Excel SS (minus the (liter) notation of course) and it spits out the right answer as a decimal point value that you can multiply by 100 to get a percentage if you want.
Manufacturers normally measure it, but there's no industry standard frequency point per se, so they often use higher frequency break-up modes to get a bigger number to tout, ergo the often lack of correlation between it and the formula's result and why I calc each driver under consideration for an app so that I can ~accurately compare 'apples to apples' since it's the most accurate for most box design types.
GM
Thanks GM.
I figured out that the Vas/Qes part is done and then multiplied by the rest as how I wrote it with the brackets.
I did some calculations for SPL using the formula you provided there and came out with pretty much what is listed for a speaker. Like the Pioneer B20, I got 89.5 db which would be the same as the listed 90 db when rounded up. But for an Eminence guitar speaker I got 98.5 dB but they list 102dB. So I looked at the chart Eminence provides for the particular loudspeaker and it measured out around 99dB for the most part and then peaked up to around 110dB. So it seems some what reasonable when having a graph to reference it to.
That will be a handy piece of knowledge to know when doing some design work.
I figured out that the Vas/Qes part is done and then multiplied by the rest as how I wrote it with the brackets.
I did some calculations for SPL using the formula you provided there and came out with pretty much what is listed for a speaker. Like the Pioneer B20, I got 89.5 db which would be the same as the listed 90 db when rounded up. But for an Eminence guitar speaker I got 98.5 dB but they list 102dB. So I looked at the chart Eminence provides for the particular loudspeaker and it measured out around 99dB for the most part and then peaked up to around 110dB. So it seems some what reasonable when having a graph to reference it to.
That will be a handy piece of knowledge to know when doing some design work.
bigwill said:
Hi.
I use Eminence drivers extensiely in my pro equipment. To get a feel of the APT80, try using the Eminence PXB5 crossover.
Ricky.
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