I need your help for choosing a compression driver, the boomer is a 12" BEYMA and I have a set of super tweeters.
The compression driver will work from 800Hz to 10000Hz.
Do I need a 2" or a 1" driver?
The compression driver will work from 800Hz to 10000Hz.
Do I need a 2" or a 1" driver?
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You can get both 1" or 2" drivers for that job. Or 1.4" for that matter. What I'm trying to say is this: Its not just the throat size that determines how low drivers go.
Assuming he's not building a huge system if 12" woofer 😀 Horn/Waveguide not specified. However, wouldn't 2" be overkill for a small system, also 1" can get plenty loud, reaches higher. Even 10K can be a challenge for a 2", am I not right?
In series connection sensitivity won't change compared to single driver. If you want higher (voltage)sensitivity, you need to connect them in parallel.
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Is a horn usable from 800Hz upwards. I read elsewhere that a compression driver that does 800 to 20000Hz are rather rare.
Besides a flat on axis response, you will also want a smooth transition from your woofer to the horn.
Is a horn usable from 800Hz upwards. I read elsewhere that a compression driver that does 800 to 20000Hz are rather rare.
Besides a flat on axis response, you will also want a smooth transition from your woofer to the horn.
You might consider a lower crossover frequency to the tweeter -- the top octave won't give it much to do, and the small percentage of compression drivers that can produce 10k beautifully tend to be less rugged (read 'easier to shred'). I have a shoebox full of variously smoked LE85 diaphragms to testify to the point.
As far as your 2 inch question goes, it would typically take more than one or two 12's to keep up with (balance properly) a 2" driver.
Cheers
As far as your 2 inch question goes, it would typically take more than one or two 12's to keep up with (balance properly) a 2" driver.
Cheers
Sensitivity:
Parallel + 6 dB
Series + 0 dB
Efficiency, at low frequencies: (wavelength >> driver spacing)
Parallel + 3 dB
Series + 3 dB
Efficiency, at high frequencies (wavelength << driver spacing)
Parallel + 0 dB
Series + 0 dB
And there is some frequency region in between where things are not that simple.
If you have a voltage source amp (most solid state amp) and the acoustical responses from multiple sources sums properly then you got a maximum of +6dB sensitivity if you use 2 drivers in parallel instead of 1. +3dB due to 2x membrane area (plus motor of course) and +3dB due to halved impedance.
Serial wiring adds +3dB due to doubled membrane area but then -3dB due to doubled value of the impedance so the sensitivity is as with 1 driver but the impedance is now 2x.
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for the 800 - 10,000 Hz range I would use a 2" throat driver. There are a few 1" throat drivers that can go that low but they are rare and there is no performance advantage to a 2" throat at 10 kHz. Choice depends on budget, desired dispersion and geographical location. With unlimited budget the AXI2050 would be a good choice, failing that I would look for a driver with a 4" voice coil (to maximise displacement) something like: file:///C:/Users/TV/Downloads/SPECSHEET-ENG-ND950%202.0.pdf
If you plan tube amp, then 16 ohms is something to consider but not mandatory
Putting two drivers in parralel doesn't reach to a lower resonant frequency, just more spl level if in // for equal cone movement...which is not a bad idea to cope with a compression driver fastness and marry the reactivity of
the compression with classic driver technology. 2 cones in // is 2 x less cone exursion so.
All is about your possibilities, amp, monney, design choices.
The most difficult is not about to find a cd for your need but more the good horn according the budget you have, mostly if you mix brands... what about the jbl horn clone made in thailand people seems to like if limited budget ? Faital hk104 if I'm correct about the ref is praised both 8 and 16 ohms models and ok till 800 hz, but don't remenber if 1.4 or 2" throat.
Putting two drivers in parralel doesn't reach to a lower resonant frequency, just more spl level if in // for equal cone movement...which is not a bad idea to cope with a compression driver fastness and marry the reactivity of
the compression with classic driver technology. 2 cones in // is 2 x less cone exursion so.
All is about your possibilities, amp, monney, design choices.
The most difficult is not about to find a cd for your need but more the good horn according the budget you have, mostly if you mix brands... what about the jbl horn clone made in thailand people seems to like if limited budget ? Faital hk104 if I'm correct about the ref is praised both 8 and 16 ohms models and ok till 800 hz, but don't remenber if 1.4 or 2" throat.
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That Beyma woofer looks like it can go to 1kHz easily. If you are using a 90° wide waveguide/horn you would probably want to cross over to a 12" driver around 1.2kHz anyways to achieve matching directivity at crossover.
There are many 1" CDs that can handle 1kHz crossover and work just fine without help above 10kHz (Radian, B&C, Peerless, to name a few). It's your stated requirement to go to 800Hz that's the problem - it's tough on the CD and it will result in poor pattern match with your horn.
BTW - If you insist on 800Hz crossover have a look at the new Eminence Textreme diaphram 1.4" CD.
There are many 1" CDs that can handle 1kHz crossover and work just fine without help above 10kHz (Radian, B&C, Peerless, to name a few). It's your stated requirement to go to 800Hz that's the problem - it's tough on the CD and it will result in poor pattern match with your horn.
BTW - If you insist on 800Hz crossover have a look at the new Eminence Textreme diaphram 1.4" CD.
True.
1", 1.4", or 1.5" should be fine.
You need a big horn for loading to 800hz.
My 2' wide horn (2384 jbl) with 1.4" compression driver crossed 24db at 800hz, but when cranking it (crossed to double 15's), it was way more comfortable crossed at 1,000hz.
I agree on a 12" crossing at 1.2khz, gets the crossover further up, smaller horn than 800hz mouth, acoustic centers closer, and easier on your compression driver (smaller that usually goes higher, so less eq).
Those 12" have a very low qts.
Maybe tune to 50hz and boost it there.
Fun setup in the making you have there.
1", 1.4", or 1.5" should be fine.
You need a big horn for loading to 800hz.
My 2' wide horn (2384 jbl) with 1.4" compression driver crossed 24db at 800hz, but when cranking it (crossed to double 15's), it was way more comfortable crossed at 1,000hz.
I agree on a 12" crossing at 1.2khz, gets the crossover further up, smaller horn than 800hz mouth, acoustic centers closer, and easier on your compression driver (smaller that usually goes higher, so less eq).
Those 12" have a very low qts.
Maybe tune to 50hz and boost it there.
Fun setup in the making you have there.
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Norman Bates,
do you mean the Bass Reflex tunned at 50 hz ? will give a stif roll off but still good sound because above the driver 42 hz Fs (though very near) ? Am I understanding correctly please ?
do you mean the Bass Reflex tunned at 50 hz ? will give a stif roll off but still good sound because above the driver 42 hz Fs (though very near) ? Am I understanding correctly please ?
Yes
If you run the formulas, you see that you will not go flat to 30hz with those.
Will you run a subwoofer ?
If you run the formulas, you see that you will not go flat to 30hz with those.
Will you run a subwoofer ?