Basically I'm desgining a low budget sub. I am going to use THIS driver and assuming that if it has two coils could I out left and right through it? I don't quite understand that tbh! Anyway I need an active low pass filter for the sub for sub 150Hz into 8ohm for this driver. Can someone give me a hand?
Thanks
Boscoe
Thanks
Boscoe
Good morning -
By looking at the sub, it is a dual voice coil driver. Each voice coil is 8 ohms. You may use one for 8 ohms, or both in series for 16 ohm, or both in parallel for 4 ohms.
An active crossover is an electronic crossover that is inline with the signal before amplification. The speakers parameters do not have anything to do with the design of the crossover.
Design link - Sub-Woofer Controller
A passive crossover is a crossover that filters a full range signal (using chokes and capacitors) from the amplifier and limits the frequencies going to the driver. See the following link for design calculators. 1 - 4th order = 6db, 12db, 18db, and 24db roll off.
Just enter the frequency (150hz) and ohm rating that you will be running the speaker at and it will calculate the correct values for you. Since you will not be using the high pass part of the calculator, just enter the same ohm value and click calculate.
Just disregard the high pass info and use the lowpass.
ERSE - Crossover Calculator - First Order 2 Way
ERSE - Crossover Calculator - Second Order 2 Way
ERSE - Crossover Calculator - Third Order 2 Way
ERSE - Crossover Calculator - Fourth Order 2 Way
Good luck
Brian
By looking at the sub, it is a dual voice coil driver. Each voice coil is 8 ohms. You may use one for 8 ohms, or both in series for 16 ohm, or both in parallel for 4 ohms.
An active crossover is an electronic crossover that is inline with the signal before amplification. The speakers parameters do not have anything to do with the design of the crossover.
Design link - Sub-Woofer Controller
A passive crossover is a crossover that filters a full range signal (using chokes and capacitors) from the amplifier and limits the frequencies going to the driver. See the following link for design calculators. 1 - 4th order = 6db, 12db, 18db, and 24db roll off.
Just enter the frequency (150hz) and ohm rating that you will be running the speaker at and it will calculate the correct values for you. Since you will not be using the high pass part of the calculator, just enter the same ohm value and click calculate.
Just disregard the high pass info and use the lowpass.
ERSE - Crossover Calculator - First Order 2 Way
ERSE - Crossover Calculator - Second Order 2 Way
ERSE - Crossover Calculator - Third Order 2 Way
ERSE - Crossover Calculator - Fourth Order 2 Way
Good luck
Brian
as Brian stated you van drive them with a mono amp series 16 ohm or 4 ohm paralel, you can also combine the stereo signal into a mono signal with a active lp filter and than feeding the left and right chanel with the same signal.
you'll need to make sure the signal is the same.
its better using a mono amp
you'll need to make sure the signal is the same.
its better using a mono amp
use a sumer (adder) circuit. An opamp wired for inverting mode ADDs the two inputs to give one output.
Repeat the input resistor for as many inputs that you want to ADD/SUM
If you use an MFB filter as your low pass then it uses the same inverting topology and you can combine the summing function with the filter function in one opamp. You get a 2pole active rolloff and sumer.
Be wary of using Left and Right into a dual VC driver. If the signals are not in phase the VC cooling will be reduced and you could burn out the driver.
Where did you learn this? Sounds complete nonsense to me so I'm curious to know how you came by the idea...
just my 2 cents.Where did you learn this? Sounds complete nonsense to me so I'm curious to know how you came by the idea...
dual vc are intended especialy 4 this purpose
just make sure they are in phase
Bass is not always in phase so you run the possibility if wasting energy and melt it (if they are out of phase at that point).
It should not however tear it self apart due to former being quite strong and made to handle the force generated in normal use.
But you never know if we are talking about cheap speakers.
Signal variant BL and Qes would be a little unpredictable one would expect. And back EMF could be dissipated by the other channel/amp if the signals differed.
It should not however tear it self apart due to former being quite strong and made to handle the force generated in normal use.
But you never know if we are talking about cheap speakers.
Signal variant BL and Qes would be a little unpredictable one would expect. And back EMF could be dissipated by the other channel/amp if the signals differed.
Yeah, that's a good point. If the signals to the two voicecoils mainly cancel out then there will be little output but plenty of heat in the coils. Normal voicecoil cooling does depend to some extent (not sure how much - does anyone know about such things?) on it moving. A static voicecoil seems to me to be more likely to fry than one in motion at the same power level.
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so what is the purpose of a dual vc speaker?
4 instance in my car i have an 18" dvc speaker
one vc connected 2 the left output of my amp the other one 2 the right channel.
this is working for 5 years.
the only thing i smell is the amp after while of d&b
my gues is that it may be sligtly out of phase some times ,but never a complet cancelation
4 instance in my car i have an 18" dvc speaker
one vc connected 2 the left output of my amp the other one 2 the right channel.
this is working for 5 years.
the only thing i smell is the amp after while of d&b
my gues is that it may be sligtly out of phase some times ,but never a complet cancelation
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I hate to pop in after much discussion, but not clear where you are coming from, where you want to go, and what efforts and education on your part you welcome performing.
While standing on one leg, let me offer a synopsis. Having a single woofer is a great idea (better one good woofer than two poor ones, eh) and owning a dual voice coil gives you options most people lack. But the cross-over frequency has to be below a frequency that upsets your stereo image (I'd say as high as 150 Hz and have more than 43 yrs of experience with mixed bass, but nobody would agree with me).
Today, and in the context of this DIY board, most would urge you to do an electronic mixer and crossover and not fuss with lousy low-level crossovers. Besides, at low frequencies, there's no way to make a sharp crossover using coils and capacitors and you must keep those low frequencies out of your mid-range. Again expecting nobody to agree with me, a third-hand amp from 1985 is a perfect match in quality to the best speakers today.
On the other hand, if all your boxes are close to one another, easy enough to create a low-level crossover over 200 Hz and just treat the woofer as if it were two units with each fed by each side.
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