Hello Friends
I lik ethe dimentionso fthis subwoofer below
https://www.alderwoodspeakers.com.au/collections/subwoofers/products/atlas-pro
how to make in DIY
TAng BAnd W8-740P 8 2 drivers and peerless XLS 10 2 nos with me
but dont know how to make this kind of cardiods.
regards
anand shah
I lik ethe dimentionso fthis subwoofer below
https://www.alderwoodspeakers.com.au/collections/subwoofers/products/atlas-pro
how to make in DIY
TAng BAnd W8-740P 8 2 drivers and peerless XLS 10 2 nos with me
but dont know how to make this kind of cardiods.
regards
anand shah
Anand,
The Alderwood Atlas Pro boast of "up to a -4db reduction in rear bass radiation" with no specified frequency means any reduction in bass is likely in the 200Hz or higher bass range, typical of any cabinet with 49cm x 29cm x 36.5cm dimensions.
Calling it "cardioid" is just marketing hype attempting to sell a 2x8" cabinet with only 11mm "Maximum cone excursion" (Xlim?) for $2950.00.
This side-mounted slotted port cabinet is probably tuned around 35Hz.
With the factory default settings, it is around -8dB at 40Hz compared to 125Hz.
Other than using lighter drivers, nothing in the specifications would indicate it would do anything better than a pair of your Tang Band W8-740P in a standard ported cabinet.
Art
The Alderwood Atlas Pro boast of "up to a -4db reduction in rear bass radiation" with no specified frequency means any reduction in bass is likely in the 200Hz or higher bass range, typical of any cabinet with 49cm x 29cm x 36.5cm dimensions.
Calling it "cardioid" is just marketing hype attempting to sell a 2x8" cabinet with only 11mm "Maximum cone excursion" (Xlim?) for $2950.00.
This side-mounted slotted port cabinet is probably tuned around 35Hz.
With the factory default settings, it is around -8dB at 40Hz compared to 125Hz.
Other than using lighter drivers, nothing in the specifications would indicate it would do anything better than a pair of your Tang Band W8-740P in a standard ported cabinet.
Art
Agreed, not gonna work. Don't waste your money.
Instead, use more care in speaker placement in the room.
Instead, use more care in speaker placement in the room.
Art Hi
Thank you for the explaination and clarification. I am learning in diy audio hobby. What would you suggest I should do with my Tang band W8-740p I have a Chinese 2.1 amp that has dual TPA3255 chips with 100watts x2 and 300 watts in 1 for sub. have a 48v 10amp powersupply all works. I have 4 nos peerless TC9 3" FullRange drivers so I was planning a 2 drivers per side and TB as sub till 100 or 150hz. I dont know how to go about making a nice dual driver sub for TB use wll be in home and a lot in open garden in backyard with kids activietes.
Cureently using Bose S1 boombox but its too low in output.
The Tang Band W8-740P is an interesting little woofer with 12.1mm Xmax, 30Hz Fs, and 20.3L VAS, it can go low and fairly loud in a small box given enough power.
If high passed just below Fb (box tuning frequency) it could run out of thermal capacity (burn up) with low crest factor music before reaching it’s excursion limits.
The small box problem is a port with enough cross-sectional area to not get “blown out” at high power and tune low in a small box is very long, which could use close to half the overall cabinet volume depending on the port wall thickness.
This simulation uses a 150 square centimeter port (23.25 square inches, 4.8”x4.8”) for an Fb of 36Hz.
The 36Hz Fb results in about 3dB more output at 40Hz than a 30Hz Fb at the same input voltage and net cabinet volume.
Since the port is 75 centimeters long (29.5”), it may need to be folded in the cabinet interior as in the example below.
Slotted ports tune lower than circular or square ports of the same cross sectional area.
The port corners should be rounded to reduce “chuffing” noise.
The box interior volume, exclusive of the volume occupied by the port, bracing and drivers should be 36 liters (1.27 cubic feet).
The simulation uses 31volts input, about 480 watts into a nominal 2 ohm load, above that level the TPA3255 amp goes from 1% THD to clipping horribly.
The drivers reach 9mm excursion around 47 Hz, 12mm at 30 Hz, a 24 dB high pass filter around 30 Hz would keep excursion under control and not reduce low frequency output.
To avoid the port resonance peak, the crossover frequency should be around 100 Hz, the sub should still have a bit more output over the four TC9.
The 3” TC9 can use a sealed volume of about 1 liter each.
Art
Art hi
thanks a million for the inputs as I said I am new in diy the picture of slot port hand drawn is what I have to make correct and 1 driver diamentions I cannot understand to tell carpenter to cut.
also what happens if I have 2 drivers in 1 box for more power I can remove TPA 3255 and use Hypex 502mp I have this module
i owe you a treat if u ever come to India buddy
regards
anand shah
thanks a million for the inputs as I said I am new in diy the picture of slot port hand drawn is what I have to make correct and 1 driver diamentions I cannot understand to tell carpenter to cut.
also what happens if I have 2 drivers in 1 box for more power I can remove TPA 3255 and use Hypex 502mp I have this module
i owe you a treat if u ever come to India buddy
regards
anand shah
Anand,
The simulation was for two four ohm drivers wired in parallel, a two ohm load powered with 31volts output, the voltage I think the TPA3255 amp may deliver before it sounds like hammered dog poop.
The Hypex 502 appears to have 30 watts less output, 450 watts at 2 ohms.
The two drivers would be placed above each other in the hand drawn picture (top down view, not to scale) example of a folded port. You could build two separate enclosures or one dual.
Separate is actually better, and you could make a pole mount on the sub to get the TC9 boxes up in the air, stereo separation and all that stuff the kids enjoy 😉 .
The port exit area is 150 square centimeters, 23.25 square inches.
For example, if the cabinet interior was 23.25" tall, the port would be 1" wide.
Art