Hi guys,
I wanted to ask you, if you can recommend me a 8" driver with 4 ohms which can be used for ported subwoofer applications. Target tuning range would be around 35-40 Hz.
A high sensitivity would be great.
For me this is just a fun project, so I would not like to spend more than max. 40$ or so per driver.
Can you recommend me something in this direction?
Maybe fyi: Please ask not why, but the target would be to build up a PA-like subwoofer. But want to use an array of 8" for this. Probably 8pcs or 10pcs per enclosure to reach similar SPL like a double-15" or double-18"
I wanted to ask you, if you can recommend me a 8" driver with 4 ohms which can be used for ported subwoofer applications. Target tuning range would be around 35-40 Hz.
A high sensitivity would be great.
For me this is just a fun project, so I would not like to spend more than max. 40$ or so per driver.
Can you recommend me something in this direction?
Maybe fyi: Please ask not why, but the target would be to build up a PA-like subwoofer. But want to use an array of 8" for this. Probably 8pcs or 10pcs per enclosure to reach similar SPL like a double-15" or double-18"
Take a look at the MCM 55-1520.
https://www.newark.com/mcm-audio-select/55-1520/woofer-8-poly-treated-cone/dp/36C6855
A 30 liter box can be tuned to 40 hz with a 2" x 3.5" port, or 2" x 4" for 38 Hz.
https://www.newark.com/mcm-audio-select/55-1520/woofer-8-poly-treated-cone/dp/36C6855
A 30 liter box can be tuned to 40 hz with a 2" x 3.5" port, or 2" x 4" for 38 Hz.
8 x 8" is slightly more cone area (Sd) than 2x 15", 10 x 8" close to the Sd of 2 x18". Problem is a cheap, high sensitivity 8", generally will have only a fraction of the linear displacement (Xmax) typical of cheap 15" or 18" PA subs.
For example, the MCM 55-1520 Dave R suggested has only 1mm Xmax, so rather than 10 units to equal the displacement of two 18", you might be looking at more like 60 or 100!
The Dayton Audio DC200-8 8" Classic Woofer has 4.5mm Xmax, about as much as you will likely find in the <$40 range, series-parallel wiring of 8 would be a 4ohm load.
Good luck!
Art
I used a couple of these: https://www.newark.com/mcm-audio-select/55-1455/woofer-8-dual-voice-coil/dp/36C6853
Years ago. They probably have 3 or 4mm of useful Xmax before they get farty.
As Art's mentioned above, you'll need a LOT of them to match a good 2x18".
Chris
Years ago. They probably have 3 or 4mm of useful Xmax before they get farty.
As Art's mentioned above, you'll need a LOT of them to match a good 2x18".
Chris
Ok thank you guys for the recommendations.
Seems maybe not the best idea if it's so difficult to find good drivers for this.
The background of the question is, that I have in my mind to make a battery powered high power speaker system.
And my goal was to use small 24V supplied Class-D amps to overcome the voltage-supply problems. Because high-power Class-D amps always need then symmetrical supply and a converter or so.
Therefore also the request with 4 Ohms. With 24V you are able to generate approx. 70 watts into 4 ohms. Therefore 4 ohm to get the most out of such small Class-D amps.
Seems maybe not the best idea if it's so difficult to find good drivers for this.
The background of the question is, that I have in my mind to make a battery powered high power speaker system.
And my goal was to use small 24V supplied Class-D amps to overcome the voltage-supply problems. Because high-power Class-D amps always need then symmetrical supply and a converter or so.
Therefore also the request with 4 Ohms. With 24V you are able to generate approx. 70 watts into 4 ohms. Therefore 4 ohm to get the most out of such small Class-D amps.
An alternative would be to use a DC-to-DC converter to step up the voltage to the sort of thing a 2x18" (or 2x15") would require. You can go further, by using 4ohm drivers in those cabinets and getting a 2ohm result. Bridging a large low-voltage amplifier (ie, 1ohm/ch, not recommended for most amps) would give you plenty of power, too.
A big pile of small amplifiers and drivers will be a PITA to build, set up and tear down.
Chris
A big pile of small amplifiers and drivers will be a PITA to build, set up and tear down.
Chris
12v to 120/240v inverters and class D amps are running are running almost 90% efficiency, while most speakers are generally under 5%.
Using battery power, speaker efficiency is the primary concern, and a TH (tapped horn) or FLH (front loaded horn) can add as much as 6-10 dB output over a BR (bass reflex) design using the same power, 70 watts into a big FLH could achieve the SPL of 700 watts driving a BR. Battery, amplifiers, and driver count could be cut in half or more, though the cabinet size and weight will increase.
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If you're planning 24V of batteries, wouldn't the +/- supply be a natural?
Yes, definitely look into some of the tricks the car guys are using. That's a pretty mature field these days with a lots of powerful techniques.
One thing that always concerns me with a battery powered, high SPL rig: Have you done the arithmetic to work out how long the power will last? In 1975 we parked the manual-shift van on enough of a hill that it would still bump-start after we'd gotten the most out of the battery, and that was only about an hour. Of course, you'll get much better mileage with Class D than we did with all those Dynaco ST-70 filaments to light up.
Cheers
Yes, definitely look into some of the tricks the car guys are using. That's a pretty mature field these days with a lots of powerful techniques.
One thing that always concerns me with a battery powered, high SPL rig: Have you done the arithmetic to work out how long the power will last? In 1975 we parked the manual-shift van on enough of a hill that it would still bump-start after we'd gotten the most out of the battery, and that was only about an hour. Of course, you'll get much better mileage with Class D than we did with all those Dynaco ST-70 filaments to light up.
Cheers
What about this once popular 4 ohm high Xmax 8" and still only $30? Downside is a long back order wait: https://www.newark.com/mcm-audio-select/55-2421/8-high-excursion-woofer-120w-rms/dp/88C7835
GM