Advice on how to choose a subwoofer for the sound system

[amthanhkhangphudat]

Hi everyone, I'm preparing to set up a sound system for stage and big hall. I want to consult people on how to choose the best subwoofer and wireless microphone.
My hall has an area of 300m2, it is necessary to use the sub capacity of the subwoofer. Besides, any micro model will meet this 300m2 space.
I am hesitant between the subwoofer of 500W and 900W. The microphone is intended to choose this type of UHF wireless microphone Đại Ly Micro Khong Day Chuyen Nghiệp Gia Rẻ Tốt Nhất
hope everyone helps me make the best decision

 

[JonSnell Electronic]

The capacity of a sub unit depends entirely on the overall power of the main PA.
Rule of thumb is twice the bass power for sub.
With no information to work on, I can be of no more help.

Your choice of microphone is good.

 

[amthanhkhangphudat]

The capacity of a sub unit depends entirely on the overall power of the main PA.
Rule of thumb is twice the bass power for sub.
With no information to work on, I can be of no more help.

Your choice of microphone is good.

thank you JonSnell Electronic
"Rule of thumb is twice the bass power for sub."
Is this a standard rule?

 

[ICG]

"Rule of thumb is twice the bass power for sub."
Is this a standard rule?

Indoors, yes. Or more than that, depending on the music genre. Outdoors double that again.

 

[JonSnell Electronic]

If you use the PA indoors and the sub is 900Watts RMS then the bass should be 450Watts followed by 250Watts of mid/top.
Outside the sub will be lost and needs doubling again.

 

[Think]

Watts is a measure for power consumption, like gas consumption of a car. It is a poor indicator of how loud a system is.
Power x efficiency (dB/W) - thermal compression (wind resistance of a car)= output.
A good read about this: Power Handling Vs. Efficiency

The location of the subwoofers is also very important; TP Audio Subwoofer Info

Boundary reinforment and cancelation are important to get: place your subwoofers less then 1/4 or more then 2 wavelengts of the frequencies they produce from each other and half of that to walls.

 

[ICG]

Watts is a measure for power consumption, like gas consumption of a car. It is a poor indicator of how loud a system is.

Since the most subs in PA are BR and of comparable close spl, it actually is an appropriate rule of thumb. Or do you know a better one?

 

[Think]

Calculated output is sometimes in the specs, but doesn't take the thermal/power compression into account and are often pure marketing lies.

TS: " I am hesitant between the subwoofer of 500W and 900W."

IMO this is just to little info to recommend anything.

 

[ICG]

Calculated output is sometimes in the specs, but doesn't take the thermal/power compression into account and are often pure marketing lies.

Yes, that's unfortunately true. But if you know which drivers are in a sub, you can get it pretty accurate. Besides that, you shouldn't go far into power compression because your subs will live much, much longer.

TS: " I am hesitant between the subwoofer of 500W and 900W."

IMO this is just to little info to recommend anything.

Yes, I completely agree, that's why I didn't suggest anything. The rule of thumb is useful though, it gives a general direction what possible combinations could be of interest and what price range it will be. To really suggest a brand or model, the music genre, live/playback/DJ/musical/theatre/voice, rough audience number etc is needed. Also which equipment is already in use/available like mixer, amps, speaker stands etc. Just 'wireless mics' doesn't say anything to be honest.

To define the requirements and what's optional will lead to a much better fit to the needs and best price/performance ratio.