Using PA Amplifier to run woofer !

[learning]

Can I run a woofer ( 4ohm/40 watts ) from a PA (Public Address System) amplifier ? Please tell me !

 

[Nigel Goodwin]

Can I run a woofer ( 4ohm/40 watts ) from a PA (Public Address System) amplifier ? Please tell me !

It depends on the spec of the amplifier, certainly you could from most.

 

[learning]

Nigel,
Thank you for your reply !

 

[audioguru]

I have seen very cheap PA amplifiers that have poor low frequency response because they are designed for voice amplification.
Many cheap PA amps cannot drive a speaker with an impedance as low as 4 ohms.

 

[learning]

I have seen very cheap PA amplifiers that have poor low frequency response because they are designed for voice amplification.
Many cheap PA amps cannot drive a speaker with an impedance as low as 4 ohms.

Here it is the specification of PA amplifier :

Power Output 75W Max., 50W RMS at 10% THD, 45W RMS at 5% THD
Input Channels 3×Mic. 0.6mV/4.7k, 1×Aux 100mV/330k
Frequency Response 50-15,000Hz ±3dB
Signal to Noise Ratio 55dB
Tone Controls Bass: ±10dB at 100Hz Treble: ±10dB at 10kHz
Outputs Line: 400mV/3.5k
Speaker Outputs 4, 8, 16 & 100V
Power Supply AC: 220-240V 50/60Hz, DC: 12-14V Car Battery

 

[audioguru]

Your amplifier is very cheap. It has very high distortion, a high noise level, cuts 50Hz to half power and cuts lower bass frequencies much more.
It also cuts high audio frequencies.

 

[learning]

Your amplifier is very cheap. It has very high distortion, a high noise level, cuts 50Hz to half power and cuts lower bass frequencies much more.
It also cuts high audio frequencies.

What is your specification for a PA amplifier ? Can you tell me !

 

[audioguru]

I used to work for a PRO Sound manufacturer. Some PA amplifiers were cheap like yours but other expensive ones had excellent spec's.

 

[learning]

I used to work for a PRO Sound manufacturer. Some PA amplifiers were cheap like yours but other expensive ones had excellent spec's.

Can you remember the excellent specification of your PA amp for me ?

 

[audioguru]

I can't find the spec sheet but the best PA amplifier is stereo 400W per channel into 8 ohms, 700W per channel into 4 ohms or bridged 1400W into 8 ohms.
Distortion is 0.05% at full power from 20Hz to 20khz, noise is -90dB and frequency response is +-3dB 7Hz to 100kHz.
When driving good speakers the sound is extremely clear.

 

[Nigel Goodwin]

Here it is the specification of PA amplifier :

Power Output 75W Max., 50W RMS at 10% THD, 45W RMS at 5% THD
Input Channels 3×Mic. 0.6mV/4.7k, 1×Aux 100mV/330k
Frequency Response 50-15,000Hz ±3dB
Signal to Noise Ratio 55dB
Tone Controls Bass: ±10dB at 100Hz Treble: ±10dB at 10kHz
Outputs Line: 400mV/3.5k
Speaker Outputs 4, 8, 16 & 100V
Power Supply AC: 220-240V 50/60Hz, DC: 12-14V Car Battery

That amp will be perfectly fine with the speaker you mentioned, but it's a Public Address amplifier, only intended for voice announcements and background music, not for HiFi or as a musical PA system.

What are you trying to do with the amp/speaker?.

 

[learning]

That amp will be perfectly fine with the speaker you mentioned, but it's a Public Address amplifier, only intended for voice announcements and background music, not for HiFi or as a musical PA system.

What are you trying to do with the amp/speaker?.

I want to use the amp/speaker combination for recording in my PC as well as play music. Can you tell me the specification of a Musical PA System ?

 

[Nigel Goodwin]

I want to use the amp/speaker combination for recording in my PC as well as play music. Can you tell me the specification of a Musical PA System ?

Musical PA systems are those used by bands - they will be similar quality to HiFi systems, but much higher power.

I don't see why you want an amp/speaker for recording?, but as long as you're happy with only mono sound the existing amp is probably all you need.

 

[learning]

I don't see why you want an amp/speaker for recording?, but as long as you're happy with only mono sound the existing amp is probably all you need.

You are right ! I will do it with your way !

 

[BluetTac]

I like crayons